Adjustment For Gaseous Pollutants Research Articles

Association between atmospheric PM2.5 and daily outpatient visits for children's respiratory diseases in Lanzhou.

The relationship between fine particulate matter (PM2.5) and respiratory disease outcomes among children aged 0 to 14years in Lanzhou, China, was evaluated. We utilized a generalized additive model linked by a quasi-Poisson distribution to examine the associations between PM2.5 and paediatric respiratory outpatient visits for time lags of 0 up to 7days, and stratified by gender, age, and season. Cases of respiratory disease in children were collected from 3 large hospitals for the years 2014-2017 and then linked with air pollutant concentrations from 4 air quality monitoring stations by date. We observed positive and significant associations between PM2.5 and respiratory disease from the lag to lag 7, and from lag01 to lag07, with ER reaching the maximum value at lag07. For each 10μg/m3 increase in PM2.5 (lag07), the associated increment in respiratory diseases was 2.83% (95% CI 1.80%-3.86%). Males were more sensitive to the adverse effects, and the association was more significant in spring (from March to May) and winter (from December to the next February). Overall, the child group (age 3-6years) demonstrated a higher risk of respiratory disease after PM2.5 exposure. The associations between ambient PM2.5 and respiratory hospital outpatients among young children became partially attenuated after the adjustment for gaseous pollutants in subgroups. The exposure-response curves were positive and generally nonlinear but flatted at concentrations over 60μg/m3. This research found a significant association between ambient PM2.5 levels and hospital outpatient visits in child with respiratory diseases in Lanzhou, China.

Differential effects of size-specific particulate matter on lower respiratory infections in children: A multi-city time-series analysis in Sichuan, China

Evidence on the short-term effects of size-specific particulate matter with aerodynamic diameter ≤2.5 μm (PM2.5), ≤10 μm (PM10), and their difference (PMC) on children’s Lower Respiratory Infections (LRI) is scare. This study aimed to estimate the differential effects of three size-specific PM on hospitalizations of children aged <18 years for pneumonia and bronchitis in 18 cities of southwestern China. The city-specific association was firstly estimated using the over-dispersed generalized additive model and then combined to obtain the regional average association. Further, to evaluate the robustness of the key findings, subgroup analyses and co-pollutant models were constructed. PM-related risks of LRI differed by PM fractions and cause-specific LRI. A 10 μg/m3 increment in PM2.5_lag03, PM10_lag06, and PMC_lag06 was associated with a 0.79% (95% CI: 0.29%, 1.29%), 0.77% (95% CI: 0.13%, 1.41%), and 2.33% (95% CI: 1.23%, 3.44%) increase in children’s LRI hospitalizations, respectively. After adjustment for gaseous pollutants, adverse effects of the three types of size-specific PM on pneumonia hospitalizations were stable, ranging from 0.29% (95% CI: 0.05%, 0.54%) for PM2.5–2.50% (95% CI: 1.38%, 3.64%) for PMC. Additionally, PMC-related risk of bronchitis hospitalizations remained stable after adjustment for gaseous pollutants. Associations of pneumonia with PMC and PM10 in infants, bronchitis with PM2.5 in children aged 6–17 years, pneumonia and bronchitis with PM2.5, PMC, and PM10 in children aged 1–5 years were all statistical significant. Specifically, the effects of PM2.5 on LRI hospitalizations increased by age, with the highest effect of 1.72% (95%CI: 1.01%, 2.43%) in children aged 6–17 years. Our study provided evidence for short-term effects of different PM fractions on children LRI hospitalizations in Southwestern China, which will be useful for making and promoting policies on air quality standards in order to protect children’s health.

Short-term associations between ambient fine particulate matter pollution and hospital visits for chronic obstructive pulmonary disease in Yinzhou District, China.

Ambient particulate matter is one of the main risk factors of chronic obstructive pulmonary disease (COPD) in developing countries. However, the studies were scant in China concerning the health effects of the fine particulate matter (PM2.5; particulate matter ≤ 2.5μm in diameter) on hospital visits for COPD. We applied a generalized additive model (GAM) to calculate relative risks (RRs) with 95% confidence intervals (CIs) for the associations between hospital visits for COPD and an interquartile range (24.50μg/m3) increment of ambient PM2.5 concentrations in Yinzhou District between 2016 and 2018. The ambient PM2.5 concentration was positively associated with hospital visits for COPD at a distributed lag of 0-7days (RR = 1.073, 95% CI, 1.016, 1.133). In the stratified analysis, we found that the association between ambient PM2.5 and COPD was stronger during the warm season (April to September) than that during the cold season (October to March), but we did not observe statistically significant differences in age groups (< 60years and ≥ 60years) or gender groups (male and female) related to the effects of PM2.5. The associations between ambient PM2.5 and COPD became partially attenuated after the adjustment for gaseous pollutants in subgroups. Our findings could provide evidence that regulations for controlling both PM2.5 and gaseous pollutants should be implemented to protect the overall population.

