Two-pollutant Models Research Articles

Long-term exposure to air pollutants (PM2.5and NO2) and incidence of type 2 diabetes in the Mexican Teachers’ Cohort.

Background/Aim: Air pollution is a risk factor for type 2 diabetes (T2D). However, no longitudinal studies have evaluated this association in a low- and middle-income countries, where 80% of the worldwide cases of T2D occur. Our aim was to evaluate the association between incident T2D and long-term exposure to PM2.5 and NO2 in the Mexican Teachers’ Cohort (MTC). Methods: We selected a subsample of female teachers from the MTC who lived and worked in the Mexico City Metropolitan Area, recruited in 2008 and with active follow-up every 3 years (n = 14,194). We assigned the time-weighted exposures (PM2.5 and NO2) in home and work addresses, from 12 months before baseline to failure or censoring. We developed two high resolution (1km x 1km) spatio-temporal predictive Generalized Additive Models of PM2.5 and NO2. We defined incident T2D when teachers self-reported at least two of the following questions: have a medical diagnosis, use of medical treatment, or date of diagnosis. We fitted time-varying Cox models to estimate hazard ratios of the relation between PM2.5 and NO2 and incident T2D; adjusting for confounding variables: age, passive and active smoking status, physical activity, SES, wood smoking and time spent outdoors. Results: Teachers were followed up for 11.5 years. There were 795 incident T2D cases (84 cases per 100,000 person-months). Incident T2D increased by 80% (HR = 1.8[1.6-2.1]) for each 10 μg/m3 increase of PM2.5 and 60% for every 10 ppb of NO2 (HR = 1.6[1.4-1.9]). In two-pollutant models, effects were attenuated. Conclusions: PM2.5 and NO2 increased the risk of T2D in Mexico, in a larger magnitude than previous published studies. Despite improvements in air quality, there are still health risks related to current pollutant levels, arguing for even stricter regulation.

Air pollution and the development of asthma from birth until young adulthood

Background: Air pollution is associated with asthma development in children and adults, but the impact on asthma development during the transition from adolescence to adulthood is unclear. Adult studies lack historical exposures and consequently cannot assess the relevance of exposure during different periods of life. We assessed the relevance of early life and more recent air pollution exposure for asthma development from birth until early adulthood. Methods: We used data of 3,687 participants of the prospective Dutch PIAMA birth cohort and linked asthma incidence until age 20 to estimated concentrations of nitrogen dioxide (NO2), PM2.5 absorbance ("soot") and particulate matter with a diameter <2.5 μm (PM2.5), <10 μm (PM10), and 2.5-10 μm (PMcoarse) at the residential address. We assessed overall and age-specific associations with air pollution exposure with discrete time hazard models, adjusting for potential confounders. Results: Overall, we found higher incidence of asthma until age 20 with higher exposure to all pollutants at the birth address [adjusted odds ratio (95% confidence interval) ranging from 1.09 (1.01-1.18) for PM10 to 1.20 (1.10-1.32) for NO2) per interquartile range increase] that were rather persistent with age and similar associations were observed with more recent exposure defined as exposure at the current home address. In two-pollutant models with PM, associations with NO2 persist. Conclusions: Exposure to air pollution, especially from motorized traffic, early in life may have long-term consequences for asthma development as it is associated with an increased odds of developing asthma through childhood and adolescence into early adulthood.

