Ambient PM2.5 and Stroke: Effect Modifiers and Population Attributable Risk in Six Low- and Middle-Income Countries

Air pollution, life's essential 8, and risk of severe non-alcoholic fatty liver disease among individuals with type 2 diabetes

BACKGROUND

The impacts of long-term exposure to air pollution on the risk of subsequent non-alcoholic fatty liver disease (NAFLD) among participants with type 2 diabetes (T2D) is ambiguous. The modifying role of Life's Essential 8 (LE8) remains unknown.

METHODS

This study included 23,129 participants with T2D at baseline from the UK Biobank. Annual means of nitrogen dioxide (NO2), nitrogen oxides (NOX), and particulate matter (PM2.5, PM2.5-10, PM10) were estimated using the land-use regression model for each participant. The associations between exposure to air pollution and the risk of severe NAFLD were evaluated using Cox proportional hazard models. The effect modification of LE8 was assessed through stratified analyses.

RESULTS

During a median 13.6 years of follow-up, a total of 1,123 severe NAFLD cases occurred. After fully adjusting for potential covariates, higher levels of PM2.5 (hazard ratio [HR] = 1.12, 95%CI:1.02, 1.23 per interquartile range [IQR] increment), NO2 (HR = 1.15, 95%CI:1.04, 1.27), and NOX (HR = 1.08, 95%CI:1.01, 1.17) were associated with an elevated risk of severe NAFLD. In addition, LE8 score was negatively associated with the risk of NAFLD (HR = 0.97, 95% CI: 0.97, 0.98 per point increment). Compared with those who had low air pollution and high LE8, participants with a high air pollution exposure and low LE8 had a significantly higher risk of severe NAFLD.

CONCLUSIONS

Our findings suggest that long-term exposure to air pollution was associated with an elevated risk of severe NAFLD among participants with T2D. A lower LE8 may increase the adverse impacts of air pollution on NAFLD.

Association of physical activity and PM2.5-attributable cardiovascular disease mortality in the United States

Objective

The study aimed to explore the association between physical activity (PA) and PM2. 5-attributable cardiovascular disease (CVD) mortality trends across the United States (US) at the state level.

Methods

We conducted a cross-sectional study using data from the Global Burden of Disease 2019 study for PM2.5-attributable CVD mortality and the Behavioral Risk Factor Surveillance System for PA prevalence. The study covered all 50 US states and the District of Columbia from 2001 to 2019. We utilized Joinpoint Regression to calculate AAPC from 2011 to 2019 and Pearson correlation coefficients to assess state-level associations between PA and PM2.5-attributable CVD mortality AAPC.

Results

During 2011-2019, a total of 244,318 PM2.5-attributable CVD deaths were recorded. The age-adjusted mortality rates (AAMR) of PM2.5-attributable CVD declined substantially from 2011 to 2019 across all US states, with the most pronounced reductions observed in industrialized states such as West Virginia (51% decline), Kentucky (32%), and Ohio (22%). AAMR ratios for the US states varied substantially, ranging from 0.1 in Hawaii to 1.7 in Arkansas. The AAPC ranged from -9.4% (West Virginia) to -1.7% (New Mexico) in the majority of states, while a few states such as Alaska, Wyoming, and Washington saw slight positive AAPCs from 0.9 to 2.9%. A significant correlation was found between PA and PM2.5-attributable CVD mortality trends (r = 0.454, p = 0.001), with similar results in subgroup analyses.

Conclusion

Our findings suggest a correlation between increased physical activity (PA) and increased PM2.5-attributable CVD mortality, highlighting the potential need to consider PM2.5 exposure when engaging in PA to mitigate adverse cardiovascular health impacts. However, further research is warranted to establish causality and underlying mechanisms in the relationship between PA and PM2.5-attributable CVD mortality. Potential limitations include reliance on self-reported PA data.

Spatiotemporal Trends of Stroke Burden Attributable to Ambient PM2.5 in 204 Countries and Territories, 1990-2019: A Global Analysis

BACKGROUND AND OBJECTIVES

Previous studies suggested that long-term exposure to ambient fine particulate matter (PM2.5) is associated with increased risk of stroke. However, limited studies evaluated the stroke burden attributable to ambient PM2.5 globally, especially comprising across different regions, countries, and social-economic levels. We thus conducted this study to estimate the spatial and temporal trends of ambient PM2.5-related stroke burden by sex, age, and subtypes from 1990 to 2019 at global, regional, and national levels.

METHODS

Information on the ambient PM2.5-related stroke burden from 1990 to 2019 was obtained from the Global Burden of Disease study 2019. The burdens of stroke attributable to ambient PM2.5 (i.e., age-standardized mortality rate [ASMR] and age-standardized disability-adjusted life-year rate [ASDR]) were estimated by sex, age, and subtypes from 1990 to 2019 at global, regional, and national levels. The estimated annual percentage change (EAPC) was used to evaluate the changing trends of ASDR and ASMR attributable to ambient PM2.5 from 1990 to 2019. The Spearman correlation coefficient was used to examine the correlation between sociodemographic index (SDI) and EAPC of ASMR and ASDR at the national level.

RESULTS

In 2019, the global ambient PM2.5-related stroke mortality and disability-adjusted life years were 1.14 million and 28.74 million, respectively, with the corresponding ASDR and ASMR of 348.1 and 14.3 per 100,000 population, respectively. The ASDR and ASMR increased with age and were highest among male patients, in the middle SDI regions, and for intracerebral hemorrhage (ICH). From 1990 to 2019, the absolute death number of stroke attributable to ambient PM2.5 and the corresponding ASMR and ASDR were both in an increasing trend. The corresponding EAPCs in ASMR and ASDR were 0.09 (95% CI -0.05 to 0.24) and 0.31 (95% CI 0.18-0.44), respectively. The significant increases of ASMR and ASDR were observed in the low, low-middle, and middle SDI regions, and for ICH. However, a decreasing trend was observed in high and middle-high SDI regions, and for subarachnoid hemorrhage.

DISCUSSION

The global burden of stroke attributable to ambient PM2.5 showed an increasing trend over the past 30 years, especially in male patients, low-income countries, and for ICH. Continued efforts on reducing the level of ambient PM2.5 are necessary to reduce the burden of stroke.

Predicting the severity of white matter lesions among patients with cerebrovascular risk factors based on retinal images and clinical laboratory data: a deep learning study

Background and purpose

As one common feature of cerebral small vascular disease (cSVD), white matter lesions (WMLs) could lead to reduction in brain function. Using a convenient, cheap, and non-intrusive method to detect WMLs could substantially benefit to patient management in the community screening, especially in the settings of availability or contraindication of magnetic resonance imaging (MRI). Therefore, this study aimed to develop a useful model to incorporate clinical laboratory data and retinal images using deep learning models to predict the severity of WMLs.

Methods

Two hundred fifty-nine patients with any kind of neurological diseases were enrolled in our study. Demographic data, retinal images, MRI, and laboratory data were collected for the patients. The patients were assigned to the absent/mild and moderate-severe WMLs groups according to Fazekas scoring system. Retinal images were acquired by fundus photography. A ResNet deep learning framework was used to analyze the retinal images. A clinical-laboratory signature was generated from laboratory data. Two prediction models, a combined model including demographic data, the clinical-laboratory signature, and the retinal images and a clinical model including only demographic data and the clinical-laboratory signature, were developed to predict the severity of WMLs.

Results

Approximately one-quarter of the patients (25.6%) had moderate-severe WMLs. The left and right retinal images predicted moderate-severe WMLs with area under the curves (AUCs) of 0.73 and 0.94. The clinical-laboratory signature predicted moderate-severe WMLs with an AUC of 0.73. The combined model showed good performance in predicting moderate-severe WMLs with an AUC of 0.95, while the clinical model predicted moderate-severe WMLs with an AUC of 0.78.

Conclusion

Combined with retinal images from conventional fundus photography and clinical laboratory data are reliable and convenient approach to predict the severity of WMLs and are helpful for the management and follow-up of WMLs patients.

Prevalence and risk factors of stroke in China: a national serial cross-sectional study from 2003 to 2018

Stroke imposes a substantial burden worldwide. With the rapid economic and lifestyle transition in China, trends of the prevalence of stroke across different geographic regions in China remain largely unknown. Capitalizing on the data in the National Health Services Surveys (NHSS), we assessed the prevalence and risk factors of stroke in China from 2003 to 2018. In this study, data from 2003, 2008, 2013, and 2018 NHSS were collected. Stroke cases were based on participants' self-report of a previous diagnosis by clinicians. We estimated the trends of stroke prevalence for the overall population and subgroups by age, sex, and socioeconomic factors, then compared across different geographic regions. We applied multivariable logistic regression to assess associations between stroke and risk factors. The number of participants aged 15 years or older were 154,077, 146,231, 230,067, and 212,318 in 2003, 2008, 2013, and 2018, respectively, among whom, 1435, 1996, 3781, and 6069 were stroke patients. The age and sex standardized prevalence per 100,000 individuals was 879 in 2003, 1100 in 2008, 1098 in 2013, and 1613 in 2018. Prevalence per 100,000 individuals in rural areas increased from 669 in 2003 to 1898 in 2018, while urban areas had a stable trend from 1261 in 2003 to 1365 in 2018. Across geographic regions, the central region consistently had the highest prevalence, but the western region has an alarmingly increasing trend from 623/100,000 in 2003 to 1898/100,000 in 2018 (P trend<0.001), surpassing the eastern region in 2013. Advanced age, male sex, rural area, central region, hypertension, diabetes, depression, low education and income level, retirement or unemployment, excessive physical activity, and unimproved sanitation facilities were significantly associated with stroke. In conclusion, the increasing prevalence of stroke in China was primarily driven by economically underdeveloped regions. It is important to develop targeted prevention programs in underdeveloped regions. Besides traditional risk factors, more attention should be paid to nontraditional risk factors to improve the prevention of stroke.

Does physical activity attenuate the association between ambient PM2.5 and physical function?

BACKGROUND

Physical function (PF), such as muscle strength, performing daily activities, has gradually declined with the increase of age, causing the occurrence of disability and diseases burden. Air pollution exposure and physical activity (PA) were both linked to PF. We aimed to explore the individual and joint effects of particulate matter <2.5 μm (PM_2.5) and PA on PF.

METHODS

A total of 4537 participants and 12,011 observations aged ≥45 years old from the China Health and Retirement Longitudinal Study (CHARLS) cohort from 2011 to 2015 were included into the study. PF was assessed by a combined score of four tests, including grip strength, walking speed, sense of balance, and chair standing tests. Air pollution exposure data was from The ChinaHighAirPollutants (CHAP) dataset. The annual PM_2.5 exposure for each individual was estimated based on county-level resident addresses. We estimated the volume of moderate-to-vigorous physical activity (MVPA) by quoting metabolic equivalent (MET). Multivariate linear model was conducted for baseline analysis, and linear mixed model with random participant intercepts was constructed for cohort longitudinal analysis.

