Baseline repeated measures from controlled human exposure studies: associations between ambient air pollution exposure and the systemic inflammatory biomarkers IL-6 and fibrinogen

Associations between fine particulate matter and its constituents and intrahepatic cholestasis of pregnancy

Few studies have reported an association between intrahepatic cholestasis of pregnancy (ICP) and preconception exposure to PM2.5 and sunlight duration, but there has been no in-depth analysis of the correlation between ICP and different constituents of PM2.5. Thus, we performed this retrospective analysis among 160,544 pregnant women who delivered between 2014 and 2020, to further estimate the impact of different constituents of PM2.5, as well as the duration of sunlight, on ICP via generalized linear models. During the three months prior to conception, the adjusted odds ratios (aORs) for ICP were 1.176 (95 % CI: 1.066, 1.298) for a 10 μg/m3 increase in PM2.5, 1.080 (95 % CI: 1.026, 1.138) for a 1 μg/m3 increase in sulfate (SO42-), 1.069 (95 % CI: 1.025, 1.115) for a 1 μg/m3 increase in organic matter (OM), 1.274 (95 % CI: 1.049, 1.546) for a 1 μg/m3 increase in black carbon (BC), and 1.213 (95 % CI: 1.088, 1.353) for a 1-hour decrease in sunlight duration. In addition, during the preconception period, increased exposure to PM2.5 constituents (including SO42-, OM, and BC) and decreased sunlight duration interactively associated with ICP. Moreover, exposure to OM during the first trimester (aOR=1.043, 95 % CI: 1.004, 1.083) and to BC during both the first trimester (aOR=1.201, 95 % CI: 1.000, 1.442) and the second trimester (aOR=1.278, 95 % CI: 1.048, 1.558) were found to elevate the risk of ICP. In the future, women preparing to conceive should increase sunlight exposure and avoid exposure to air pollution, and the constituents related to anthropogenic emissions should be controlled to prevent these associations.

Blood-Based DNA Methylation Biomarkers to Identify Risk and Progression of Cardiovascular Disease

Non-communicable diseases (NCDs) are the leading cause of death worldwide, with cardiovascular disease (CVD) accounting for half of all NCD-related deaths. The biological onset of CVD may occur long before the development of clinical symptoms, hence the urgent need to understand the molecular alterations underpinning CVD, which would facilitate intervention strategies to prevent or delay the onset of the disease. There is evidence to suggest that CVD develops through a complex interplay between genetic, lifestyle, and environmental factors. Epigenetic modifications, including DNA methylation, serve as proxies linking genetics and the environment to phenotypes and diseases. In the past decade, a growing list of studies has implicated DNA methylation in the early events of CVD pathogenesis. In this regard, screening for these epigenetic marks in asymptomatic individuals may assist in the early detection of CVD and serve to predict the response to therapeutic interventions. This review discusses the current literature on the relationship between blood-based DNA methylation alterations and CVD in humans. We highlight a set of differentially methylated genes that show promise as candidates for diagnostic and prognostic CVD biomarkers, which should be prioritized and replicated in future studies across additional populations. Finally, we discuss key limitations in DNA methylation studies, including genetic diversity, interpatient variability, cellular heterogeneity, study confounders, different methodological approaches used to isolate and measure DNA methylation, sample sizes, and cross-sectional study design.

Chinese Expert Consensus on the Impact of Ambient Air Pollution on Allergic Rhinitis and Recommendations for Mitigation Strategies

Ambient air pollution poses a significant yet manageable threat to human health. The growing consensus on the impact of ambient air pollutants on allergic rhinitis (AR) emphasizes the importance of prevention, control, and treatment strategies. A multidisciplinary consensus development group was established to further standardize management strategies for AR in the presence of exposure to ambient air pollutants. The quality of the evidence and the strength of the recommendations were evaluated using the grading of recommendations, assessment, development, and evaluation (GRADE) system based on domestic and international relevant medical evidence. This consensus evaluates the effects of key air pollutants on public health in relation to AR, including the synergistic effects of air pollutants with meteorological conditions and aeroallergens. At the same time, the consensus provides recommendations for targeted therapeutic and preventive measures for AR under conditions of ambient air pollution, aiming to improve AR-related health outcomes. These recommendations aim to increase public and clinical awareness of the contribution of environmental factors to AR, and offer evidence-based insights for policymakers and regulators to establish informed ambient air quality standards.

Ozone exposure and cardiovascular disease: A narrative review of epidemiology evidence and underlying mechanisms

Ozone (O3) poses a significant global public health concern as it exerts adverse effects on human cardiovascular health. Nevertheless, there remains a lack of comprehensive understanding regarding the relationships between O3 exposure and the risk of cardiovascular diseases (CVD), as well as the underlying biological mechanisms. To address this knowledge gap, this narrative review meticulously summarizes the existing epidemiological evidence, susceptibility, and potential underlying biological mechanisms linking O3 exposure with CVD. An increasing body of epidemiological studies has demonstrated that O3 exposure heightens the incidence and mortality of CVD, including specific subtypes such as ischemic heart disease, hypertension, and heart failure. Certain populations display heightened vulnerability to these effects, particularly children, the elderly, obese individuals, and those with pre-existing conditions. Proposed biological mechanisms suggest that O3 exposure engenders respiratory and systemic inflammation, oxidative stress, disruption of autonomic nervous and neuroendocrine systems, as well as impairment of coagulation function, glucose, and lipid metabolism. Ultimately, these processes contribute to vascular dysfunction and the development of CVD. However, some studies have reported the absence of associations between O3 and CVD, or even potentially protective effects of O3. Inconsistencies among the literature may be attributed to inaccurate assessment of personal O3 exposure levels in epidemiologic studies, as well as confounding effects stemming from co-pollutants and temperature. Consequently, our findings underscore the imperative for further research, including the development of reliable methodologies for assessing personal O3 exposure, exploration of O3 exposure's impact on cardiovascular health, and elucidation of its biological mechanisms. These endeavors will consolidate the causal relationship between O3 and cardiovascular diseases, subsequently aiding efforts to mitigate the risks associated with O3 exposure.

Prenatal exposure to air pollution and maternal depression: Combined effects on brain aging and mental health in young adulthood

INTRODUCTION

Both maternal depression problems during pregnancy and prenatal exposure to air pollution have been associated with changes in the brain as well as worse mood and anxiety in the offspring in adulthood. However, it is not clear whether these effects are independent or whether and how they might interact and impact the brain age and mental health of the young adult offspring.

METHODS

A total of 202 mother-child dyads from a prenatal birth cohort were assessed for maternal depression during pregnancy through self-report questionnaires administered in the early 90s, exposure to air pollutants (Sulfur dioxide [SO2], nitrogen oxides [NOx], and suspended particle matter [SPM]) during each trimester based on maternal address and air quality data, mental health of the young adult offspring (28-30 years of age; 52% men, all of European ancestry) using self-report questionnaires for depression (Beck Depression Inventory), mood dysregulation (Profile of Mood States), anxiety (State-Trait Anxiety Inventory), and psychotic symptoms (Schizotypal Personality Questionnaire), and brain age, estimated from structural magnetic resonance imaging (MRI) and previously published neuroanatomical age prediction model using cortical thickness maps. The brain age gap estimate (BrainAGE) was computed by subtracting structural brain age from chronological age. Trajectories of exposure to air pollution during pregnancy were assessed using Growth Mixture Modeling. The interactions of prenatal depression and prenatal exposure to air pollutants on adult mental health and BrainAGE were assessed using hierarchical linear regression.

RESULTS

We revealed two distinct trajectories of exposure to air pollution during pregnancy: "early exposure," characterized by high exposure during the first trimester, followed by a steady decrease, and "late exposure," characterized by low exposure during the first trimester, followed by a steady increase in the exposure during the subsequent trimesters. Maternal depression during the first half of pregnancy interacted with NOX exposure trajectory, predicting mood dysregulation and schizotypal symptoms in young adults. In addition, maternal depression during the second half of pregnancy interacted with both NOx and SO2 exposure trajectories, respectively, and predicted BrainAGE in young adults. In those with early exposure to NOx, maternal depression during pregnancy was associated with worse mental health and accelerated brain aging in young adulthood. In contrast, in those with early exposure to SO2, maternal depression during pregnancy was associated with slower brain aging in young adulthood.

CONCLUSIONS

Our findings provide the first evidence of the combined effects of prenatal exposure to air pollution and maternal depression on mental health outcomes and brain age in young adult offspring. Moreover, they point out the importance of the timing and trajectory of the exposure during prenatal development.

Association of ambient ozone exposure and greenness exposure with hemorrhagic stroke mortality at different times: A cohort study in Shandong Province, China

Evidence on the association between long-term ozone exposure and greenness exposure and hemorrhagic stroke (HS) is limited, with mixed results. One potential source of this inconsistency is the difference in exposure time metrics. This study aimed to investigate the association between long-term exposure to ambient ozone, greenness, and mortality from HS using exposure metrics at different times. We also examined whether greenness exposure modified the relationship between ozone exposure and mortality due to HS. The study population consisted of 45771 participants aged ≥40 y residing in 20 counties in Shandong Province who were followed up from 2013 to 2019. Ozone exposure metrics (annual mean and warm season) and the normalized difference a measure of greenness exposure, were calculated. The relationship between environmental exposures (ozone and greenness exposures) and mortality from HS was assessed using time-dependent Cox proportional hazards models, and the modification of greenness exposure was examined using stratified analysis with interaction terms. The person-years at the end of follow-up were 90,663. With full adjustments, the risk of death from hemorrhagic stroke increased by 5% per interquartile range increase in warm season ozone [hazard ratio =1.05; 95 % confidence interval: 1.01-1.08]. No clear association was observed between annual ozone and mortality HS. Both the annual and summer NDVI were found to reduce the risk of HS mortality. The relationships were influenced by age, sex, and residence (urban or rural). Furthermore, greenness exposure was shown to have a modifying effect on the relationship between ozone exposure and the occurrence of HS mortality (P for interaction = 0.001). Long-term exposure to warm season O3 was positively associated with HS mortality, while greenness exposure was inversely associated with HS mortality. Greenness exposure may mitigate the negative effects of warm season ozone exposure on HS mortality.