Associations between PM2.5 metal components and QT interval length

Background/Aim: Several studies have found associations between increases in QT interval length, a marker of cardiac electrical instability, and short-term fine particulate matter (PM2.5). To our knowledge, this is the first study to examine the association between specific PM metal components and QT interval length. Methods: We measured heart-rate corrected QT interval (QTc) duration among 630 participants in the Normative Aging Cohort (NAS) based in Eastern Massachusetts between 2000 to 2012. We utilized time-varying linear mixed-effects regressions with a random intercept to analyze associations between QTc interval and moving averages (0 to 7-day moving averages) of 24-hour mean concentrations of PM metal components (vanadium, nickel, copper, zinc and lead) measured at the Harvard Supersite monitoring station. Models were adjusted for daily PM2.5 mass estimated at a 1 km x 1 km grid cell from a previously validated prediction model and other covariates. Bayesian kernel machine regression (BKMR) was utilized to assess the overall effect of the PM components and the exposure-dose response curves. Results: We found consistent results with higher lead (Pb) associated with significant higher QTc intervals for both the multi-pollutant and the two pollutant (PM2.5 and a PM component) models across the moving averages. The greatest effect of lead on QTc interval was detected for the 4-day moving average lead exposure. In the multi-pollutant model, each 2.72 ng/m3 increase in daily lead levels for a 4-day moving average was associated with an 8.77 ms (95% CI: 4.25,13.29) increase in QTc interval. In the two-pollutant models with PM2.5 mass and lead, each 2.72 ng/m3 increase in daily lead levels for a 4-day moving average was associated with a 9.19 ms (95% CI: 5.09,13.30) increase in QTc interval. Conclusions: Our findings suggest that metals contained in PM2.5 are associated with acute changes (0 to 7-day moving averages) in ventricular repolarization.

Short-term effect of fine particular matter on daily hospitalizations for ischemic stroke: A time-series study in Yancheng, China

ObjectiveTo investigate the associations between short-term exposure to fine particular matter (PM2.5) and ischemic stroke (IS) in Yancheng, China, from 2017 to 2019. MethodsWe designed a time-series study based on generalized additive models to explore the association of PM2.5 and IS admitted in two major hospitals in Yancheng. We built different lag patterns and conducted stratification analyses by age, gender, and season. Moreover, we examined the robustness of the associations adopting two-pollutant models and fitted the concentration-response curves. ResultWe observed positive and significant associations at lag 0 day. Every 10 μg/m3 increase in PM2.5 (lag0) was associated with 1.06% (95% CI: 0.21%–1.91%) increases in hospitalizations for IS. The association remained stable and statistically significant to the adjustment of carbon monoxide and ozone. We observed that the associations were stronger in females and during cold seasons. The overall concentration-response relationship curve was linear positive and increased slowly but rose sharply at higher concentrations in the cold season. ConclusionOur study added to the evidence that short-term exposure to PM2.5 may induce IS, and the government should take action to address the air pollution issues and protect susceptible populations.

The association between ambient air pollution and blood lipids: A longitudinal study in Shijiazhuang, China

BackgroundFew studies have explored the associations between ambient air pollution and blood lipid levels. This study aimed to fill this knowledge gap based on a routine health examination cohort in Shijiazhuang, China. MethodsWe included 7063 participants who took the routine health examination for 2–3 times at Hebei General Hospital from January 2016 to December 2018. Individual serum levels of cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) were measured. Their three-month average exposure to air pollution prior to the routine health examinations was estimated using inverse distance weighted method. We used linear mixed-effects regression models to examine the associations between air pollution and levels of blood lipids while controlling for age, gender, body mass index (BMI), smoking, alcohol drinking, temperature, humidity, with a random effect for each individual. ResultsParticles with diameters ≤2.5 μm and ≤10 μm (PM2.5 and PM10), nitrogen dioxide (NO2), sulfur dioxide (SO2) and ozone (O3) were all positively associated with TC, TG, and LDL-C and negatively associated with HDL-C, in single pollutant models. Each 10 μg/m3 increment of 3-month average PM2.5 was associated with 0.65% [95% confidence interval (CI): 0.03%–1.28%], 0.56% (95%CI: 0.33%–0.79%) and 0.63% (95%CI: 0.35%–0.91%) increment in TG, TC, and LDL-C, and 0.91% (95%CI: 0.68%–1.13%) decrease in HDL-C. In two-pollutant models, the effects of gaseous pollutants on blood lipids were weakened, while those of PMs were strengthened. Stronger associations were presented in the elderly (≥60 years) and overweight/obese (BMI ≥ 24) participants. ConclusionsAmbient air pollution had significantly adverse effects on blood lipid levels, especially in overweight/obese and elderly individuals. CapsuleSignificant associations between increased air pollution and worse blood lipid levels were found, especially in overweight/obese and elderly individuals.