RESULTS

PM_2.5 was negatively associated with PF, while PA was positively associated with PF in baseline analysis. In cohort longitudinal analysis, a 10 μg/m³ increase in PM_2.5 was associated to a 0.025 point (95 % CI: -0.047, -0.003) decrease in PF score, and a 10-MET-h/week increase in PA was related to a 0.004 point (95 % CI: 0.001, 0.008) increase in PF score. The association between PM_2.5 and PF decreased by increased PA intensity, and PA reversed the detrimental effects between PM_2.5 and PF.

CONCLUSION

PA attenuated the association of air pollution with PF at both high and low levels of air pollution, implying that PA may be an effective behavior to reduce the adverse effects of poor air quality on PF.

Hospitalisations for cardiovascular and respiratory disease among older adults living near unconventional natural gas development: a difference-in-differences analysis

BACKGROUND

During 2008-15, the Marcellus shale region of the US state of Pennsylvania experienced a boom in unconventional natural gas development (UNGD) or "fracking". However, despite much public debate, little is known about the effects of UNGD on population health in local communities. Among other mechanisms, air pollution from UNGD might affect individuals living nearby through cardiovascular or respiratory disease, and older adults could be particularly susceptible.

METHODS

To study the health impacts of Pennsylvania's fracking boom, we exploited the ban on UNGD in neighbouring New York state. Using 2002-15 Medicare claims, we conducted difference-in-differences analyses over multiple timepoints to estimate the risk of living near UNGD for hospitalisation with acute myocardial infarction (AMI), chronic obstructive pulmonary disease (COPD) and bronchiectasis, heart failure, ischaemic heart disease, and stroke among older adults (aged ≥65 years).

FINDINGS

Pennsylvania ZIP codes that started UNGD in 2008-10 were associated with more hospitalisations for cardiovascular diseases in 2012-15 than would be expected in the absence of UNGD. Specifically, in 2015, we estimated an additional 11·8, 21·6, and 20·4 hospitalisations for AMI, heart failure, and ischaemic heart disease, respectively, per 1000 Medicare beneficiaries. Hospitalisations increased even as UNGD growth slowed. Results were robust in sensitivity analyses.

INTERPRETATION

Older adults living near UNGD could be at high risk of poor cardiovascular outcomes. Mitigation policies for existing UNGD might be needed to address current and future health risks. Future consideration of UNGD should prioritise local population health.

FUNDING

University of Chicago and Argonne National Laboratories.

Association Between Pollution and Frailty in Older People: A Cross-Sectional Analysis of the UK Biobank

OBJECTIVES

Frailty is a relevant issue in older people, being associated with several negative outcomes. Increasing literature is reporting that pollution (particularly air pollution) can increase the risk of frailty, but the research is still limited. We aimed to investigate the potential association of pollution (air, noise) with frailty and prefrailty among participants 60 years and older of the UK Biobank study.

DESIGN

Cross-sectional.

SETTINGS AND PARTICIPANTS

Older participants (age ≥ 60 years) participating to the UK Biobank.

METHODS

Frailty and prefrailty presence were ascertained using a model including 5 indicators (weakness, slowness, weight loss, low physical activity, and exhaustion). Air pollution was measured through residential exposures to nitrogen oxides (NO_x) and particulate matter (PM_2.5, PM_2.5-10, PM₁₀). The average residential sound level during the daytime, the evening, and night was used as an index for noise pollution.

RESULTS

A total of 220,079 subjects, aged 60 years and older, was included. The partial proportional odds model, adjusted for several confounders, showed that the increment in the exposure to NO_x was associated with a higher probability of being in both the prefrail and frail category [odds ratio (OR) 1.003; 95% CI 1.001-1.004]. Similarly, the increase in the exposure to PM_2.5-10 was associated with a higher probability of being prefrail and frail (OR 1.014; 95% CI 1.001-1.036), such as the increment in the exposure to PM_2.5 that was associated with a higher probability of being frail (OR 1.018; 95% CI 1.001-1.037).

CONCLUSIONS AND IMPLICATIONS

Our study indicates that the exposure to air pollutants as PM_2.5, PM_2.5-10, or NO_x might be associated with frailty and prefrailty, suggesting that air pollution can contribute to frailty and indicating that the frailty prevention and intervention strategies should take into account the dangerous impact of air pollutants.

Ambient particulate matter pollution of different sizes associated with recurrent stroke hospitalization in China: A cohort study of 1.07 million stroke patients

BACKGROUND

To estimate the associations between ambient particulate matter (PM) pollution of different sizes (PM₁, PM_2.5, and PM₁₀) and risk of rehospitalization among stroke patients, as well as the attributable burden in China.

METHODS

We built a cohort of 1,066,752 participants with an index stroke hospitalization in Sichuan, China from 2017 to 2019. Seven-day and annual average exposures to PM pollution prior to the date of the index hospitalization were linked with residential address using a bilinear interpolation approach. Cox proportional hazard models were constructed to assess the association between ambient PM and the risk of rehospitalization. The burden of stroke rehospitalization was estimated using a counterfactual approach.

RESULTS

245,457 (23.0 %) participants experienced rehospitalization during a mean of 1.15 years (SD: 0.90 years) of follow-up. Seven-day average concentrations of PM were associated with increased risk of rehospitalization: the hazard ratios (HRs) per 10 μg/m³ were 1.034 (95 % confidence interval [CI]: 1.029-1.038) for PM₁, 1.033 (1.031-1.036) for PM_2.5, and 1.030 (1.028-1.031) for PM₁₀; the hazard ratios were larger for annual average concentrations: 1.082 (1.074-1.090) for PM₁, 1.109 (1.104-1.114) for PM_2.5, and 1.103 (1.099-1.106) for PM₁₀. The associations were stronger in participants who were female, of minority ethnicity (non-Han Chinese), who suffered from an ischemic stroke, and those admitted under normal conditions. Population attributable fractions for stroke rehospitalization ranged from 4.66 % (95 % CI: 1.69 % to 7.63 %) for the 7-day average of PM₁ to 17.05 % (14.27 % to 19.83 %) for the annual average of PM₁₀; the reducible average cost of rehospitalization per participant attributable to PM ranged from 492.09 (178.19 to 806) RMB for the 7-day average of PM₁ to 1801.65 (1507.89 to 2095.41) RMB for the annual average of PM₁₀.

CONCLUSIONS

Ambient PM pollution may increase the risk of rehospitalization in stroke patients and is responsible for a significant burden of stroke rehospitalization.

The pathophysiological and molecular mechanisms of atmospheric PM2.5 affecting cardiovascular health: A review

BACKGROUND

Exposure to ambient fine particulate matter (PM2.5, with aerodynamic diameter less than 2.5 µm) is a leading environmental risk factor for global cardiovascular health concern.

OBJECTIVE

To provide a roadmap for those new to this field, we reviewed the new insights into the pathophysiological and cellular/molecular mechanisms of PM2.5 responsible for cardiovascular health.

MAIN FINDINGS

PM2.5 is able to disrupt multiple physiological barriers integrity and translocate into the systemic circulation and get access to a range of secondary target organs. An ever-growing body of epidemiological and controlled exposure studies has evidenced a causal relationship between PM2.5 exposure and cardiovascular morbidity and mortality. A variety of cellular and molecular biology mechanisms responsible for the detrimental cardiovascular outcomes attributable to PM2.5 exposure have been described, including metabolic activation, oxidative stress, genotoxicity, inflammation, dysregulation of Ca2+ signaling, disturbance of autophagy, and induction of apoptosis, by which PM2.5 exposure impacts the functions and fates of multiple target cells in cardiovascular system or related organs and further alters a series of pathophysiological processes, such as cardiac autonomic nervous system imbalance, increasing blood pressure, metabolic disorder, accelerated atherosclerosis and plaque vulnerability, platelet aggregation and thrombosis, and disruption in cardiac structure and function, ultimately leading to cardiovascular events and death. Therein, oxidative stress and inflammation were suggested to play pivotal roles in those pathophysiological processes.

CONCLUSION

Those biology mechanisms have deepen insights into the etiology, course, prevention and treatment of this public health concern, although the underlying mechanisms have not yet been entirely clarified.

Associations between conjunctivitis and ambient PM2.5 and physical activity: A nationwide prospective cohort study

BACKGROUND

Currently, there is no evidence of fine particulate matter pollution (PM_2.5) altering the relationship between physical activity (PA) and the risk of conjunctivitis.

METHODS

Based on the UK Biobank study, we included 308,507 participants aged 40-69 years at baseline (2006 to 2010) and prospectively followed up for conjunctivitis diagnosis till 2020. Annual concentrations of PM_2.5 in 2010 were estimated for each participant using Land Use Regression models. PA levels during work and leisure time were reported via the International Physical Activity Questionnaire at baseline. We used Cox proportional hazards models to examine the associations of PM_2.5 and PA with incident conjunctivitis, as well as their interaction at both multiplicative and additive scales.

RESULTS

During the 11.6 years of follow up, we identified 4002 incident conjunctivitis cases. High-PA (≥3000 metabolic equivalent of task [MET]-mins/week) was associated with lower risk of conjunctivitis (hazard ratio [HR]: 0.79, 95% confidence interval [CI]: 0.73-0.86) compared to low-PA (0 to <600 MET-mins/week), while every 1 μg/m³ increment in PM_2.5 was associated with a 16% higher risk of conjunctivitis (HR = 1.16, 95% CI: 1.09-1.23). We did not observe statistically significant interactions between PM_2.5 and PA on their associations with conjunctivitis.

CONCLUSION

Habitual PA and PM_2.5 exposure were oppositely related to incident conjunctivitis. The benefits of PA remain in people irrespective of exposure to air pollution.

Long-term air pollution exposure and incident stroke in American older adults: A national cohort study

Aims

Stroke is a leading cause of death and disability for Americans, and growing evidence suggests that air pollution may play an important role. To facilitate pollution control efforts, the National Academy of Sciences and the World Health Organization have prioritized determining which air pollutants are most toxic. However, evidence is limited for the simultaneous effects of multiple air pollutants on stroke.

Methods and results

We constructed a nationwide population-based cohort study, using the Medicare Chronic Conditions Warehouse (2000-2017) and high-resolution air pollution data, to investigate the impact of long-term exposure to ambient PM2.5, NO2, and ground-level O3 on incident stroke. Hazard ratios (HR) for stroke incidence were estimated using single-, bi-, and tri-pollutant Cox proportional hazards models. We identified ~2.2 million incident stroke cases among 17,443,900 fee-for-service Medicare beneficiaries. Per interquartile range (IQR) increase in the annual average PM2.5 (3.7 μg/m3), NO2 (12.4 ppb), and warm-season O3 (6.5 ppb) one-year prior to diagnosis, the HRs were 1.022 (95% CI: 1.017-1.028), 1.060 (95% CI: 1.054-1.065), and 1.021 (95% CI: 1.017-1.024), respectively, from the tri-pollutant model. There was strong evidence of linearity in concentration-response relationships for all three air pollutants in single-pollutant models. This linear relationship remained robust for NO2 and O3 in tri-pollutant models while the effect of PM2.5 attenuated at the lower end of concentrations.

