Long-term exposure to outdoor air pollution and the incidence of chronic obstructive pulmonary disease in a national English cohort

Joint effect of long-term exposure to ambient air pollution on the prevalence of chronic obstructive pulmonary disease using the Korea National Health and Nutrition Examination Survey 2010-2019

BACKGROUND

Little is known about the relationship between long-term joint exposure to mixtures of air pollutants and the prevalence of chronic obstructive pulmonary disease (COPD). We aimed to assess the joint impact of long-term exposure to ambient air pollution on the prevalence of COPD in Korea, especially in areas with high levels of air pollution.

METHODS

We included 22,387 participants who underwent spirometry tests in 2010-2019. The community multiscale air quality model was used to estimate the levels of ambient air pollution at residential addresses. The average exposure over the 5 years before the examination date was used to calculate the concentrations of air pollution. Forced expiratory volume in 1 s and forced vital capacity were used to define restrictive lung disease, COPD, and moderate-to-severe COPD. Quantile-based g-computation models were used to assess the joint impact of air pollution on COPD prevalence.

RESULTS

A total of 2535 cases of restrictive lung disease, 2787 cases of COPD, and 1399 cases of moderate-to-severe COPD were identified. In the individual pollutant model, long-term exposure was significantly associated with both restrictive lung disease and COPD. In the mixture pollutant model, the odds ratios (ORs, 95% confidence intervals) for restrictive lung disease increased with each quartile increment in the 1- to 5-year average mixtures: 1.14 (1.02-1.28, 1 year), 1.25 (1.11-1.41, 2 years), 1.26 (1.11-1.42, 3 years), 1.32 (1.16-1.51, 4 years), and 1.37 (1.19-1.58, 5 years), respectively. The increase in ORs of restrictive lung disease accelerated over time. By contrast, the ORs of COPD showed a decreasing trend over time.

CONCLUSIONS

Long-term exposure to air pollutants, both individually and jointly, was associated with an increased risk of developing COPD, particularly restrictive lung disease. Our findings highlight the importance of comprehensively assessing exposure to various air pollutants in relation to COPD.

Influencing factors of good quality of life among chronic obstructive pulmonary disease patients living in Zhejiang Province, China

Chronic obstructive pulmonary disease (COPD) is a chronic, progressive and debilitating disease that affects quality of life (QOL), especially among patients living in poor environments. This study aimed to determine the influencing factors of good QOL among COPD patients living in Zhejiang, China. A cross-sectional study was conducted to collect data from participants in six tertiary hospitals in Zhejiang Province by a simple random sampling method. A validated questionnaire was used to collect general information, environmental factors, and COPD stage. The standardized St. George's Respiratory Questionnaire (SGRQ) was used to assess QOL. Logistic regression was used to determine influencing factors of good QOL among COPD patients at a significance level of α = 0.05. A total of 420 participants were recruited for analysis. The overall prevalence of patients with good QOL was 25.7%. Six variables were found to be associated with good QOL in the multivariable analysis. Patients who were employed had 2.35 times (95% CI 1.03-5.34) greater odds of having good QOL than those who were unemployed. Those whose family income was higher than 100,000 CNY had 2.49 times (95% CI 1.15-5.39) greater odds of having good QOL than those whose family income was lower than 100,000 CNY. Those who had treatment expenses less than 5,000 CNY had 4.57 (95% CI 1.57-13.30) times greater odds of having good QOL than those who had treatment expenses of 5,000 CNY or higher. Those who had mild or moderate airflow limitation were 5.27 times (95% CI 1.61-17.26) more likely to have good QOL than those who were in a severe or very severe stage of COPD. Those who had a duration of illness less than 60 months had 5.57 times (95% CI 1.40-22.12) greater odds of having good QOL than those who had a duration of illness of 120 months or more. Those who were not hospitalized within the past 3 months had 9.39 times (95% CI 1.62-54.43) greater odds of having good QOL than those who were hospitalized more than twice over the past 3 months. Socioeconomic status, disease stage and accessibility were associated with good QOL among COPD patients in Zhejiang Province, China. Increasing family income and implementing measures to improve the accessibility of medical care, including developing a proper system to decrease the cost of treatment for COPD patients, can improve patients' QOL.

Causal relationship between air pollution and chronic obstructive pulmonary disease in European and East Asian populations: a Mendelian randomization study

Epidemiologic studies have suggested a possible association between air pollution and chronic obstructive pulmonary disease (COPD), but it is controversial and difficult to draw causal inferences. Five methods were adopted to evaluate the causal relationship between air pollution and COPD in European and East Asian populations by using MR Analysis. A statistically significant causal relationship between PM2.5 and COPD was observed in the European population (OR: 2.34; 95% CI: 1.06-5.05; p = 0.033). Statistical significance remained after adjustment for confounding factors (adjusted OR: 2.28; 95% CI: 1.01-5.20; p = 0.048). In East Asian populations, PM2.5 absorbance, a proxy for black carbon, was statistically associated with COPD (OR: 1.41; 95% CI: 1.09-1.81; p = 0.007). We did not adjust for confounders in East Asian populations, as the association was independent of known confounders (e.g. smoking, respiratory tract infections, etc.). In conclusion, increased concentrations of PM2.5 and PM2.5 absorbance were associated with an increased risk of COPD.

Exposure to outdoor particulate matter and risk of respiratory diseases: a systematic review and meta-analysis

According to epidemiological studies, particulate matter (PM) is an important air pollutant that poses a significant threat to human health. The relationship between particulate matter and respiratory diseases has been the subject of numerous studies, but these studies have produced inconsistent findings. The purpose of this systematic review was to examine the connection between outdoor particulate matter (PM2.5 and PM10) exposure and respiratory disorders (COPD, lung cancer, LRIs, and COVID-19). For this purpose, we conducted a literature search between 2012 and 2022 in PubMed, Web of Science, and Scopus. Out of the 58 studies that were part of the systematic review, meta-analyses were conducted on 53 of them. A random effect model was applied separately for each category of study design to assess the pooled association between exposure to PM2.5 and PM10 and respiratory diseases. Based on time-series and cohort studies, which are the priorities of the strength of evidence, a significant relationship between the risk of respiratory diseases (COPD, lung cancer, and COVID-19) was observed (COPD: pooled HR = 1.032, 95% CI: 1.004-1.061; lung cancer: pooled HR = 1.017, 95% CI: 1.015-1.020; and COVID-19: pooled RR = 1.004, 95% CI: 1.002-1.006 per 1 μg/m3 increase in PM2.5). Also, a significant relationship was observed between PM10 and respiratory diseases (COPD, LRIs, and COVID-19) based on time-series and cohort studies. Although the number of studies in this field is limited, which requires more investigations, it can be concluded that outdoor particulate matter can increase the risk of respiratory diseases.

Combined effect of ozone and household air pollution on COPD in people aged less than 50 years old

OBJECTIVES

Air pollution has been suggested as an important risk factor for chronic obstructive pulmonary disease (COPD); however, evidence of interactive effects on COPD between different factors was sparse, especially for young adults. We aimed to assess the combined effects of ambient ozone (O3) and household air pollution on COPD in young individuals.

METHODS

We conducted a population-based study of residents aged 15-50 years in the low-income and middle-income regions of western China. We used multivariable logistic regression models to examine the associations between long-term ozone exposure and COPD in young individuals.

RESULTS

A total of 6537 young cases were identified among the participants, with a COPD prevalence rate of 7.8 (95% CI 7.2% to 8.5%), and most young COPD individuals were asymptomatic. Exposure to household air pollution was associated with COPD in young patients after adjustment for other confounding factors (OR 1.82, 95% CI 1.41 to 2.37). We also found positive associations of COPD with O3 per IQR increase of 20 ppb (OR 1.92, 95% CI 1.59 to 2.32). The individual effects of household air pollution and O3 were 1.68 (95% CI 1.18 to 2.46) and 1.55 (95% CI 0.99 to 2.43), respectively, while their joint effect was 3.28 (95% CI 2.35 to 4.69) with the relative excess risk due to interaction of 1.05 (95% CI 0.33 to 1.78).

CONCLUSIONS

This study concludes that exposure to ambient O3 and household air pollution might be important risk factors for COPD among young adults, and simultaneous exposure to high levels of the two pollutants may intensify their individual effects.

ATM participates in fine particulate matter-induced airway inflammation through regulating DNA damage and DNA damage response

The relationship between fine particulate matter (PM2.5) and chronic airway inflammatory diseases, such as chronic obstructive pulmonary disease and asthma, have garnered public attention, while the detailed mechanisms of PM2.5-induced airway inflammation remain unclear. This study reveals that PM2.5 induces airway inflammation both in vivo and in vitro, and, moreover, identifies DNA damage and DNA damage repair (DDR) as results of this exposure. Ataxia telangiectasia-mutated heterozygous (ATM+/- ) and wild-type C57BL/6 (WT) mice were exposed to PM2.5. The results show that, following exposure to PM2.5, the number of neutrophils in broncho alveolar lavage fluid and the mRNA expression of CXCL-1 in lung tissues of the ATM+/- mice were lower than those of the WT mice. The mRNA expression of FANCD2 and FANCI were also down-regulated. Human bronchial epithelial (HBE) cells were transfected with ATM-siRNA to induce down-regulation of ATM gene expression and were subsequently stimulated with PM2.5. The results show that the mRNA expression of TNF-α decreased in the ATM-siRNA-transfected cells. The mRNA expression of CXCL-1 and CXCL-2 in peritoneal macrophages, derived from ATM-null mice in which experiments showed that the protein expression of FANCD2 and FANCI decreased, were also decreased after PM2.5 exposure in ATM-siRNA-transfected HBE cells. In conclusion, PM2.5-induced airway inflammation is alleviated in ATM+/- mice compared with WT mice. ATM promotes PM2.5-induced airway inflammation, which may be attributed to the regulation of DNA damage and DDR.