Diesel exhaust particles exposure exacerbates pro-thrombogenic plasma features ex-vivo after cerebral ischemia and accelerates tPA-induced clot-lysis in hypertensive subjects

The combustion of fossil fuels, mainly by diesel engines, generates Diesel Exhaust Particles (DEP) which are the main source of Particulate Matter (PM), a major air pollutant in urban areas. These particles are a risk factor for stroke with 5.6% of cases attributed to PM exposure. Our aim was to evaluate the effect of DEP exposure on clot formation and lysis in the context of stroke. An ex-vivo clot formation and lysis turbidimetric assay has been conducted in human and mouse plasma samples from ischemic stroke or control subjects exposed to DEP or control conditions. Experimental DEP exposure was achieved by nasal instillation in mice, or by ex-vivo exposure in human plasma. Results show consistent pro-thrombogenic features in plasma after human ischemic stroke and mouse cerebral ischemia (distal MCAo), boosted by the presence of DEP. Otherwise, thrombolysis times were increased after ischemia in chronically exposed mice but not in the DEP exposed group. Finally, subjects living in areas with high PM levels presented accelerated thrombolysis compared to those living in low polluted areas. Overall, our results point at a disbalance of the thrombogenic/lytic system in presence of DEP which could impact on ischemic stroke onset, clot size and thrombolytic treatment.

A review of air pollution as a driver of cardiovascular disease risk across the diabetes spectrum

The prevalence of diabetes is estimated to reach almost 630 million cases worldwide by the year 2045; of current and projected cases, over 90% are type 2 diabetes. Air pollution exposure has been implicated in the onset and progression of diabetes. Increased exposure to fine particulate matter air pollution (PM2.5) is associated with increases in blood glucose and glycated hemoglobin (HbA1c) across the glycemic spectrum, including normoglycemia, prediabetes, and all forms of diabetes. Air pollution exposure is a driver of cardiovascular disease onset and exacerbation and can increase cardiovascular risk among those with diabetes. In this review, we summarize the literature describing the relationships between air pollution exposure, diabetes and cardiovascular disease, highlighting how airborne pollutants can disrupt glucose homeostasis. We discuss how air pollution and diabetes, via shared mechanisms leading to endothelial dysfunction, drive increased cardiovascular disease risk. We identify portable air cleaners as potentially useful tools to prevent adverse cardiovascular outcomes due to air pollution exposure across the diabetes spectrum, while emphasizing the need for further study in this particular population. Given the enormity of the health and financial impacts of air pollution exposure on patients with diabetes, a greater understanding of the interventions to reduce cardiovascular risk in this population is needed.

The Climate Crisis and Breastfeeding: Opportunities for Resilience

The climate crisis is an emerging global challenge that poses potential risks to breastfeeding practices and outcomes. There are multifaceted effects of climate change affecting the breastfeeding dyad across environmental, societal, and human health dimensions. Breastfeeding support in the face of climate change will require solutions at the structural level-healthcare, community, and workplace settings-and at the mother-infant dyad level. Breastfeeding can additionally be an adaptive response to crisis situations and can mitigate some of the environmental challenges associated with climate change. Despite the undeniable significance of climate change on breastfeeding (and vice versa), our perspective as experts in the field is that this topic has not been systematically addressed. Although we highlight some of the challenges, potential solutions, and co-benefits of breastfeeding in the context of climate change, there are numerous issues that could be further explored and necessitate additional preparedness planning.

Indoor air pollution and cognitive function among older adults in India: a multiple mediation approach through depression and sleep disorders

BACKGROUND

Studies across multiple countries reveal that depression and sleep disorders can lead to cognitive decline. This study aims to speculate on the effect of different sources of indoor air pollution on cognition and to explore the mediation effect of depression and sleep disorders on cognition when exposed to indoor air pollution. We hypothesize that an older adult experiences higher cognitive decline from indoor pollution when mediated by depression and sleep disorders.

METHODS

We use data from Longitudinal Aging Study in India (LASI), 2017-2018, and employ a multiple mediation model to understand the relationship between indoor air pollution and cognition through sleep disorders and depression while adjusting for possible confounders. Sensitivity analysis was applied to see the effect of different sources of indoor pollution (cooking fuel, indoor smoke products, and secondhand smoke) on cognitive performance.

RESULTS

The effect of three sources of indoor pollutants on cognition increased when combined, indicating stronger cognitive decline. Unclean cooking practices, indoor smoke (from incense sticks and mosquito coils), and secondhand smoke were strongly associated with sleep disorders and depression among older adults. Indoor air pollution was negatively associated with cognitive health (β= -0.38) while positively associated with depression (β= 0.18) and sleep disorders (β= 0.038) acting as mediators. Sensitivity analysis explained 45% variability while adjusting for confounders.

CONCLUSION

The study lays a foundation for future investigations into the nexus of indoor pollution and mental health. It is essential to formulate policies to reduce exposure to varying sources of indoor air pollutants and improve screening for mental health services as a public health priority.

The risk of being bitten by a dog is higher on hot, sunny, and smoggy days

Humans commit more violent crimes when temperature and air pollution is higher. Here, we investigate if also the day-to-day rates of dogs biting humans is influenced by environmental factors. 69,525 reports of dogs biting humans, sourced from public records on animal control requests and from ER records, were analyzed. The impact of temperature and air pollutants were evaluated with a zero-inflated Poisson generalized additive model, while controlling for regional and calendar effects. Exposure-response curves were used to assess the association between outcome and major exposure variables. We find that the rates of dogs biting humans increases with increasing temperature and ozone, but not PM2.5 exposure. We also observed that higher UV irradiation levels were related to higher rats of dog bites. We conclude that dogs, or the interactions between humans and dogs, are more hostile on hot, sunny, and smoggy days, indicating that the societal burden of extreme heat and air pollution also includes the costs of animal aggression.

Association of Long-term exposure to air pollution and residential greenness with lipid profile: Mediating role of inflammation

Lipidemic effect of air pollutants are still inconsistent and their joint effects are neglected. Meanwhile, identified inflammation pathways in animal have not been applied in epidemiological studies, and beneficial effect of residential greenness remained unclear. Therefore, we used data from typically air-polluted Chinese cities to answer these questions. Particulate matter (PM) with a diameter of ≤ 1 µm (PM₁), PM with a diameter of ≤ 2.5 µm (PM_2.5), PM with a diameter of ≤ 10 µm (PM₁₀), sulphur dioxide (SO₂), nitrogen dioxide (NO₂), and ozone (O₃) were predicted by space-time extremely randomized trees model. Residential greenness was reflected by Normalized Difference Vegetation Index (NDVI). Total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) were measured, and atherogenic coefficient (AC) and TG/HDL-C (TGH) ratio were calculated to indicate lipid metabolism. Generalized additive mixed model and quantile g-computation were respectively conducted to investigate individual and joint lipidemic effect of air pollutants. Covariates including demographical characteristics, living habits, meteorological factors, time trends, and disease information were considered to avoid confounding our results. Complement C3 and high-sensitivity C-reactive protein (hsCRP) were analyzed as potential mediators. Finally, association between NDVI and lipid markers were explored. We found that long-term air pollutants exposure were positively associated with lipid markers. Complement C3 mediated 54.72% (95% CI: 0.30, 63.10) and 72.53% (95% CI: 0.65, 77.61) of the association between PM₁ and TC and LDL-C, respectively. We found some significant associations of lipid markers with NDVI_1000 m rather than NDVI_500 m. BMI, disease status, smoke/drink habits are important effect modifiers. Results are robust in sensitive analysis. Our study indicated that air pollutants exposure may detriment lipid metabolism and inflammation may be the potential triggering pathways, while greenness may exert beneficial effects. This study provided insights for the lipidemic effects of air pollution and greenness.

The characters of antibodies against PLA2R in healthy individuals and in the patient with PLA2R associated membranous nephropathy

BACKGROUND

Most primary membranous nephropathy (MN) is mediated by anti-phospholipase A2 receptor (PLA2R) antibodies. Recently, these antibodies have been revealed months to years before the disease's onset. Their production and pathogenicity need further investigation.

METHODS

Anti-PLA2R antibodies were purified from plasma of eight healthy individuals, 12 patients with PLA2R-related MN and negative circulating antibody (Ab-), and 18 patients with positive anti-PLA2R antibodies (Ab +), using affinity column coupled with recombinant human PLA2R. The antigen specificity, antibody amount, titer, IgG subclass, and affinity were assessed by Western blot, immunofluorescence, ELISA, and surface plasmon resonance.

RESULTS

The natural anti-PLA2R antibodies recognized the conformational structure of PLA2R which locates on the cell membrane of podocytes. The amount of natural IgG was 0.12 ± 0.04 g/L, which accounted for 0.80% of total IgG and was lower than that of patients (2.36%, P < 0.001). The titer of natural antibodies was lower than that of patients in Ab- and Ab + groups (1:16 vs. 1:43 vs. 1:274, P < 0.001). IgG2(45.1%) was predominant in natural antibodies, while IgG4 was predominant in Ab + group (45.7 vs. 25.0%, P < 0.001). IgG1 was increasing from natural antibodies to Ab- and Ab + groups. The affinity of natural antibodies was lower than that of patients (K_D: 641.0 vs. 269.0 vs. 99.6 nM, P = 0.002). The antibody titer, affinity, and IgG4 percentage were associated with the severity of proteinuria and the stages of membranous lesion.

CONCLUSIONS

The natural anti-PLA2R antibodies exist in healthy plasma. The antibody titer, IgG subclass, and affinity may participate in the pathogenesis of anti-PLA2R antibodies.