Differential effects of fine and coarse particulate matter on hospitalizations for ischemic heart disease: A population-based time-series analysis in Southwestern China

Few studies have explored the associations of ischemic heart disease (IHD) hospitalizations with fine (diameter ≤ 2.5 μm, PM2.5) and coarse particulate matter (diameter between 2.5 and 10 μm, PMC) simultaneously; and studies to distinguish the susceptible populations by sex, age, and comorbidity status are sparse and inconsistent. This study aimed to assess the differential effects of PM2.5 and PMC on IHD hospitalizations and to investigate modifiers of demographic characters, causes of hospitalizations, and comorbidity status on these differential effects. A time-series analysis using an over-dispersed generalized additive model on 33017 IHD hospitalizations was conducted in urban areas of Chengdu, Southwestern China, from 1 January 2015 to 31 December 2016. Z-test was used to test whether PMC- or PM2.5-related effects were differential within each modifier. Furthermore, to evaluate the robustness of the key findings for gaseous pollutants exposure adjustment, co-pollutant models were constructed. We identified differential effects of PM2.5 and PMC on IHD hospitalizations in terms of the effect magnitude, effect stability, and susceptible populations. A 10 μg/m³ increment of PM2.5 and PMC at lag06 was associated with a 1.2% (95% confidence interval (CI): 0.3%, 2.2%) and 2.5% (95%CI: 1.1%, 3.8%) increase in IHD hospitalizations, respectively. After adjustment for gaseous pollutants, PMC effect was independent, particularly among males, angina, chronic IHD, and patients with comorbidity of chronic heart failure, hypertension, or chronic obstructive pulmonary disease (COPD); whereas, PM2.5 effect remained significant among patients with comorbidity of hypertension. Males, comorbidity of hypertension or COPD substantially increased the PMC-related risk for IHD hospitalizations; whereas, only comorbidity of hypertension increased the PM2.5-related risk for IHD hospitalizations. Interestingly, the PMC effect was comparable between the middle-aged and the elderly. Our study found differential effects of PM2.5 and PMC on IHD hospitalizations and identified susceptible populations, which are important to establish guidelines or recommendations for high-risk individuals.

Ambient Particulate Air Pollution and Daily Mortality in 652 Cities

BackgroundThe systematic evaluation of the results of time-series studies of air pollution is challenged by differences in model specification and publication bias.MethodsWe evaluated the associations of inhalable particulate matter (PM) with an aerodynamic diameter of 10 μm or less (PM10) and fine PM with an aerodynamic diameter of 2.5 μm or less (PM2.5) with daily all-cause, cardiovascular, and respiratory mortality across multiple countries or regions. Daily data on mortality and air pollution were collected from 652 cities in 24 countries or regions. We used overdispersed generalized additive models with random-effects meta-analysis to investigate the associations. Two-pollutant models were fitted to test the robustness of the associations. Concentration–response curves from each city were pooled to allow global estimates to be derived.ResultsOn average, an increase of 10 μg per cubic meter in the 2-day moving average of PM10 concentration, which represents the average over the current and previous day, was associated with increases of 0.44% (95% confidence interval [CI], 0.39 to 0.50) in daily all-cause mortality, 0.36% (95% CI, 0.30 to 0.43) in daily cardiovascular mortality, and 0.47% (95% CI, 0.35 to 0.58) in daily respiratory mortality. The corresponding increases in daily mortality for the same change in PM2.5 concentration were 0.68% (95% CI, 0.59 to 0.77), 0.55% (95% CI, 0.45 to 0.66), and 0.74% (95% CI, 0.53 to 0.95). These associations remained significant after adjustment for gaseous pollutants. Associations were stronger in locations with lower annual mean PM concentrations and higher annual mean temperatures. The pooled concentration–response curves showed a consistent increase in daily mortality with increasing PM concentration, with steeper slopes at lower PM concentrations.ConclusionsOur data show independent associations between short-term exposure to PM10 and PM2.5 and daily all-cause, cardiovascular, and respiratory mortality in more than 600 cities across the globe. These data reinforce the evidence of a link between mortality and PM concentration established in regional and local studies. (Funded by the National Natural Science Foundation of China and others.)

