Two-pollutant Models Research Articles

Association between ambient air pollution and mortality from chronic obstructive pulmonary disease in Wuhan, China: a population-based time-series study.

Evidence on the short-term effects of ambient air pollution on chronic obstructive pulmonary disease (COPD) mortality is still not conclusive. The aim of this study was to investigate the relationships between them in Wuhan China. Daily death numbers, concentrations of air pollutants (PM2.5, PM10, SO2, NO2, and O3), and meteorological characteristics in Wuhan from January 1, 2014, to December 31, 2019, were collected. Time-series analysis using generalized additive model was applied. The results showed that a total of 16,150 deaths (7.37 deaths per day) from COPD were observed. The daily average concentrations of PM2.5, PM10, SO2, NO2, and O3 were 59.03, 90.48, 12.91, 48.84, and 91.77 μg/m3, respectively. In single pollutant model, for every increase of 10 μg/m3 in PM10, SO2, and NO2 levels, COPD mortality increased by 0.583% (95% CI: 0.055–1.113%), 4.299% (95% CI: 0.978–7.729%), and 1.816% (95% CI: 0.515–3.313%) at lag03, respectively. No significant associations were found for PM2.5 and O3. Subgroup analysis demonstrated that females were more susceptible to PM2.5, PM10, SO2, and NO2. The concentrations of PM10, SO2, and NO2 were significantly associated with COPD mortality for older adults. The effects of PM2.5 and O3 on COPD mortality were higher in warm period. In two-pollutant models, the significantly positive associations between SO2 and NO2 and COPD mortality remained after adjusting for PM2.5 or O3. In conclusions, short-term exposure to PM10, SO2, and NO2 are significantly associated with a higher risk of COPD mortality. Female or elderly are more susceptible to air pollution. It is urgent to implement the environmental protection policy.Supplementary InformationThe online version contains supplementary material available at 10.1007/s11356-021-13180-6.

Associations between air pollutant exposure and renal function: A prospective study of older adults without chronic kidney disease.

We used real-world exposure scenarios to evaluate the effect of six ambient air pollutant (PM2.5, PM10, NO2, SO2, CO, and O3) exposure on renal function among older adults without chronic kidney disease (CKD). We recruited 169 older adults without CKD in Beijing, China, for a longitudinal study from 2016 to 2018. The Modification of Diet in Renal Disease (MDRD) and the Chronic Kidney Disease Epidemiology Collaboration (EPI) equations were employed to derive the estimated glomerular filtration rate (eGFR). A linear mixed-effects model with random intercepts for participants was employed to determine the effects of air pollutants on renal function evaluated on the basis of eGFR and urinary albumin/creatinine ratio at different exposure windows (1-, 2-, 3-, 5-, 7-, 14-, 28-, 45-, and 60-days moving averages). An interquartile range (IQR) increase in NO2 for was associated with significant decreases of in eGFR (MDRD equation) [percentage changes: -4.49 (95% confidence interval: -8.44,-0.37),-5.51 (-10.43,-0.33),-2.26 (-4.38,-0.08),-3.71 (-6.67,-0.65),-5.44 (-9.58,-1.11),-5.50 (-10.24,-0.51),-6.15 (-10.73,-1.33), and-6.34 (-11.17,-1.25) for 1-, 2-, 5-, 7-, 14-, 28-, 45-, and 60-days moving averages, respectively] and in eGFR (EPI equation) [percentage changes: -5.04 (-7.09,-2.94),-6.25 (-8.81,-3.62),-5.16 (-7.34,-2.92),-5.10 (-7.85,-2.28),-5.83 (-8.23,-3.36),-6.04 (-8.55,-3.47) for 1-, 2-, 14-, 28-, 45-, and 60-days moving averages, respectively]. In two-pollutant model, only the association of NO2 exposure with eGFR remained robust after adjustment for any other pollutant. This association was stronger for individuals with hypertension for the EPI equation or BMI <25kg/m2 for the MDRD equation at lags 1 and 1-2. Our findings suggest that NO2 exposure is associated with eGFR reduction among older adults without CKD for short (1-, 2-days) and medium (14-, 28-, 45-, 60-days) term exposure periods; thus, NO2 exposure may contribute to renal impairment.