Airborne Particulate Matter Size and Chronic Obstructive Pulmonary Disease Exacerbations: A Prospective, Risk-Factor Analysis Comparing Global Initiative for Obstructive Lung Disease 3 and 4 Categories

Current research primarily emphasizes the generalized correlations between airborne pollution and respiratory diseases, seldom considering the differential impacts of particular particulate matter sizes on chronic obstructive pulmonary disease (COPD) exacerbations in distinct Global Initiative for Obstructive Lung Disease (GOLD) categories. This study hypothesizes a critical association between particulate matter sizes (PM 1.0, PM 2.5, and PM 10) and exacerbation frequency in COPD patients categorized under GOLD 3 and GOLD 4, with a potential augmenting role played by proximity to main roads and industrial areas. This research aspires to offer a nuanced perspective on the exacerbation patterns in these groups, setting the stage for targeted intervention strategies. Utilizing a prospective design, this study followed 79 patients divided into GOLD 3 (n = 47) and GOLD 4 (n = 32) categories. The participants were monitored for ten days for daily activity levels, symptoms, living conditions, and airborne particulate matter concentrations, with spirometric evaluations employed to measure lung function. Statistical analyses were used to identify potential risk factors and significant associations. The analysis revealed substantial disparities in airborne particulate matter sizes between the two groups. The mean PM 1.0 concentration was notably higher in GOLD 4 patients (26 µg/m3) compared to GOLD 3 patients (18 µg/m3). Similarly, elevated PM 2.5 levels were observed in the GOLD 4 category (35 µg/m3) in contrast to the GOLD 3 category (24 µg/m3). A vital finding was the increased frequency of exacerbations in individuals residing within 200 m of main roads compared to those living further away (OR = 2.5, 95% CI: 1.5-4.1). Additionally, patients residing in homes smaller than 50 square meters demonstrated a greater frequency of exacerbations. Spirometry results corroborated the exacerbated condition in GOLD 4 patients, indicating a significant decline in lung function parameters compared to the GOLD 3 group. This study substantiates a significant association between airborne particulate matter sizes and exacerbation frequencies in COPD patients, particularly accentuating the increased risk in GOLD 4 patients. Our findings underscore the pivotal role of environmental factors, including the size of living areas and proximity to main roads, in influencing COPD exacerbations. These results suggest the need for personalized healthcare strategies and interventions, which account for environmental risk factors and the distinctions between GOLD 3 and GOLD 4 categories of COPD patients.

Analyzing the Impact of Diesel Exhaust Particles on Lung Fibrosis Using Dual PCR Array and Proteomics: YWHAZ Signaling

Air pollutants are associated with exacerbations of asthma, chronic bronchitis, and airway inflammation. Diesel exhaust particles (DEPs) can induce and worsen lung diseases. However, there are insufficient data to guide polymerase chain reaction (PCR) array proteomics studies regarding the impacts of DEPs on respiratory diseases. This study was performed to identify genes and proteins expressed in normal human bronchial epithelial (NHBE) cells. MicroRNAs (miRNAs) and proteins expressed in NHBE cells exposed to DEPs at 1 μg/cm2 for 8 h and 24 h were identified using PCR array analysis and 2D PAGE/LC-MS/MS, respectively. YWHAZ gene expression was estimated using PCR, immunoblotting, and immunohistochemical analyses. Genes discovered through an overlap analysis were validated in DEP-exposed mice. Proteomics approaches showed that exposing NHBE cells to DEPs led to changes in 32 protein spots. A transcriptomics PCR array analysis showed that 6 of 84 miRNAs were downregulated in the DEP exposure groups compared to controls. The mRNA and protein expression levels of YWHAZ, β-catenin, vimentin, and TGF-β were increased in DEP-treated NHBE cells and DEP-exposed mice. Lung fibrosis was increased in mice exposed to DEPs. Our combined PCR array-omics analysis demonstrated that DEPs can induce airway inflammation and lead to lung fibrosis through changes in the expression levels of YWHAZ, β-catenin, vimentin, and TGF-β. These findings suggest that dual approaches can help to identify biomarkers and therapeutic targets involved in pollutant-related respiratory diseases.

Evidence relating cigarette, cigar and pipe smoking to lung cancer and chronic obstructive pulmonary disease: Meta-analysis of recent data from three regions

BACKGROUND

There is a need to have up-to-date information for various diseases on the risk related to the use of different smoked products and the use of other nicotine-containing products. Here, we contribute to the information pool by presenting up-to-date quantitative evidence for North America, Europe and Japan and for both lung cancer and chronic obstructive pulmonary disease (COPD) on the relative risk (RR) relating to current vs never product use for each of the three smoked tobacco products, cigarettes, cigars and pipes.

AIM

To estimate lung cancer and COPD current smoking RRs for the three products using recent data for the three regions.

METHODS

Publications in English from 2010 to 2020 were considered that, based on epidemiological studies in the three regions, estimated the current smoking RR of lung cancer and/or COPD for one or more of the three products. The studies should involve at least 100 cases of the disease considered, not be restricted to specific lung cancer types or populations with specific medical conditions, and should be of cohort or nested case-control study design or randomized controlled trials. Literature searches were conducted on MEDLINE separately for lung cancer and for COPD, examining titles and abstracts initially, and then full texts. Additional papers were sought from reference lists of selected papers, reviews and meta-analyses. For each study identified, the most recent available data on each product were entered on current smoking, as well as on characteristics of the study and the RR estimates. Combined RR estimates were derived using random-effects meta-analysis. For cigarette smoking, where far more data were available, heterogeneity was studied by a wide range of factors. For cigar and pipe smoking, a more limited heterogeneity analysis was carried out. Results were compared with those from previous meta-analyses published since 2000.

RESULTS

Current cigarette smoking: For lung cancer, 44 studies (26 North American, 14 European, three Japanese, and one in multiple continents), gave an overall estimate of 12.14 [95% confidence interval (CI) 10.30-14.30]. The estimates were higher (heterogeneity P < 0.001) for North American (15.15, CI 12.77-17.96) and European studies (12.30, CI 9.77-15.49) than for Japanese studies (3.61, CI 2.87-4.55), consistent with previous evidence of lower RRs for Asia. RRs were higher (P < 0.05) for death (14.85, CI 11.99-18.38) than diagnosis (10.82, CI 8.61-13.60). There was some variation (P < 0.05) by study population, with higher RRs for international and regional studies than for national studies and studies of specific populations. RRs were higher in males, as previously reported, the within-study male/female ratio of RRs being 1.52 (CI 1.20-1.92). RRs did not vary significantly (P ≥ 0.05) by other factors. For COPD, RR estimates were provided by 18 studies (10 North American, seven European, and one Japanese). The overall estimate of 9.19 (CI 6.97-12.13), was based on heterogeneous data (P < 0.001), and higher than reported earlier. There was no (P > 0.1) variation by sex, region or exclusive use, but limited evidence (0.05 < P < 0.1) that RR estimates were greater where cases occurring shortly after baseline were ignored; where bronchiectasis was excluded from the COPD definition; and with greater confounder adjustment. Within-study comparisons showed adjusted RRs exceeded unadjusted RRs. Current cigar smoking: Three studies gave an overall lung cancer RR of 2.73 (CI 2.36-3.15), with no heterogeneity, lower than the 4.67 (CI 3.49-6.25) reported in an earlier review. Only one study gave COPD results, the RR (2.44, CI 0.98-6.05) being imprecise. Current pipe smoking: Four studies gave an overall lung cancer RR of 4.93 (CI 1.97-12.32), close to the 5.20 (CI 3.50-7.73) given earlier. However, the estimates were heterogeneous, with two above 10, and two below 3. Only one study gave COPD results, the RR (1.12, CI 0.29-4.40), being imprecise. For both diseases, the lower RR estimates for cigars and for pipes than for current smoking of cigarettes aligns with earlier published evidence.

CONCLUSION

Current cigarette smoking substantially increases lung cancer and COPD risk, more so in North America and Europe than Japan. Limited evidence confirms lower risks for cigars and pipes than cigarettes.

Protective Effect of Lonicera japonica on PM2.5-Induced Pulmonary Damage in BALB/c Mice via the TGF-β and NF-κB Pathway

This study aimed to assess the protective effect of an extract of Lonicera japonica against particulate-matter (PM)_2.5-induced pulmonary inflammation and fibrosis. The compounds with physiological activity were identified as shanzhiside, secologanoside, loganic acid, chlorogenic acid, secologanic acid, secoxyloganin, quercetin pentoside, and dicaffeoyl quinic acids (DCQA), including 3,4-DCQA, 3,5-DCQA, 4,5-DCQA, and 1,4-DCQA using ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS^E). The extract of Lonicera japonica reduced cell death, reactive oxygen species (ROS) production, and inflammation in A549 cells. The extract of Lonicera japonica decreased serum T cells, including CD4⁺ T cells, CD8⁺ T cells, and total T helper 2 (Th2) cells, and immunoglobulins, including immunoglobulin G (IgG) and immunoglobulin E (IgE), in PM_2.5-induced BALB/c mice. The extract of Lonicera japonica protected the pulmonary antioxidant system by regulating superoxide dismutase (SOD) activity, reduced glutathione (GSH) contents, and malondialdehyde (MDA) levels. In addition, it ameliorated mitochondrial function by regulating the production of ROS, mitochondrial membrane potential (MMP), and ATP contents. Moreover, the extract of Lonicera japonica exhibited a protective activity of apoptosis, fibrosis, and matrix metalloproteinases (MMPs) via TGF-β and NF-κB signaling pathways in lung tissues. This study suggests that the extract of Lonicera japonica might be a potential material to improve PM_2.5-induced pulmonary inflammation, apoptosis, and fibrosis.