Characteristics and determinants of personal exposure to typical air pollutants: A pilot study in Beijing and Baoding, China

Personal exposure to fine particulate matter (PM_2.5), nitrogen oxides (NO_x, NO₂ and NO), ozone (O₃) and sulfur dioxide (SO₂) was repeatedly measured among fourteen office workers in Beijing and Baoding, China in summer, autumn and winter of 2019. Time-activity patterns were simultaneously recorded. Determinants of personal air pollution exposure were investigated for each pollutant via a linear mixed effect model. The personal concentrations of PM_2.5, NO₂, NO and O₃ were higher in autumn and winter than those in summer. A decreasing trend was found in the personal PM_2.5 level for a typical indoor population in Beijing, indicating that particulate pollution was effectively controlled in Beijing and its surrounding area. The personal levels of PM_2.5, NO₂, and O₃ were weakly correlated with those monitored at ambient stations and were lower than the respective ambient levels except for PM_2.5 in summer and NO₂ in winter. This pilot study showed that the indoor air environment, ambient pollution, traffic-related variables and temperature were significant exposure sources for office workers. Our study highlighted the significance of controlling traffic emissions and improving the workplace air quality to protect the health of office workers. More importantly, we demonstrated the feasibility of model development for personal air pollution exposure prediction.

Assessment of inflammatory cytokines in exhaled breath condensate and exposure to mixtures of organic pollutants in brick workers

Brick production causes a lot of pollution in the form of dust, fumes, and toxic substances. Therefore, brick workers are highly exposed to pollutants and present a high risk of developing respiratory diseases. The objective of this research was to determine the exposure to polycyclic aromatic hydrocarbons (PAHs) and toluene in urine and evaluate the effects on health using markers of oxidative stress in exhaled breath condensate (EBC) as well as the exposure to pollutants in suspended particles of the studied area. Exposure to PAHs and toluene was evaluated using hydroxylated markers (OH) of PAHs and hippuric acid in urine, respectively. Cytokines like TNF-α, INF-y, IL-2, IL-4, IL-6, IL-8, IL-10 y GMCSF in EBC were also evaluated. PM_2.5 particles were measured during an 8-h work shift. The results in brick workers presented a total OH-PAHs concentration of 97.3 µg/L and hippuric acid concentration of 0.2 g/L. The environmental concentrations of suspended particles were found within a range of 41.67-3541.6 μg/m³. The median of cytokines oscillated between 11.8 pg/mL to 1041 pg/mL. In conclusion, these results are similar to those of occupations in which there is high exposure to pollutants and populations with lung diseases. For that reason, the brick production sector requires prevention and control strategies against the pollutants emitted.

Interactive effects of ambient air pollution and sunshine duration on the risk of intrahepatic cholestasis of pregnancy

INTRODUCTION

While the associations among ambient pollutants and various pregnancy complications are well documented, the effect of ambient pollutants on intrahepatic cholestasis of pregnancy (ICP) has not been examined. This study aimed to explore the effects of ambient pollutants and sunshine duration on ICP.

METHODS

The study enrolled 169,971 pregnant women who delivered between 2015 and 2020 in two hospitals. The associations between ICP and exposure to ambient pollutants and sunshine duration, averaged throughout different periods (including the 3 months before conception, 1st trimester and 2nd trimester), were estimated using a generalized linear model. The interaction effects of ambient pollutants and sunshine duration on ICP were estimated.

RESULTS

The fitted curves for ICP incidence were similar to the temporal trends of PM_2.5, PM₁₀, SO₂, CO and NO₂ but not that of O₃. The risk of ICP was significantly elevated following a 10-μg/m³ increase in PM_2.5 (aOR [adjusted odds ratio] = 1.057, 95% CI [confidence interval]: 1.017-1.099) and PM₁₀ (aOR = 1.043, 95% CI: 1.013-1.074) and a 1-h decrease in sunshine duration (aOR = 1.039, 95% CI: 1.011-1.068) during the 3 months before conception. In the second trimester, a 1-μg/m³ increase in the concentration of SO₂ was associated with an increased risk of ICP (aOR = 1.011, 95% CI: 1.001-1.021). Increased concentrations of PM_2.5 and PM₁₀ had interactive effects with reduced sunshine duration during the 3 months before conception on increasing the risk of ICP.

CONCLUSIONS

Exposure to PM_2.5 and PM₁₀ during the 3 months before conception and exposure to SO₂ in the second trimester were associated with an increased ICP risk. Reduced sunshine duration had an interactive effect with increased concentrations of PM_2.5 and PM₁₀ during the 3 months before conception on the occurrence of ICP.

Acute effects of exposure to fine particulate matter and ozone on lung function, inflammation and oxidative stress in healthy adults

Both fine particulate matter (PM_2.5) and ozone (O₃) may have adverse effects on human health. However, previous studies on the effects of air pollutants mainly have focused on susceptible population, and evidence on healthy young adults is limited. We aimed to examine the associations of the two main air pollutants (PM_2.5 and O₃) with lung function, inflammation and oxidative stress in healthy young adults. We recruited 30 healthy young adults for a longitudinal panel study in Beijing and implemented health examination seven times, including lung function (FEV₁ and PEF) and biomarkers of inflammation and oxidative stress (i.e. C-reactive protein, CRP; interleukin-6, IL-6; malondialdehyde, MDA) from December 2019 to May 2021. Hourly ambient air pollutants data were obtained from the closest air quality monitoring station. Linear mixed-effect model was applied to explore the associations between air pollutants and lung function, inflammation and oxidative stress. We observed higher PM_2.5 exposure was associated with decrement in lung function and increment in CRP and MDA. Each 10 μg/m³ increase in PM_2.5 (lag 2 day) is associated with a 17.06 ml (95% CI: -31.53, -2.58) decrease in FEV₁, 46.34 ml/s (95% CI: -76.41, -16.27) decrease in PEF and increments of 2.86% (95% CI: 1.47%, 4.27%) in CRP, 1.63% (95% CI: 0.14%, 3.14%) in MDA respectively. However, there is no significant association between ozone exposure and health indicators. The study suggested that short-term exposure to PM_2.5 may decrease lung function and induce inflammation and oxidative stress in healthy adults, but there is no association between O₃ and each outcome.

Short-term ambient air pollution exposure and adult primary insomnia outpatient visits in Chongqing, China: A time-series analysis

Growing evidence suggest that air pollutants can be associated with sleep disorders. However, no study has explored the association of short-term air pollution exposure with primary insomnia, a specific type of sleep disorders. To evaluate the correlation of short-term air pollution exposure with adult primary insomnia outpatient visits in Chongqing, China, we collected data of adult primary insomnia outpatient visits and air pollutants' concentrations between 2013 and 2019 and the associations were estimated with single-day lags as well as moving average lags using a generalized additive model. Totally, 23,919 outpatient visits for adult primary insomnia were identified. The daily data of adult insomnia outpatient visits, air pollutants (NO₂, CO, SO₂, O₃, PM₁₀ and PM_2.5) and meteorological conditions (daily mean temperature and relative humidity) were gathered. Short-term exposure to multiple air pollutants, especially NO₂ and SO₂, was associated with adult primary insomnia visits. A 10 μg/m³ increase in NO₂ and SO₂ at lag 05 corresponded to increased primary insomnia outpatient visits 3.87% (95% CI: 1.50%-6.24%) and 7.22% (95% CI: 2.10%-12.35%), respectively. Moreover, stronger links were presented in females and cool seasons for NO₂ while in the elderly for SO₂. Collectively, this time-series study suggested that short-term exposure to air pollutants, especially to NO₂ and SO₂, was associated with higher risk of adult primary insomnia outpatient visits, and such association could to be sex-, age-, and season-modified.

The role of solar and geomagnetic activity in endothelial activation and inflammation in the NAS cohort

This study investigated the associations between solar and geomagnetic activity and circulating biomarkers of systemic inflammation and endothelial activation in the Normative Aging Study (NAS) cohort. Mixed effects models with moving day averages from day 0 to day 28 were used to study the associations between solar activity (sunspot number (SSN), interplanetary magnetic field (IMF)), geomagnetic activity (planetary K index (Kp index), and various inflammatory and endothelial markers. Biomarkers included intracellular adhesion molecule-1 (sICAM-1), vascular cell adhesion molecule-1 (sVCAM-1), C-reactive protein (CRP), and fibrinogen. After adjusting for demographic and meteorological variables, we observed significant positive associations between sICAM-1 and sVCAM-1 concentrations and solar and geomagnetic activity parameters: IMF, SSN, and Kp. Additionally, a negative association was observed between fibrinogen and Kp index and a positive association was observed for CRP and SSN. These results demonstrate that solar and geomagnetic activity might be upregulating endothelial activation and inflammation.

Association of Daily Exposure to Air Pollutants with the Risk of Tuberculosis in Xuhui District of Shanghai, China

Previous studies have suggested that air pollutant exposure is related to tuberculosis (TB) risk, but results have not been consistent. This study evaluated the relation between daily air pollutant exposure and TB incidence in Shanghai from 2014 to 2019. Overall, there were four pollutants that were positively related to the risk of new TB cases. After a 5 μg/m³ increase, the maximum lag-specific and cumulative relative risk (RR) of SO₂ were 1.081, (95% CI: 1.035–1.129, lag: 3 days) and 1.616 (95% CI: 1.119–2.333, lag: 0–13 days), while for NO₂, they were 1.061 (95% CI: 1.015–1.11, lag: 4 days) and 1.8 (95% CI: 1.113–2.91, lag: 0–15 days). As for PM_2.5, with a 50 μg/m³ increase, the lag-specific and cumulative RR were 1.064 (95% CI: 1–1.132, lag: 6 days) and 3.101 (95% CI: 1.096–8.777, lag: 0–21 days), while for CO, the lag-specific RR was 1.03 (95% CI: 1.005–1.057, lag: 8 days) and the cumulative RR was 1.436 (95% CI: 1.004–2.053, lag: 0–16 days) with a 100 μg/m³ increase. The associations tended to be stronger in male and elderly patients and differed with seasons. Air pollutant exposure may be a risk factor for TB incidence.