Ultrafine particulate air pollution and pediatric emergency-department visits for main respiratory diseases in Shanghai, China

BackgroundFew studies have explored the short-term effects of ultrafine particles (UFPs, particles < 0.1 μm) air pollution on the exacerbations of pediatric respiratory diseases. ObjectivesWe aimed to evaluate short-term association between UFP and emergency-department visits (EDVs) for main pediatric respiratory diseases. MethodsWe collected daily data on UFP and pediatric EDVs for main respiratory diseases [asthma, pneumonia, bronchitis and upper respiratory tract infections (URTI)] from 66 hospitals in Shanghai, China from 2016 to 2018. Generalized additive models combined with polynomial distributed lag models were applied to explore the associations between UFP level and pediatric EDVs for respiratory diseases. We fitted two-pollutant models with criteria air pollutants and performed stratified analyses by gender and age. ResultsUFP was associated with increased EDVs for all respiratory diseases in cumulative lags up to 2 d and 3 d. The greatest risk was found at cumulative lags (0–2 d) for all respiratory diseases. At cumulative lags (0–2 d), an interquartile range increase in concentrations of UFP (1800 particles/cm3) was associated with relative risks of EDVs due to asthma [1.35, 95% confidence interval (CI): 1.14–1.59], pneumonia (1.20, 95% CI: 1.04–1.38), bronchitis (1.17, 95% CI: 1.03–1.33) and URTI (1.14, 95% CI: 1.02–1.28). These associations were almost unchanged when controlling for criteria air pollutants, and there was no threshold below which the associations were not present. There were stronger associations in children aged 0–13 years. ConclusionsShort-term exposure to UFP may independently increase the risks of EDVs for asthma, pneumonia, bronchitis and URTI exacerbations among children.

Acute effects of ambient air pollution on clinic visits of college students for upper respiratory tract infection in Wuhan, China.

Ambient air pollutants have been linked to adverse health outcomes, but evidence is still relatively rare in college students. Upper respiratory tract infection (URTI) is a common disease of respiratory system among college students. In this study, we assess the acute effect of air pollution on clinic visits of college students for URTI in Wuhan, China. Data on clinic visits due to URTI were collected from Wuhan University Hospital, meteorological factors (including daily temperature and relative humidity) provided by Wuhan Meteorological Bureau, and air pollutants by Wuhan Environmental Protection Bureau. In the presentstudy, generalized additive model with a quasi-Poisson distribution link function was used to examine the association between ambient air pollutants (fine particulate matter (PM2.5), particulate matter (PM10), sulfur dioxide (SO2), nitrogen dioxide (NO2), and ozone (O3)) and the daily number of clinic visits of college students for URTI at Wuhan University Hospital in Wuhan, China. In the meantime, the model was adjusted for the confounding effects of long-term trends, seasonality, day of the week, public holidays, vacation, and meteorological factors. The best degrees of free in model were selected based on AIC (Akaike Information Criteria). The effect modification by gender was also examined. A total of 44,499 cases with principal diagnosis of URTI were included from January 1, 2016, to December 31, 2018. In single-pollutant models, the largest increment of URTI visits were found at lag 0 day in single-day lags, and the effect values in cumulative lags were greater than those in single-day lags. PM2.5 (0.74% (95%CI: 0.05, 1.44)) at lag 0 day, PM10 (0.61% (95%CI: 0.12, 1.11)) and O3 (1.01% (95%CI: 0.24, 1.79)) at lag 0-1 days, and SO2 (9.18% (95%CI: 3.27, 15.42)) and NO2 (3.40% (95% CI:1.64, 5.19)) at lag 0-3 days were observed to be strongly and significantly associated with clinic visits for URTI. PM10 and NO2 were almost still significantly associated with URTI after controlling for the other pollutants in our two-pollutant models, where the effect value of SO2 after inclusion of O3 appeared to be the largest and the effects of NO2 were also obvious compared with the other pollutants. Subgroups analysis demonstrated that males were more vulnerable to PM10 and O3, while females seemed more vulnerable to exposure to SO2 and NO2. This study implied that short-term exposure to ambient air pollution was associated with increased risk of URTI among college students at Wuhan University Hospital in Wuhan, China. And gaseous pollutants had more negative health impact than solid pollutants. SO2 and NO2 were the major air pollutants affecting the daily number of clinic visits on URTI, to which females seemed more vulnerable than males.

Association of particulate matter with autoimmune rheumatic diseases among adults in South Korea.