Associations between short-term exposure to ambient PM2.5 and incident cases of cerebrovascular disease in Yantai, China

There are limited studies examining the association between PM_2.5 exposure and incident cerebrovascular disease (CD) cases in China. In this study, daily counts of incident CD cases and daily PM_2.5 concentrations were obtained in Yantai, Shandong Province, China from 2014 to 2019. We used a combination of the Poisson-distribution generalized linear model (GLM) and a distributed lag nonlinear model (DLNM) to examine the association of short-term exposure to ambient PM_2.5 and incident cases of CD. The results revealed that for every 10 μg/m³ increment of PM_2.5 would increase the incident CD cases by 0.216% (RR:1.00216, 95%CI:1.0016-1.0028) at lag4. The stratified analysis demonstrated that the females and residents aged 65 years or above presented higher short-term PM_2.5-associated CD risks than the males and aged below 65 years. Targeted prevention strategies should be adopted to reduce the PM_2.5-related CD burden, especially for the susceptible population in China.

Health effects of exposure to sulfur dioxide, nitrogen dioxide, ozone, and carbon monoxide between 1980 and 2019: A systematic review and meta-analysis

The burden of disease attributed to the indoor exposure to sulfur dioxide (SO₂ ), nitrogen dioxide (NO₂ ), ozone (O₃ ), and carbon monoxide (CO) is not clear, and the quantitative concentration-response relationship is a prerequisite. This is a systematic review to summarize the quantitative concentration-response relationships by screening and analyzing the polled effects of population-based epidemiological studies. After collecting literature published between 1980 and 2019, a total of 19 health outcomes in 101 studies with 182 health risk estimates were recruited. By meta-analysis, the leave-one-out sensitivity analysis and Egger's test for publication bias, the robust and reliable effects were found for SO₂ (per 10 μg/m³ ) with chronic obstructive pulmonary diseases (COPD) (pooled relative risks [RRs] 1.016, 95% CI: 1.012-1.021) and cardiovascular diseases (CVD) (RR 1.012, 95%CI: 007-1.018), respectively. NO₂ (per 10 μg/m³ ) had the pooled RRs for childhood asthma, preterm birth, lung cancer, diabetes, and COPD by 1.134 (1.084-1.186), 1.079 (1.007-1.157), 1.055 (1.010-1.101), 1.019 (1.009-1.029), and 1.016 (1.012-1.120), respectively. CO (per 1 mg/m³ ) was significantly associated with Parkinson's disease (RR 1.574, 95% CI: 1.069-2.317) and CVD (RR 1.024, 95% CI: 1.011-1.038). No robust effects were observed for O₃ . This study provided evidence and basis for further estimation of the health burden attributable to the four gaseous pollutants.

Long-term exposure to low air pollutant concentrations and hospitalisation for respiratory diseases in older men: A prospective cohort study in Perth, Australia

Background

Acute exposure to ambient air pollution even at low concentrations has been associated with increased hospitalisation for respiratory diseases but the effects of long-term exposure are less certain. In this study, we investigated the associations between long-term exposures to PM_2.5, PM_2.5 absorbance and NO₂ and hospitalisation for asthma, chronic obstructive pulmonary disease and pneumonia in a cohort of older men living in Perth, Western Australia, a city where the levels of air pollutants are well below the world standards.

Materials and methods

The study population of 11,156 men with no prior hospitalisation for respiratory disease was drawn from the Health in Men Study (HIMS) cohort of men aged >65 years living in Perth, Western Australia between 1996-1999. PM_2.5, PM_2.5 absorbance (PM_2.5a) and NO₂ were measured across the Perth metropolitan area over three seasons in 2012. Land use regression (LUR) models were used to estimate annual concentrations of PM_2.5, PM_2.5 absorbance and NO₂ at the residential address of each participant from inception (1996) to 2015. Hospitalisation for respiratory disease between inception and 2015 was ascertained using the Western Australian Data Linkage System. The association between exposure to air pollution with hospitalisation for respiratory disease was examined using Cox regression analysis.

Results

No statistically significant associations were observed in the fully adjusted models. However, positive associations were observed with first hospitalisation for pneumonia (HR 1.08, 95% CI: 1.01–1.16) when adjusted for age, year of enrolment, smoking status, education, BMI and physical activity.

Conclusions

In this longitudinal study of older men we found no evidence of associations between increased long-term exposure to low-level air pollution with increased risk of hospitalisation for respiratory diseases in Perth, Australia. More studies on respiratory morbidity associated with exposure to low levels of air pollution are needed for more comprehensive understanding of the overall risk.

Long-term PM2.5 exposure in association with chronic respiratory diseases morbidity: A cohort study in Northern China

Several literatures have examined the risk of chronic respiratory diseases in association with short-term ambient PM2.5 exposure in China. However, little evidence has examined the chronic impacts of PM2.5 exposure on morbidity of chronic respiratory diseases in cohorts from high pollution countries. Our study aims to investigate the associations. Based on a retrospective cohort among adults in northern China, a Cox regression model with time-varying PM2.5 exposure and a concentration-response (C-R) curve model were performed to access the relationships between incidence of chronic respiratory diseases and long-term PM2.5 exposure during a mean follow-up time of 9.8 years. Individual annual average PM2.5 estimates were obtained from a satellite-based model with high resolution. The incident date of a chronic respiratory disease was identified according to self-reported physician diagnosis time and/or intake of medication for treatment. Among 38,047 urban subjects analyzed in all-cause chronic respiratory disease cohort, 482 developed new cases. In CB (38,369), asthma (38,783), and COPD (38,921) cohorts, the onsets were 276, 89, and 14, respectively. After multivariable adjustment, hazard ratio and 95% confidence interval for morbidity of all-cause chronic respiratory disease, CB, asthma, and COPD were 1.15 (1.01, 1.31), 1.20 (1.00, 1.42), 0.76 (0.55, 1.04), and 0.66 (0.29, 1.47) with each 10 μg/m3 increment in PM2.5, respectively. Stronger effect estimates were suggested in alcohol drinkers across stratified analyses. Additionally, the shape of C-R curve showed an increasing linear relationship before 75.00 μg/m3 concentrations of PM2.5 for new-onset all-cause chronic respiratory disease, and leveled off at higher levels. These findings indicated that long-term exposure to high-level PM2.5 increased the risks of incident chronic respiratory diseases in China. Further evidence of C-R curves is warranted to clarify the associations of adverse chronic respiratory outcomes involving air pollution.

Short term exposure to air pollution and mortality in the US: a double negative control analysis

RATIONALE

Studies examining the association of short-term air pollution exposure and daily deaths have typically been limited to cities and used citywide average exposures, with few using causal models.

OBJECTIVES

To estimate the associations between short-term exposures to fine particulate matter (PM_2.5), ozone (O₃), and nitrogen dioxide (NO₂) and all-cause and cause-specific mortality in multiple US states using census tract or address exposure and including rural areas, using a double negative control analysis.

METHODS

We conducted a time-stratified case-crossover study examining the entire population of seven US states from 2000-2015, with over 3 million non-accidental deaths. Daily predictions of PM_2.5, O₃, and NO₂ at 1x1 km grid cells were linked to mortality based on census track or residential address. For each pollutant, we used conditional logistic regression to quantify the association between exposure and the relative risk of mortality conditioning on meteorological variables, other pollutants, and using double negative controls.

RESULTS

A 10 μg/m³ increase in PM_2.5 exposure at the moving average of lag 0-2 day was significantly associated with a 0.67% (95%CI: 0.34-1.01%) increase in all-cause mortality. 10 ppb increases in NO₂ or O₃ exposure at lag 0-2 day were marginally associated with and 0.19% (95%CI: -0.01-0.38%) and 0.20 (95% CI-0.01, 0.40), respectively. The adverse effects of PM_2.5 persisted when pollution levels were restricted to below the current global air pollution standards. Negative control models indicated little likelihood of omitted confounders for PM_2.5, and mixed results for the gases. PM_2.5 was also significantly associated with respiratory mortality and cardiovascular mortality.

CONCLUSIONS

Short-term exposure to PM_2.5 and possibly O₃ and NO₂ are associated with increased risks for all-cause mortality. Our findings delivered evidence that risks of death persisted at levels below currently permissible.

Characteristics of Composite Deprivation Indices Used in Public Health: A Scoping Review Protocol

Introduction: A deprivation index has become a more popular tool to rank levels of deprivation within different geographic areas. It is extensively used for monitoring health inequalities, evaluating health care services, developing and modifying health policies and programs, and allocating health resources equitably. Our objectives are (1) to explore the relevant literature to describe features of composite deprivation measures; (2) create a list and classification of original deprivation indices. We will develop the classification of indices to systematize knowledge and improve the functional utility of the information. Methods: Any original deprivation index mentioned in peer-reviewed or grey literature documents will be eligible for inclusion if it assesses deprivation at a population level and used in relation to health. The study area will be limited to the geographic areas of North America, Europe, Australia, and New Zealand. Tables and a narrative summary will be used to describe features of deprivation indices. Diagrammatic form will be used to create the classification of deprivation indices. Discussion: Practically, the results of this study could facilitate finding a common language among researchers and specialists who create and use deprivation indices, thus helping the development and implementation of appropriate deprivation indices for different countries.