Association between ozone air pollution levels and hospitalizations for depression in Taipei: a time-stratified case-crossover study

ABSTRACT Epidemiologic studies reported an association between exposure to ambient air pollutants and increased mortality rate attributed to suicide and suicide attempts. The investigation sought to determine whether there is an association between short-term ambient ozone (O3) level exposure and daily hospital admissions for depression in Taipei from 2009 to 2013 using a time-stratified case-crossover design. In our single-pollutant model (with no adjustment for other pollutants), the % increase in daily hospital admissions for depression was 12% on warm days and 30% on cool days, per interquartile range (IQR) rise in O3 levels, respectively. Ozone levels were significantly correlated with daily number of depression admissions both on warm and cool days. In our two-pollutant models, O3 levels remained significant after adjusting for other air pollutants, including particulate matter (PM10, PM2.5), sulfur dioxide (SO2), nitrogen dioxide (NO2), and carbon monoxide (CO) both on warm and cool days. Although O3 levels tended to be higher on warm days, admissions for depression were higher on cool days, suggesting that the relationship between O3 concentrations and depression may be affected by temperature. Further study is needed to better understand these findings.

Associations of short-term exposure to air pollution and emergency department visits for pediatric asthma in Shanghai, China

There is limited evidence regarding the relationship between air pollution and pediatric asthma in developing countries. This study aimed to investigate the association between short-term exposure to ambient air pollutants and pediatric asthma emergency department (ED) visits in Shanghai, China. We collected data on six criteria air pollutants (PM2.5, PM10, NO2, SO2, CO, and O3) and daily ED visits for pediatric asthma patients from 66 hospitals in Shanghai from 2016 to 2018. The generalized additive model combined with polynomial distributed lag model was applied to explore the associations. We fitted two-pollutant models and stratified the analyses by sex, age, and season. In total, we identified 108,817 emergency department visits for pediatric asthma. A 10 μg/m3 increase in the concentrations of PM2.5, NO2, SO2, and O3 was significantly associated with increased risks of pediatric asthma ED visits, with relative risk of pediatric asthma of 1.011 [95% confidence interval (CI): 1.002, 1.021], 1.030 (95%CI: 1.017, 1.043), 1.106 (95%CI: 1.041, 1.174), and 1.009 (95%CI: 1.001, 1.017), respectively. The associations of NO2 remained robust in the two-pollutant models. There were stronger associations for older children (6–18 years) and in warm seasons. The concentration-response curves for pediatric asthma and PM2.5, NO2, SO2, and O3 were steeper at lower and moderate concentrations but became flatter at higher concentrations. This analysis provided evidence that short-term exposure to air pollutants (PM2.5, NO2, SO2, and O3) could increase the risk of asthma exacerbations among children, and health benefits would be gained from improved air quality.

Associations of Preconception Exposure to Air Pollution and Greenness with Offspring Asthma and Hay Fever.

We investigated if greenness and air pollution exposure in parents’ childhood affect offspring asthma and hay fever, and if effects were mediated through parental asthma, pregnancy greenness/pollution exposure, and offspring exposure. We analysed 1106 parents with 1949 offspring (mean age 35 and 6) from the Respiratory Health in Northern Europe, Spain and Australia (RHINESSA) generation study. Mean particulate matter (PM2.5 and PM10), nitrogen dioxide (NO2), black carbon (BC), ozone (O3) (µg/m3) and greenness (normalized difference vegetation index (NDVI)) were calculated for parents 0–18 years old and offspring 0–10 years old, and were categorised in tertiles. We performed logistic regression and mediation analyses for two-pollutant models (clustered by family and centre, stratified by parental lines, and adjusted for grandparental asthma and education). Maternal medium PM2.5 and PM10 exposure was associated with higher offspring asthma risk (odds ratio (OR) 2.23, 95%CI 1.32–3.78, OR 2.27, 95%CI 1.36–3.80), and paternal high BC exposure with lower asthma risk (OR 0.31, 95%CI 0.11–0.87). Hay fever risk increased for offspring of fathers with medium O3 exposure (OR 4.15, 95%CI 1.28–13.50) and mothers with high PM10 exposure (OR 2.66, 95%CI 1.19–5.91). The effect of maternal PM10 exposure on offspring asthma was direct, while for hay fever, it was mediated through exposures in pregnancy and offspring’s own exposures. Paternal O3 exposure had a direct effect on offspring hay fever. To conclude, parental exposure to air pollution appears to influence the risk of asthma and allergies in future offspring.