Conclusion

Using a large nationwide cohort, our study suggests that long-term exposure to PM2.5, NO2, and O3 may independently increase the risk of stroke among the US elderly, among which traffic-related air pollution plays a particularly crucial role.

Association of physical activity and air pollution exposure with the risk of type 2 diabetes: a large population-based prospective cohort study

BACKGROUND

The interplay between physical activity (PA) and air pollution in relation to type 2 diabetes (T2D) remains largely unknown. Based on a large population-based cohort study, this study aimed to examine whether the benefits of PA with respect to the risk of T2D are moderated by exposure to air pollution.

METHODS

UK Biobank participants (n = 359,153) without diabetes at baseline were included. Information on PA was obtained using the International Physical Activity Questionnaire short form. Exposure to air pollution, including PM_2.5, PM_coarse (PM_2.5-10), PM₁₀, and NO_2, was estimated from land use regression models. Cox regression models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (95% CIs).

RESULTS

During a median of 8.9 years of follow-up, 13,706 T2D events were recorded. Compared with a low PA level, the HRs for the risk of T2D among individuals with moderate and high PA were 0.82 (95% CI, 0.79-0.86) and 0.73 (95% CI, 0.70-0.77), respectively. Compared with low levels of air pollution, the HRs for risk of T2D for high levels of air pollution (PM_2.5, PM_coarse, PM₁₀, and NO₂) were 1.19 (1.14-1.24), 1.06 (1.02-1.11), 1.13 (1.08-1.18), and 1.19 (1.14-1.24), respectively. There was no effect modification of the associations between PA and T2D by air pollution (all P-interactions > 0.05). The inverse associations between PA and T2D in each air pollution stratum were generally consistent (all P for trend < 0.05).

CONCLUSION

A higher PA and lower air pollution level were independently associated with a lower risk of T2D. The beneficial effects of PA on T2D generally remained stable among participants exposed to different levels of air pollution. Further studies are needed to replicate our findings in moderately and severely polluted areas.

A critical review on air pollutant exposure and age-related macular degeneration

Age-related macular degeneration (AMD) is the leading cause of visual impairments and blindness worldwide in the elderly and its incidence strongly increases with ages. The etiology of AMD is complex and attributed to the genetic modifiers, environmental factors and gene-environment interactions. Recently, the impacts of air pollution on the development of eye diseases have become the new area of focus, and disordered air exposure combined with inadequate health management has caused problems for the eye health, such as dry eye, glaucoma, and retinopathy, while its specific role in the occurrence of AMD is still not well understood. In order to summarize the progress of this research field, we performed a critical review to summarize the epidemiological and mechanism evidence on the association between air pollutants exposure and AMD. This review documented that exposure to air pollutants will accelerate or worsen the morbidity and prevalence of AMD. Air pollutants exposure may change the homeostasis, interfere with the inflammatory response, and take direct action on the lipid metabolism and oxidative stress in the macula. More attention should be given to understanding the impact of ambient air pollution on AMD worldwide.

Associations of long-term exposure to ambient ozone with hypertension, blood pressure, and the mediation effects of body mass index: A national cross-sectional study of middle-aged and older adults in China

BACKGROUND

The associations between long-term exposure to ozone (O₃) and respiratory diseases are well established. However, its association with cardiovascular disease (CVD) remains controversial. In this study, we examined the associations between O₃ and the prevalence of hypertension and blood pressure, and the mediation effects of body mass index (BMI) in Chinese middle-aged and older adults.

METHODS

In this national cross-sectional study, we estimated the O₃ exposure of 12,028 middle-aged and older adults from 126 county-level cities in China, using satellite-based spatiotemporal models. Generalized linear mixed models were used to evaluate the associations of long-term exposure to O₃ with hypertension and blood pressure, including systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and pulse pressure (PP). Mediation effect models were applied to examine the mediation effects of BMI among O₃-induced hypertension and elevated blood pressure.

RESULTS

Each 10 μg/m³ increase in O₃ concentration was significantly associated with an increase of 13.7% (95% confidence interval (CI): 4.8%, 23.3%) in the prevalence of hypertension, an increase of 1.128 mmHg (95% CI: 0.248, 2.005), 0.679 mmHg (95% CI: 0.059, 1.298), 0.820 mmHg (95%CI: 0.245, 1.358) in SBP, DBP, and MAP, respectively. Mediation effect models showed that BMI played 40.08%, 37.25%, 39.95%, and 33.51% mediation roles in the effects of long-term exposure to O₃ on hypertension, SBP, DBP, and MAP, respectively.

CONCLUSIONS

Long-term exposure to O₃ can increase the prevalence of hypertension and blood pressure levels of middle-aged and older adults, and an increase of BMI would be an important modification effect for O₃-induced hypertension and blood pressure increase.

Outdoor Physical Activity in an Air Polluted Environment and Its Effect on the Cardiovascular System-A Systematic Review

Air pollution is a global public health threat. Evidence suggests that increased air pollution leads to increased cardiovascular morbidity and mortality. The aim of this review was to systematically review and synthesize scientific evidence to understand the effect of performing outdoor physical activity (PA) in a polluted environment on cardiovascular outcomes. This review was developed and reported in accordance with the PRISMA guidelines. Electronic searches in Embase, Web of Science, and PubMed were undertaken through March 2021 initially, and later updated through to 31st January 2022, for observational studies published in peer-reviewed journals that report cardiovascular mortality or morbidity due to outdoor PA in air polluted environment. These searches yielded 10,840 citations. Two reviewers independently reviewed each citation for its eligibility. Seven studies were found to be eligible. Of these, five were cohort studies and two were cross-sectional studies. Pollutants measured in the selected studies were Particulate Matter (PM)-PM10, PM2.5, nitrogen oxides (NO_x), and ozone (O₃). The most common study outcome was myocardial infarction, followed by cardiovascular mortality, hypertension and heart rate variability. Six studies emphasized that the PA has beneficial effects on cardiovascular outcomes, though air pollutants attenuate this effect to an extent. Two studies showed that walking, even in the polluted environment, significantly reduced the heart rate and heart rate variability indices. The beneficial effects of outdoor PA outweigh the harmful effects of air pollution on cardiovascular health, though the benefits reduce to an extent when PA is carried out in a polluted environment. Because a limited number of studies (n = 7) were eligible for inclusion, the review further emphasizes the critical need for more primary studies that differentiate between outdoor and indoor PA and its effect on cardiovascular health.

Personalized Spiking Neural Network Models of Clinical and Environmental Factors to Predict Stroke

The high incidence of stroke occurrence necessitates the understanding of its causes and possible ways for early prediction and prevention. In this respect, statistical methods offer the “big picture,” but they have a weak predictive ability at an individual level. This research proposes a new personalized modeling method based on computational spiking neural networks (SNN) for the identification of causal associations between clinical and environmental time series data that can be used to predict individual stroke events. The method is tested on 804 stroke patients. Given a clinical data set of patients who experienced a stroke in the past and the corresponding environmental time-series data for a selected time-window before the stroke event, the method identifies the clusters of individuals with a high risk for stroke under similar conditions. The methodology involves a pipeline of processes when creating a personalized model for an individual $$x$$ x : (1) selecting a group of individuals $$Gx$$ Gx with similar personal records to $$x$$ x ; (2) training a personalized SNN $$x$$ x model of several days of environmental data related to the $$Gx$$ Gx group to predict the risk of stroke for $$x$$ x at least one day earlier; (3) model interpretability through 3D visualization; (4) discovery of personalized predictive markers. The results are twofold, first proposing a new computational methodology and second presenting new findings. It is found that certain environmental factors, such as SO2, PM10, CO, and PM2.5, increase the risk of stroke if an individual $$x$$ x belongs to a certain cluster of people, characterized by a combination of family history of stroke and diabetes, overweight, vascular/heart disease, age, and other. For the used population data, the proposed method can predict accurately individual risk of stroke before the day of the stroke. The paper presents a new methodology for personalized machine learning methods to define subgroups of the population with a high risk of stroke and to predict early individual risk of the stroke event. This makes the proposed cognitive computation method useful to reduce morbidity and mortality in society. The method is broadly applicable for predicting individual risk of other diseases and mental health conditions.

A replicable strategy for mapping air pollution's community-level health impacts and catalyzing prevention

BACKGROUND

Air pollution was responsible for an estimated 6.7 million deaths globally in 2019 and 197,000 deaths in the United States. Fossil fuel combustion is the major source.

HYPOTHESIS

Mapping air pollution's health impacts at the community level using publicly available data and open-source software will provide a replicable strategy for catalyzing pollution prevention.

METHODS

Using EPA's Environmental Benefits Mapping and Analysis (BenMAP-CE) software and state data, we quantified the effects of airborne fine particulate matter (PM_2.5) pollution on disease, death and children's cognitive function (IQ Loss) in each city and town in Massachusetts. To develop a first-order estimate of PM_2.5 pollution's impact on child IQ, we derived a concentration-response coefficient through literature review.

FINDINGS

The annual mean PM_2.5 concentration in Massachusetts in 2019 was 6.3 μg/M³, a level below EPA's standard of 12 μg/M³ and above WHO's guideline of 5 μg/M³. In adults, PM_2.5 pollution was responsible for an estimated 2780 (Confidence Interval [CI] 2726 - 2853) deaths: 1677 (CI, 1346 - 1926) from cardiovascular disease, 2185 (CI, 941-3409) from lung cancer, 200 (CI, 66-316) from stroke, and 343 (CI, 222-458) from chronic respiratory disease. In children, PM_2.5 pollution was responsible for 308 (CI, 105-471) low-weight births, 15,386 (CJ, 5433-23,483) asthma cases, and a provisionally estimated loss of nearly 2 million Performance IQ points; IQ loss impairs children's school performance, reduces graduation rates and decreases lifetime earnings. Air-pollution-related disease, death and IQ loss were most severe in low-income, minority communities, but occurred in every city and town in Massachusetts regardless of location, demographics or median family income.

CONCLUSION

Disease, death and IQ loss occur at air pollution exposure levels below current EPA standards. Prevention of disease and premature death and preservation of children's cognitive function will require that EPA air quality standards be tightened. Enduring prevention will require government-incentivized transition to renewable energy coupled with phase-outs of subsidies and tax breaks for fossil fuels. Highly localized information on air pollution's impacts on health and on children's cognitive function has potential to catalyze pollution prevention.

Association of Physical Activity with Incidence of Dementia Is Attenuated by Air Pollution

INTRODUCTION

Physical activity (PA) is recognized as one of the key lifestyle behaviors that reduces risk of developing dementia late in life. However, PA also leads to increased respiration, and in areas with high levels of air pollution, PA may increase exposure to pollutants linked with higher risk of developing dementia. Here, we investigate whether air pollution attenuates the association between PA and dementia risk.