Circulation weather types and hospital admissions for cardiovascular disease in Changchun, China

Epidemiological studies have reported significant associations between weather situations and health. Cardiovascular disease is a serious chronic non-communicable disease which causes mortality and morbidity, bringing large economic burden to patients' families. This study explored the relationship between cardiovascular disease (CVD) and weather conditions in Changchun, northeast China. The frequency distributions of 13 main circulation weather types (CWTs) were analyzed, and a comparison between air mass classification and hospital admissions was performed for various groups using an admission index (AI). The results indicated that women had a lower risk of CVD than men did. The risk of CVD for older people (aged ≥ 65 years) was lower than that for young people (aged < 65 years). Younger men had the highest risk. The risks of CVD were higher in all groups (i.e., men, women, older, and younger) under southwesterly (SW) and northerly (N) CWTs and were lowest under the anticyclone (A) CWT. The risk of CVD among men was higher than that for women under these CWTs. N type circulation is characterized by cold, dry weather and was most closely associated with an increased incidence of CVD. The most significant effect of N type circulation on AI was observed with a delay of 2 days. SW type circulation is characterized by humid, hot weather and was the CWT that was second most closely associated with an increased incidence of CVD, with a peak in AI on the day that SW type circulation occurred. The results of this study could be provided to local health authorities as scientific guidelines for controlling and preventing CVD in Changchun, China.

Particulate matter in COPD pathogenesis: an overview

Chronic obstructive pulmonary disease (COPD) is a progressive lung disorder with substantial patient burden and leading cause of death globally. Cigarette smoke remains to be the most recognised causative factor behind COPD pathogenesis. Given the alarming increase in prevalence of COPD amongst non-smokers in recent past, a potential role of air pollution particularly particulate matter (PM) in COPD development has gained much attention of the scientists. Indeed, several epidemiological studies indicate strong correlation between airborne PM and COPD incidence/exacerbations. PM-induced oxidative stress seems to be the major player in orchestrating COPD inflammatory cycle but the exact molecular mechanism(s) behind such a process are still poorly understood. This may be due to the complexity of multiple molecular pathways involved. Oxidative stress-linked mitochondrial dysfunction and autophagy have also gained importance and have been the focus of recent studies regarding COPD pathogenesis. Accordingly, the present review is aimed at understanding the key molecular players behind PM-mediated COPD pathogenesis through analysis of various experimental studies supported by epidemiological data to identify relevant preventive/therapeutic targets in the area.

Air pollution and risk of chronic obstructed pulmonary disease: The modifying effect of genetic susceptibility and lifestyle

BACKGROUND

The effect of long-term exposure to air pollution on the development of chronic obstructive pulmonary disease (COPD) is still controversial, and the role of the interactions of air pollution with genetic risk and lifestyle in COPD risk is unclear.

METHODS

We included 452762 participants derived from the UK Biobank. Annual concentrations of air pollutions, including particle matter (PM_2.5, PM₁₀), nitrogen oxides (NO_x), and nitrogen dioxide (NO₂), were assessed using land-use regression model. We applied Cox proportional hazard model to evaluate the associations between air pollution and COPD risk. In addition, we constructed a polygenic risk score and a lifestyle score, and assessed whether genetic susceptibility and lifestyle modified the effect of air pollution on the COPD risk.

FINDINGS

Each interquartile range (IQR) increase in annual concentrations of PM_2.5, PM₁₀, NO_x, and NO₂ was associated with 1.17 (95% CI: 1.15,1.19), 1.05 (95% CI: 1.03,1.06), 1.13 (95% CI: 1.11,1.14), and 1.19 (95% CI: 1.16,1.21) times the risk of COPD, respectively. We observed an additive interaction between PM_2.5 and genetic risk (P-_interact=0.095), and a negative interaction between PM_2.5 and lifestyle (P-_interact=0.062). The HRs for each IQR increase in PM_2.5 were 1.21, (95% CI: 1.16-1.25) and 1.24, (95% CI: 1.21-1.26) in individuals with healthy and unfavourable lifestyle, respectively; and 1.16, (95% CI: 1.13-1.19) and 1.19, (95% CI: 1.16-1.22) in those with low genetic risk and high genetic risk, respectively. Participants with high air pollution exposure, high genetic risk and unfavourable lifestyle showed the highest risk of COPD.

INTERPRETATION

Long-term exposure to air pollution was associated with increased risk of COPD, especially in those with high genetic risk and unfavourable lifestyle.

FUNDING

None.

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.

Air pollution and surrounding greenness in relation to ischemic stroke: A population-based cohort study

BACKGROUND

Evidence for the association between environmental exposures and ischemic stroke (IS) is limited and inconsistent. We aimed to assess the relationship between exposure to air pollutants, residential surrounding greenness, and incident IS, and to identify population subgroups particularly sensitive to these exposures.

METHODS

We used data from administrative health registries of the public healthcare system in Catalonia, Spain to construct a cohort of individuals aged 18 years and older without a previous stroke diagnosis at 1st January 2016 (n = 3 521 274). We collected data on sociodemographic characteristics and cerebrovascular risk factors, and derived exposure at the participant's residence to ambient levels of fine particulate matter (PM_2.5), black carbon (BC), nitrogen dioxide (NO₂), and Normalized Difference Vegetation Index (NDVI) in a 300 m buffer as an indicator of greenness. The primary outcome was IS diagnosis at any point during the follow-up. We used Cox proportional hazards models to estimate associations between environmental exposures and incident IS and stratified analyses to investigate effect modification.

RESULTS

Between 1st January 2016 and 31st December 2017, 10 865 individuals were admitted to public hospitals with an IS diagnosis. Median exposure levels were: 17 µg/m³ PM_2.5, 35 µg/m³ NO₂, 2.28 µg/m³ BC and 0.27 NDVI. Individuals with higher residential exposure to air pollution were at greater risk of IS: HR 1·04 (95% CI:0·99-1·10) per 5 µg/m³ of PM_2.5; HR 1.05 (95% CI:1·00-1·10) per 1 µg/m³ of BC; HR 1·04 (95% CI:1·03-1·06) per 10 µg/m³ of NO₂. Conversely, individuals with higher residential surrounding green space, had lower risk of IS (HR 0·84; CI 95%:0·7-1.0). There was no evidence of effect modification by individual characteristics.

CONCLUSIONS

Higher incidence of IS was observed in relation to long-term exposures to air pollution, particularly NO₂, in a region that meets European health-based air quality standards. Residential surrounding greenness was associated with lower incidence of IS.

Using Bayesian networks for environmental health risk assessment

The study investigated the potential relationships between air pollution, socio-economy, and proven pathologies (e.g., respiratory, cardiovascular) within an industrial area in Southern France (Etang de Berre), gathering steel industries, oil refineries, shipping, road traffic and experiencing a Mediterranean climate. A total of 178 variables were simultaneously integrated within a Bayesian model at intra-urban scale. Various unsupervised and supervised algorithms (maximum spanning tree, tree-augmented naive classifier) as well as sensitivity analyses were used to better understand the links between all variables, and highlighted correlations between population exposure to air pollutants and some pathologies. Adverse health effects (bronchus and lung cancers for 15-65 years old people) were observed for hydrofluoric acid at low background concentration (<0.003 μg m^-3) while exposure to particulate cadmium (0.210-0.250 μg m^-3) disrupts insulin metabolism for people over 65 years-old leading to diabetes. Bronchus and lung cancers for people over 65 years-old occurred at low background SO₂ concentration (6 μg m^-3) below European limit values. When benzo[k]fluoranthene exceeded 0.672 μg m^-3, we observed a high number of hospital admissions for respiratory diseases for 15-65 years-old people. The study also revealed the important influence of socio-economy (e.g., single-parent family, people with no qualification at 15 years-old) on pathologies (e.g., cardiovascular diseases). Finally, a diffuse polychlorinated biphenyl (PCB) pollution was observed in the study area and can potentially cause lung cancers.

Preventing heart failure: a position paper of the Heart Failure Association in collaboration with the European Association of Preventive Cardiology

The heart failure epidemic is growing and its prevention, in order to reduce associated hospital readmission rates and its clinical and economic burden, is a key issue in modern cardiovascular medicine. The present consensus document aims to provide practical evidence-based information to support the implementation of effective preventive measures. After reviewing the most common risk factors, an overview of the population attributable risks in different continents is presented, to identify potentially effective opportunities for prevention and to inform preventive strategies. Finally, potential interventions that have been proposed and have been shown to be effective in preventing HF are listed.

Preventing heart failure: a position paper of the Heart Failure Association in collaboration with the European Association of Preventive Cardiology

The heart failure epidemic is growing and its prevention, in order to reduce associated hospital readmission rates and its clinical and economic burden, is a key issue in modern cardiovascular medicine. The present position paper aims to provide practical evidence-based information to support the implementation of effective preventive measures. After reviewing the most common risk factors, an overview of the population attributable risks in different continents is presented, to identify potentially effective opportunities for prevention and to inform preventive strategies. Finally, potential interventions that have been proposed and have been shown to be effective in preventing heart failure are listed.

Local attributable burden disease to PM 2.5 ambient air pollution in Medellín, Colombia, 2010-2016

Background: Exposure to 2.5-micron diameter air pollutants (PM _2.5) has been associated with an increased risk of illness and death worldwide; however, in Latin American health impacts assessment of this risk factor is scarce. Medellín is one of the most polluted cities in the region, with a population growth rate that is twice as high as that of other Colombian cities, which implies a growing population at risk.

Methods: A descriptive study of the disease burden was carried out using the city as the unit of observation. Health events were selected based on epidemiologic evidence and the availability of the population attributable fraction associated with PM _2.5. The mortality records were taken from the module of deceased of the Single Registry of Affiliates of the Health System; the morbidity records were taken from the Individual Health Services Registries. For the estimation of the burden of disease, the current Global Burden of Disease guidelines were followed.

Results: Attributable disability-adjusted life years to exposure to ambient PM _2.5 pollution (DALYs _PM2.5) constituted 13.8% of total burden of the city. Males showed the greatest loss of DALYs _PM2.5 due to acute events, while in women the greatest loss was due to chronic events. Ischemic heart disease, chronic diseases of the lower respiratory tract, and influenza and pneumonia were the events that contributed the most to DALYs _PM2.5. 71.4% of the DALYs _PM2.5 corresponded to mortality, mainly in the population over 65 years of age. Regarding attributable morbidity, acute events were more prevalent in both sexes, especially due to respiratory diseases

Conclusion: Premature death among the elderly population has the greatest weight on burden of disease attributable to ambient PM _2.5 pollution, mainly due to respiratory and cardiovascular diseases, without significant differences according to gender.