Ambient air pollution exposure associated with glucose homeostasis during pregnancy and gestational diabetes mellitus

BackgroundTo investigate the effects of air pollution exposure during pregnancy on the indicators of glucose homeostasis and gestational diabetes mellitus (GDM). MethodsWe conducted a birth cohort study in Foshan, China during 2015–2019. Oral glucose tolerance test (OGTT) was administered to each participant during pregnancy. GDM was defined according to the International Association of Diabetes and Pregnancy Study Groups criteria (IADPSG). Air pollutant (fine particulate matter (PM2.5), particulate matter with an aerodynamic diameter of 10 μm or less (PM10), sulfate dioxide (SO2), nitrogen dioxide (NO2) and ozone (O3)) concentrations from the air monitoring stations in Foshan were used to estimate individual air pollutant exposure during the first two trimesters. Linear and logistic regression models were employed to estimate the associations between air pollution exposure during the first two trimesters and OGTT glucose levels and GDM. ResultsOf 12,842 pregnant women, 3055 (23.8%) had GDM. A 10 μg/m3 increase in PM2.5, PM10 and SO2 during trimester 1, trimester 2 and two trimesters were associated with 0.07 mmol/L to 0.29 mmol/L increment in OGTT-fasting glucose levels in single-pollutant model. A 10 μg/m3 increase in NO2 and O3 during two trimesters were associated with 0.15 mmol/L and 0.12 mmol/L decrease in OGTT-fasting glucose in single-pollutant model. However, no significant or weaker effects of O3 during two trimesters on OGTT-fasting glucose were observed in two-pollutant models. Moreover, exposure to PM2.5, PM10 and SO2 were associated with increased risk of GDM in both single- and two-pollutant models. ConclusionsOur study suggests PM2.5, PM10 and SO2 exposure during the first two trimesters might increase the risk of GDM.

Associations of long-term exposure to ambient air pollution with cardiac conduction abnormalities in Chinese adults: The CHCN-BTH cohort study

BackgroundEvidence regarding the effects of long-term and high-level ambient air pollution exposure on cardiac conduction systems remains sparse. ObjectivesTo investigate the associations of long-term exposure to air pollution and cardiac conduction abnormalities in Chinese adults and explore the susceptibility characteristics. MethodsIn 2017, a total of 27,047 participants aged 18–80 years were recruited from the baseline survey of the Cohort Study on Chronic Disease of Communities Natural Population in Beijing, Tianjin and Hebei (CHCN-BTH). The three year (2014–2016) average pollutant concentrations were assessed by a spatial statistical model for PM2.5 and air monitoring stations for PM10, SO2, NO2, O3 and CO. Residential proximity to a roadway was calculated by neighborhood analysis. Associations were estimated by two-level generalized linear mixed models. Stratified analyses related to demographic characteristics, health behaviors, and cardiometabolic risk factors were performed. Two-pollutant models were used to evaluate the possible role of single pollutants. ResultsWe detected significant associations of long-term air pollutant exposure with increased heart rate (HR), QRS and QTc, such that an interquartile range increase in PM2.5 was associated with 3.63% (95% CI: 3.07%, 4.19%), 1.21% (95% CI: 0.83%, 1.60%), and 0.13% (95% CI: 0.07%, 0.18%) changes in HR, QRS and QTc, respectively. Compared to the other pollutants, the estimates of PM2.5 remained the most stable across all two-pollutant models. Similarly, significant associations were observed between living closer to a major roadway and higher HR, QRS and QTc. Stratified analyses showed generally greater association estimates in older people, males, smokers, alcohol drinkers, and those with obesity, hypertension and diabetes. ConclusionsLong-term exposure to ambient air pollution was associated with cardiac conduction abnormalities in Chinese adults, especially in older people, males, smokers, alcohol drinkers, and those with cardiometabolic risk factors. PM2.5 may be the most stable pollutant to reflect the associations.