Attributable risk of hospital admissions for overall and specific mental disorders due to particulate matter pollution: A time-series study in Chengdu, China

The associations of particulate matter (PM) pollution with the morbidity of overall and subtypes of mental disorders (MDs), as well as the corresponding morbidity burden, remain understudied, especially in developing countries. This study aimed to evaluate the short-term effects of PM2.5 (diameters ≤ 2.5 µm), PM10 (diameters ≤ 10 µm) and PMC (diameters between 2.5 and 10 µm) on hospital admissions (HAs) for MDs in Chengdu, China, during 2015–2016, and calculate corresponding attributable risks. A generalized additive model (GAM) with controlling for time trend, meteorological conditions, holidays and day of the week was used to estimate the associations. Stratified analyses were also performed by age, gender and season. We further estimated the burden of HAs for MDs attributable to PM exposure. During the study period, a total of 10,947 HAs for MDs were collected. PM2.5, PM10 and PMC were significantly associated with elevated risks of MDs hospitalizations. Each 10 μg/m3 increase in PM2.5, PM10 and PMC at lag06 corresponded to an increase of 2.89% (95% CI: 0.75–5.08%), 1.91% (95% CI: 0.57–3.28%) and 3.95% (95% CI: 0.84–7.15%) in daily HAs for MDs, respectively. The risk estimates of PM on MDs hospitalizations were generally robust after adjustment for gaseous pollutants in two-pollutant models. We found stronger associations between PM pollution and MDs in males and in cool seasons than in females and in warm seasons. For specific subtypes of MDs, significant associations of PM pollution with dementia,schizophrenia and depression were observed. Using WHO's air quality guidelines as the reference concentrations, 9.53% (95% CI: 2.67–15.58%), 9.17% (95% CI: 2.91–14.70%) and 6.10% (95% CI: 1.40–10.32%) of HAs for MDs could be attributable to PM2.5, PM10 and PMC, respectively. Our results suggested that PM exposure might be an important trigger of hospitalizations for MDs in Chengdu, China, and account for substantial morbidity burden.

DIFFERENCE IN THE EFFECT OF COARSE PARTICULATE MATTER ON FIRST, SECOND AND OVERALL ADMISSIONS FOR RESPIRATORY DISEASE AMONG THE ELDERLY IN VANCOUVER, CANADA

ISEE-107 Purpose: To examine the difference in the effect of particulate matter on first, second, and overall hospital admissions for respiratory disease among the elderly. Methods: We studied 8,989 adults 65 years of age or older living in greater Vancouver, who were admitted to hospital for any acute respiratory disease (ICD-9 codes 460–519) during the period from June 1, 1995 to March 31, 1999. Time-series analysis was used to evaluate the association between respiratory admissions and daily measures of particulate matter (PM10, PM2.5 and PM10–2.5) after adjustment for gaseous pollutants (CO, O3, NO2 and SO2) and meteorological variables. Results: Repeated admissions for respiratory disease were common among the elderly. Approximately 30 percent of the subjects were readmitted to hospital, and 9% had more than two admissions for respiratory disease during the 4-year study period. PM10–2.5 was significantly associated with the second and overall admissions for respiratory disease, but not with the first admission. The adjusted relative risks for an increment of 4.2 μg/m3 in 3-day average PM10–2.5 concentrations were 1.03 (95% confidence interval: 0.98–1.09) for first admission, 1.22 (1.10–1.36) for second admission, and 1.06 (1.02, 1.11) for overall admissions. There was no significant effect of PM2.5 on hospital admissions for respiratory disease among the elderly. Conclusions: Our data suggest that: 1) coarse particulate matter may be associated with exacerbations of respiratory conditions, rather than disease induction; 2) analysis based on overall hospital admissions tends to provide conservative relative risk estimates; and 3) PM10–2.5 has a larger effect on respiratory admissions than PM2.5.

Association Between Particulate Air Pollution and First Hospital Admission for Childhood Respiratory Illness in Vancouver, Canada

In this study, the authors assessed the impact of particulate air pollution on first respiratory hospitalization. Study subjects were children less than 3 years of age living in Vancouver, British Columbia, who had their first hospitalization as a result of any respiratory disease (ICD-9 codes 460-519) during the period from June 1, 1995, to March 31, 1999. The authors used logistic regression to estimate the associations between ambient concentrations of particulate matter (PM) and first hospitalization. The adjusted odds ratios for first respiratory hospitalization associated with mean and maximal PM10-2.5 with a lag of 3 days were 1.12 (95% confidence interval: 0.98, 1.28) and 1.13 (1.00, 1.27). After adjustment for gaseous pollutants, the corresponding odds ratios were 1.22 (1.02, 1.48) and 1.14 (0.99, 1.32). The data indicated the possibility of harmful effects from coarse PM on first hospitalization for respiratory disease in early childhood.