Biochemical clusters predict mortality and reported inability to work 10 ​years later

BACKGROUND

Chronic systemic inflammation has been linked to premature mortality and limited somatic as well as mental health with consequences for capability to work and everyday functioning. We recently identified three biochemical clusters of endocrine and immune parameters (C-reactive protein (CRP), interleukin-6 (IL-6), fibrinogen, cortisol and creatinine) in participants, age 35-81 years, of the open access Midlife in the United States Study (MIDUS) dataset. These clusters have been validated in an independent cohort of Japanese mid-life adults. Among these clusters, the one characterized by high inflammation coupled with low cortisol and creatinine concentrations was associated with the highest disease burden, referred to as high-risk cluster in the following. The current study aims to further examine the nature of this cluster and specifically whether it predicts mortality and the reported inability to work the last 30 days 10 years after the biomarker assessment.

METHODS AND FINDINGS

Longitudinally assessed health data from N ​= ​1234 individuals were analyzed in the current study. Logistic regression analyses were performed to predict mortality within one decade after first assessment (T0 ​= ​first assessment; T1 ​= ​second assessment). General linear models were used to predict the number of days study participants were unable to work due to health issues in the last 30 days (assessed at T1, analyses restricted to individuals <70 years of age). Biological sex, disease burden, and age at T0 were used as covariates in all analyses. Individuals in the previously identified high-risk cluster had a higher risk for mortality (22% of individuals deceased between T0 and T1 versus 10% respectively 9% in the two other clusters). Logistic regression models predicting mortality resulted in a significant difference between individuals from the high-risk cluster compared to those from an identified reference cluster (indicator method, p ​= ​.012), independently of age and disease burden. Furthermore, individuals in the high-risk cluster reported a higher number of disability days during the past 30 days (3.4 days in the high-risk cluster versus 1.5 respectively 1.0 days in the reference clusters) assessed at T1. All pairwise comparisons involving the high-risk cluster were significant (all ps ​< ​.001).

CONCLUSIONS

Immune-endocrine profiles are predictive of mortality within the following decade over and above age and disease burden. The findings thus highlight the importance of biomarker-based risk profiling that may provide new targets for interventions in the context of preventive medicine in the transition from health to disease and disease-related mortality.

Acute and lag effects of ambient fine particulate matter on the incidence of dyslipidemia in Chengdu, China: A time-series study

High levels of ambient fine particulate matter (PM_2.5) might increase the risk of death due to cardiovascular diseases (CVDs). As a critical risk factor for CVDs, dyslipidemia can cause CVDs or exacerbate pre-existing ones. This study aimed to investigate whether a short-time exposure to PM_2.5 leads to dyslipidemia (HyperTC, HyperLDL-C, HyperTG and HypoHDL-C) in adults. The serum lipid data were provided by the Sichuan Provincial People's Hospital Medical Examination Center. We included 309,654 subjects aged 18-79 between May 10, 2015, and May 10, 2017. An advanced distributed lag nonlinear model (DLNM) was applied to investigate the acute and lag effects of ambient PM_2.5 on the risk of dyslipidemia. This study was also stratified by sex, age, BMI and season to examine potential effect modification. We observed that the associations between an interquartile increase in PM_2.5 (43 μg/m³) and dyslipidemia were [relative risk (RR); 95% confidence interval (CI)]: 1.042 (1.013, 1.071) for HyperLDL-C and 1.027 (1.006, 1.049) for HyperTC at lag0 day. The lag effects were found at lag6 day for HyperLDL-C, in lag4-6 days for HyperTC and lag4-7 days for HyperTG. Short-term exposure to ambient PM_2.5 was related to dyslipidemia and the effect modification was observed in the subgroup analysis. The female and normal-weight populations were more susceptible to the risks of PM_2.5 on HyperLDL-C and HyperTC.

Effects of short-term increases in personal and ambient pollutant concentrations on pulmonary and cardiovascular function: A panel study analysis of the Multicenter Ozone Study in oldEr subjects (MOSES 2)

BACKGROUND

The cardiovascular effects of ozone exposure are unclear. Using measurements from the 87 participants in the Multicenter Ozone Study of oldEr Subjects (MOSES), we examined whether personal and ambient pollutant exposures before the controlled exposure sessions would be associated with adverse changes in pulmonary and cardiovascular function.

METHODS

We used mixed effects linear regression to evaluate associations between increased personal exposures and ambient pollutant concentrations in the 96 h before the pre-exposure visit, and 1) biomarkers measured at pre-exposure, and 2) changes in biomarkers from pre-to post-exposure.

RESULTS

Decreases in pre-exposure forced expiratory volume in 1 s (FEV₁) were associated with interquartile-range increases in concentrations of particulate matter ≤2.5 μm (PM_2.5) 1 h before the pre-exposure visit (-0.022 L; 95% CI -0.037 to -0.006; p = 0.007), carbon monoxide (CO) in the prior 3 h (-0.046 L; 95% CI -0.076 to -0.016; p = 0.003), and nitrogen dioxide (NO₂) in the prior 72 h (-0.030 L; 95% CI -0.052 to -0.008; p = 0.007). From pre-to post-exposure, increases in FEV₁ were marginally significantly associated with increases in personal ozone exposure (0.010 L; 95% CI 0.004 to 0.026; p = 0.010), and ambient PM_2.5 and CO at all lag times. Ambient ozone concentrations in the prior 96 h were associated with both decreased pre-exposure high frequency (HF) heart rate variability (HRV) and increases in HF HRV from pre-to post-exposure.

CONCLUSIONS

We observed associations between increased ambient PM_2.5, NO₂, and CO levels and reduced pulmonary function, and increased ambient ozone concentrations and reduced HRV. Pulmonary function and HRV increased across the exposure sessions in association with these same pollutant increases, suggesting a "recovery" during the exposure sessions. These findings support an association between short term increases in ambient PM_2.5, NO₂, and CO and decreased pulmonary function, and increased ambient ozone and decreased HRV.

The circular RNA circTXNRD1 promoted ambient particulate matter-induced inflammation in human bronchial epithelial cells by regulating miR-892a/COX-2 axis

Particulate matter (PM)-induced airway inflammation contributes to the development and exacerbation of chronic airway diseases. Circular RNA (circRNA) is a new class of non-coding RNA that participates in gene regulation in various respiratory diseases, but the regulatory role of circRNA in PM-induced airway inflammation has not been fully elucidated. In this study, we performed the human circRNA microarray to reveal differentially expressed circRNAs in PM-induced human bronchial epithelial cells (HBECs). A total of 176 upregulated and 15 downregulated circRNAs were identified. Of these, a new circRNA termed circTXNRD1 was upregulated by PM exposure in a dose- and time-dependent manner. Knockdown of circTXNRD1 significantly attenuated PM-induced expression of proinflammatory cytokine interleukin 6 (IL-6). CircRNA pull-down, dual-luciferase reporter assay and fluorescence in situ hybridization showed that circTXNRD1 acted as an endogenous sponge to decrease miR-892a levels in HBECs. Downregulation of miR-892a could increase cyclooxygenase-2 (COX-2) expression and eventually promote IL-6 secretion in PM-induced HBECs. Taken together, our findings reveal circTXNRD1 as a novel inflammatory mediator in PM-induced inflammation in HBECs via regulating miR-892a/COX-2 axis. These results provide new insight into the biological mechanism underlying PM-induced inflammation in chronic airway diseases.

How biomarker patterns can be utilized to identify individuals with a high disease burden: a bioinformatics approach towards predictive, preventive, and personalized (3P) medicine

Prevalences of non-communicable diseases such as depression and a range of somatic diseases are continuously increasing requiring simple and inexpensive ways to identify high-risk individuals to target with predictive and preventive approaches. Using k-mean cluster analytics, in study 1, we identified biochemical clusters (based on C-reactive protein, interleukin-6, fibrinogen, cortisol, and creatinine) and examined their link to diseases. Analyses were conducted in a US American sample (from the Midlife in the US study, N = 1234) and validated in a Japanese sample (from the Midlife in Japan study, N = 378). In study 2, we investigated the link of the biochemical clusters from study 1 to childhood maltreatment (CM). The three identified biochemical clusters included one cluster (with high inflammatory signaling and low cortisol and creatinine concentrations) indicating the highest disease burden. This high-risk cluster also reported the highest CM exposure. The current study demonstrates how biomarkers can be utilized to identify individuals with a high disease burden and thus, may help to target these high-risk individuals with tailored prevention/intervention, towards personalized medicine. Furthermore, our findings raise the question whether the found biochemical clusters have predictive character, as a tool to identify high-risk individuals enabling targeted prevention. The finding that CM was mostly prevalent in the high-risk cluster provides first hints that the clusters could indeed have predictive character and highlight CM as a central disease susceptibility factor and possibly as a leverage point for disease prevention/intervention.

Ambient PM2.5-induced brain injury is associated with the activation of PI3K/AKT/FoxO1 pathway

PM_2.5-related neurological and mental diseases, such as cognitive impairment and stroke, tend to cause disability. Six-week-old male C57BL/6 mice were divided into 6 groups and exposed to concentrated PM_2.5 or filtered air for 2, 4, and 6 months, respectively. The neurobehavioral changes of mice were tested. The weight of the whole brain and olfactory bulbs were recorded at the end of exposure, and the brain structure was observed by hematoxylin and eosin (HE) staining. Serum indicators, mRNA, and protein expressions were detected. The spatial learning memory ability was impaired, and the mice were more anxious after PM_2.5 exposure. Relative brain weight decreased with age, and PM_2.5 exposure exceeded the decrease of relative brain weight. Interestingly, superoxide dismutase (SOD) and albumin decreased in the PM_2.5-exposed groups although neuronal morphology and other serum indicators did not show significant difference between PM and FA groups. Moreover, PM_2.5 induced the increase of plasminogen at 2 months but recovered at 4 months and then increased at 6 months again. The results from protein expression and transcriptomic test demonstrated that PI3K/AKT/FoxO1 pathway might be activated after 6-month PM_2.5 exposure in mice. Indicators albumin, the percentage of albumin over IgG (A/G value), and plasminogen were the main serous changes in mice after early-stage (2 months) and long-term (6 months) PM_2.5 exposure. In addition, early-stage injury induced by PM_2.5 might recover at later time point and display significant injury again with the exposure time. PM_2.5 exposure-induced brain injury might be associated with the activation of PI3K/AKT/FoxO1 pathway.