ObjectiveThe primary objective of this study was to investigate adverse effects of ambient particulate matter of various sizes on the incidence of the prevalent autoimmune rheumatic diseases (AIRDs): RA, AS and SLE.MethodsWe investigated 230 034 participants in three metropolitan cities of South Korea from the National Health Insurance Service–National Sample Cohort (NHIS-NSC). Starting from January 2010, subjects were followed up until the first event of prevalent AIRDs, death, or December 2013. The 2008–2009 respective averages of particulate matter2.5 (<2.5 μm) and particulate mattercoarse (2.5 μm to 10 μm) were linked with participants’ administrative district codes. Adjusted hazard ratios (aHRs) and 95% CIs were estimated using Cox regression analysis in one- and two-pollutant models.ResultsAdjusted for age, sex, region, and household income, in the two-pollutant model, RA incidence was positively associated with the 10 μg/m³ increment of particulate matter2.5 (aHR = 1.74, 95% CI: 1.06, 2.86), but not with particulate mattercoarse (aHR = 1.27, 95% CI: 0.87, 1.85). In the one-pollutant model, the elevated incidence rate of RA was slightly attenuated (particulate matter2.5 aHR = 1.61, 95% CI: 0.99, 2.61; particulate mattercoarse aHR = 1.13, 95% CI: 0.80, 1.61), with marginal statistical significance for particulate matter2.5. The RA incidence was also higher in the 4th quartile group of particulate matter2.5 compared with the first quartile group (aHR = 1.83, 95% CI: 1.07, 3.11). Adverse effects from particulate matter were not found for AS or SLE in either the one- or two-pollutant models.ConclusionThe important components of particulate matter10 associated with RA incidence were the fine fractions (particulate matter2.5); no positive association was found between particulate matter and AS or SLE.

Associations between PM2.5 metal components and QT interval length in the Normative Aging Study

BackgroundSeveral studies have found associations between increases in QT interval length, a marker of cardiac electrical instability, and short-term fine particulate matter (PM2.5) exposures. To our knowledge, this is the first study to examine the association between specific PM2.5 metal components and QT interval length. MethodsWe measured heart-rate corrected QT interval (QTc) duration among 630 participants in the Normative Aging Study (NAS) based in Eastern Massachusetts between 2000 and 2011. We utilized time-varying linear mixed-effects regressions with a random intercept for each participant to analyze associations between QTc interval and moving averages (0–7 day moving averages) of 24-h mean concentrations of PM2.5 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 × 1 km grid cell from a previously validated prediction model and other covariates. Bayesian kernel machine regression (BKMR) was utilized to assess the overall joint effect of the PM2.5 metal components. ResultsWe found consistent results with higher lead (Pb) associated with significant higher QTc intervals for both the multi-pollutant and the two pollutant (PM2.5 mass and a PM2.5 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 a 7.91 ms (95% CI: 3.63, 12.18) 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 an 8.50 ms (95% CI: 4.59, 12.41) increase in QTc interval. We found that 4-day moving average of copper has a negative association with QTc interval when compared to the other PM2.5 metal components. In the multi-pollutant model, each 1.81 ng/m3 increase in daily copper levels for a 4-day moving average was associated with an −3.89 ms (95% CI: -6.98, −0.79) increase in QTc interval. Copper's essential function inside the human body could mediate its cardiotoxicity on cardiac conductivity and explain why we found that copper in comparison to the other metals was less harmful for QTc interval. ConclusionsExposure to metals contained in PM2.5 are associated with acute changes in ventricular repolarization as indicated by QT interval characteristics.

Association between fine particulate matter and heart failure hospitalizations: a time-series analysis in Yancheng, China.

Heart failure (HF) is a global public health problem of increasing importance. The association between acute exposure to air pollution and HF has been well established in developed countries, but little evidence is available in developing countries where air pollution levels are much higher. To explore the associations between PM2.5 and HF hospitalizations in Yancheng, China. In this time-series study, daily HF hospitalizations admitted in three major hospitals in Yancheng from May 1, 2015 to Apr 30, 2020 were collected. We used a generalized additive model with quasi-Poisson regression to investigate the association between PM2.5 and HF hospitalizations. The robustness of the associations was tested using two-pollutant models, and we examined the potential effect modification by age, gender, and season via stratification analyses. Lastly, we pooled the concentration-response curves. A total of 10,466 HF hospitalizations were recorded, with a daily average of 6 cases. We observed the most robust estimates on lag 0 day, and the associated increment in HF was 1.28% (95% CI 0.45%, 2.11%) for a 10-μg/m3 increase of PM2.5. The association remained after adjustment of O3, but not for NO2, CO, and SO2. The PM2.5-HF associations were positive in females, patients aged ≥ 65 years, and in cold season. The C-R relationship curve was generally increasing below 30 μg/m3. This study provided evidence on the association of PM2.5 with acute exacerbation of chronic heart failure, which may benefit future prevention strategy and policymaking.