METHODS

This prospective cohort study included 35,562 adults 60 yrs and older from the UK Biobank. Average acceleration magnitude (ACCave) from wrist-worn accelerometers was used to assess PA levels. Air pollution levels (NO, NO2, PM10, PM2.5, PM2.5-10, and PM2.5 absorbance) were estimated with land use regression methods. Incident all-cause dementia was derived from inpatient hospital records and death registry data.

RESULTS

In adjusted models, ACCave was associated with reduced risk of developing dementia (HR = 0.71, 95% confidence interval [CI] = 0.60-0.83), whereas air pollution variables were not associated with dementia risk. There were significant interactions between ACCave and PM2.5 (HRinteraction = 1.33, 95% CI = 1.13-1.57) and PM2.5 absorbance (HRinteraction = 1.24, 95% CI = 1.07-1.45) on incident dementia. At the lowest tertiles of pollution, ACCave was associated with reduced risk of incident dementia (HRPM 2.5 = 0.66, 95% CI = 0.49-0.91; HRPM 2.5 absorbance = 0.60, 95% CI = 0.44-0.81). At the highest tertiles of these pollutants, there was no significant association of ACCave with incident dementia (HRPM 2.5 = 0.88, 95% CI = 0.68-1.14; HRPM 2.5 absorbance = 0.79, 95% CI = 0.60-1.04).

CONCLUSIONS

PA is associated with reduced risk of developing all-cause dementia. However, exposure to even moderate levels of air pollution attenuates the benefits of PA on risk of dementia.

Frailty Risk in Older Adults Associated With Long-Term Exposure to Ambient PM2.5 in 6 Middle-Income Countries

BACKGROUND

A series of studies have explored the health effects of long-term exposure to ambient PM2.5 among older adults. However, few studies have investigated the adverse effect of long-term exposure to ambient PM2.5 on frailty, and the results are inconclusive. This study sought to investigate the associations between long-term exposure to ambient PM2.5 and frailty in 6 low- and middle-income countries.

METHODS

We included an analytical sample of 34 138 individuals aged 50 and older from the Study on global AGEing and adult health Wave 1 (2007/2010). Air pollution estimates were generated using a standard methodology derived from Moderate Resolution Imaging Spectroradiometer observations and Multiangle Imaging Spectroradiometer instruments from the Terra satellite, along with simulations from the GEOS-Chem chemical transport model. A 3-level hierarchical logistic model was used to evaluate the association between frailty index and long-term PM2.5 exposure at 3 levels (individual, province, and country).

RESULTS

In rural areas, each 10 μg/m3 increase in ambient PM2.5 was associated with a 30% increase in the odds of frailty (OR = 1.30, 95% CI: 1.21-1.39) after adjusting for various potential confounding factors. The gender-stratified analysis showed that the association seemed to be slightly stronger in men (OR = 1.31, 95% CI: 1.18-1.46) than in women (OR = 1.21, 95% CI: 1.07-1.36) in rural areas.

CONCLUSION

In a large sample of community-based older adults from 6 middle-income countries, we found evidence that long-term PM2.5 exposure was associated with frailty in rural areas.

Sex Differences in Cardiovascular Risk Associated With Long-Term PM2.5 Exposure: A Systematic Review and Meta-Analysis of Cohort Studies

Background

Established evidence suggests risks of developing cardiovascular disease are different by sex. However, it remains unclear whether associations of PM_2.5 with cardiovascular risk are comparable between women and men. The meta-analysis aimed to examine sex differences in associations of ischemic heart disease (IHD) and stroke with long-term PM_2.5 exposure.

Methods

PubMed, EMBASE and Cochrane Library were searched until May 2, 2021. We included cohort studies reporting sex-specific associations of long-term PM_2.5 exposure (e.g., ≥1 year) with IHD and stroke. The primary analysis was to estimate relative risk (RR) of PM_2.5-outcome in women and men separately, and the additional women-to-men ratio of RR (RRR) was explored to compare sex differences, using random-effect models.

Results

We identified 25 eligible studies with 3.6 million IHD and 1.3 million stroke cases among 63.7 million participants. A higher level of PM_2.5 exposure was significantly associated with increased risk of IHD in both women (RR = 1.21; 95% CI, 1.15–1.27) and men (RR = 1.12; 95% CI, 1.07–1.17). The women-to-men RRR of IHD was 1.05 (95% CI, 1.02–1.08) per 10 μg/m³ increment in PM_2.5 exposure, indicating significant excess risk of IHD in women. The significant risks of stroke associated with PM_2.5 were obtained in both women (RR = 1.11; 95% CI, 1.08–1.13) and men (RR = 1.11; 95% CI, 1.07–1.14), but no significant women-to-men RRR was observed in stroke (RRR = 1.00; 95% CI, 0.96–1.04).

Conclusions

The study identified excess risk of IHD associated with long-term PM_2.5 exposure in women. The findings would not only have repercussions on efforts to precisely evaluate the burden of IHD attributable to PM_2.5, but would also provide novel clues for cardiovascular risk prevention accounting for sex-based differences.

Long-term exposure to ambient fine particulate matter (PM2.5) and associations with cardiopulmonary diseases and lung cancer in Taiwan: a nationwide longitudinal cohort study

BACKGROUND

Although a number of studies have reported on the health effects of fine particulate matter (PM2.5) exposure, particularly in North American and European countries as well as China, the evidence about intermediate to high levels of PM2.5 exposures is still limited. We aimed to investigate the associations between long-term exposure to PM2.5 and risk of cardiopulmonary disease incidence in Taiwan with intermediate levels of PM2.5 exposure.

METHODS

A cohort of Taiwanese adults, who participated in the 2001, 2005, 2009 and 2013 National Health Interview Surveys, was followed through 2016 to identify cardiopulmonary disease onset. Exposure to PM2.5 was estimated by incorporating a widespread monitoring network of air quality monitoring stations and microsensors. We used time-dependent Cox regression models to examine the associations between the PM2.5 exposures and health outcomes, adjusting for individual characteristics and ecological covariates. The natural cubic spline functions were used to explore the non-linear effects of the PM2.5 exposure.

RESULTS

A total of 62 694 adults from 353 towns were enrolled. Each 10-μg/m3 increase in 5-year average exposure to PM2.5 was associated with a 4.8% increased risk of incident ischaemic heart disease (95% CI: -3.3, 13.6), 3.9% increased risk of incident stroke (95% CI: -2.9, 11.1), 6.7% increased risk of incident diabetes (95% CI: 1.1, 12.7), 15.7% increased risk of incident lung cancer (95% CI: -0.9, 35.1) and 11.5% increased risk of incident chronic obstructive pulmonary disease (95% CI: -0.8, 25.2). The concentration-response curve showed that there was no statistical evidence of non-linearity for most of the disease outcomes except for ischaemic heart disease (P for non-linearity = 0.014).

CONCLUSIONS

Long-term exposure to intermediate levels of ambient PM2.5 was associated with cardiopulmonary health outcomes. Our study adds value to future application and national burden of disease estimation in evaluating the health co-benefits from ambient air pollution reduction policy in Asian countries.

PM2.5 exposure increases the risk of preterm birth in pre-pregnancy impaired fasting glucose women: A cohort study in a Southern province of China

Previous studies have indicated maternal exposure to particles with aerodynamic diameter <2.5 μm (PM_2.5) is associated with preterm birth (PTB). However, no study has investigated this effect in pre-pregnancy impaired fasting glucose (IFG) women. This study aimed to differentiate the effects of maternal PM_2.5 exposure on PTB between pre-pregnancy IFG and normoglycemia women, and to further identify the susceptible window. This cohort study was conducted between January 2014 and December 2017 in 21 Chinese cities. All the recruited women received pre-pregnancy fasting serum glucose (FSG) tests and were followed up for their delivery outcomes. The PM_2.5 exposures were estimated by the daily air pollution concentrations of the nearby monitors. Women with FSG below 7.0 mmol/L were included in the analysis. We employed the Cox proportional hazards models to examine whether PM_2.5 exposure was associated with PTB. 237957 women were included and 7055 (3.0%) of them were pre-pregnancy IFG. During the entire pregnancy, we found 24.1% (HR = 1.241; 95% CI: 1.069, 1.439), 61.8% (HR = 1.618; 95% CI: 1.311, 1.997) and 18.6% (HR = 1.186; 95% CI: 1.004, 1.402) of increases in risk for all PTB, early PTB (20-33 gestational weeks) and late PTB (34-36 gestational weeks) among the pre-pregnancy IFG women, and 15.9% (HR = 1.159; 95% CI: 1.127, 1.192), 33.9% (HR = 1.339; 95% CI: 1.255, 1.430) and 13.2% (HR = 1.132; 95% CI: 1.098, 1.168) of increases in risk for all PTB, early PTB and late PTB among the normoglycemia women, with each 10 μg/m³ increment of PM_2.5 exposure, respectively. Furthermore, PM_2.5 exposure had the strongest effect on all PTB during trimester 1 (0-12 gestational weeks) among the pre-pregnancy IFG women, compared with the less strong effect during trimester 1 among the normoglycemia women. In conclusion, pre-pregnancy IFG increases the risk of PTB attributed to PM_2.5, especially during trimester 1. Moreover, the effects of PM_2.5 are greater on early PTB than late PTB for both pre-pregnancy IFG and normoglycemia women.

Using Distributed Lag Non-Linear Models to Estimate Exposure Lag-Response Associations between Long-Term Air Pollution Exposure and Incidence of Cardiovascular Disease

Long-term air pollution exposure increases the risk for cardiovascular disease, but little is known about the temporal relationships between exposure and health outcomes. This study aims to estimate the exposure-lag response between air pollution exposure and risk for ischemic heart disease (IHD) and stroke incidence by applying distributed lag non-linear models (DLNMs). Annual mean concentrations of particles with aerodynamic diameter less than 2.5 µm (PM_2.5) and black carbon (BC) were estimated for participants in five Swedish cohorts using dispersion models. Simultaneous estimates of exposure lags 1-10 years using DLNMs were compared with separate year specific (single lag) estimates and estimates for lag 1-5- and 6-10-years using moving average exposure. The DLNM estimated no exposure lag-response between PM_2.5 total, BC, and IHD. However, for PM_2.5 from local sources, a 20% risk increase per 1 µg/m³ for 1-year lag was estimated. A risk increase for stroke was suggested in relation to lags 2-4-year PM_2.5 and BC, and also lags 8-9-years BC. No associations were shown in single lag models. Increased risk estimates for stroke in relation to lag 1-5- and 6-10-years BC moving averages were observed. Estimates generally supported a greater contribution to increased risk from exposure windows closer in time to incident IHD and incident stroke.