Oxidative Stress Biomarkers in the Relationship between Type 2 Diabetes and Air Pollution

The incidence and prevalence of type 2 diabetes have increased in the last decades and are expected to further grow in the coming years. Chronic hyperglycemia triggers free radical generation and causes increased oxidative stress, affecting a number of molecular mechanisms and cellular pathways, including the generation of advanced glycation end products, proinflammatory and procoagulant effects, induction of apoptosis, vascular smooth-muscle cell proliferation, endothelial and mitochondrial dysfunction, reduction of nitric oxide release, and activation of protein kinase C. Among type 2 diabetes determinants, many data have documented the adverse effects of environmental factors (e.g., air pollutants) through multiple exposure-induced mechanisms (e.g., systemic inflammation and oxidative stress, hypercoagulability, and endothelial and immune responses). Therefore, here we discuss the role of air pollution in oxidative stress-related damage to glycemic metabolism homeostasis, with a particular focus on its impact on health. In this context, the improvement of new advanced tools (e.g., omic techniques and the study of epigenetic changes) may provide a substantial contribution, helping in the evaluation of the individual in his biological totality, and offer a comprehensive assessment of the molecular, clinical, environmental, and epidemiological aspects.

The health effects of wearing facemasks on cardiopulmonary system of healthy young adults: A double-blinded, randomized crossover trial

BACKGROUND

Facemask had increasingly been utilized as a personal protective measure to reduce exposure to ambient particulate matter (PM) during heavily-polluted days and routine life. However, evidence on the potential effects on cardiovascular system by wearing particulate-filtering facemask was limited.

METHODS

We conducted a double-blinded randomized crossover trial (RCT) to evaluate the effects of wearing N95 facemasks on the molecular responses of cardiopulmonary system among 52 healthy college students in Beijing, China. We measured cardiopulmonary health indicators and collected biological samples before and after (up to 5 h at multiple time points) a 2-h walk to examine the changes in lung function, biomarkers of respiratory and systemic oxidative stress/inflammation. We applied linear mixed-effect models to evaluate the effect of the facemask-intervention on the health of cardio-pulmonary system.

RESULTS

In the trial wearing real facemasks, FEV₁ increased by 2.05% (95% CI: 0.27%-3.87%), 2.80% (95% CI: 1.00%-4.63%), and 2.87% (95% CI: 1.07%-4.70%) at V1 (30-min), V2 (3-h), and V3 (5-h) after the 2-h walk outsides, respectively. Compared with participants wearing the sham mask, the percentage change of nitrate in EBC was lower among those wearing the real mask. After the 2-h exposure, urinary MDA levels increased compared to the baseline in both trials. Real trial was lower than sham trial for 6 cytokines (i.e., IL-6, IL-10, IL-13, IL-17A, IFN-γ and TNF-α) in serum at 5-h post-exposure. Wearing facemasks on polluted days produced better improvement, however, on cleaner days, the improvement was weaker.

CONCLUSIONS

Short-term use of N95 facemasks appeared to effectively reduce the levels of lung function declines, the respiratory oxidative stress, and the systemic inflammation/oxidative stress which may be induced by short-term exposure to PM. Wearing facemasks on polluted days (PM_2.5 > 75 μg/m³) presented larger beneficial effects on the cardiopulmonary health than in clean days (PM_2.5 < 75 μg/m³).

Solid fuels use for cooking and sleep health in adults aged 45 years and older in China

Outdoor air pollution has been linked to poor sleep health, but limited studies have investigated the relationship between solid cooking fuels and sleep health in adults. Therefore, we analyzed data from the China Health and Retirement Survey (CHARLS), a national survey of about 17,000 residents aged over 45. Participants were restricted to those who participated in CHARLS 2011, 2013 and 2015 (n = 8,668). Sleep health was indicated by self-reported average sleep hours at night and the numbers of unrested days/week in CHARLS 2015. We analyzed cooking fuel types reported and assessed the duration of solid fuels usage as consistent (indicated use in all three surveys or 6 + years) or inconsistent use (indicated use in one or two surveys or 1-4 years). We found consistent use of solid fuels was associated with a shorter sleep duration (OR = 1.17 95% CI 1.01, 1.35 for ≤ 6 h vs. 7-9 h/day) and higher frequencies of feeling unrested (OR = 1.32 95% CI 1.12, 1.55 for ≥ 5 days/week vs. none) compared with cleaner fuels use. The associations for inconsistent solid fuels use and sleep health were in the similar direction but smaller in magnitude. Further research is needed to confirm our findings and evaluate the exposure impact of specific fuel types to inform intervention strategies.

Long-Term Ambient Air Pollution Exposures and Circulating and Stimulated Inflammatory Mediators in a Cohort of Midlife Adults

BACKGROUND

Chronic exposure to air pollution may prime the immune system to be reactive, increasing inflammatory responses to immune stimulation and providing a pathway to increased risk for inflammatory diseases, including asthma and cardiovascular disease. Although long-term exposure to ambient air pollution has been associated with increased circulating markers of inflammation, it is unknown whether it also relates to the magnitude of inflammatory response.

OBJECTIVES

The aim of this study was to examine associations between chronic ambient pollution exposures and circulating and stimulated levels of inflammatory mediators in a cohort of healthy adults.

METHODS

Circulating interleukin (IL)-6, C-reactive protein (CRP) (n=392), and lipopolysaccharide stimulated production of IL-1β, IL-6, and tumor necrosis factor (TNF)-α (n=379) were measured in the Adult Health and Behavior II cohort. Fine particulate matter [particulate matter with aerodynamic diameter less than or equal to 2.5 μm (PM2.5)] and constituents [black carbon (BC), and lead (Pb), manganese (Mn), zinc (Zn), and iron (Fe)] were estimated for each residential address using hybrid dispersion land use regression models. Associations between pollutant exposures and inflammatory measures were examined using linear regression; models were adjusted for age, sex, race, education, smoking, body mass index, and month of blood draw.

RESULTS

There were no significant correlations between circulating and stimulated measures of inflammation. Significant positive associations were found between exposure to PM2.5 and BC with stimulated production of IL-6, IL-1β, and TNF-α. Pb, Mn, Fe, and Zn exposures were positively associated with stimulated production of IL-1β and TNF-α. No pollutants were associated with circulating IL-6 or CRP levels.

DISCUSSION

Exposure to PM2.5, BC, Pb, Mn, Fe, and Zn was associated with increased production of inflammatory mediators by stimulated immune cells. In contrast, pollutant exposure was not related to circulating markers of inflammation. These results suggest that chronic exposure to some pollutants may prime immune cells to mount larger inflammatory responses, possibly contributing to increased risk for inflammatory disease. https://doi.org/10.1289/EHP7089.

Prevalence of pre-clinical autoimmunity in the normal adult population residing in a metropolitan city of India: A cross-sectional study

OBJECTIVE

A steep rise in the incidence of autoimmune diseases over the decades has been observed, which is simply not explainable with population-level genetic changes, indicating thereby that environmental factors play an important role in their causation. Then again, how air pollution affects the immune system is still not completely elucidated. This study intends to check the presence of autoantibodies and inflammatory markers in normal adults residing for more than 10 years in a highly polluted region.

METHODS

In this observational cross-sectional study design, 1,500 subjects residing in Delhi, India, for more than 10 years were screened, of whom 500 were recruited for the study. Distance from the main road to an individual's house was calculated, which was taken as a proxy for traffic pollution exposure. These subjects were analyzed for autoantibodies and inflammatory markers.

RESULTS

The mean age of our cohort was 31.0±8.3 years. Autoantibody positivity was observed in 18% of the subjects, whereas inflammatory markers were elevated in 68% of the subjects. Subjects residing within 200 m of the main road had a higher prevalence of autoantibodies antinuclear antibody (12.5% vs 6.5% p=0.03) and rheumatoid factor (9.6% vs 4.5% p=0.02) than the subjects residing at or more than 250 m away from the main road.

CONCLUSION

A total of 18% of normal subjects had autoantibody positivity. The odds of developing antinuclear antibodies were twice higher in subjects who resided within 200 m of the main road where the exposure to pollution was higher.

Acute ozone exposure can cause cardiotoxicity: Mitochondria play an important role in mediating myocardial apoptosis

OBJECTIVE

To clarify the cardiotoxicity induced by acute exposure to different concentrations of ozone in both gender rats and explore the underlying mechanisms.

METHODS

A total of 240 rats were randomly sorted into 6 groups with equal numbers of male and female rats in each group. The rats were subjected to ozone inhalation at concentrations of 0, 0.12, 0.5, 1.0, 2.0 and 4.0 ppm, respectively, for 6 h. After ozone exposure, function indicators, myocardial injury indexes and risk factors of cardiovascular disease in blood were assayed.

RESULTS

High ozone exposure resulted in sustained ventricular tachycardia in male and female rats. Myocardial apoptosis in male rats started from 1.0 ppm ozone, and that in female rats started from 2.0 ppm ozone (p < 0.05). Caspase-9 increased significantly from 0.12 ppm ozone (p < 0.01) in both gender rats, while caspase-3 was initially activated at 0.5 ppm ozone. From 1.0 ppm ozone, mitochondrial cristae and myofilaments dissolved. The ratio of Bcl-2/Bax decreased significantly from 0.12 ppm and MRCC-IV decreased significantly from 2.0 ppm by ozone.

CONCLUSION

Acute ozone exposure can cause paroxysmal ventricular tachycardia in rats. Moreover, the changes of inflammatory factors in the heart tissues of female and male rats after ozone exposure were greater than those of oxidative stress. This study reported for the first time that 6 h ozone exposure does not cause acute cardiomyocyte necrosis, but promotes cardiomyocyte apoptosis in a mitochondrial-dependent manner. Ozone could regulate caspases-3 dependent cardiomyocyte apoptosis by affecting the balance between caspase-9 and XIAP.