Ambient air pollution and obesity in school-aged children and adolescents: A multicenter study in China

BackgroundEnvironmental factors such as air pollution may contribute to the development of childhood obesity. However, current epidemiological evidence is limited and inconsistent. ObjectiveWe investigated the associations between long-term air pollution exposure and obesity in a large population of Chinese children and adolescents. MethodsA total of 44,718 children and adolescents (50.5% boys) aged 7 to 18 years were recruited from seven provinces/municipalities in China. Body mass index (BMI), waist circumference, waist-to-height ratio (WHtR) and the prevalence of general and central obesity were measured. Satellite-based spatial-temporal models were used to estimate ambient concentrations of particulate matter with aerodynamic diameter < 1.0 μm (PM1), <2.5 μm (PM2.5), <10.0 μm (PM10) and nitrogen dioxide (NO2). We used mixed-effects linear and logistic regression models to examine the associations between air pollution exposure and body weight measures. ResultsExposure to PM1, PM2.5, PM10 and NO2 was associated with increased BMI Z-score, waist circumference and WHtR, and higher prevalence of both general and central obesity. Generally, stronger associations were observed for particles, especially PM1 and PM2.5, than for NO2. Also, the associations of particles were generally more stable in two-pollutant models. Overall, the associations were more pronounced in boys than in girls except for general obesity. ConclusionsLong-term exposure to air pollution was associated with increased body weight and higher prevalence of obesity in children and adolescents, suggesting potential obesogenic effects of air pollution.

The association between gaseous pollutants and non-accidental mortality: a time series study.

To evaluate the effects of gaseous pollutants (SO2, NO2) on non-accidental mortality of residents in Hefei city, we collected non-accidental deaths, air pollutants and meteorological data of Hefei city from 2014 to 2017. After controlling confounding factors with Poisson generalized additive model, we analyzed the relationship between air pollutants and non-accidental mortality and used subgroup analysis to identify susceptible groups. The number of non-accidental deaths during the study period was 42,116, with an average of 28.83 per day. The average concentrations of SO2 and NO2 were 16.08μg/m3 and 39.10μg/m3, respectively. In the single-pollutant model, every 10μg/m3 increase in SO2 and NO2 concentrations was significantly associated with non-accidental mortality, and there was a significant lag effect. SO2 increased the risk of non-accidental death by 4.93% (95% CI: 1.94% ~ 8.00%) at lag0-3. In addition, male, the elderly, non-elderly and low-education people were more susceptible (P < 0.05). NO2 increased the risk of non-accidental death by 2.11% (95% CI: 1.18% ~ 3.05%) at lag0-1 and had an effect on all subgroups (P < 0.05). For every 10μg/m3 increase in SO2 and NO2, the two-pollutant model showed that the risk of non-accidental death, respectively, increased by 3.34% (95% CI: 0.29% ~ 6.50%) and 1.82% (95% CI: 0.85% ~ 2.79%), suggesting that the effect was weakened. Our study suggested that SO2 and NO2 were associated with non-accidental mortality, and there were lag effects. Therefore, environmental management should be strengthened and health protection education should be carried out for different groups.

Short-Term Exposure to Fine Particulate Matter and Hospitalizations for Acute Lower Respiratory Infection in Korean Children: A Time-Series Study in Seven Metropolitan Cities.