Associations between ambient fine particulate (PM2.5) exposure and cardiovascular disease: findings from the China Health and Retirement Longitudinal Study (CHARLS)

The evidence regarding the association between long-term fine particulate (PM_2.5) exposure and cardiovascular disease (CVD) in developing countries is limited. This study investigated the association between long-term exposure to PM_2.5 and the prevalence of CVD among middle-aged and older adults. A total of 13,484 adults ≥ 45 years of age were surveyed in China, and logistic regression models were used to examine the association between PM_2.5 and the prevalence of CVD. Furthermore, stratified analyses were conducted to explore potential effect modifiers. In addition, the burden of CVD attributable to PM_2.5 was estimated. The analyses revealed that PM_2.5 was associated with CVD, with an adjusted odds ratio (OR) of 1.18 (95% confidence interval [CI]: 1.12, 1.26) for each 10 μg/m³ increment in ambient PM_2.5. Stratified analyses found that the elderly may be a vulnerable population. It was further estimated that approximately 20.27% (95% CI: 11.86%, 29.96%) of CVD cases could be attributable to PM_2.5. This nationwide study confirmed that long-term exposure to PM_2.5 was associated with an increased prevalence of CVD in China.

Ambient Air Pollution and Cardiorespiratory Outcomes amongst Adults Residing in Four Informal Settlements in the Western Province of South Africa

Few studies have investigated the relationship between ambient air pollution and cardiorespiratory outcomes in Africa. A cross-sectional study comprising of 572 adults from four informal settlements in the Western Cape, South Africa was conducted. Participants completed a questionnaire adapted from the European Community Respiratory Health Survey, and the National Health and Nutrition Examination Survey questionnaire. Exposure estimates were previously modelled using Land-Use Regression for Particulate Matter (PM_2.5) and Nitrogen Dioxide (NO₂) at participants' homes. The median age of the participants was 40.7 years, and 88.5% were female. The median annual NO₂ level was 19.7 µg/m³ (interquartile range [IQR: 9.6-23.7]) and the median annual PM_2.5 level was 9.7 µg/m³ (IQR: 7.3-12.4). Logistic regression analysis was used to assess associations between outcome variables and air pollutants. An interquartile range increase of 5.12 µg/m³ in PM_2.5 was significantly associated with an increased prevalence of self-reported chest-pain, [Odds ratio: 1.38 (95% CI: 1.06-1.80)], adjusting for NO₂, and other covariates. The study found preliminary circumstantial evidence of an association between annual ambient PM_2.5 exposure and self-reported chest-pain (a crude proxy of angina-related pain), even at levels below the South African National Ambient Air Quality Standards.

Analysis of long- and medium-term particulate matter exposures and stroke in the US-based Health Professionals Follow-up Study

PURPOSE

Stroke is a leading cause of mortality worldwide, and air pollution is the third largest contributor to global stroke burden. Existing studies investigating the association between long-term exposure to particulate matter (PM) and stroke incidence have been mixed and very little is known about the associations with medium-term exposures. Therefore, we wanted to evaluate these associations in an cohort of male health professionals.

METHODS

We assessed the association of PM exposures in the previous 1 and 12 months with incident total, ischemic, and hemorrhagic stroke in 49,603 men in the prospective US-based Health Professionals' Follow-up Study 1988-2007. We used spatiotemporal prediction models to estimate monthly PM less than 10 (PM10) and less than 2.5 (PM2.5), and PM2.5-10 at all mailing addresses. We used time-varying Cox proportional hazards models adjusted for potential confounders based on previous literature to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for each 10-μg/m3 increase in exposure in the preceding 1 and 12 months. We explored possible effect modification by age, obesity, smoking, aspirin use, diet quality, physical activity, diabetes, and Census region.

RESULTS

We observed 1,467 cases of incident stroke. Average levels of 12-month PM10, PM2.5-10, and PM2.5 were 20.7, 8.4, and 12.3 µg/m3, respectively. In multivariable adjusted models, we did not observe consistent associations between PM and overall or ischemic stroke. There was a suggestion of increased risk of hemorrhagic stroke (12-month PM10 multivariable HR: 1.13 [0.86, 1.48]; PM2.5-10: 1.12 [0.78, 1.62]; PM2.5:1.17 [0.76, 1.81], all per 10 µg/m3). There was little evidence of effect modification.

CONCLUSIONS

We observed only weak evidence of an association between long-term exposure to PM and risks of overall incident stroke. There was a suggestion of increasing hemorrhagic stroke risk.

Periconception air pollution, metabolomic biomarkers, and fertility among women undergoing assisted reproduction

BACKGROUND

Air pollution exposure has been linked with diminished fertility. Identifying the metabolic changes induced by periconception air pollution exposure among women could enhance our understanding of the potential biological pathways underlying air pollution's reproductive toxicity.

OBJECTIVE

To identify serum metabolites associated with periconception air pollution exposure and evaluate the extent to which these metabolites mediate the association between air pollution and live birth.

METHODS

We included 200 women undergoing a fresh assisted reproductive technology (ART) cycle at Massachusetts General Hospital Fertility Center (2005-2015). A serum sample was collected during stimulation, and untargeted metabolic profiling was conducted using liquid chromatography with ultra-high-resolution mass spectrometry. Exposure to nitrogen dioxide (NO₂), ozone (O₃), fine particulate matter <2.5 µm (PM_2.5), and black carbon (BC) was estimated using validated spatiotemporal models. Multivariable linear regression models were used to evaluate the associations between the air pollutants, live birth, and metabolic feature intensities. A meet in the middle approach was used to identify overlapping features and metabolic pathways.

RESULTS

From the C18 and HILIC chromatography columns, 10,803 and 12,968 metabolic features were extracted. There were 190 metabolic features and 18 pathways that were significantly associated with both air pollution and live birth (P < 0.05) across chromatography columns. Eight features were confirmed metabolites implicated in amino acid and nutrient metabolism with downstream effects on oxidative stress and inflammation. Six confirmed metabolites fell into two intuitive clusters - "antioxidants" and "oxidants"- which could potentially mediate some of the association between air pollution and lower odds of live birth. Tryptophan and vitamin B3 metabolism were common pathways linking air pollution exposure to decreased probability of live birth.

CONCLUSION

Higher periconception air pollution exposure was associated with metabolites and biologic pathways involved in inflammation and oxidative stress that may mediate the observed associations with lower probability of live birth following ART.

Effects of air pollution and habitual exercise on the risk of death: a longitudinal cohort study

Background:

Exercise may exacerbate the adverse health effects of air pollution by increasing the inhalation of air pollutants. We investigated the combined effects of long-term exposure to fine particle matter (PM_2.5) and habitual exercise on deaths from natural causes in Taiwan.

Methods:

We recruited 384 130 adults (aged ≥ 18 yr) with 842 394 medical examination records between 2001 and 2016, and followed all participants until May 31, 2019. We obtained vital data from the National Death Registry of Taiwan. We estimated PM_2.5 exposure using a satellite-based spatiotemporal model, and collected information on exercise habits using a standard self-administered questionnaire. We analyzed the data using a Cox regression model with time-dependent covariates.

Results:

A higher level of habitual exercise was associated with a lower risk of death from natural causes, compared with inactivity (hazard ratio [HR] 0.84, 95% confidence interval [CI] 0.80–0.88 for the moderate exercise group; HR 0.65, 95% CI 0.62–0.68 for the high exercise groups), whereas a higher PM_2.5 exposure was associated with a higher risk of death from natural causes compared with lower exposure (HR 1.02, 95% CI 0.98–1.07, and HR 1.15, 95% CI 1.10–1.20, for the moderate and high PM_2.5 exposure groups, respectively). Compared with inactive adults with high PM_2.5 exposure, adults with high levels of habitual exercise and low PM_2.5 exposure had a substantially lower risk of death from natural causes. We found a minor, but statistically significant, interaction effect between exercise and PM_2.5 exposure on risk of death (HR 1.03 95% CI 1.01–1.06). Subgroup analyses, stratified by PM_2.5 categories, suggested that moderate and high levels of exercise were associated with a lower risk of death in each PM_2.5 stratum, compared with inactivity.

Interpretation:

Increased levels of exercise and reduced PM_2.5 exposure are associated with a lower risk of death from natural causes. Habitual exercise can reduce risk regardless of the levels of PM_2.5 exposure. Our results suggest that exercise is a safe health improvement strategy, even for people residing in relatively polluted regions.

Ambient air pollution and the risk of ischaemic and haemorrhagic stroke

Stroke is a leading cause of disability and the second most common cause of death worldwide. Increasing evidence suggests that air pollution is an emerging risk factor for stroke. Over the past decades, air pollution levels have continuously increased and are now estimated to be responsible for 14% of all stroke-associated deaths. Interpretation of previous literature is difficult because stroke was usually not distinguished as ischaemic or haemorrhagic, nor by cause. This Review summarises the evidence on the association between air pollution and the different causes of ischaemic stroke and haemorrhagic stroke, to clarify which people are most at risk. The risk for ischaemic stroke is increased after short-term or long-term exposure to air pollution. This effect is most pronounced in people with cardiovascular burden and stroke due to large artery disease or small vessel disease. Short-term exposure to air pollution increases the risk of intracerebral haemorrhage, a subtype of haemorrhagic stroke, whereas the effects of long-term exposure are less clear. Limitations of the current evidence are that studies are prone to misclassification of exposure, often rely on administrative data, and have insufficient clinical detail. In this Review, we provide an outlook on new research opportunities, such as those provided by the decreased levels of air pollution due to the current COVID-19 pandemic.

Long-term temperature variability and the incidence of cardiovascular diseases: A large, representative cohort study in China

In the context of global climate change, far less is known about the impact of long-term temperature variability (TV), especially in developing countries. The current study aimed to estimate the effect of long-term TV on the incidence of cardiovascular disease (CVD) in China. A total of 23,721 individuals with a mean age of 56.15 years were enrolled at baseline from 2012 to 2016 and followed up during 2017-2019. TV was defined as the standard deviation of daily temperatures during survey years and was categorized into tertiles (lowest≤ 8.78 °C, middle = 8.78-10.07 °C, highest ≥ 10.07 °C). The Cox proportional hazards regression was used to estimate the multivariable-adjusted hazard ratio (HR) between TV and CVD. During the median follow-up of 4.65 years, we ascertained 836 cases of incident CVD. For per 1 °C increase in TV, there was a 6% increase of CVD (HR = 1.06 [95% confidence interval (CI): 1.01-1.11]). A significant positive trend was observed between CVD risk and increasing levels of TV compared to the lowest tertile [HR = 1.34 (95% CI: 1.13-1.59) for the medium tertile, HR = 1.72 (95% CI: 1.35-2.19) for the highest tertile, P_trend < 0.001]. Exposure to high TV would lose 2.11 disease-free years for the population aged 35-65 years and 66 CVD cases (or 7.95% cases) could been attributable to TV higher than 8.11 °C in the current study. The current findings suggested that long-term TV was associated with a higher risk of CVD incidence, it is needed to reduce the TV-related adverse health effect.