Local attributable burden disease to PM 2.5 ambient air pollution in Medellín, Colombia, 2010-2016

Background: Exposure to 2.5-micron diameter air pollutants (PM _2.5) has been associated with an increased risk of illness and death worldwide; however, in Latin American health impacts assessment of this risk factor is scarce. Medellín is one of the most polluted cities in the region, with a population growth rate that is twice as high as that of other Colombian cities, which implies a growing population at risk. Methods: A descriptive study of the disease burden was carried out using the city as the unit of observation. Health events were selected based on epidemiologic evidence and the availability of the population attributable fraction associated with PM _2.5. The mortality records were taken from the module of deceased of the Single Registry of Affiliates of the Health System; the morbidity records were taken from the Individual Health Services Registries. For the estimation of the burden of disease, the current Global Burden of Disease guidelines were followed. Results: Attributable disability-adjusted life years to exposure to ambient PM _2.5 pollution (DALYs _PM2.5) constituted 13.8% of total burden of the city. Males showed the greatest loss of DALYs _PM2.5 due to acute events, while in women the greatest loss was due to chronic events. Ischemic heart disease, chronic diseases of the lower respiratory tract, and influenza and pneumonia were the events that contributed the most to DALYs _PM2.5. 71.4% of the DALYs _PM2.5 corresponded to mortality, mainly in the population over 65 years of age. Regarding attributable morbidity, acute events were more prevalent in both sexes, especially due to respiratory diseases Conclusion: Premature death among the elderly population has the greatest weight on burden of disease attributable to ambient PM _2.5 pollution, mainly due to respiratory and cardiovascular diseases, without significant differences according to gender.

YG-1 Extract Improves Acute Pulmonary Inflammation by Inducing Bronchodilation and Inhibiting Inflammatory Cytokines

YG-1 extract used in this study is a mixture of Lonicera japonica, Arctic Fructus, and Scutellariae Radix. The present study was designed to investigate the effect of YG-1 extract on bronchodilatation (ex vivo) and acute bronchial and pulmonary inflammation relief (in vivo). Ex vivo: The bronchodilation reaction was confirmed by treatment with YG-1 concentration-accumulation (0.01, 0.03, 0.1, 0.3, and 1 mg/mL) in the bronchial tissue ring pre-contracted by acetylcholine (10 μM). As a result, YG-1 extract is considered to affect bronchodilation by increased cyclic adenosine monophosphate, cAMP) levels through the β2-adrenergic receptor. In vivo: experiments were performed in C57BL/6 mice were divided into the following groups: control group; PM2.5 (fine particulate matter)-exposed group (PM2.5, 200 μg/kg/mL saline); and PM2.5-exposed + YG-1 extract (200 mg/kg/day) group. The PM2.5 (200 μg/kg/mL saline) was exposed for 1 h for 5 days using an ultrasonic nebulizer aerosol chamber to instill fine dust in the bronchi and lungs, thereby inducing acute lung and bronchial inflammation. From two days before PM2.5 exposure, YG-1 extract (200 mg/kg/day) was administered orally for 7 days. The PM2.5 exposure was involved in airway remodeling and inflammation, suggesting that YG-1 treatment improves acute bronchial and pulmonary inflammation by inhibiting the inflammatory cytokines (NLRP3/caspase-1 pathway). The application of YG-1 extract with broncho-dilating effect to acute bronchial and pulmonary inflammation animal models has great significance in developing therapeutic agents for respiratory diseases. Therefore, these results can provide essential data for the development of novel respiratory symptom relievers. Our study provides strong evidence that YG-1 extracts reduce the prevalence of respiratory symptoms and the incidence of non-specific lung diseases and improve bronchial and lung function.

Pulmonary toxicity of actual alveolar deposition concentrations of ultrafine particulate matters in human normal bronchial epithelial cell

Air pollution is a major worldwide concern, and exposure to particulate matter (PM) can increase the risks of pulmonary diseases. Normal human bronchial epithelial cells were applied to clarify the role of ultrafine PM (UFPM) in the pathogenesis of pulmonary toxic effects with realistic alveolar deposition doses. The UFPM used in this research originated from vehicular emissions and coal combustion. UFPM exposure of up to 72 h was found to induce significant time- and concentration-dependent decreases in cell viability. Exposure to UFPM increased reactive oxygen species (ROS) accumulation through heme oxygenase-1 (HO-1) inhibition and induced massive oxidative stress that increased the interleukin-8 (IL-8) expression. UFPM also reduced the pulmonary trans-epithelial electrical resistance through the depletion of zonula occludens (ZO) proteins. Finally, UFPM decreased the α1-antitrypsin (A1AT) expression, which implies high risk of chronic obstructive pulmonary disease (COPD). The evidence demonstrates that exposure to UFPM, even at very low concentrations, may affect the functions of the respiratory system.

The Impact of the Synergistic Effect of Temperature and Air Pollutants on Chronic Lung Diseases in Subtropical Taiwan

Previous studies have suggested an association between air pollution and lung disease. However, few studies have explored the relationship between chronic lung diseases classified by lung function and environmental parameters. This study aimed to comprehensively investigate the relationship between chronic lung diseases, air pollution, meteorological factors, and anthropometric indices. We conducted a cross-sectional study using the Taiwan Biobank and the Taiwan Air Quality Monitoring Database. A total of 2889 participants were included. We found a V/U-shaped relationship between temperature and air pollutants, with significant effects at both high and low temperatures. In addition, at lower temperatures (<24.6 °C), air pollutants including carbon monoxide (CO) (adjusted OR (aOR):1.78/Log 1 ppb, 95% CI 0.98–3.25; aOR:5.35/Log 1 ppb, 95% CI 2.88–9.94), nitrogen monoxide (NO) (aOR:1.05/ppm, 95% CI 1.01–1.09; aOR:1.11/ppm, 95% CI 1.07–1.15), nitrogen oxides (NO_x) (aOR:1.02/ppm, 95% CI 1.00–1.05; aOR:1.06/ppm, 95% CI 1.04–1.08), and sulfur dioxide (SO₂) (aOR:1.29/ppm, 95% CI 1.01–1.65; aOR:1.77/ppm, 95% CI 1.36–2.30) were associated with restrictive and mixed lung diseases, respectively. Exposure to CO, NO, NO₂, NO_x and SO₂ significantly affected obstructive and mixed lung disease in southern Taiwan. In conclusion, temperature and air pollution should be considered together when evaluating the impact on chronic lung diseases.

Challenges in the Implementation of Chronic Obstructive Pulmonary Disease Guidelines in Low- and Middle-Income Countries: An Official American Thoracic Society Workshop Report

There is a substantial burden of chronic respiratory diseases, including chronic obstructive pulmonary disease (COPD), in low- and middle-income countries (LMICs). LMICs have particular challenges in delivering cost-effective prevention, diagnosis, and management of COPD. Optimal care can be supported by effective implementation of guidelines. This American Thoracic Society workshop considered challenges to implementation of COPD guidelines in LMICs. We make 10 specific recommendations: 1) relevant organizations should provide LMIC-specific COPD management guidance; 2) patient and professional organizations must persuade policy-makers of the importance of lung function testing programs in LMICs; 3) healthcare education and training should emphasize the early-life origins of COPD; 4) urgent action is required by governments to reduce airborne exposures, including exposures to tobacco smoke and indoor and outdoor air pollution; 5) guidance for COPD in LMICs should explicitly link across Essential Medicine Lists and the World Health Organization package of essential noncommunicable disease interventions for primary health care in low-resource settings and should consider availability, affordability, sustainability, and cost-effective use of medicines; 6) the pharmaceutical industry should work to make effective COPD and tobacco-dependence medicines globally accessible and affordable; 7) implementation of locally adapted, cost-effective pulmonary rehabilitation programs should be an international priority; 8) the World Health Organization Global Action Plan for the Prevention and Control of Noncommunicable Diseases should specify how improvements in respiratory health will be achieved; 9) research funders should increase the proportion of funding allocated to COPD in LMICs; and 10) the respiratory community should leverage the skills and enthusiasm of earlier-career clinicians and researchers to improve global respiratory health.

Air Pollution as a Risk Factor for Incident Chronic Obstructive Pulmonary Disease and Asthma. A 15-Year Population-based Cohort Study

Rationale: Current evidence on the relationship between long-term exposure to air pollution and new onset of chronic lung disease is inconclusive.Objectives: To examine associations of incident chronic obstructive pulmonary disease (COPD) and adult-onset asthma with past exposure to fine particulate matter ≤ 2.5 μm in diameter (PM_2.5), nitrogen dioxide (NO₂), ozone (O₃), and the redox-weighted average of NO₂ and O₃ (O_x) and characterize the concentration-response relationship.Methods: We conducted a population-based cohort study of all Ontarians, aged 35-85 years, from 2001 to 2015. A 3-year moving average of residential exposures to selected pollutants with a 1-year lag were estimated during follow-up. We used Cox proportional hazard models and Aalen additive-hazard models to quantify the pollution-disease associations and characterized the shape of these relationships using newly developed nonlinear risk models.Measurements and Main Results: Among 5.1 million adults, we identified 340,733 and 218,005 incident cases of COPD and asthma, respectively. We found positive associations of COPD with PM_2.5 per interquartile-range (IQR) increase of 3.4 μg/m³ (hazard ratio, 1.07; 95% confidence interval, 1.06-1.08), NO₂ per IQR increase of 13.9 ppb (1.04; 1.02-1.05), O₃ per IQR increase of 6.3 ppb (1.04; 1.03-1.04), and O_x per IQR increase of 4.4 ppb (1.03; 1.03-1.03). By contrast, we did not find strong evidence linking these pollutants to adult-onset asthma. In addition, we quantified that each IQR increase in pollution exposure yielded 3.0 (2.4-3.6), 3.2 (2.0-4.3), 1.9 (1.3-2.5), and 2.3 (1.7-2.9) excess cases of COPD per 100,000 adults for PM_2.5, NO₂, O₃, and O_x, respectively. Furthermore, most pollutant-COPD relationships exhibited supralinear shapes.Conclusions: Air pollution was associated with a higher incidence of COPD but was not associated with a higher incidence of adult-onset asthma.