Short term associations of ambient nitrogen dioxide with daily total, cardiovascular, and respiratory mortality: multilocation analysis in 398 cities

OBJECTIVE

To evaluate the short term associations between nitrogen dioxide (NO₂) and total, cardiovascular, and respiratory mortality across multiple countries/regions worldwide, using a uniform analytical protocol.

DESIGN

Two stage, time series approach, with overdispersed generalised linear models and multilevel meta-analysis.

SETTING

398 cities in 22 low to high income countries/regions.

MAIN OUTCOME MEASURES

Daily deaths from total (62.8 million), cardiovascular (19.7 million), and respiratory (5.5 million) causes between 1973 and 2018.

RESULTS

On average, a 10 μg/m³ increase in NO₂ concentration on lag 1 day (previous day) was associated with 0.46% (95% confidence interval 0.36% to 0.57%), 0.37% (0.22% to 0.51%), and 0.47% (0.21% to 0.72%) increases in total, cardiovascular, and respiratory mortality, respectively. These associations remained robust after adjusting for co-pollutants (particulate matter with aerodynamic diameter ≤10 μm or ≤2.5 μm (PM₁₀ and PM_2.5, respectively), ozone, sulfur dioxide, and carbon monoxide). The pooled concentration-response curves for all three causes were almost linear without discernible thresholds. The proportion of deaths attributable to NO₂ concentration above the counterfactual zero level was 1.23% (95% confidence interval 0.96% to 1.51%) across the 398 cities.

CONCLUSIONS

This multilocation study provides key evidence on the independent and linear associations between short term exposure to NO₂ and increased risk of total, cardiovascular, and respiratory mortality, suggesting that health benefits would be achieved by tightening the guidelines and regulatory limits of NO₂.

Associations between short term exposure to ambient particulate matter from dust storm and anthropogenic sources and inflammatory biomarkers in healthy young adults

This study examined the association between particulate matter from anthropogenic and natural sources and inflammatory biomarkers, including hs-CRP, IL-6, sTNF-RII, and WBCs, in two groups of healthy young subjects. We followed up subjects of two panels (16 to 22 years old), including 22 subjects selected from the urban area (Tehran city) with high-level pollution background and 22 subjects selected from the rural area (Ahmadabad) with low-level pollution background. In each group, we collected 4 times blood samples in various air pollution conditions, In the subjects of the urban group, there was a substantial difference (p < 0.05) between inversion days and cold season control days, and between dust storm days and warm season control days for concentrations of hs-CRP, IL-6, and WBCs biomarkers. In the subjects of the rural group, a significant difference could be detected in the concentration of hs-CRP, IL-6, and WBCs biomarkers (p < 0.05) between inversion days and cold season control days, and between dust storm and warm control days. We found that the difference in concentrations of hs-CRP, IL-6, and WBCs biomarkers between dust storm days and warm control conditions in the rural group were higher than the difference in inversion and cold control conditions, which can be attributed to low background air pollution in the rural area. In the urban area, the health effect of anthropogenic sources of PM is higher than the dust storm condition, which can be attributed to the stronger effect of anthropogenic pollution effect.

Long-term exposure to ambient PM1 strengthened the association of depression/anxiety symptoms with poor sleep quality: The Henan Rural Cohort study

Evidence from numerous epidemiological studies for the relationship between mental disorder and sleep quality was inconclusive and few studies assessed the modification effect of exposure to ambient air PM1 (particulate matter with an aerodynamic diameter ≤ 1.0 µm) on this association. In this study, 27,572 participants aged 18-79 years from The Henan Rural Cohort study were included in the final analyses. The Patient Health Questionnaire-2 (PHQ-2) and Generalized Anxiety Disorder-2 (GAD-2) scales were used to estimate the frequency of depression and anxiety symptoms of all participants, respectively. The Pittsburgh Sleep Quality Index (PSQI) scale was used to assess night sleep quality and PSQI global score (GSC) ≥ 6 was classified as poor sleep quality. The three-year average exposure concentration of PM1 before the baseline survey was determined as long-term exposure concentration of ambient PM1. Logistic regression model was conducted to estimate the independent or joint effect of depression/anxiety symptoms and ambient PM1 exposure on poor sleep quality. In the adjusted models, the odds ratios (ORs) and 95% confidence intervals (95% CIs) of poor sleep quality associated with depression and anxiety symptoms were 3.75 (3.37, 4.17) and 3.42 (3.06, 3.81), respectively, and that associated with long-term exposure to PM1 was 1.06 (1.03, 1.09). An interaction effect was observed between anxiety symptoms score and PM1 concentration on poor sleep quality. With the increment of PM1 concentration, the association was strengthened between depression/anxiety symptoms and poor sleep quality. Besides, compared with the reference group, the ORs (95% CIs) of poor sleep quality in those with comorbidity of depression and anxiety symptoms were 4.98 (3.95, 6.29), 5.23 (3.98, 6.87), 5.76 (4.42, 7.49), and 5.58 (3.83, 8.14), respectively, from the first to the fourth quartile level of the PM1 concentration. These findings suggested that long-term exposure to PM1 strengthened the association of depression/anxiety symptoms with poor sleep quality in rural China.

Long-term exposure to ozone and sulfur dioxide increases the incidence of type 2 diabetes mellitus among aged 30 to 50 adult population

AIMS/HYPOTHESIS

Worldwide, the information regarding the associations between long-term exposure to ozone (O₃) and sulfur dioxide (SO₂) and the development of type 2 diabetes remains scarce, especially in Asia. This study aimed to investigate the long-term effects of exposure to ambient O₃ and SO₂ on the incidence of type 2 diabetes with consideration of other air pollutants in Taiwanese adults aged 30 to 50 years.

METHODS

A total of 6,426,802 non-diabetic participants aged between 30 and 50 years old were obtained from the National Health Insurance Research Database between 2005 and 2016. Incident type 2 diabetes was the main diagnosis at medical visits. Air quality data were provided by the Taiwan Environmental Protection Administration. The air pollutant concentrations for each participant were estimated using the ordinary kriging method to interpolate daily concentrations of O₃, SO₂, carbon monoxide (CO), nitrogen dioxide (NO₂), suspended fine particles (with an aerodynamic diameter less than 2.5 μm; PM_2.5), and suspended particles (with an aerodynamic diameter less than 10 μm; PM₁₀) in residential districts across Taiwan. Six-year average concentrations of pollutants were calculated from January 1, 2005 to December 31, 2010, and data were categorized into quartiles. We performed Cox regression models to analyze the long-term effects of exposure to O₃ and SO₂ on the incidence of type 2 diabetes.

RESULTS

The hazard ratio (HR) for the incidence of diabetes per each interquartile range (IQR) increase in ozone exposure (3.30 ppb) was 1.058 (95% confidence interval (CI): 1.053, 1.064) and 1.011 (95% CI: 1.007, 1.015) for SO₂ exposure (1.77 ppb) after adjusting for age, sex, socioeconomic status, urbanization level, temperature, humidity, and chronic comorbidities (Model 3). Furthermore, for every 3.30 ppb increase of O₃, the HR for incident type 2 diabetes was 1.093 (95% CI: 1.087, 1.100) after controlling factors shown in Model 3 plus SO₂ and PM_2.5. On the other hand, for every 1.77 ppb increase of SO₂, the HR for incident type 2 diabetes was 1.073 (95% CI: 1.068, 1.079) after controlling factors shown in Model 3 plus NO₂ and PM_2.5.

CONCLUSIONS

Long-term exposure to ambient O₃ and SO₂ was associated with a higher risk of developing type 2 diabetes for Taiwanese population. Exposure to O₃ and SO₂ may play a role in the adult early-onset type 2 diabetes.

Preconceptional and prenatal exposure to air pollution increases incidence of childhood pneumonia: A hypothesis of the (pre-)fetal origin of childhood pneumonia

BACKGROUND

Increasing evidence has linked childhood pneumonia with early exposure to ambient air pollution. However, the impact of exposure to air pollutants before birth is unclear.

OBJECTIVE

To further clarify whether exposure to a particular pollutant during preconceptional and prenatal periods, may pose a higher risk of developing childhood pneumonia.

METHODS

This case-control cohort study consisted of 1510 children aged 0-14 years in Changsha, China between 2017 and 2019. Data of children's history of pneumonia and blood biomarkers were obtained from the XiangYa Hospital records. Each child's exposure to air pollutants, including nitrogen dioxide (NO₂), sulfur dioxide (SO₂), and particulate matter with an aerodynamic diameter ≤ 10 µm (PM₁₀), was calculated using data from ten air pollution monitoring stations. A multivariate logistic regression model was used to quantify the relationship between childhood pneumonia and exposure to ambient air pollution during the preconceptional and prenatal periods.

RESULTS

Childhood pneumonia was significantly associated with preconceptional and prenatal exposure to the industrial-related air pollutant, SO₂, for 1 year before conception, for 3 months before conception and for the entire pregnancy, with ORs(95% CI)= 4.01(3.17-5.07), 4.06(3.29-5.00) and 6.51(4.82-8.79). Also, children who were sick with pneumonia had higher white blood cell and neutrophil counts, and children with low eosinophil count or hemoglobin are likely to get pneumonia. Sensitivity analysis showed that boys, and children in high temperature area were susceptible to the effect of both preconceptional and prenatal exposure to industrial SO₂.

CONCLUSION

Preconceptional and prenatal exposure to industrial-related air pollution plays a significant role in the incidence and progression of childhood pneumonia, supporting the hypothesis of "(pre-)fetal origin of childhood pneumonia".