Temporal changes in short-term associations between cardiorespiratory emergency department visits and PM2.5 in Los Angeles, 2005 to 2016

BackgroundEmissions control programs targeting certain air pollution sources may alter PM2.5 composition, as well as the risk of adverse health outcomes associated with PM2.5. ObjectivesWe examined temporal changes in the risk of emergency department (ED) visits for cardiovascular diseases (CVDs) and asthma associated with short-term increases in ambient PM2.5 concentrations in Los Angeles, California. MethodsPoisson log-linear models with unconstrained distributed exposure lags were used to estimate the risk of CVD and asthma ED visits associated with short-term increases in daily PM2.5 concentrations, controlling for temporal and meteorological confounders. The models were run separately for three predefined time periods, which were selected based on the implementation of multiple emissions control programs (EARLY: 2005–2008; MIDDLE: 2009–2012; LATE: 2013–2016). Two-pollutant models with individual PM2.5 components and the remaining PM2.5 mass were also considered to assess the influence of changes in PM2.5 composition on changes in the risk of CVD and asthma ED visits associated with PM2.5 over time. ResultsThe relative risk of CVD ED visits associated with a 10 μg/m3 increase in 4-day PM2.5 concentration (lag 0–3) was higher in the LATE period (rate ratio = 1.020, 95% confidence interval = [1.010, 1.030]) compared to the EARLY period (1.003, [0.996, 1.010]). In contrast, for asthma, relative risk estimates were largest in the EARLY period (1.018, [1.006, 1.029]), but smaller in the following periods. Similar temporal differences in relative risk estimates for CVD and asthma were observed among different age and season groups. No single component was identified as an obvious contributor to the changing risk estimates over time, and some components exhibited different temporal patterns in risk estimates from PM2.5 total mass, such as a decreased risk of CVD ED visits associated with sulfate over time. ConclusionsTemporal changes in the risk of CVD and asthma ED visits associated with short-term increases in ambient PM2.5 concentrations were observed. These changes could be related to changes in PM2.5 composition (e.g., an increasing fraction of organic carbon and a decreasing fraction of sulfate in PM2.5). Other factors such as improvements in healthcare and differential exposure misclassification might also contribute to the changes.

The Gender-Based Differences in Vulnerability to Ambient Air Pollution and Cerebrovascular Disease Mortality: Evidences Based on 26781 Deaths.

The gender-based differences in the vulnerability to ambient air pollution have not been widely explored. This study aimed to investigate vulnerability differences to the short-term effects of PM2.5, PM10 and O3 between cerebrovascular diseases (CEVD) deaths of men and women. The general additive models (GAMs) and distributed lag non-linear models (DLNMs) were adopted, and both single-pollutant and two-pollutant models were performed to analyze the associations between ambient air pollution and daily CEVD deaths. Both models indicated that O3 was the most suspicious pollutant that could induce excess CEVD deaths, and women tended to be more vulnerable to O3. These results were confirmed by seasonal analysis, in which we also found both genders were more vulnerable to O3 in winter. The exposure-response relationships revealed that women were usually more vulnerable to ambient air pollution than men, and the exposure-response curves differed significantly between genders. Our findings suggested that more attention should be paid on the adverse effects of ambient O3, and the protection of women CEVD population against air pollution should be emphasized.

Effect of Ambient Air Pollution on Hospital Readmissions among the Pediatric Asthma Patient Population in South Texas: A Case-Crossover Study.