Although several studies have evaluated the association between fine particulate matter (PM2.5) and acute lower respiratory infection (ALRI) in children, their results were inconsistent Therefore, we aimed to evaluate the association between short-term exposure to PM2.5 and ALRI hospitalizations in children (0–5 years) living in seven metropolitan cities of Korea. The ALRI hospitalization data of children living in seven metropolitan cities of Korea from 2008 to 2016 was acquired from a customized database constructed based on National Health Insurance data. The time-series data in a generalized additive model were used to evaluate the relationship between ALRI hospitalization and 7-day moving average PM2.5 exposure after adjusting for apparent temperature, day of the week, and time trends. We performed a meta-analysis using a two-stage design method. The estimates for each city were pooled to generate an average estimate of the associations. The average PM2.5 concentration in 7 metropolitan cities was 29.0 μg/m3 and a total of 713,588 ALRI hospitalizations were observed during the 9-year study period. A strong linear association was observed between PM2.5 and ALRI hospitalization. A 10 μg/m3 increase in the 7-day moving average of PM2.5 was associated with a 1.20% (95% CI: 0.71, 1.71) increase in ALRI hospitalization. While we found similar estimates in a stratified analysis by sex, we observed stronger estimates of the association in the warm season (1.71%, 95% CI: 0.94, 2.48) compared to the cold season (0.31%, 95% CI: −0.51, 1.13). In the two-pollutant models, the PM2.5 effect adjusted by SO2 was attenuated more than in the single pollutant model. Our results suggest a positive association between PM2.5 exposure and ALRI hospitalizations in Korean children, particularly in the warm season. The children need to refrain from going out on days when PM2.5 is high.

Acute respiratory response to individual particle exposure (PM1.0, PM2.5 and PM10) in the elderly with and without chronic respiratory diseases.

Limited data were on the acute respiratory responses in the elderly in response to personal exposure of particulate matter (PM). In order to evaluate the changes of airway inflammation and pulmonary functions in the elderly in response to individual exposure of particles (PM1.0, PM2.5 and PM10), we analyzed 43 elderly subjects with either asthma, chronic obstructive pulmonary disease (COPD) or Asthma COPD Overlap (ACO) and 40 age-matched subjects without asthma nor COPD in an urban community in Shanghai, China. Data were collected at the baseline and in 6 follow-ups from August 2016 to December 2018, once every 3 months except for the last twice with a 6-month interval. In each follow-up, pulmonary functions, fractional exhaled nitric oxide (FeNO), 7-day continuous personal exposure to airborne particles were measured. Multivariate linear mixed effect regression models were applied to investigate the quantitative changes of pulmonary functions and FeNO in two respective groups. The results showed that on average 4.7 follow-up visits were completed in each participant. In subjects with CRDs, an inter-quartile range (IQR) increase of personal exposure to PM1.0, PM2.5 and PM10 was significantly associated with an average increase of FeNO(Lag1) of 6.7ppb (95%CI 1.2, 9.9ppb), 6.2ppb (95%CI 1.5, 12.0ppb) and 5.6ppb (95%CI 1.5, 11.0ppb), respectively, and an average decrease of FEV1(Lag2) of-3.6L (95%CI -6.0,-1.1L),-3.6L (95%CI -6.4,-0.8L) and-3.2L (95%CI -5.8,-0.6L), respectively, in the single-pollutant model. These associations remained consistent in the two-pollutant models adjusting for gaseous air pollutants. Stratified analysis showed that subjects with lower BMI, females and non-allergies were more sensitive to particle exposure. No robust significant effects were observed in the subjects without CRDs. Our study provided data on the susceptibility of the elderly with CRDs to particle exposure of PM1.0 and PM2.5, and the modification effects by BMI, gender and history of allergies.

Long-term exposure to low-level air pollution and incidence of asthma: the ELAPSE project

Long-term exposure to ambient air pollution has been linked to childhood-onset asthma, while evidence is still insufficient. Within the multicentre project "Effects of Low-Level Air Pollution: A Study in Europe" (ELAPSE), we examined the associations of long-term exposures to particulate matter with diameter<2.5 µm (PM2.5), nitrogen dioxide (NO2), and black carbon (BC) with asthma incidence in adults. We pooled data from three cohorts in Denmark and Sweden with information on asthma hospital diagnoses. The average concentrations of air pollutants in 2010 were modelled by hybrid land use regression models at participants' baseline residential addresses. Associations of air pollution exposures with asthma incidence were explored with Cox proportional hazard models, adjusting for potential confounders. Of 98 326 participants, 1965 developed asthma during a 16.6 years mean follow-up. We observed associations in fully adjusted models with hazard ratios and 95% confidence intervals of 1.22 (1.04-1.43) per 5 μg·m-3 for PM2.5, 1.17 (1.10-1.25) per 10 µg·m-3 for NO2, and 1.15 (1.08-1.23) per 0.5 10-5 m-1 for BC. Hazard ratios were larger in cohort subsets with exposure levels below the EU and US limit values and possibly WHO guidelines for PM2.5 and NO2. NO2 and BC estimates remained unchanged in two-pollutant models with PM2.5, whereas PM2.5 estimates were attenuated to unity. The concentration response curves showed no evidence of a threshold. Long-term exposure to air pollution, especially from fossil fuel combustion sources such as motorised traffic, was associated with adult-onset asthma, even at levels below the current limit values.