Environmental pollution and mental health: a narrative review of literature

Pollutant agents are exponentially increasing in modern society since industrialization processes and technology are being developed worldwide. Impact of pollution on public health is well known but little has been described on the association between environmental pollutants and mental health. A literature search on PubMed and EMBASE has been conducted and 134 articles published on the issue of pollution and mental health have been included, cited, reviewed, and summarized. Emerging evidences have been collected on association between major environmental pollutants (air pollutants, heavy metals, ionizing radiation [IR], organophosphate pesticides, light pollution, noise pollution, environmental catastrophes) and various mental health disorders including anxiety, mood, and psychotic syndromes. Underlying pathogenesis includes direct and indirect effects of these agents on brain, respectively, due to their biological effect on human Central Nervous System or related to some levels of stress generated by the exposure to the pollutant agents over the time. Most of emerging evidences are still nonconclusive. Further studies should clarify how industrial production, the exploitation of certain resources, the proximity to waste and energy residues, noise, and the change in lifestyles are connected with psychological distress and mental health problems for the affected populations.

Relationship Between Exposure to Sulphur Dioxide Air Pollution, White Cell Inflammatory Biomarkers and Enzymatic Infarct Size in Patients With ST-segment Elevation Acute Coronary Syndromes

Aims: To analyse the relationship among air pollutants, markers of inflammation and infarct size in patients with acute coronary syndrome (ACS). Methods: This was a prospective analysis of consecutive patients admitted to hospital because of ACS. Cardiac biomarkers were drawn. The daily mean values of the air pollutants from the day before until 7 days before admission were analysed. The study population was stratified according to infarct size, based on median peak troponin value. Results: Patients were divided into two groups of 108 subjects each, according to median peak troponin value. Patients with extensive MIs had a higher neutrophil:lymphocyte ratio and leukocyte and neutrophil counts than patients with smaller MIs. In addition, they were exposed to higher concentrations of sulphur dioxide (9.7 ± 4.1 versus 8.4 ± 3.1 μg/m3; p=0.009) and lower concentrations of ozone (33.8 ± 13.7 versus 38.6 ± 14.5 μg/m3; p=0.014). Multivariate analysis showed that sulphur dioxide levels (OR 1.12; 95% CI [1.031-1.21]; p=0.007) and neutrophil/lymphocyte ratio (OR 1.08; 95% CI [1.011-1.17]; p=0.024) were independent predictors of infarct size. Conclusion: Patients with extensive MIs had higher white cell inflammatory levels and had been exposed to higher sulphur dioxide concentrations in the ambient air.

Acute exposure to traffic-related air pollution alters antioxidant status in healthy adults

BACKGROUND

Exposure to traffic-related air pollution is associated with an increased risk of cardiovascular and respiratory disease. Evidence suggests that inhaled pollutants precipitate these effects via multiple pathways involving oxidative stress.

OBJECTIVE

Postulating that a decrease in circulating antioxidant levels reflect an oxidative response, we investigated the effect of inhaled diesel exhaust (DE) on the ratio of reduced to oxidized glutathione (GSH/GSSG) in healthy adults, and whether pre-exposure antioxidant supplementation blunted this response. We also examined exposure-related changes in antioxidant/stress response leukocyte gene expression (GCLc, HMOX-1, IL-6, TGFβ) and plasma IL-6 levels.

METHODS

Nineteen nonsmoking adults participated in a double-blind, randomized, four-way crossover study. Each subject completed 120-min exposures to filtered air and DE (200 μg/m3), with and without antioxidant pretreatment. Antioxidant comprised 1000 mg ascorbate for 7 days and 1200 mg N-acetylcysteine 1 day prior to exposure, with 1000 mg and 600 mg, respectively, administered 2 h prior to exposure. Whole blood glutathione was measured pre- and post-exposure; plasma IL-6 and mRNA expression were quantified pre, during and post exposure.

RESULTS

Diesel exhaust exposure was associated with significantly decreased GSH/GSSG (p = 0.001) and a 4-fold increase in IL-6 mRNA (p = 0.01) post exposure. Antioxidant pretreatment did not significantly mediate the effect of DE exposure on GSH/GSSG, though appeared to decrease the effect of exposure on IL-6 mRNA expression.

CONCLUSIONS

Acute DE inhalation induced detectable oxidative effects in healthy adults, which were not significantly attenuated by the selected antioxidant pre-treatment. This finding supports the premise that oxidative stress is one mechanism underlying the adverse effects of traffic-related air pollution.

Ambient PM Toxicity Is Correlated with Expression Levels of Specific MicroRNAs

Uncertainties regarding optimized air pollution control remain as the underlying mechanisms of city-specific ambient particulate matter (PM)-induced health effects are unknown. Here, water-soluble extracts of PMs collected from four global cities via automobile air-conditioning filters were consecutively injected three times by an amount of 1, 2, and 2 mg into the blood circulation of Wistar rats after filtration by a 0.45 μm pore size membrane. Acute health effects, such as immune and inflammatory responses and hemorrhage in alveoli, were observed right after the PM extraction injection. Significant differences between cities in biomarker tumor necrosis factor-α (TNF-α) and monocyte chemoattractant protein-1 (MCP-1) levels were detected following the second and third PM injections. Rats' inflammatory responses varied substantially with the injections of city-specific PMs. Repeated PM extract exposure rendered the rats more vulnerable to subsequent challenges, and downregulation of certain microRNAs was observed in rats. Among the studied miRNAs, miR-125b, and miR-21 were most sensitive to the PM exposure, exhibiting a negative dose-response-type relationship with a source-specific PM (oxidative potential) toxicity (r² = 0.63 and 0.57; p-values < 0.05). The results indicated that city-specific PMs could induce different health effects by selectively regulating different miRNAs, and that certain microRNAs, e.g., miR-125b and miR-21, may be externally mediated to neutralize PM-related health damages.

Inflammatory and oxidative stress responses of healthy adults to changes in personal air pollutant exposure

Exposure to air pollutants has been associated with respiratory and cardiovascular mortality, but the underlying molecular mechanisms remain inadequately understood. We aimed to examine molecular-level inflammatory and oxidative stress responses to personal air pollutant exposure. Fifty-three healthy adults aged 22-52 were measured three times for their blood inflammatory cytokines and urinary malondialdehyde (MDA, an oxidative stress biomarker) within 2 consecutive months. Pollutant concentrations monitored indoors and outdoors were combined with the time-activity data to calculate personal O₃, PM_2.5, NO₂, and SO₂ exposures averaged over 12 h, 24 h, 1 week, and 2 weeks, respectively, prior to biospecimen collection. Inflammatory cytokines and MDA were associated with pollutant exposures using linear mixed-effects models controlling for various covariates. After adjusting for a co-pollutant, we found that concentrations of proinflammatory cytokines were significantly and negatively associated with 12-h O₃ exposures and significantly but positively associated with 2-week O₃ exposures. We also found significant and positive associations of proinflammatory cytokines with 12-h and 24-h NO₂ exposures, respectively. However, we did not find clear associations of PM_2.5 and SO₂ exposure with proinflammatory cytokines and with MDA. The removal of an O₃-generating electrostatic precipitator in the mechanical ventilation systems of the offices and residences of the subjects was associated with significant decreases in IL-1β, IL-2, IL-6, IL-8, IL-17A, and TNF-α. These findings suggest that exposure to O₃ for different time durations may affect systemic inflammatory responses in different ways.

Pathogenic Role of Air Pollution Particulate Matter in Cardiometabolic Disease: Evidence from Mice and Humans

Significance: Air pollution is a considerable global threat to human health that dramatically increases the risk for cardiovascular pathologies, such as atherosclerosis, myocardial infarction, and stroke. An estimated 4.2 million cases of premature deaths worldwide are attributable to outdoor air pollution. Among multiple other components, airborne particulate matter (PM) has been identified as the major bioactive constituent in polluted air. While PM-related illness was historically thought to be confined to diseases of the respiratory system, overwhelming clinical and experimental data have now established that acute and chronic exposure to PM causes a systemic inflammatory and oxidative stress response that promotes cardiovascular disease. Recent Advances: A large body of evidence has identified an impairment of redox metabolism and the generation of oxidatively modified lipids and proteins in the lung as initial tissue response to PM. In addition, the pathogenicity of PM is mediated by an inflammatory response that involves PM uptake by tissue-resident immune cells, the activation of proinflammatory pathways in various cell types and organs, and the release of proinflammatory cytokines as locally produced tissue response signals that have the ability to affect organ function in a remote manner. Critical Issues: In the present review, we summarize and discuss the functional participation of PM in cardiovascular pathologies and its risk factors with an emphasis on how oxidative stress, inflammation, and immunity interact and synergize as a response to PM. Future Directions: The impact of PM constituents, doses, and novel anti-inflammatory therapies against PM-related illness is also discussed.

Effects of hourly levels of ambient air pollution on ambulance emergency call-outs in Shenzhen, China

Some researches have shown the associations between air pollution and hospital-based emergency department visits, while the evidence about the acute effects of air pollution on emergency ambulance dispatches for the whole population is rarely available, especially on an hourly time scale. This paper aimed to investigate the effects of hourly concentrations of ambient air pollution on hourly number of ambulance emergency call-outs (AECOs) in Shenzhen, China. AECO data were collected from Shenzhen Emergency Center from January 2013 to December 2016. A time-stratified case-crossover design with conditional Poisson regression was performed to fit the relationship between hourly air pollution and AECOs. The distributed lag model was applied to determine lag structure of the effects of air pollutants. There were a total of 502,862 AECOs during the study period. The significant detrimental effects of SO₂, PM_2.5, and PM₁₀ appeared immediately with a following harvesting effect after 5 h and the effects lasted for about 96 h. The cumulative effect estimates of four pollutants over 0-96 h were 13.99% (95% CI 7.52-20.85%), 2.07% (95% CI 0.72-3.43%), 1.20% (95% CI 0.54-1.87%), and 2.46% (95% CI 1.63-3.29%), respectively. We did not observe significant effects of O₃. This population-based study quantifies the adverse effects of air pollution on ambulance dispatches and provides evidence of the lag structure of the effects on an hourly time scale.