Few studies have evaluated the association between ambient air pollution and hospital readmissions among children with asthma, especially in low-income communities. This study examined the short-term effects of ambient air pollutants on hospital readmissions for pediatric asthma in South Texas. A time-stratified case-crossover study was conducted using the hospitalization data from a children’s hospital and the air pollution data, including particulate matter 2.5 (PM2.5) and ozone concentrations, from the Centers for Disease Control and Prevention between 2010 and 2014. A conditional logistic regression analysis was performed to investigate the association between ambient air pollution and hospital readmissions, controlling for outdoor temperature. We identified 111 pediatric asthma patients readmitted to the hospital between 2010 and 2014. The single-pollutant models showed that PM2.5 concentration had a significant positive effect on risk for hospital readmissions (OR = 1.082, 95% CI = 1.008–1.162, p = 0.030). In the two-pollutant models, the increased risk of pediatric readmissions for asthma was significantly associated with both elevated ozone (OR = 1.023, 95% CI = 1.001–1.045, p = 0.042) and PM2.5 concentrations (OR = 1.080, 95% CI = 1.005–1.161, p = 0.036). The effects of ambient air pollutants on hospital readmissions varied by age and season. Our findings suggest that short-term (4 days) exposure to air pollutants might increase the risk of preventable hospital readmissions for pediatric asthma patients.

Short-term exposure to air pollution and occurrence of emergency stroke in Chongqing, China.

This study aimed to study the relationship between air pollution and stroke (especially emergency stroke) in different regions and determine which air pollutant is the most significantly associated with stroke. The number of patients with emergency stroke, air pollutant data and related meteorological indicators were collected from December 2013 to May 2018 for large comprehensive hospitals in Chongqing. The generalized additive model was used to analyse the relationship between air pollution and emergency stroke. After analysis and adjusting for meteorological indicators and day-of-the-week effects, in the one-pollutant model, every 10μg/m3 increase in ozone(O3) was associated with a 2.482% (95% CI 1.044%, 3.919%) change in emergency strokes within lag0. For males, every 10μg/m3 increase of O3 contributed to a 0.77% percent greater change compared with females. For the group younger than 60years, we observed a 1.14% increase in risk with every 10μg/m3 increase in O3. The group with pre-existing hypertension had a 0.26% higher risk than the group with no pre-existing hypertension with every 10μg/m3 increase in O3. In two-pollutant model, when O3 was combined with a 10μg/m3 increase of NO2, it increased the most significant risk of emergency stroke by 0.22%. These findings suggest that short-term exposure to O3 within 0days is associated with emergency outpatient strokes, and younger people (age < 60years) males and people with hypertension are more sensitive than older people, females and people without pre-existing hypertension.

Association of air pollution with outpatient visits for respiratory diseases of children in an ex-heavily polluted Northwestern city, China

BackgroundA great number of studies have confirmed that children are a particularly vulnerable population to air pollution.MethodsIn the present study, 332,337 outpatient visits of 15 hospitals for respiratory diseases among children (0–13 years), as well as the simultaneous meteorological and air pollution data, were obtained from 2014 to 2016 in Lanzhou, China. The generalized additive model was used to examine the effects of air pollutants on children’s respiratory outpatient visits, including the stratified analysis of age, gender and season.ResultsWe found that PM2.5, NO2 and SO2 were significantly associated with the increased total respiratory outpatient visits. The increments of total respiratory outpatient visits were the highest in lag 05 for NO2 and SO2, a 10 μg/m3 increase in NO2 and SO2 was associated with a 2.50% (95% CI: 1.54, 3.48%) and 3.50% (95% CI: 1.51, 5.53%) increase in total respiratory outpatient visits, respectively. Those associations remained stable in two-pollutant models. Through stratification analysis, all air pollutants other than PM10 were significantly positive associated with the outpatients of bronchitis and upper respiratory tract infection. Besides, both NO2 and SO2 were positively related to the pneumonia outpatient visits. PM2.5 and SO2 were significantly related to the outpatient visits of other respiratory diseases, while only NO2 was positively associated with the asthma outpatients. We found these associations were stronger in girls than in boys, particularly in younger (0–3 years) children. Interestingly, season stratification analysis indicated that these associations were stronger in the cold season than in the transition or the hot season for PM10, PM2.5 and SO2.ConclusionsOur results indicate that the air pollution exposure may account for the increased risk of outpatient visits for respiratory diseases among children in Lanzhou, particularly for younger children and in the cold season.

Association between Ambient Air Pollution and Hospital Length of Stay among Children with Asthma in South Texas.