Change in risk of hospital admissions for ischemic heart disease after the implementation of a mass rapid transit system in Taipei

ABSTRACT Numerous epidemiologic studies demonstrated an association between an increase in levels of fine particles (particulate matter less than 2.5 um in diameter, PM2.5) and elevation in the number of hospital admissions for cardiovascular diseases. Air pollution levels including PM2.5 clearly decreased in Taipei City after the mass rapid transit (MRT) system began operations in 1996. The aim of this study was to investigate the extent of changes in the risk of daily hospital admissions for ischemic heart disease (IHD) over a 17-year period after the installation of a MRT system in Taipei. The full study was divided into Period 1 (1997–2000), total track length 65.1 km; Period 2 (2001–2008), total track length 75.8 km; and Period 3 (2009–2013), total track length 121.3 km. A time-stratified case-crossover analysis was conducted to estimate relative risk (RR) of hospital admissions for IHD for each 10 ug/m3 increase in PM2.5 for different periods. On cool days, the associated RR of IHD for Period 3 was consistently lower compared to period 2 in both our single- and two-pollutant models. However, the daily risk for IHD admissions was found to be significantly higher for period 3 compared to period 2 in our single-pollutant model and in our two-pollutant models (PM2.5+ SO2) on warm days. The basis for this difference is unknown. Data suggests that an MRT system may provide substantial health benefits, a finding that may be helpful to urban communities, urban planners, and public health specialists.

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

BackgroundAir pollution has been suggested as a risk factor for chronic obstructive pulmonary disease (COPD), but evidence is sparse and inconsistent. ObjectivesWe examined the association between long-term exposure to low-level air pollution and COPD incidence. MethodsWithin 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 (PM2.5), 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. ResultsOf 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 PM2.5, 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 PM2.5 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 PM2.5, whereas the HR for PM2.5 was attenuated to unity with NO2 or BC. ConclusionsLong-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 association between air pollution and hospitalization for patients with systemic lupus erythematosus in Chile: A daily time series analysis

Genetic and environmental factors are thought to influence the activity of systemic lupus erythematosus (SLE), but relatively little is known about the effects of ambient air pollution. Using pollution data from air monitoring stations in the urban centers in Santiago Chile, along with daily patient hospitalization data from 2001 to 2012, an association between ambient air pollution and daily hospital admissions for SLE was tested using generalized linear models. Averaged over all regions pollutant mean 24 h concentrations were: 0.96 ppm carbon monoxide (CO), 64 ppb ozone (O3), 43 ppb nitrogen dioxide (NO2), 9 ppb sulphur dioxide (SO2), 29 μg/m3 particulate matter ≤ 2.5 μm in mean aerodynamic diameter (PM2.5), and 67 μg/m3 particulate matter ≤ 10 μm in diameter (PM10). The relative risk estimates in single pollutant models for an interquartile range (IQR) increase in pollutant were: RR = 1.34 (95% CI: 1.06–1.83) for SO2, RR = 1.60 (95% CI: 1.15–2.24) for CO, and RR = 1.41 (95% CI: 1.14–1.86) for PM2.5. In two-pollutant models, the significance of SO2 and PM2.5 persisted despite adjustments for each of the other measured pollutants. These findings suggest that acute increases in air pollution increase the risk of hospitalization with a primary diagnosis of SLE.