Long-term air pollution and road traffic noise exposure and COPD: the Danish Nurse Cohort

BACKGROUND

While air pollution has been linked to the development of chronic obstructive pulmonary disease (COPD), evidence on the role of environmental noise is just emerging. We examined the associations of long-term exposure to air pollution and road traffic noise with COPD incidence.

METHODS

We defined COPD incidence for 24 538 female nurses from the Danish Nurse Cohort (age>44 years) as the first hospital contact between baseline (1993 or 1999) and 2015. We estimated residential annual mean concentrations of particulate matter with diameter<2.5 µm (PM_2.5) since 1990 and nitrogen dioxide (NO₂) since 1970 by the Danish DEHM/UBM/AirGIS modeling system, and road traffic noise (L_den) since 1970 by the Nord2000 model. Time-varying Cox regression models were applied to assess the associations of air pollution and road traffic noise with COPD incidence.

RESULTS

977 nurses developed COPD during 18.6 years' mean follow-up. We observed associations with COPD for all three exposures with hazard ratios (HRs) and 95% confidence intervals (CIs) of 1.19 (1.01, 1.41) per 6.26 µg·m^-3 for PM_2.5, 1.13 (1.05, 1.20) per 8.19 µg·m^-3 for NO₂, and 1.15 (1.06, 1.25) per 10 dB for L_den. Associations with NO₂ and L_den attenuated slightly after mutual adjustment, but were robust to adjustment for PM_2.5. Associations with PM_2.5 were attenuated to null after adjustment for either NO₂ or L_den. No potential interaction effect was observed between air pollutants and noise.

CONCLUSIONS

Long-term exposure to air pollution, especially traffic-related NO₂, and road traffic noise were independently associated with COPD.

Multiple air pollutant exposure and lung cancer in Tehran, Iran

Lung cancer is the most rapidly increasing malignancy worldwide with an estimated 2.1 million cancer cases in the latest, 2018 World Health Organization (WHO) report. The objective of this study was to investigate the association of air pollution and lung cancer, in Tehran, Iran. Residential area information of the latest registered lung cancer cases that were diagnosed between 2014 and 2016 (N = 1,850) were inquired from the population-based cancer registry of Tehran. Long-term average exposure to PM₁₀, SO₂, NO, NO₂, NO_X, benzene, toluene, ethylbenzene, m-xylene, p-xylene, o-xylene (BTEX), and BTEX in 22 districts of Tehran were estimated using land use regression models. Latent profile analysis (LPA) was used to generate multi-pollutant exposure profiles. Negative binomial regression analysis was used to examine the association between air pollutants and lung cancer incidence. The districts with higher concentrations for all pollutants were mostly in downtown and around the railway station. Districts with a higher concentration for NOx (IRR = 1.05, for each 10 unit increase in air pollutant), benzene (IRR = 3.86), toluene (IRR = 1.50), ethylbenzene (IRR = 5.16), p-xylene (IRR = 9.41), o-xylene (IRR = 7.93), m-xylene (IRR = 2.63) and TBTEX (IRR = 1.21) were significantly associated with higher lung cancer incidence. Districts with a higher multiple air-pollution profile were also associated with more lung cancer incidence (IRR = 1.01). Our study shows a positive association between air pollution and lung cancer incidence. This association was stronger for, respectively, p-xylene, o-xylene, ethylbenzene, benzene, m-xylene and toluene.

Particulate Matter Short-Term Exposition, Mobility Trips and COVID-19 Diffusion: A Correlation Analyses for the Italian Case Study at Urban Scale

The conjecture discussed in this paper was that the daily number of certified cases of COVID-19 is direct correlated to the average particular matter (PM) concentrations observed several days before when the contagions occurred (short-term effect), and this correlation is higher for areas with a higher average seasonal PM concentration, as a measure of prolonged exposure to a polluted environment (long-term effect). Furthermore, the correlations between the daily COVID-19 new cases and the mobility trips and those between the daily PM concentrations and mobility trips were also investigated. Correlation analyses were performed for the application case study consisting in 13 of the main Italian cities, through the national air quality and mobility monitoring systems. Data analyses showed that the mobility restrictions performed during the lockdown produced a significant improvement in air quality with an average PM concentrations reduction of about 15%, with maximum variations ranging between 25% and 42%. Estimation results showed a positive correlation (stronger for the more highly polluted cities) between the daily COVID-19 cases and both the daily PM concentrations and mobility trips measured about three weeks before, when probably the contagion occurred. The obtained results are original, and if confirmed in other studies, it would lay the groundwork for the definition of the main context variables which influenced the COVID-19 spread. The findings highlighted in this research also supported by the evidence in the literature and allow concluding that PM concentrations and mobility habits could be considered as potential early indicators of COVID-19 circulation in outdoor environments. However, the obtained results pose significant ethical questions about the proper urban and transportation planning; the most polluted cities have not only worst welfare for their citizens but, as highlighted in this research, could lead to a likely greater spread of current and future respiratory and/or pulmonary health emergencies. The lesson to be learned by this global pandemic will help planners to better preserve the air quality of our cities in the post-COVID-19 era.

Outdoor Air Pollution and New-Onset Airway Disease. An Official American Thoracic Society Workshop Report

Although it is well accepted that air pollution exposure exacerbates preexisting airway disease, it has not been firmly established that long-term pollution exposure increases the risk of new-onset asthma or chronic obstruction pulmonary disease (COPD). This Workshop brought together experts on mechanistic, epidemiological, and clinical aspects of airway disease to review current knowledge regarding whether air pollution is a causal factor in the development of asthma and/or COPD. Speakers presented recent evidence in their respective areas of expertise related to air pollution and new airway disease incidence, followed by interactive discussions. A writing committee summarized their collective findings. The Epidemiology Group found that long-term exposure to air pollution, especially metrics of traffic-related air pollution such as nitrogen dioxide and black carbon, is associated with onset of childhood asthma. However, the evidence for a causal role in adult-onset asthma or COPD remains insufficient. The Mechanistic Group concluded that air pollution exposure can cause airway remodeling, which can lead to asthma or COPD, as well as asthma-like phenotypes that worsen with long-term exposure to air pollution, especially fine particulate matter and ozone. The Clinical Group concluded that air pollution is a plausible contributor to the onset of both asthma and COPD. Available evidence indicates that long-term exposure to air pollution is a cause of childhood asthma, but the evidence for a similar determination for adult asthma or COPD remains insufficient. Further research is needed to elucidate the exact biological mechanism underlying incident childhood asthma, and the specific air pollutant that causes it.

Impact of long-term exposure to ambient air pollution on the incidence of chronic obstructive pulmonary disease: A systematic review and meta-analysis

BACKGROUND

It is well known that air pollution causes respiratory morbidity and mortality by inducing airway inflammation. However, whether long-term exposure to air pollution is associated with increased incidence of chronic obstructive pulmonary disease (COPD) is controversial.

METHODS

We conducted a systematic review and meta-analysis with a random-effects model to calculate the pooled risk estimates of COPD development per 10 μg/m³ increase in individual air pollutants. PubMed, Embase, and Cochrane Library were searched from the date of their inception to August 2019 to identify long-term (at least three years of observation) prospective longitudinal studies that reported the risk of COPD development due to exposure to air pollutants. The air pollutants studied included particulate matter (PM_2.5 and PM₁₀) and nitrogen dioxide (NO₂).

RESULTS

Of the 436 studies identified, seven met our eligibility criteria. Among the seven studies, six, three, and five had data on PM_2.5, PM₁₀, and NO₂, respectively. The meta-analysis results showed that a 10 μg/m³ increase in PM_2.5 is associated with increased incidence of COPD (pooled HR 1.18, 95% CI 1.13-1.23). We also noted that a 10 μg/m³ increase in NO₂ is marginally associated with increased incidence of COPD (pooled HR 1.07, 95% CI 1.00-1.16). PM₁₀ seems to have no significant impact on the incidence of COPD (pooled HR 0.95, 95% CI 0.83-1.08), although the number of studies was too small. Meta-regression analysis found no significant effect modifiers.

CONCLUSIONS

Long-term exposure to PM_2.5 and NO₂ can be associated with increased incidence of COPD.

Long-term exposure to low-level air pollution and incidence of chronic obstructive pulmonary disease: The ELAPSE project

BACKGROUND

Air pollution has been suggested as a risk factor for chronic obstructive pulmonary disease (COPD), but evidence is sparse and inconsistent.

OBJECTIVES

We examined the association between long-term exposure to low-level air pollution and COPD incidence.

METHODS

Within the 'Effects of Low-Level Air Pollution: A Study in Europe' (ELAPSE) study, we pooled data from three cohorts, from Denmark and Sweden, with information on COPD hospital discharge diagnoses. Hybrid land use regression models were used to estimate annual mean concentrations of particulate matter with a diameter < 2.5 µm (PM_2.5), nitrogen dioxide (NO₂), and black carbon (BC) in 2010 at participants' baseline residential addresses, which were analysed in relation to COPD incidence using Cox proportional hazards models.