Although hospital length of stay (LOS) has been identified as a proxy measure of healthcare expenditures in the United States, there are limited studies investigating the potentially important association between outdoor air pollution and LOS for pediatric asthma. This study aims to examine the effect of ambient air pollution on LOS among children with asthma in South Texas. It included retrospective data on 711 children aged 5–18 years old admitted for asthma to a pediatric tertiary care hospital in South Texas between 2010 and 2014. Air pollution data including particulate matter (PM2.5) and ozone were collected from the U.S. Centers for Disease Control and Prevention. The multivariate binomial logistic regression analyses were performed to determine the association between each air pollutant and LOS, controlling for confounders. The regression models showed the increased ozone level was significantly associated with prolonged LOS in the single- and two-pollutant models (p < 0.05). Furthermore, in the age-stratified models, PM2.5 was positively associated with LOS among children aged 5–11 years old (p < 0.05). In conclusion, this study revealed a concerning association between ambient air pollution and LOS for pediatric asthma in South Texas.

Depression and anxiety with exposure to ozone and particulate matter: An epidemiological claims data analysis

Depression and anxiety have complex etiologies and are associated with a significant burden of disease. Although air pollution has been hypothesized as a possible risk factor of these disorders, the associations are still under-investigated. We aimed to analyze associations between long-term exposure to ambient ozone and particulate matter with diameter <10μm (PM10) and diagnoses of depression and anxiety in a general population. We utilized data from a large statutory health insurance company from Saxony, Germany. Information on outpatient clinical diagnoses of depression and anxiety was available for the years 2005-2014. We assigned ambient ozone and PM10 estimates to residential districts of 1.13 million individuals aged 16 and older. Depression and anxiety were defined as diagnoses counts. Associations with depression and anxiety were assessed using adjusted generalized estimating equations models. In the ten-year study period, the observed prevalences of depression and anxiety were 7.40% and 3.82%, respectively. In the two-pollutant model, 10 more days with a maximum 8-h average ozone concentration exceeding 120μg/m³ resulted in a relative risk (RR) of 1.010 with 95% confidence interval (CI) (1.005, 1.014) for depression and an RR of 1.007 (95% CI (1.000, 1.014)) for anxiety. The effect estimates of PM10 for depression and anxiety were 1.180 (95% CI (1.160, 1.201)) and 1.176 (95% CI (1.148, 1.205)) per 10μg/m³ increase in PM10 concentration, respectively. Age, sex, and access to healthcare of the individual were also associated with the diagnosis of the disorders. The associations were consistent across one- and two-pollutant models. Our findings indicate that increased levels of ambient ozone and PM10 may elevate the risk of a depression or anxiety diagnosis in the general population. However, given the lack of data on individual air pollutant exposure and socioeconomic status, our results should be interpreted with caution. Further well-designed epidemiological studies should replicate our findings.

Short-term exposure to coarse particulate matter and outpatient visits for cardiopulmonary disease in a Chinese city.

Limited studies have been conducted to evaluate the short-term relationships between exposure to coarse particulate matter (PM2.5-10) and outpatient visits in China. We designed this time-series analysis in a Chinese city Yancheng, to explore the relationship of PM2.5-10 with outpatient visits for cardiopulmonary diseases. The study period was from 2013 to 2015. A typical generalized additive model was used. We explored the lag patterns by building a series of lag of exposure. We also built two-pollutant models to ascertain the independence of PM2.5-10. Stratified analyses were applied to compare the season-specific associations. Finally, we pooled the concentration-response (C-R) curves for PM2.5-10 and outpatient visits. We recorded a daily average of 85 and 43 outpatient visits for cardiovascular and respiratory causes, respectively. PM2.5-10 exposures of lag 05 day yielded the best estimates for both outcomes. Per 10-μg/m3 increase in PM2.5-10, there was a 1.69% (95% confidence interval [CI]: 0.68%-2.72%) increase in outpatient visits for respiratory causes, and a 0.85% (95% CI: 0.13%-1.57%) increase for cardiovascular causes. The association kept robust after adjusting for PM2.5 and O3, and there were larger associations in warm seasons. The C-R curves had a larger slope for respiratory diseases in relatively lower concentrations (<30μg/m3), and PM2.5-10 was positively associated with cardiovascular diseases in higher concentrations (>30μg/m3). This study indicated significant associations of PM2.5-10 with cardiopulmonary outpatient visit. Such results may be used for health risk assessment and policy making for particulate air pollution control.