Association between past exposure to fine particulate matter (PM2.5) and peptic ulcer: A cross-sectional study in eastern China

Ambient fine particulate matter (particle diameter < 2.5 μm, or PM2.5) is a major public health concern in China. Exposure to PM2.5 has been associated with a wide range of adverse health outcomes. The current study aimed to estimate the association between exposure to PM2.5 and the risk of peptic ulcer diseases (PUDs). We conducted a hospital-based cross-sectional study of seven major cities in Zhejiang Province, China (combined population > 57 million people), which included a total of 647,092 subjects who underwent gastroscopy examination (86,852 subjects were diagnosed with PUDs) recorded in 13 large hospitals from 2014 to 2018. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to evaluate the relationship between PM2.5 and PUDs, including duodenal ulcers (DUs) and gastric ulcers (GUs). The overall estimated OR (95% CI) associated with every 10-μg/m3 increase in the 1-month average PM2.5 before the detection of PUDs was 1.050 (95% CI: 1.038, 1.063). The association between PM2.5 concentration and the prevalence of PUDs tended to be attenuated but remained significant when considering different exposure periods (OR = 1.030, 95% CI = 1.018–1.043 for the 3-month moving average; OR = 1.020, 95% CI = 1.005–1.037 for the 6-month moving average). Stronger associations were observed for DUs than GUs. The observed positive association of PM2.5 exposure with PUDs remained significant in the two-pollutant models after adjusting for other air pollutants. Our findings could provide scientific evidence for a more general adverse role of air pollution on PUDs.

Natural and cause-specific mortality and long-term exposure to particle components in a pooled cohort of 323,782 participants in Europe: the ELAPSE project

Background/Aim Inconsistent associations between long-term exposure to components of particulate matter (PM) air pollution and adverse health outcomes have been reported. The aim of this study was to investigate the associations between long-term exposure to elemental components of PM and mortality in a pooled European cohort.Methods We pooled data from nine ongoing European cohorts with 323,782 participants. Residential exposure to annual 2010 mean concentrations of eight a priori-selected components of PM (copper, iron, potassium, nickel, sulfur, silicon, vanadium, and zinc) were assessed based on Europe-wide land use regression models at 100 m spatial scale. After harmonizing individual and area-level variables between cohorts, we applied Cox proportional hazard models with increasing adjustment for potential confounders to investigate the association between long-term air pollution exposure and natural and cause-specific mortality. Two-pollutant models were conducted for each element by adjusting for PM2.5 and NO2.Results The total study population contributed 6,317,234 person-year at risk (average follow-up 19.5 years). For natural-cause mortality, the hazard ratios were significantly positive for all components, and were strongly attenuated in two-pollutant models with adjustment for PM2.5 or NO2. Hazard ratios (HRs) in two-pollutant models for PM2.5 nickel, PM2.5 sulfur, PM2.5vanadium and PM2.5 zinc remained (borderline) significant [HRs adjusted for PM2.5: PM2.5 nickel: 1.04 (95% CI: 1.02, 1.07) per 1 ng/m3; PM2.5 sulfur: 1.05 (95% CI: 1.01, 1.09) per 200 ng/m3; PM2.5 vanadium: 1.0 (95% CI: 1.00, 1.03) per 2 ng/m3; PM2.5 zinc: 1.03 (95% CI: 1.02, 1.05) per 10 ng/m3; HRs adjusted for NO2 were similar]. The effect estimates for the more traffic-related pollutants copper and iron were especially reduced after adjustment for NO2. For cardiovascular and respiratory mortality, no consistent associations were found in two-pollutant models.Conclusions Long-term exposure to nickel, sulfur, vanadium and zinc in PM2.5 were associated with natural-cause mortality.

Low-level air pollution exposure 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 limited. We examined the association between long-term exposure to low-levels of air pollution and incidence of COPD. Methods. Within the multicenter ‘Effects of Low-Level Air Pollution: A Study in Europe’ (ELAPSE) study, we pooled data from three prospective cohorts, from Denmark and Sweden. Hybrid land use regression models (100m resolution) were used to estimate annual mean concentrations of fine particulate matter (PM2.5), nitrogen dioxide (NO2), black carbon (BC), and warm season ozone (O3) in 2010 based on participants’ baseline addresses. Cox proportional hazard models were used to examine the association between air pollution and COPD incidence, defined as first-ever hospital contacts. We also assessed the shape of the concentration-response function with natural cubic splines, and investigated two-pollutant models. Results. Among 98,058 participants, 4,928 (5.0%) developed COPD during a mean follow-up period of 16.6 years. Annual average concentrations of PM2.5, NO2, BC, and O3 were 12.1 μg/m3, 25.1 μg/m3, 1.2 10-5m-1, and 78.1 μg/m3, respectively. The fully adjusted hazard ratios (HRs) and 95% confidential intervals for associations between air pollutants and COPD incidence were 1.17 (1.06-1.29) per 5 µg/m3 for PM2.5, 1.11 (1.06-1.16) per 10 µg/m3 for NO2, 1.11 (1.06-1.15) per 0.5 10-5m-1 for BC, and 0.99 (0.93-1.05) per 10 µg/m3 for O3. Associations persisted in the subset of participants with PM2.5 and NO2 levels below the European limit values. NO2 and BC remained unchanged in two-pollutant models with PM2.5, whereas PM2.5 attenuated to unity. The HR for O3 became positive and significant after adjustment for NO2 or BC. No significant deviation from linearity was observed for any of the associations. Conclusion. Long-term exposure to low-levels of air pollution can lead to the development of COPD, even below current European limit values.