RESULTS

Of 98,058 participants, 4,928 developed COPD during 16.6 years mean follow-up. The adjusted hazard ratios (HRs) and 95% confidence intervals for associations with COPD incidence were 1.17 (1.06, 1.29) per 5 µg/m³ for PM_2.5, 1.11 (1.06, 1.16) per 10 µg/m³ for NO₂, and 1.11 (1.06, 1.15) per 0.5 10^-5m^-1 for BC. Associations persisted in subset participants with PM_2.5 or NO₂ levels below current EU and US limit values and WHO guidelines, with no evidence for a threshold. HRs for NO₂ and BC remained unchanged in two-pollutant models with PM_2.5, whereas the HR for PM_2.5 was attenuated to unity with NO₂ or BC.

CONCLUSIONS

Long-term exposure to low-level air pollution is associated with the development of COPD, even below current EU and US limit values and possibly WHO guidelines. Traffic-related pollutants NO₂ and BC may be the most relevant.

The Respiratory Risks of Ambient/Outdoor Air Pollution

Globally, exposure to ambient air pollutants is responsible for premature mortality and is implicated in the development and exacerbation of several acute and chronic lung disease across all ages. In this article, we discuss the source apportionment of ambient pollutants and the respiratory health effects in humans. We specifically discuss the evidence supporting ambient pollution in the development of asthma and chronic obstructive pulmonary disease and acute exacerbations of each condition. Practical advice is given to health care providers in how to promote a healthy environment and advise patients with chronic conditions to avoid unsafe air quality.

The effect of air-pollution and weather exposure on mortality and hospital admission and implications for further research: A systematic scoping review

BACKGROUND

Air-pollution and weather exposure beyond certain thresholds have serious effects on public health. Yet, there is lack of information on wider aspects including the role of some effect modifiers and the interaction between air-pollution and weather. This article aims at a comprehensive review and narrative summary of literature on the association of air-pollution and weather with mortality and hospital admissions; and to highlight literature gaps that require further research.

METHODS

We conducted a scoping literature review. The search on two databases (PubMed and Web-of-Science) from 2012 to 2020 using three conceptual categories of "environmental factors", "health outcomes", and "Geographical region" revealed a total of 951 records. The narrative synthesis included all original studies with time-series, cohort, or case cross-over design; with ambient air-pollution and/or weather exposure; and mortality and/or hospital admission outcomes.

RESULTS

The final review included 112 articles from which 70 involved mortality, 30 hospital admission, and 12 studies included both outcomes. Air-pollution was shown to act consistently as risk factor for all-causes, cardiovascular, respiratory, cerebrovascular and cancer mortality and hospital admissions. Hot and cold temperature was a risk factor for wide range of cardiovascular, respiratory, and psychiatric illness; yet, in few studies, the increase in temperature reduced the risk of hospital admissions for pulmonary embolism, angina pectoris, chest, and ischemic heart diseases. The role of effect modification in the included studies was investigated in terms of gender, age, and season but not in terms of ethnicity.

CONCLUSION

Air-pollution and weather exposure beyond certain thresholds affect human health negatively. Effect modification of important socio-demographics such as ethnicity and the interaction between air-pollution and weather is often missed in the literature. Our findings highlight the need of further research in the area of health behaviour and mortality in relation to air-pollution and weather, to guide effective environmental health precautionary measures planning.

Proximity to livestock farms and exposure to livestock-related particulate matter are associated with lower probability of medication dispensing for obstructive airway diseases

OBJECTIVES

The aim of this study is to assess whether medication use for obstructive airway diseases is associated with environmental exposure to livestock farms. Previous studies in the Netherlands at a regional level suggested that asthma and chronic obstructive pulmonary disease (COPD) are less prevalent among persons living near livestock farms.

METHODS

A nationwide population-based cross-sectional study was conducted among 7,735,491 persons, with data on the dispensing of drugs for obstructive airway diseases in the Netherlands in 2016. Exposure was based on distances between home addresses and farms and on modelled atmospheric particulate matter (PM₁₀) concentrations from livestock farms. Data were analysed for different regions by logistic regression analyses and adjusted for several individual-level variables, as well as modelled PM₁₀ concentration of non-farm-related air pollution. Results for individual regions were subsequently pooled in meta-analyses.

RESULTS

The probability of medication for asthma or COPD being dispensed to adults and children was lower with decreasing distance of their homes to livestock farms, particularly cattle and poultry farms. Increased concentrations of PM₁₀ from cattle were associated with less dispensing of medications for asthma or COPD, as well (meta-analysis OR for 10th-90th percentile increase in concentration of PM₁₀ from cattle farms, 95%CI: 0.92, 0.86-0.97 for adults). However, increased concentrations of PM₁₀ from non-farm sources were positively associated (meta-analysis OR for 10th-90th percentile increase in PM₁₀-concentration, 95%CI: 1.29, 1.09-1.52 for adults).

CONCLUSIONS

The results show that the probability of dispensing medication for asthma or COPD is inversely associated with proximity to livestock farms and modelled exposure to livestock-related PM₁₀ in multiple regions within the Netherlands. This finding implies a notable prevented risk: under the assumption of absence of livestock farms in the Netherlands, an estimated 2%-5% more persons (an increase in tens of thousands) in rural areas would receive asthma or COPD medication.

PM2.5 Induces the Expression of Inflammatory Cytokines via the Wnt5a/Ror2 Pathway in Human Bronchial Epithelial Cells

Background and Purpose

Recently, fine particulate matter (PM2.5) was identified as the main exposure risk for COPD, and inflammation is central to the development of COPD. In this study, we investigated whether PM2.5 can induce the secretion of interleukin-6 (IL-6), IL-8 and IL-1β in human bronchial epithelial cells (HBECs) in vitro via the wingless-related integration site 5A (Wnt5a)/receptor tyrosine kinase-like orphan receptor 2 (Ror2) signaling.

Methods

The expression of Wnt5a and Ror2 was assessed by immunohistochemistry in motor vehicle exhaust (MVE)-induced Sprague-Dawley rats. HBECs were transfected with small interfering RNA (siRNA) targeting Wnt5a or Ror2 and subsequently stimulated with PM2.5.The secretion of IL-6, IL-8 and IL-1β was assessed by ELISAs, and the expression of Wnt5a/Ror2 signaling were assessed by RT-PCR and Western blotting.

Results

Both Wnt5a and Ror2 protein were increased in the lung of MVE-induced rats. HBECs exposed to PM2.5 for 24 h significantly upregulated Wnt5a and Ror2 expression and subsequently promoted the nuclear translocation of NF-κB, which increased the production of IL-1β, IL-6 and IL-8. Wnt5a siRNA prevented these outcomes. Wnt5a antagonist (BOX5) also prevented inflammatory effects. Furthermore, Ror2 siRNA blocked the NF-κB activity and inhibited the release of IL-6, IL-8 and IL-1β from PM2.5-exposed HBECs.

Conclusion

PM2.5 induces the secretion of IL-6, IL-8 and IL-1β in HBECs via the Wnt5a/Ror2 signaling, demonstrating a novel mechanism for PM2.5-associated airway inflammation.

Long-term exposure to fine particulate matter and development of chronic obstructive pulmonary disease in the elderly

BACKGROUND

Studies evaluating the role of long-term exposure to fine particulate matter (PM_2.5) on chronic obstructive pulmonary disease (COPD) development showed inconsistent results and were limited to Western countries. We aimed to determine the association between long-term exposure to PM_2.5 and COPD development in metropolitan cities in Korea, which have higher PM_2.5 levels than those in Western country studies.

METHODS

We constructed a retrospective cohort (elderly aged over 65 years who resided in 7 metropolitan cities in 2008) using Korea health insurance data. A total of 687,940 elderlies who had not visited hospitals due to COPD for 3 years (from 2008 to 2010) were followed-up from 2011 to 2016. The first hospital visit due to COPD during the follow-up period was regarded as COPD development. Daily district-level PM_2.5 concentrations were estimated by chemical transport model and 60-month moving average PM_2.5 were assigned to each subject in time-varying Cox proportional hazard model.

RESULTS

The mean concentration of modelled PM_2.5 in 7 metropolitan cities during the study period (from 2006 to 2016) was 28.0 μg/m³ and 259,700 subjects newly visited the hospital due to COPD. COPD hospital visit hazard ratio for a 10 μg/m³ increase in 60-month moving average PM_2.5 concentration was 1.09 (95% confidence interval: 1.07, 1.11). Risks remained unchanged following different PM_2.5 exposure levels (48-month moving average, and average PM_2.5 concentrations for 2008 and 2008-2010) and in subgroup analysis by subject characteristics (sex, age, and income groups).

DISCUSSION

By following-up 687,940 elderly subjects who resided in metropolitan cities in Korea for 6 years, long-term PM_2.5 exposure showed association with COPD development.

Mitochondrial alterations triggered by repeated exposure to fine (PM2.5-0.18) and quasi-ultrafine (PM0.18) fractions of ambient particulate matter

Nowadays ambient particulate matter (PM) levels still regularly exceed the guideline values established by World Health Organization in most urban areas. Numerous experimental studies have already demonstrated the airway toxicity of the fine fraction of PM (FP), mainly triggered by oxidative stress-induced airway inflammation. However, only few studies have actually paid close attention to the ultrafine fraction of PM (UFP), which is likely to be more easily internalized in cells and more biologically reactive. Mitochondria are major endogenous sources of reactive oxygen species (ROS) through oxidative metabolism, and coordinate many critical cellular signaling processes. Mitochondria have been often studied in the context of PM toxicity and generally associated with apoptosis activation. However, little is known about the underlying adaptation mechanisms that could occur following exposure at sub-apoptotic doses of ambient PM. Here, normal human bronchial epithelial BEAS-2B cells were acutely or repeatedly exposed to relatively low doses (5 µg.cm^-2) of FP (PM_2.5-0.18) or quasi-UFP (Q-UFP; PM_0.18) to better access the critical changes in mitochondrial morphology, functions, and dynamics. No significant cytotoxicity nor increase of apoptotic events were reported for any exposure. Mitochondrial membrane potential (ΔΨm) and intracellular ATP content were also not significantly impaired. After cell exposure to sub-apoptotic doses of FP and notably Q-UFP, oxidative phosphorylation was increased as well as mitochondrial mass, resulting in increased production of mitochondrial superoxide anion. Given this oxidative boost, the NRF2-ARE signaling pathway was significantly activated. However, mitochondrial dynamic alterations in favor of accentuated fission process were observed, in particular after Q-UFP vs FP, and repeated vs acute exposure. Taken together, these results supported mitochondrial quality control and metabolism dysfunction as an early lung underlying mechanism of toxicity, thereby leading to accumulation of defective mitochondria and enhanced endogenous ROS generation. Therefore, these features might play a key role in maintaining PM-induced oxidative stress and inflammation within lung cells, which could dramatically contribute to the exacerbation of inflammatory chronic lung diseases. The prospective findings of this work could also offer new insights into the physiopathology of lung toxicity, arguably initiate and/or exacerbate by acutely and rather repeated exposure to ambient FP and mostly Q-UFP.