An investigation for airflow and deposition of PM2.5 contaminated with SAR-CoV-2 virus in healthy and diseased human airway

This study is motivated by the amplified transmission rates of the SAR-CoV-2 virus in areas with high concentrations of fine particulates (PM_2.5) as reported in northern Italy and Mexico. To develop a deeper understanding of the contribution of PM_2.5 in the propagation of the SAR-CoV-2 virus in the population, the deposition patterns and efficiencies (DEs) of PM_2.5 laced with the virus in healthy and asthmatic airways are studied. Physiologically correct 3-D models for generations 10-12 of the human airways are applied to carry out a numerical analysis of two-phase flow for full breathing cycles. Two concentrations of PM_2.5 are applied for the simulation, i.e., 30 μg⋅m^-3 and 80 μg⋅m^-3 for three breathing statuses, i.e., rest, light exercise, and moderate activity. All the PM_2.5 injected into the control volume is assumed to be 100% contaminated with the SAR-CoV-2 virus. Skewed air-flow phenomena at the bifurcations are proportional to the Reynolds number at the inlet, and their intensity in the asthmatic airway exceeded that of the healthy one. Upon exhalation, two peak air-flow vectors from daughter branches combine to form one big vector in the parent generation. Asthmatic airway models has higher deposition efficiencies (DEs) for contaminated PM_2.5 as compared to the healthy one. Higher DEs arise in the asthmatic airway model due to complex secondary flows which increase the impaction of contaminated PM_2.5 on airways' walls.

Ambient fine particulate matter exposure and incident mild cognitive impairment and dementia

BACKGROUND/OBJECTIVE

Poor air quality is implicated as a risk factor for cognitive impairment and dementia. Few studies have examined these associations longitudinally in well-characterized population-based cohorts with standardized annual assessment of both mild cognitive impairment (MCI) and dementia. We investigated the association between estimated ambient fine particulate matter (PM_2.5 ) and risk of incident MCI and dementia in a post-industrial region known for historically poor air quality.

SETTING/PARTICIPANTS

Adults aged 65+ years in a population-based cohort (n = 1572).

MEASUREMENTS

Census tract level PM_2.5 from Environmental Protection Agency (EPA) air quality monitors; Clinical Dementia Rating (CDR)®.

DESIGN

We estimated ambient PM_2.5 exposure (μg/m³ , single-year and 5-year averages) by geocoding participants' residential addresses to census tracts with daily EPA PM_2.5 measurements from 2002 to 2014. Using Bayesian spatial regression modeling adjusted for age, sex, education, smoking history, and household income, we examined the association between estimated PM_2.5 exposure and risk of incident MCI (CDR = 0.5) and incident dementia (CDR ≥ 1.0).

RESULTS

Modeling estimated single-year exposure, each 1 μg/m³ higher ambient PM_2.5 was associated with 67% higher adjusted risk of incident dementia (hazard ratio [HR] = 1.669, 95% credible interval [CI]: 1.298, 2.136) and 75% higher adjusted risk of incident MCI (HR = 1.746, 95% CI: 1.518, 2.032). Estimates were higher when modeling 5-year ambient PM_2.5 exposure for incident dementia (HR = 2.082, 95% CI: 1.528, 3.015) and incident MCI (HR = 3.419, 95% CI: 2.806, 4.164).

CONCLUSIONS

Higher estimated ambient PM_2.5 was associated with higher risk of incident MCI and dementia, particularly when considering longer-term exposure, and independent of demographic characteristics and smoking history. Targeting poor air quality may be a reasonable population-wide intervention to reduce the risk of cognitive impairment in older adults, particularly in regions exceeding current recommendations for safe exposure to PM_2.5 .

Association between exposure to ambient air pollution and hospital admission, incidence, and mortality of stroke: an updated systematic review and meta-analysis of more than 23 million participants

BACKGROUND

Previous studies have suggested that exposure to air pollution may increase stroke risk, but the results remain inconsistent. Evidence of more recent studies is highly warranted, especially gas air pollutants.

METHODS

We searched PubMed, Embase, and Web of Science to identify studies till February 2020 and conducted a meta-analysis on the association between air pollution (PM_2.5, particulate matter with aerodynamic diameter less than 2.5 μm; PM₁₀, particulate matter with aerodynamic diameter less than 10 μm; NO₂, nitrogen dioxide; SO₂, sulfur dioxide; CO, carbon monoxide; O₃, ozone) and stroke (hospital admission, incidence, and mortality). Fixed- or random-effects model was used to calculate pooled odds ratios (OR)/hazard ratio (HR) and their 95% confidence intervals (CI) for a 10 μg/m³ increase in air pollutant concentration.

RESULTS

A total of 68 studies conducted from more than 23 million participants were included in our meta-analysis. Meta-analyses showed significant associations of all six air pollutants and stroke hospital admission (e.g., PM_2.5: OR = 1.008 (95% CI 1.005, 1.011); NO₂: OR = 1.023 (95% CI 1.015, 1.030), per 10 μg/m³ increases in air pollutant concentration). Exposure to PM_2.5, SO₂, and NO₂ was associated with increased risks of stroke incidence (PM_2.5: HR = 1.048 (95% CI 1.020, 1.076); SO₂: HR = 1.002 (95% CI 1.000, 1.003); NO₂: HR = 1.002 (95% CI 1.000, 1.003), respectively). However, no significant differences were found in associations of PM₁₀, CO, O₃, and stroke incidence. Except for CO and O₃, we found that higher level of air pollution (PM_2.5, PM₁₀, SO₂, and NO₂) exposure was associated with higher stroke mortality (e.g., PM₁₀: OR = 1.006 (95% CI 1.003, 1.010), SO₂: OR = 1.006 (95% CI 1.005, 1.008).

CONCLUSIONS

Exposure to air pollution was positively associated with an increased risk of stroke hospital admission (PM_2.5, PM₁₀, SO₂, NO₂, CO, and O₃), incidence (PM_2.5, SO₂, and NO₂), and mortality (PM_2.5, PM₁₀, SO₂, and NO₂). Our study would provide a more comprehensive evidence of air pollution and stroke, especially SO₂ and NO₂.

Long-Term PM2.5 Exposure and Risks of Ischemic Heart Disease and Stroke Events: Review and Meta-Analysis

Background

Fine particulate matter <2.5 µm in diameter (PM_2.5) has known effects on cardiovascular morbidity and mortality. However, no study has quantified and compared the risks of incident myocardial infarction, incident stroke, ischemic heart disease (IHD) mortality, and cerebrovascular mortality in relation to long‐term PM_2.5 exposure.

Methods and Results

We sought to quantitatively summarize studies of long‐term PM_2.5 exposure and risk of IHD and stroke events by conducting a review and meta‐analysis of studies published by December 31, 2019. The main outcomes were myocardial infarction, stroke, IHD mortality, and cerebrovascular mortality. Random effects meta‐analyses were used to estimate the combined risk of each outcome among studies. We reviewed 69 studies and included 42 studies in the meta‐analyses. In meta‐analyses, we found that a 10‐µg/m³ increase in long‐term PM_2.5 exposure was associated with an increased risk of 23% for IHD mortality (95% CI, 15%–31%), 24% for cerebrovascular mortality (95% CI, 13%–36%), 13% for incident stroke (95% CI, 11%–15%), and 8% for incident myocardial infarction (95% CI, −1% to 18%). There were an insufficient number of studies of recurrent stroke and recurrent myocardial infarction to conduct meta‐analyses.

Conclusions

Long‐term PM_2.5 exposure is associated with increased risks of IHD mortality, cerebrovascular mortality, and incident stroke. The relationship with incident myocardial infarction is suggestive of increased risk but not conclusive. More research is needed to understand the relationship with recurrent events.

Prolonged Life Expectancy for Those Dying of Stroke by Achieving the Daily PM2.5 Targets

This time-series study collects data on stroke-related mortality, years of life lost (YLL), air pollution, and meteorological conditions in 96 Chinese cities from 2013 to 2016 and proposes a three-stage strategy to generate the national and regional estimations of avoidable YLL, gains in life expectancy and stroke-related population attributable fraction by postulating that the daily fine particulate matter (PM2.5) has been kept under certain standards. A total of 1 318 911 stroke deaths are analyzed. Each 10 µg m-3 increment in PM2.5 at lag03 is associated with a city-mean increase of 0.31 (95% CI: 0.19, 0.44) years of life lost from stroke. A number of 914.11 (95% CI: 538.28, 1288.94) years of city-mean life lost from stoke could be avoided by attaining the WHO's Air Quality Guidelines (AQG) (25 µg m-3). Moreover, by applying the AQG standard, 0.11 (0.08, 0.15) years of life lost might be prevented for each death, and about 0.91% (95% CI: 0.62%, 1.19%) of the total years of life lost from stroke might be explained by the daily excess PM2.5 exposure. This study indicates that stroke patients can have a longer life expectancy if stricter PM2.5 standards are put in place, especially ischemic stroke patients.

Earth Observation Data Supporting Non-Communicable Disease Research: A Review

A disease is non-communicable when it is not transferred from one person to another. Typical examples include all types of cancer, diabetes, stroke, or allergies, as well as mental diseases. Non-communicable diseases have at least two things in common—environmental impact and chronicity. These diseases are often associated with reduced quality of life, a higher rate of premature deaths, and negative impacts on a countries’ economy due to healthcare costs and missing work force. Additionally, they affect the individual’s immune system, which increases susceptibility toward communicable diseases, such as the flu or other viral and bacterial infections. Thus, mitigating the effects of non-communicable diseases is one of the most pressing issues of modern medicine, healthcare, and governments in general. Apart from the predisposition toward such diseases (the genome), their occurrence is associated with environmental parameters that people are exposed to (the exposome). Exposure to stressors such as bad air or water quality, noise, extreme heat, or an overall unnatural surrounding all impact the susceptibility to non-communicable diseases. In the identification of such environmental parameters, geoinformation products derived from Earth Observation data acquired by satellites play an increasingly important role. In this paper, we present a review on the joint use of Earth Observation data and public health data for research on non-communicable diseases. We analyzed 146 articles from peer-reviewed journals (Impact Factor ≥ 2) from all over the world that included Earth Observation data and public health data for their assessments. Our results show that this field of synergistic geohealth analyses is still relatively young, with most studies published within the last five years and within national boundaries. While the contribution of Earth Observation, and especially remote sensing-derived geoinformation products on land surface dynamics is on the rise, there is still a huge potential for transdisciplinary integration into studies. We see the necessity for future research and advocate for the increased incorporation of thematically profound remote sensing products with high spatial and temporal resolution into the mapping of exposomes and thus the vulnerability and resilience assessment of a population regarding non-communicable diseases.

Independent and Opposing Associations of Habitual Exercise and Chronic PM2.5 Exposures on Hypertension Incidence

BACKGROUND

We investigated the joint associations of habitual physical activity (PA) and long-term exposure to fine particulate matter (PM_2.5) with the development of hypertension in a longitudinal cohort in Taiwan.