Long-term effects of traffic-related air pollution on mortality in the Southeastern US

Background Mounting evidence has shown that the long-term exposure to fine particulate matter and ozone can increase mortality. However, the health effects associated with long-term exposure to nitrogen dioxide (NO2) are less clear. Methods We conducted a large population-based cohort study that included all Medicare beneficiaries (aged ≥65, N=15,646,962) in the Southeastern US from 2000-2016, with 124,019,974 person-years of follow-up. We applied previously estimated spatially- and temporally-resolved NO2 concentrations and assigned annual means to study subjects based on ZIP code of residence. Cox proportional hazards models were used to examine the association between long-term exposure to NO2 and all-cause mortality, adjusting for potential confounders. Results We observed a statistically significant association between long-term exposure to NO2 and all-cause mortality, with a hazard ratio (HR) of 1.036 (95% CI: 1.029, 1.043) in two-pollutant models (adjusting for PM2.5) and a HR of 1.032 (95% CI: 1.021, 1.043) in multi-pollutant models (adjusting for PM2.5 and ozone), per 10 ppb increase in annual NO2 concentrations. The penalized spline indicates a linear dose-response relationship across the entire NO2 exposure range. Subjects who are female, Black, Medicaid-eligible, and residing in urban areas are more vulnerable to long-term NO2 exposure. Conclusion Using a large cohort, we provide epidemiological evidence that long-term exposure to NO2 was significantly associated with a higher risk of mortality, independent of PM2.5 and ozone. Improving air quality by reducing NO2 emissions may yield substantial health benefits.

Iron and copper in fine particulate matter, reactive oxygen species concentration in lung epithelial fluid and respiratory health: A population-based cohort study

Background: Metal components in fine particulate matter (PM2.5) originating from non-tailpipe emissions may play important roles in underlying its adverse effects on respiratory health due to the potential in generating reactive oxygen species (ROS). However, relevant epidemiological evidence is scarce. Methods: We investigated the associations of long-term exposure to iron (Fe) and copper (Cu) in PM2.5 (two metal components mainly originating from non-tailpipe emissions), and their combined impact on the concentration of reactive oxygen species (ROS) with respiratory health in a population-based cohort of ~0.8 million adults in Toronto, Canada. Incidence of asthma, chronic obstructive pulmonary disease (COPD) and respiratory mortality was ascertained using health administrative databases. Exposures to Fe and Cu in PM2.5 and their combined impact on ROS were estimated using land use regression models. We used mixed-effects Cox regression models to examine the associations between the exposures and health outcomes. Results: We found positive associations between long-term exposure to Fe, Cu and ROS, and the risks of all three respiratory outcomes. The associations were more robust for COPD and respiratory disease death than for asthma. In terms of exposures, we observed stronger associations for ROS than for Fe or Cu individually. For example, the hazard ratios (95% confidence interval) for respiratory death associated with an interquartile-range increment in Fe, Cu and ROS were 1.046 (1.034, 1.058), 1.020 (1.008, 1.033) and 1.076 (1.058, 1.094), respectively. In two-pollutant models, adjustment for NO2 attenuated the associations while PM2.5 had little influence. Conclusions: Long-term exposure to Fe and Cu in PM2.5 and estimated ROS concentration in lung fluid was associated with increased incidence of respiratory outcomes, particularly COPD and respiratory mortality, suggesting adverse respiratory effects of non-tailpipe emitted air pollution.