Air pollution and its effects on the immune system

A well-functioning immune system is vital for a healthy body. Inadequate and excessive immune responses underlie diverse pathologies such as serious infections, metastatic malignancies and auto-immune conditions. Therefore, understanding the effects of ambient pollutants on the immune system is vital to understanding how pollution causes disease, and how that pathology could be abrogated. The immune system itself consists of multiple types of immune cell that act together to generate (or fail to generate) immune responses and in this article we review evidence of how air pollutants can affect different immune cell types such as particle-clearing macrophages, inflammatory neutrophils, dendritic cells that orchestrate adaptive immune responses and lymphocytes that enact those responses. Common themes that emerge are of the capacity of air pollutants to stimulate pro-inflammatory immune responses across multiple classes of immune cell. Air pollution can enhance T helper lymphocyte type 2 (Th2) and T helper lymphocyte type 17 (Th17) adaptive immune responses, as seen in allergy and asthma, and dysregulate anti-viral immune responses. The clinical effects of air pollution, in particular the known association between elevated ambient pollution and exacerbations of asthma and chronic obstructive pulmonary disease (COPD), are consistent with these identified immunological mechanisms. Further to this, as inhaled air pollution deposits primarily on the respiratory mucosa this review focuses on mechanisms of respiratory disease. However, as discussed in the article, air pollution also affects the wider immune system for example in the neonate and gastrointestinal tract. Whilst the many identified actions of air pollution on the immune system are notably diverse, immunological research does suggest potential strategies to ameliorate such effects, for example with vitamin D supplementation. An in-depth understanding of the immunological effects of ambient pollutants should hopefully yield new ideas on how to reduce the adverse health effects of air pollution.

The association of short-term effects of air pollution and sleep disorders among elderly residents in China

Sleep disorders, oftentimes co-occurring with other mental and neurological disorders in the elderly, have been previously linked to short-term exposures to air pollution. Here we assessed such associations among 395,651 elderly Chinese in Ningbo, China where air pollution exposures are high and the proportion of elderly in the population is growing. We utilized a regional health information database in China (2008-2017) that collected information on hospital visits for sleep disorders among the elderly (age 60+). Measures of daily air pollution concentrations including nitrogen dioxide (NO2), sulfur dioxide (SO2), ozone (O3), inhalable particles (PM10), and ambient fine particulate matter (PM2.5) were generated from seven environmental air quality monitoring sites in the study area. We used a generalized additive model to evaluate the associations between hospital visits for sleep disorders and short-term air pollution exposures for up to 7 days prior to a hospital visit. Short-term exposure to multiple air pollutants was associated with hospital visits for sleep disorders in an elderly population; with the strongest associations during 2-3 days prior to a clinic visits for traffic-related pollutants including air quality index (AQI), PM2.5, PM10, and NO2 and for SO2 and O3 for 5 days prior to the visits. Our study based on large health care record system suggested that short-term air pollution exposures are associated with sleep disorders in the elderly. Considering the individual covariates that could not be adjusted in time-series analyses, future studies with individual level data and an ability to evaluate the severity of sleep disorders and their relation to mental and physical health in general and air pollution are needed. An aging population with increasing health problems and the frequency of high and very high air pollution events in China make our findings very health policy relevant.

Multicenter Ozone Study in oldEr Subjects (MOSES): Part 2. Effects of Personal and Ambient Concentrations of Ozone and Other Pollutants on Cardiovascular and Pulmonary Function

INTRODUCTION

The Multicenter Ozone Study of oldEr Subjects (MOSES) was a multi-center study evaluating whether short-term controlled exposure of older, healthy individuals to low levels of ozone (O3) induced acute changes in cardiovascular biomarkers. In MOSES Part 1 (MOSES 1), controlled O3 exposure caused concentration-related reductions in lung function with evidence of airway inflammation and injury, but without convincing evidence of effects on cardiovascular function. However, subjects' prior exposures to indoor and outdoor air pollution in the few hours and days before each MOSES controlled O3 exposure may have independently affected the study biomarkers and/or modified biomarker responses to the MOSES controlled O3 exposures.

METHODS

MOSES 1 was conducted at three clinical centers (University of California San Francisco, University of North Carolina, and University of Rochester Medical Center) and included healthy volunteers 55 to 70 years of age. Consented participants who successfully completed the screening and training sessions were enrolled in the study. All three clinical centers adhered to common standard operating procedures and used common tracking and data forms. Each subject was scheduled to participate in a total of 11 visits: screening visit, training visit, and three sets of exposure visits consisting of the pre-exposure day, the exposure day, and the post-exposure day. After completing the pre-exposure day, subjects spent the night in a nearby hotel. On exposure days, the subjects were exposed for 3 hours in random order to 0 ppb O3 (clean air), 70 ppb O3, and 120 ppm O3. During the exposure period the subjects alternated between 15 minutes of moderate exercise and 15 minutes of rest. A suite of cardiovascular and pulmonary endpoints was measured on the day before, the day of, and up to 22 hours after each exposure.

In MOSES Part 2 (MOSES 2), we used a longitudinal panel study design, cardiopulmonary biomarker data from MOSES 1, passive cumulative personal exposure samples (PES) of O3 and nitrogen dioxide (NO2) in the 72 hours before the pre-exposure visit, and hourly ambient air pollution and weather measurements in the 96 hours before the pre-exposure visit. We used mixed-effects linear regression and evaluated whether PES O3 and NO2 and these ambient pollutant concentrations in the 96 hours before the pre-exposure visit confounded the MOSES 1 controlled O3 exposure effects on the pre- to post-exposure biomarker changes (Aim 1), whether they modified these pre- to post-exposure biomarker responses to the controlled O3 exposures (Aim 2), whether they were associated with changes in biomarkers measured at the pre-exposure visit or morning of the exposure session (Aim 3), and whether they were associated with differences in the pre- to post-exposure biomarker changes independently of the controlled O3 exposures (Aim 4).

RESULTS

Ambient pollutant concentrations at each site were low and were regularly below the National Ambient Air Quality Standard levels. In Aim 1, the controlled O3 exposure effects on the pre- to post-exposure biomarker differences were little changed when PES or ambient pollutant concentrations in the previous 96 hours were included in the model, suggesting these were not confounders of the controlled O3 exposure/biomarker difference associations. In Aim 2, effects of MOSES controlled O3 exposures on forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) were modified by ambient NO2 and carbon monoxide (CO), and PES NO2, with reductions in FEV1 and FVC observed only when these concentrations were "Medium" or "High" in the 72 hours before the pre-exposure visit. There was no such effect modification of the effect of controlled O3 exposure on any other cardiopulmonary biomarker.

As hypothesized for Aim 3, increased ambient O3 concentrations were associated with decreased pre-exposure heart rate variability (HRV). For example, high frequency (HF) HRV decreased in association with increased ambient O3 concentrations in the 96 hours before the pre-exposure visit (-0.460 ln[ms2]; 95% CI, -0.743 to -0.177 for each 10.35-ppb increase in O3; P = 0.002). However, in Aim 4 these increases in ambient O3 were also associated with increases in HF and low frequency (LF) HRV from pre- to post-exposure, likely reflecting a "recovery" of HRV during the MOSES O3 exposure sessions. Similar patterns across Aims 3 and 4 were observed for LF (the other primary HRV marker), and standard deviation of normal-to-normal sinus beat intervals (SDNN) and root mean square of successive differences in normal-to-normal sinus beat intervals (RMSSD) (secondary HRV markers).

Similar Aim 3 and Aim 4 patterns were observed for FEV1 and FVC in association with increases in ambient PM with an aerodynamic diameter ≤ 2.5 μm (PM2.5), CO, and NO2 in the 96 hours before the pre-exposure visit. For Aim 3, small decreases in pre-exposure FEV1 were significantly associated with interquartile range (IQR) increases in PM2.5 concentrations in the 1 hour before the pre-exposure visit (-0.022 L; 95% CI, -0.037 to -0.006; P = 0.007), CO in the 3 hours before the pre-exposure visit (-0.046 L; 95% CI, -0.076 to -0.016; P = 0.003), and NO2 in the 72 hours before the pre-exposure visit (-0.030 L; 95% CI, -0.052 to -0.008; P = 0.007). However, FEV1 was not associated with ambient O3 or sulfur dioxide (SO2), or PES O3 or NO2 (Aim 3). For Aim 4, increased FEV1 across the exposure session (post-exposure minus pre-exposure) was marginally significantly associated with each 4.1-ppb increase in PES O3 concentration (0.010 L; 95% CI, 0.004 to 0.026; P = 0.010), as well as ambient PM2.5 and CO at all lag times. FVC showed similar associations, with patterns of decreased pre-exposure FVC associated with increased PM2.5, CO, and NO2 at most lag times, and increased FVC across the exposure session also associated with increased concentrations of the same pollutants, reflecting a similar recovery. However, increased pollutant concentrations were not associated with adverse changes in pre-exposure levels or pre- to post-exposure changes in biomarkers of cardiac repolarization, ST segment, vascular function, nitrotyrosine as a measure of oxidative stress, prothrombotic state, systemic inflammation, lung injury, or sputum polymorphonuclear leukocyte (PMN) percentage as a measure of airway inflammation.

CONCLUSIONS

Our previous MOSES 1 findings of controlled O3 exposure effects on pulmonary function, but not on any cardiovascular biomarker, were not confounded by ambient or personal O3 or other pollutant exposures in the 96 and 72 hours before the pre-exposure visit. Further, these MOSES 1 O3 effects were generally not modified, blunted, or lessened by these same ambient and personal pollutant exposures. However, the reductions in markers of pulmonary function by the MOSES 1 controlled O3 exposure were modified by ambient NO2 and CO, and PES NO2, with reductions observed only when these pollutant concentrations were elevated in the few hours and days before the pre-exposure visit. Increased ambient O3 concentrations were associated with reduced HRV, with "recovery" during exposure visits. Increased ambient PM2.5, NO2, and CO were associated with reduced pulmonary function, independent of the MOSES-controlled O3 exposures. Increased pollutant concentrations were not associated with pre-exposure or pre- to post-exposure changes in other cardiopulmonary biomarkers. Future controlled exposure studies should consider the effect of ambient pollutants on pre-exposure biomarker levels and whether ambient pollutants modify any health response to a controlled pollutant exposure.