Association of ambient non-methane hydrocarbons exposure with respiratory hospitalizations: A time series study in Taipei, Taiwan

Ambient hydrocarbons are important precursors of ground-level ozone and secondary organic aerosol formation. However, few studies have assessed the health impact of airborne hydrocarbons. We conducted this time series ecological study to evaluate the association of short-term airborne hydrocarbons exposure with hospital admissions for respiratory diseases, while controlling for co-exposure to criteria pollutants. Taipei air pollution and weather data for the period spanning from January 2010 to December 2017 were obtained from Taiwan Air Quality Monitoring Network. Subsequently, daily pollutant concentrations were linked with daily hospital admission counts for respiratory diseases into a time series data frame. The standard generalized additive Poisson model adjusted for temporal trends, seasonal variations, weather conditions, and calendar effects, was applied to examine the short-term associations of acute airborne hydrocarbon exposure with respiratory hospital admissions. Next, the robustness of the associations was tested using two-pollutant models with further adjustment for fine particulate matter (PM2.5) and gaseous pollutants. The results demonstrated that an interquartile range increase in non-methane hydrocarbon (NMHC) exposure on lag0 day (0.15 ppm) was associated with a 0.86% (95% confidence interval: 0.37%–1.36%), 2.06% (0.77%–3.38%), and 1.25% (0.31%–2.20%) increment in all-respiratory-disease-, asthma-, and chronic-obstructive-pulmonary-disease-linked hospital admissions, respectively. The associations were robust with further adjustment for co-exposure to PM2.5 and ozone. The acute effect estimate of methane on each respiratory category was sensitive to the co-pollutant adjustment and lost statistical significance in the two-pollutant models. In conclusion, we confirmed that airborne NMHC exposure increased the risk of respiratory-disease-related hospital admissions in Taipei; this information may aid in the regulation of hydrocarbon pollution.

The association between ambient NO2 and PM2.5 with the respiratory health of school children residing in informal settlements: A prospective cohort study

BackgroundNo previous epidemiological study has investigated the combined association of long-term ambient nitrogen dioxide (NO2) and particulate matter of diameter size-2.5 (PM2.5) exposure with asthma outcomes among schoolchildren in Africa. ObjectivesThis study investigated the independent and co-pollutant association of long-term exposures to ambient air pollutants on asthma-associated outcomes in a cohort of schoolchildren in the Western Cape Province of South Africa. MethodsA total of 590 grade-4 schoolchildren residing in four informal settlements were studied. Spirometry and fractional exhaled nitric-oxide (FeNO) measurements were conducted, including a standardized questionnaire administered to caregivers at baseline and 12-months follow-up. Annual NO2 and PM2.5 levels were estimated for each child's home using land-use regression modelling. Single- and two-pollutant models were constructed to assess the independent and co-pollutant association of both air pollutants (NO2 and PM2.5) on new cases of asthma-associated outcomes adjusting-for host characteristics, indoor exposures and study area. ResultsThe annual average concentration of PM2.5 and NO2 were 10.01μg/m3 and 16.62μg/m3 respectively, across the four study areas, and were below the local Standards of 20μg/m3 and 40μg/m3, for both pollutants, respectively. In the two-pollutant-adjusted models, an interquartile range (IQR) increase of 14.2μg/m3 in NO2 was associated with an increased risk of new onset of ocular-nasal symptoms (adjusted odds ratio–aOR: 1.63, 95% CI: 1.01–2.60), wheezing (aOR: 3.57, 95% CI: 1.18–10.92), more than two or more asthma symptom score (aOR: 1.71, 95% CI: 1.02–2.86), and airway inflammation defined as FeNO > 35 ppb (aOR: 3.10, 95% CI: 1.10–8.71), independent of PM2.5 exposures. ConclusionThis study provided evidence that ambient NO2 levels below local standards and international guidelines, independent of PM2.5 exposure, increases new cases of asthma-associated outcomes after 12-months.