METHODS

We selected 140 072 adults (≥18 years of age) without hypertension who joined a standard medical screening program with 360 905 medical examinations between 2001 and 2016. PM_2.5 exposure was estimated at each participant's address using a satellite data-based spatiotemporal model with 1 km² resolution. Information on habitual PA and a wide range of covariates was collected using a standard self-administered questionnaire. We used the Cox regression model with time-dependent covariates to examine the joint associations.

RESULTS

The mean age of all observations was 41.7 years, and 48.8% were male. The mean value for systolic and diastolic blood pressure was 112.5 and 68.7mm Hg, respectively. Approximately 34.2% of all observations were inactive (0 metabolic equivalence values-hours), 29.8% had moderate-PA (median [interquartile range]; 3.75 [3.38 to 4.38] metabolic equivalence values-hours), and 36.0% had high-PA (15.7 [10.3 to 24.8] metabolic equivalence values-hours). The mean±SD of PM_2.5 was 26.1±7.3 μg/m³. The prevalence of cardiovascular disease, diabetes mellitus, and cancer was 2.1%, 2.9%, and 1.5%, respectively. After adjusting for a wide range of covariates (including a mutual adjustment for PA or PM_2.5), a higher PA level was associated with a lower risk of hypertension (hazard ratio [HR] for the moderate- and high-PA was 0.93 [95% CI, 0.89-0.97] and 0.92 [95% CI, 0.88-0.96], respectively, as compared with the inactive-PA), whereas a higher level of PM_2.5 was associated with a higher risk of hypertension (HR for the moderate- and high-PM_2.5 was 1.37 [95% CI, 1.32-1.43] and 1.92 [95% CI, 1.81-2.04], respectively, as compared with the low-PM_2.5 group]. No significant interaction was observed between PA and PM_2.5 (HR 1.01 [95% CI, 1.00-1.02]).

CONCLUSIONS

A high-PA and low PM_2.5 exposure were associated with a lower risk of hypertension. The negative association between PA and hypertension remained stable in people exposed to various levels of PM_2.5, and the positive association between PM_2.5 and hypertension was not modified by PA. Our results indicated that PA is a suitable hypertension prevention strategy for people residing in relatively polluted regions.

Exposure to Fine Particulate Matter and Ovarian Reserve Among Women from a Fertility Clinic

BACKGROUND

An increasing number of studies have linked air pollution to decreased fertility. Whether this is due to an effect on ovarian reserve is unknown.

METHOD

Our study included 632 women attending the Massachusetts General Hospital Fertility Center (2004-2015) who had a measured antral follicle count. Validated spatiotemporal models estimated daily particulate matter <2.5 µg/m (PM2.5) (based on residential address) for the 3 months before the antral follicle count. We analyzed associations with Poisson regression.

RESULTS

Every 2 µg/m increase in estimated PM2.5 exposure was associated with a -7.2% (95% confidence interval = -10.4%, -3.8%) lower antral follicle count adjusting for age, body mass index, smoking status, and year and season of the count. The association of PM2.5 with antral follicle count was stronger among women with female factor infertility (-16.3% per 2 µg/m).

CONCLUSIONS

Among women from an infertility clinic, higher PM2.5 exposure was associated with lower ovarian reserve, raising concern that air pollution may accelerate reproductive aging.

Investigation of the Relationship Between the Level of Fine Particulate Matter and Stroke Mortality Rate in Mashhad in 2014 and 2015

Background: Air pollution is a major social problem, particularly in developing countries, where the rapid expansion of industries, cities, and traffic is the main cause of increased air pollution. Objectives: This ecological study (correlation) has been conducted with the aim of analyzing the correlation between ambient fine particulate matter (PM2.5) amount and the rate of stroke mortality in Mashhad during the years 2014 and 2015. Methods: Data were collected from hospitals, the Monitoring Center of Environmental Pollutants, and the Bureau of Meteorology in Khorasan Razavi Province and were analyzed to evaluate the correlation. Results: The results show that the correlation coefficient between PM2.5 and the rate of stroke mortality in different seasons in 2014 and 2015 are 0.997 and 0.902, respectively. The correlation was stronger in 2014 and is significant at a confidence level of 0.01. Conclusions: According to the results, the annual average concentration of PM2.5 decreased from 29.261 (μg/m3) in 2014 to 25.283 (μg/m3) in 2015, and also, the annual rate of stroke mortality decreased by 4.4% in 2015.

Ambient Air Pollution Exposure Association with Anaemia Prevalence and Haemoglobin Levels in Chinese Older Adults

BACKGROUND

Health effects of air pollution on anaemia have been scarcely studied worldwide. We aimed to explore the associations of long-term exposure to ambient air pollutants with anaemia prevalence and haemoglobin levels in Chinese older adults.

METHODS

We used two-level linear regression models and modified Poisson regression with robust error variance to examine the associations of particulate matter (PM) and nitrogen dioxide (NO₂) on haemoglobin concentrations and the prevalence of anaemia, respectively, among 10,611 older Chinese adults enrolled in World Health Organization (WHO) Study on global AGEing and adult health (SAGE) China. The average community exposure to ambient air pollutants (PM with an aerodynamic diameter of 10 μm or less (PM₁₀), 2.5 μm or less (PM_2.5), 1 μm or less (PM₁) and nitrogen dioxide (NO₂)) for each participant was estimated using a satellite-based spatial statistical model. Haemoglobin levels were measured for participants from dried blood spots. The models were controlled for confounders.

RESULTS

All the studied pollutants were significantly associated with increased anaemia prevalence in single pollutant model (e.g., the prevalence ratios associated with an increase in inter quartile range in three years moving average PM₁₀ (1.05; 95% CI: 1.02-1.09), PM_2.5 (1.11; 95% CI: 1.06-1.16), PM₁ (1.13; 95% CI: 1.06-1.20) and NO₂ (1.42; 95% CI: 1.34-1.49), respectively. These air pollutants were also associated with lower concentrations of haemoglobin: PM₁₀ (-0.53; 95% CI: -0.67, -0.38); PM_2.5 (-0.52; 95% CI: -0.71, -0.33); PM₁ (-0.55; 95% CI: -0.69, -0.41); NO₂ (-1.71; 95% CI: -1.85, -1.57) respectively.

CONCLUSIONS

Air pollution exposure was significantly associated with increased prevalence of anaemia and decreased haemoglobin levels in a cohort of older Chinese adults.

A time-to-event analysis on air pollutants with the risk of cardiovascular disease and mortality: A systematic review and meta-analysis of 84 cohort studies

OBJECTIVE

Air pollution is one of the most substantial problems globally. Aerodynamic toxic of particulate matter with <10 mm in diameter (PM₁₀ ), or <2.5 mm (PM_2.5 ), as well as nitric dioxide (NO₂ ), have been linked with health issues. We aimed to perform a comprehensive analysis of the time-to-event for different types of air pollutants on cardiovascular disease (CVD) events based on cohort studies.

METHODS

A comprehensive search on topics that assesses air pollution and cardiovascular disease with keywords up until July 2019 was performed.

RESULTS

There were a total of 28 215 394 subjects from 84 cohorts. Increased PM_2.5 was associated with composite CVD [HR 1.10 (1.02, 1.19)], acute coronary events [HR 1.15 (1.12, 1.17)], stroke [HR 1.13 (1.06, 1.19)], and hypertension [HR 1.07 (1.01, 1.14)], all-cause mortality [HR 1.07 (1.04, 1.09)], CVD mortality [HR 1.10 (1.07, 1.12)], and ischemic heart disease (IHD) mortality [HR 1.11 (1.07, 1.16)]. Association with AF became significant after removal of a study. Increased PM₁₀ was associated with heart failure [HR 1.25 (1.04, 1.50)], all-cause mortality [HR 1.16 (1.06, 1.27)], CVD mortality [HR 1.17 (1.04, 1.30)], and IHD mortality [HR 1.03 (1.01, 1.05)]. Increased of NO₂ was associated with increased composite CVD [HR 1.15 (1.02, 1.29)], atrial fibrillation [HR 1.01 (1.01, 1.02)], acute coronary events [HR 1.08 (1.02, 1.13)], all-cause mortality [HR 1.23 (1.14, 1.32)], CVD mortality [HR 1.17 (1.10, 1.25)], and IHD mortality [HR 1.05 (1.03, 1.08)].

CONCLUSION

Air pollutants are associated with an increased incidence of cardiovascular diseases, all-cause mortality, and CVD mortality.

Association between long-term exposure to ambient air pollution and obesity in a Chinese rural population: The Henan Rural Cohort Study

Association between long-term exposure to ambient air pollution and obesity remains inconclusive, and the evidence from rural areas was limited. Thus, this study aimed to assess the association between ambient air pollution and obesity based on different anthropometric indices in Chinese rural adults, and further to compare the effect sizes of different air pollution types. A total of 38,824 participants (aged 18-79 years) were recruited from the Henan Rural Cohort Study. Logistic and multivariable linear regression model were used to examine the association between ambient air pollution exposure (including particulate matter with aerodynamic diameters ≤ 1.0 μm (PM₁), ≤2.5 μm (PM_2.5), and ≤10 μm (PM₁₀), and nitrogen dioxide (NO₂)) and obesity as well as obese anthropometric indices (including body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), body fat percentage (BFP), and visceral fat index (VFI)). The potential effect modifications were also examined. Positive associations were found between long-term exposure to PM₁, PM_2.5, PM₁₀ and NO₂ and obesity regardless of how obesity was defined (false discovery rate (FDR) < 0.05). Moreover, BMI, WC, WHR, WHtR, BFP, and VFI displayed increased trends with PM₁, PM_2.5, PM₁₀ and NO₂ concentrations increasing (all FDR<0.05). PM₁₀ had the largest effects on obesity among the four types of air pollution. The elderly, women, individuals with low level of education and income, and those who had high fat diet were more vulnerable to the adverse effects of air pollution. In addition, the results of the sensitivity analysis showed that those associations between ambient air pollution and obesity remained robust. These findings suggest that long-term exposure to ambient air pollutant (particularly PM₁₀) may be positively associated with obesity in Chinese rural adults, especially among the elderly, women, individuals with low education and income, as well as unhealthy lifestyles.

Stroke burden and mortality attributable to ambient fine particulate matter pollution in 195 countries and territories and trend analysis from 1990 to 2017

BACKGROUND

Fine particulate matter (PM_2.5) exposure is associated with stroke incidence and mortality. However, the global distribution and trends of stroke burden and mortality attributable to PM_2.5 are rarely studied. We estimated the spatial patterns and temporal trends of PM_2.5-attributable stroke burden in 195 countries and territories from 1990 to 2017.