LncRNA RP11-86H7.1 promotes airway inflammation induced by TRAPM2.5 by acting as a ceRNA of miRNA-9-5p to regulate NFKB1 in HBECS

Traffic-related air pollution particulate matter 2.5 (TRAPM2.5), is involved in chronic obstructive pulmonary disease (COPD), which is characterized by airway inflammation. Specifically, these harmful particles or gases can increase chronic airway inflammation. Some recent studies have shown that lncRNAs are closely related to COPD and participate in the regulation of airway inflammation. However, the precise mechanisms remain unknown. In the present study, we investigated the effect of TRAPM2.5 on airway inflammation in human bronchial epithelial cells (HBECs) and the underlying mechanisms mediated by a lncRNA. After exposure to TRAPM2.5, the novel lncRNA RP11-86H7.1 was markedly upregulated in HBECs. Functional assays indicated that the lncRNA RP11-86H7.1 was required for the TRAPM2.5-induced expression of inflammatory factors in HBECs. A mechanistic study demonstrated that lncRNA RP11-86H7.1 might participate in TRAPM2.5-induced inflammatory responses by activating the NF-κB signaling pathway. Moreover, the lncRNA RP11-86H7.1 can promote the inflammatory response by acting as a competing endogenous RNA of miR-9-5p, reversing the inhibitory effect of its target gene NFKB1, and sustaining NF-κB activation. In summary, our study elucidates the pro-inflammatory roles of the lncRNA RP11-86H7.1–miR-9-5p–NFKB1 regulatory network in airway inflammation induced by TRAPM2.5 and indicates that the components of this network might serve as novel diagnostic biomarkers and potential therapeutic targets.

Air pollution and chronic obstructive pulmonary disease

There is considerable epidemiological evidence indicating that air pollution has adverse effects on human health and is closely related to respiratory diseases, including chronic obstructive pulmonary disease (COPD). These effects, which can be divided into short- and long-term effects, can manifest as an exacerbation of existing symptoms, impaired lung function, and increased hospitalization and mortality rates. Long-term exposure to air with a high concentration of pollutants may also increase the incidence of COPD. The combined effects of different pollutants may become more complex in the future; hence, there is a need for more intensive research on specific at-risk populations, and formulating corresponding protective strategies is crucial. We aimed to review the epidemiological evidence on the effect of air pollution on COPD, the possible pathophysiological mechanisms underlying this effect, as well as protective measures against the effects of air pollutants in patients with COPD.

Effects of Particulate Matter on the Incidence of Respiratory Diseases in the Pisan Longitudinal Study

The current study aimed at assessing the effects of exposure to Particulate Matter (PM) on the incidence of respiratory diseases in a sub-sample of participants in the longitudinal analytical epidemiological study in Pisa, Italy. Three hundred and five subjects living at the same address from 1991 to 2011 were included. Individual risk factors recorded during the 1991 survey were considered, and new cases of respiratory diseases were ascertained until 2011. Average PM10 and PM2.5 exposures (µg/m3, year 2011) were estimated at the residential address (1-km2 resolution) through a random forest machine learning approach, using a combination of satellite data and land use variables. Multivariable logistic regression with Firth's correction was applied. The median (25th-75th percentile) exposure levels were 30.1 µg/m3 (29.9-30.7 µg/m3) for PM10 and 19.3 µg/m3 (18.9-19.4 µg/m3) for PM2.5. Incidences of rhinitis and chronic phlegm were associated with increasing PM2.5: OR = 2.25 (95% CI: 1.07, 4.98) per unit increase (p.u.i.) and OR = 4.17 (1.12, 18.71) p.u.i., respectively. Incidence of chronic obstructive pulmonary disease was associated with PM10: OR = 2.96 (1.50, 7.15) p.u.i. These results provide new insights into the long-term respiratory health effects of PM air pollution.

Geographical Disparity and Associated Factors of COPD Prevalence in China: A Spatial Analysis of National Cross-Sectional Study

Purpose

COPD prevalence has rapidly increased in China, but the geographical disparities in COPD prevalence remain largely unknown. This study aimed to assess city-level disparities in COPD prevalence and identify the relative importance of COPD related risk factors in mainland China.

Patients and Methods

A nationwide cross-sectional study of COPD recruited 66,752 adults across the mainland China between 2014 and 2015. Patients with COPD were ascertained by a post-bronchodilator pulmonary function test. We estimated the city-specific prevalence of COPD by spatial kriging interpolation method. We detected spatial clusters with a significantly higher prevalence of COPD by spatial scan statistics. We determined the relative importance of COPD associated risk factors by a nonparametric and nonlinear classification and regression tree (CART) model.

Results

The three spatial clusters with the highest prevalence of COPD were located in parts of Sichuan, Gansu, and Shaanxi, etc. (relative risks (RRs)) ranging from 1.55 (95% CI 1.55–1.56) to 1.33 (95% CI 1.33–1.33)). CART showed that advanced age (≥60 years) was the most important factor associated with COPD in the overall population, followed by smoking. We estimated that there were about 28.5 million potentially avoidable cases of COPD among people aged 40 or older if they never smoked. PM_2.5 was an important associated risk factor for COPD in the north, northeast, and southwest of China. After adjusting for age and smoking, the spatial cluster with the highest prevalence shifted to most of Sichuan, Gansu, Qinghai, and Ningxia, etc. (RR 1.65 (95% CI 1.63–1.67)).

Conclusion

The spatial clusters of COPD at the city level and regionally varied important risk factors for COPD would help develop tailored interventions for COPD in China. After adjusting for the main risk factors, the spatial clusters of COPD shifted, indicating that there would be other potential risk factors for the remaining clusters which call for further studies.

Self-reported traffic-related air pollution and respiratory symptoms among adults in an area with modest levels of traffic

Health effects of traffic-related air pollution (TRAP) concentrations in densely populated areas are previously described. However, there is still a lack of knowledge of the health effects of moderate TRAP levels. The aim of the current study, a population-based survey including 16 099 adults (response rate 33%), was to assess the relationship between TRAP estimates and respiratory symptoms in an area with modest levels of traffic; Telemark County, Norway. Respondents reported respiratory symptoms the past 12 months and two TRAP exposure estimates: amount of traffic outside their bedroom window and time spent by foot daily along a moderate to heavy traffic road. Females reported on average more symptoms than males. Significant relationships between traffic outside their bedroom window and number of symptoms were only found among females, with the strongest associations among female occasional smokers (incidence rate ratio [IRR], 1.75, 95% confidence interval (CI) [1.16–2.62] for moderate or heavy traffic compared to no traffic). Significant relationship between time spent daily by foot along a moderate to heavy traffic road and number of symptoms was found among male daily smokers (IRR 1.09, 95% CI [1.04–1.15] per hour increase). Associations between traffic outside bedroom window and each respiratory symptom were found. Significant associations were primarily detected among females, both among smokers and non-smokers. Significant associations between time spent by foot daily along a moderate to heavy traffic road (per hour) and nocturnal dyspnoea (odds ratio (OR) 1.20, 95% CI [1.05–1.38]), nocturnal chest tightness (OR 1.13 [1.00–1.28]) and wheezing (OR 1.14 [1.02–1.29]) were found among daily smokers, primarily men. Overall, we found significant associations between self-reported TRAP exposures and respiratory symptoms. Differences between genders and smoking status were identified. The findings indicate an association between TRAP and respiratory symptoms even in populations exposed to modest levels of TRAP.

Asthma and Chronic Obstructive Pulmonary Disease Overlap in Women. Incidence and Risk Factors

RATIONALE

Women with asthma are at a high risk of developing chronic obstructive pulmonary disease (COPD) or asthma and COPD overlap syndrome (ACOS) as they age, which is a condition associated with a high mortality rate, low quality of life, and high healthcare costs. However, factors influencing the development of ACOS remain unclear.

OBJECTIVES

To quantify the risk of developing COPD in women in Ontario with asthma and identify factors that are associated with increased risk.

METHODS

Data for women in Ontario with asthma who participated in the Canadian National Breast Screening Study from 1980 to 1985 were linked to health administrative databases, and participants were followed from 1992 to 2015. A competing risks survival model was used to measure the associations between sociodemographic, lifestyle, and environmental risk factors and time to COPD incidence, accounting for death as a competing risk.

RESULTS

A total of 4,051 women with asthma were included in the study, of whom 1,701 (42.0%) developed COPD. The mean age at the study end date was 79 years. Low education, high body mass index, rurality, and high levels of cigarette smoking were associated with ACOS incidence, whereas exposure to fine particulate matter, a major air pollutant, was not.

CONCLUSIONS

Individual risk factors appear to play a more significant role in the development of ACOS in women than environmental factors, such as air pollution. Prevention strategies targeting health promotion and education may have the potential to reduce ACOS incidence in this population.