METHODS

Detailed data on stroke burden attributable to PM_2.5 were extracted from the Global Burden of Disease Study (GBD) 2017. The numbers and age-standardized rates of stroke disability-adjusted life years (DALYs) and mortality (ASDR and ASMR) were estimated by age, sex, subtype, region, and country. Temporal trends in ASDR and ASMR were analyzed using estimated annual percentage change (EAPC).

RESULTS

Globally, in 2017, 10.5 million DALYs and 0.4 million deaths related to stroke were attributable to PM_2.5. The corresponding ASDR and ASMR increased with age, were highest in males and for intracerebral hemorrhage, and varied greatly across countries, with the largest burden in high-middle sociodemographic index (SDI) regions and East Asia. The global ASDR and ASMR decreased by 7.2% and 12.2% from 1990 to 2017, with EAPCs of -0.42 (95% confidence interval [CI]: -0.55, -0.28) and -0.57 (95% CI: -0.72, -0.42), respectively. Age-specific stroke burden rates declined significantly, except in the middle-aged population. The decrease was more pronounced in women and for subarachnoid hemorrhage, while proportions of ischemic stroke burden increased globally and in all SDI regions. Most geographic regions achieved significant declines in ASDR and ASMR since 1990; however, Asia and approximately 30% of countries and territories, especially in low-income countries, showed undesirable increasing trends.

CONCLUSIONS

The patterns and trends were heterogeneous across countries. Strengthened and tailored approaches for stroke prevention and air pollution management are still needed to reduce the disease burden associated with PM_2.5, particularly in males, middle-age populations, and low-income countries and for ischemic stroke.

Long-term exposure to air pollution might increase prevalence of osteoporosis in Chinese rural population

OBJECTIVES

The associations of long-term exposure to air pollution with osteoporosis are rarely reported, especially in rural China. This study aimed to explore the association among rural Chinese population.

METHODS

A total of 8033 participants (18-79 years) derived from the Henan Rural Cohort Study (n = 39,259) were included in this cross-sectional study. Exposure to air pollutants was estimated using machine learning algorithms with satellite remote sensing, land use information, and meteorological data [including particulate matter with aerodynamic diameters ≤1.0 μm (PM₁), ≤2.5 μm (PM_2.5), and ≤10 μm (PM₁₀), and nitrogen dioxide (NO₂)]. The bone mineral density of each individual was measured by using ultrasonic bone density apparatus and osteoporosis was defined based on the T-score ≤ -2.5. Multiple logistic regression models were used to examine the association of air pollution and osteoporosis prevalence.

RESULTS

We observed that per 1 μg/m³ increase in PM₁, PM_2.5, PM₁₀ and NO₂ were associated with a 14.9%, 14.6%, 7.3%, and 16.5% elevated risk of osteoporosis. Compared with individuals in the first quartile, individuals in the fourth quartile had higher odds ratio (OR) of osteoporosis (P-trend < 0.001), the ORs (95% confidence interval) were 2.08 (1.72, 2.50) for PM₁, 2.28 (1.90, 2.74) for PM_2.5, 1.93 (1.60, 2.32) for PM₁₀, and 2.02 (1.68, 2.41) for NO₂. It was estimated that 20.29%-24.36% of osteoporosis cases could be attributable to air pollution in the rural population from China.

CONCLUSIONS

Long-term exposure to air pollutants were positively associated with high-risk of osteoporosis, indicated that improving air quality may be beneficial to improve rural residents health.

Prevention of cardiovascular disease among people living with HIV in sub-Saharan Africa

As longevity has increased for people living with HIV (PLWH) in the United States and Europe, there has been a concomitant increase in the prevalence of cardiovascular disease (CVD) risk factors and morbidity in this population. Whereas the availability of HIV antiretroviral therapy has resulted in dramatic increases in life expectancy in sub-Saharan Africa (SSA), where over two thirds of PLWH reside, if and how these trends impact the epidemiology of CVD is less clear. In this review, we describe the current state of the science on how both HIV and its treatment impact CVD risk factors and outcomes among PLWH in sub-Saharan Africa, including regional factors (unique to SSA) likely to differentiate these relationships from the global North. We then outline how current regional guidelines address CVD prevention among PLWH and which clinical and structural interventions are best poised to confront the co-epidemics of HIV and CVD in the region. We conclude with a discussion of key research gaps that need to be addressed to optimally develop an actionable public health response.

Associations between long-term exposure to air pollution and blood pressure and effect modifications by behavioral factors

BACKGROUND

Studies on the hypertensive effect of long-term air pollution exposure were inconclusive and showed scarce evidence from rural areas in developing countries. In this context, we examined the associations of air pollution exposure with hypertension and blood pressure, and their effect modifiers in rural Chinese adults.

METHODS

We studied 39,259 participants from a cohort established in five rural regions of central China. Individual exposures to PM2.5 and PM10 (particulate matter with an aerodynamic diameter less than or equal to 2.5 μm and 10 μm) and nitrogen dioxide (NO2) was evaluated using satellite-based spatiotemporal models. Mixed-effect regression models were applied to examine the associations of long-term exposure to air pollution with hypertension and four blood pressure component measurements, including systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP) and pulse pressure (PP). Several potential effect modifiers related to demographic and behavioral factors were also examined.

RESULTS

The results showed that for each 1 μg/m3 increase in PM2.5, PM10 and NO2, the adjusted odds ratio of hypertension was 1.029 (95%CI: 1.001,1.057), 1.015 (95%CI: 1.001, 1.029) and 1.069 (95%CI: 1.038, 1.100), respectively. These three air pollutants were also associated with increased SBP (except for PM10), DBP and MAP. The hypertensive effects of air pollution were more pronounced among males, smokers, drinkers, individuals with a high-fat diet, and those with high-level physical activity.

CONCLUSION

Long-term exposure to PM2.5, PM10 and NO2 was associated with increased blood pressure and hypertension in rural Chinese adults, and the associations were modified by several behavioral factors.

Association of Indoor and Outdoor Air Pollution With Hand-Grip Strength Among Adults in Six Low- and Middle-Income Countries

BACKGROUND

Air pollution has been associated with various health outcomes. Its effect on hand-grip strength, a measurement of the construct of muscle strength and health status, remains largely unknown.

METHODS

We used the survey data from 31,209 adults ≥ 50 years of age within Wave 1 of the Study on Global AGEing and Adult Health in six low- and middle-income countries. The outdoor concentration of fine particulate matter pollution (PM2.5) was estimated using satellite data. Domestic fuel type and ventilation were used as indicators of indoor air pollution. We used multilevel linear regression models to examine the association between indoor and outdoor air pollution and hand-grip strength, as well as the potential effect modifiers.

RESULTS

We found inverse associations between both indoor and outdoor air pollution and hand-grip strength. Each 10 μg/m3 increase in 3 years' averaged concentrations of outdoor PM2.5 corresponded to 0.70 kg (95% CI: -1.26, -0.14) lower hand-grip strength; and compared with electricity/liquid/gas fuel users, those using solid fuels had lower hand-grip strength (β = -1.25, 95% CI: -1.74, -0.75). However, we did not observe a statistically significant association between ventilation and hand-grip strength. We further observed that urban residents and those having a higher education level had a higher association between ambient PM2.5 and hand-grip strength, and men, young participants, smokers, rural participants, and those with lower household income had higher associations between indoor air pollution and hand-grip strength.

CONCLUSION

This study suggests that both indoor and outdoor air pollution might be important risk factors of poorer health and functional status as indicated by hand-grip strength.

Environmental Health Research in Africa: Important Progress and Promising Opportunities

The World Health Organization in 2016 estimated that over 20% of the global disease burden and deaths were attributed to modifiable environmental factors. However, data clearly characterizing the impact of environmental exposures and health endpoints in African populations is limited. To describe recent progress and identify important research gaps, we reviewed literature on environmental health research in African populations over the last decade, as well as research incorporating both genomic and environmental factors. We queried PubMed for peer-reviewed research articles, reviews, or books examining environmental exposures and health outcomes in human populations in Africa. Searches utilized medical subheading (MeSH) terms for environmental exposure categories listed in the March 2018 US National Report on Human Exposure to Environmental Chemicals, which includes chemicals with worldwide distributions. Our search strategy retrieved 540 relevant publications, with studies evaluating health impacts of ambient air pollution (n=105), indoor air pollution (n = 166), heavy metals (n = 130), pesticides (n = 95), dietary mold (n = 61), indoor mold (n = 9), per- and polyfluoroalkyl substances (PFASs, n = 0), electronic waste (n = 9), environmental phenols (n = 4), flame retardants (n = 8), and phthalates (n = 3), where publications could belong to more than one exposure category. Only 23 publications characterized both environmental and genomic risk factors. Cardiovascular and respiratory health endpoints impacted by air pollution were comparable to observations in other countries. Air pollution exposures unique to Africa and some other resource limited settings were dust and specific occupational exposures. Literature describing harmful health effects of metals, pesticides, and dietary mold represented a context unique to Africa. Studies of exposures to phthalates, PFASs, phenols, and flame retardants were very limited. These results underscore the need for further focus on current and emerging environmental and chemical health risks as well as better integration of genomic and environmental factors in African research studies. Environmental exposures with distinct routes of exposure, unique co-exposures and co-morbidities, combined with the extensive genomic diversity in Africa may lead to the identification of novel mechanisms underlying complex disease and promising potential for translation to global public health.

Methods, availability, and applications of PM2.5 exposure estimates derived from ground measurements, satellite, and atmospheric models

Fine particulate matter (PM2.5) is a well-established risk factor for public health. To support both health risk assessment and epidemiological studies, data are needed on spatial and temporal patterns of PM2.5 exposures. This review article surveys publicly available exposure datasets for surface PM2.5 mass concentrations over the contiguous U.S., summarizes their applications and limitations, and provides suggestions on future research needs. The complex landscape of satellite instruments, model capabilities, monitor networks, and data synthesis methods offers opportunities for research development, but would benefit from guidance for new users. Guidance is provided to access publicly available PM2.5 datasets, to explain and compare different approaches for dataset generation, and to identify sources of uncertainties associated with various types of datasets. Three main sources used to create PM2.5 exposure data are ground-based measurements (especially regulatory monitoring), satellite retrievals (especially aerosol optical depth, AOD), and atmospheric chemistry models. We find inconsistencies among several publicly available PM2.5 estimates, highlighting uncertainties in the exposure datasets that are often overlooked in health effects analyses. Major differences among PM2.5 estimates emerge from the choice of data (ground-based, satellite, and/or model), the spatiotemporal resolutions, and the algorithms used to fuse data sources.Implications: Fine particulate matter (PM2.5) has large impacts on human morbidity and mortality. Even though the methods for generating the PM2.5 exposure estimates have been significantly improved in recent years, there is a lack of review articles that document PM2.5 exposure datasets that are publicly available and easily accessible by the health and air quality communities. In this article, we discuss the main methods that generate PM2.5 data, compare several publicly available datasets, and show the applications of various data fusion approaches. Guidance to access and critique these datasets are provided for stakeholders in public health sectors.