Ambient Fine Particulate Matter Pollution Research Articles

AhR Agonistic Components in Urban Particulate Matter Regulate Astrocytic Activation and Function.

Exposure to atmospheric particulate matter (PM) has been found to accelerate the onset of neurological disorders via the induction of detrimental neuroinflammatory responses. To reveal how astrocytes respond to urban atmospheric PM stimulation, a commercially available standard reference material (SRM1648a) was tested in this study on the activation of rat cortical astrocytes. The results showed that SRM1648a stimulation induced both A1 and A2 phenotypes in astrocytes, as characterized by the exposure concentration-dependent increases in Fkbp5, Sphk1, S100a10, and Il6 mRNA levels. Studying the functional alterations of astrocytes indicated that the neurotrophic factors of Gdnf and Ngf were transcriptionally upregulated due to astrocytic A2-type activation. SRM1648a also promoted autonomous motility of astrocytes and elevated the expressions of chemokines. The aryl hydrocarbon receptor (AhR) agonistic components, such as polycyclic aromatic hydrocarbons (PAHs), were recognized to greatly contribute to SRM1648a-induced effects on astrocytes, which was confirmed by the attenuation of PM-disturbed astrocytic effects via AhR blockage. This study, for the first time, uncovered the direct regulation of urban atmospheric PM on astrocytic activation and function and traced the containing bioactive components (e.g., PAHs) with AhR agonistic activity. The findings provided new knowledge on understanding the ambiguous neurological disturbance from ambient fine PM pollution.

Ambient fine particulate matter chemical composition associated with in-hospital case fatality, hospital expenses, and length of hospital stay among patients with heart failure in China.

Previous studies have observed the adverse effects of ambient fine particulate matter pollution (PM2.5) on heart failure (HF). However, evidence regarding the impacts of specific PM2.5 components remains scarce. We included 58 129 patients hospitalised for HF between 2013 and 2017 in 11 cities of Shanxi, China from inpatient discharge database. We evaluated exposure to PM2.5 and its components ((sulphate (SO42-), nitrate (NO3-), ammonium (NH4+), organic matter (OM) and black carbon (BC)), along with meteorological factors using bilinear interpolation at each patients' residential address. We used multivariable logistic and linear regression models to assess the associations of these components with in-hospital case fatality, hospital expenses, and length of hospital stay. Increase equivalents to the interquartile range (IQR) in OM (odds ratio (OR) = 1.13; 95% confidence interval (CI) = 1.02, 1.26) and BC (OR = 1.14; 95% CI = 1.02, 1.26) were linked to in-hospital case fatality. Per IQR increments in PM2.5, SO42-, NO3-, OM, and BC were associated with cost increases of 420.62 (95% CI = 285.75, 555.49), 221.83 (95% CI = 96.95, 346.71), 214.93 (95% CI = 68.66, 361.21), 300.06 (95% CI = 176.96, 423.16), and 303.09 (95% CI = 180.76, 425.42) CNY. Increases of 1 IQR in PM2.5, SO42-, OM, and BC were associated with increases in length of hospital stay of 0.10 (95% CI = 0.02, 0.19), 0.09 (95% CI = 0.02, 0.17), 0.10 (95% CI = 0.03, 0.17), and 0.16 (95% CI = 0.08, 0.23) days. Our findings suggest that ambient SO42-, OM, and BC might be significant risk factors for HF, emphasising the importance of formulating customised guidelines for the chemical constituents of PM and controlling the emissions of the most dangerous components.

Changing patterns for cardiovascular disease and subtypes mortality attributable to ambient fine particulate matter pollution between China and India during 1990 to 2019

Changing patterns for cardiovascular disease and subtypes mortality attributable to ambient fine particulate matter pollution between China and India during 1990 to 2019

Trends in global ambient fine particulate matter pollution and diabetes mortality rates attributable to it in the 1990–2019: 30 years systematic analysis of global burden of disease

AimTo analyze the trends in ambient fine particulate matter pollution (PM2.5) and the age-standardized mortality rate (ASMR) of diabetes attributable to it from 1990 to 2019 by region, country, and socio-economic development status. MethodsThe main data, including the summary exposure value (SEV) of ambient PM2.5 and the ASMR of diabetes due to ambient PM2.5, was collected from the Global Burden of Disease 2019 database. The socio-demographic index (SDI) was employed for assessing a particular region or country's degree of socio-economic development. Joinpoint regression analysis was used to assess the changes of ambient PM2.5 and ASMR of diabetes attributable to it. ResultsGlobally, the SEV of ambient PM2.5 increased from 15.65 μg/m3 in 1990 to 26.22 μg/m3 in 2019, with an annual average percent change (AAPC) of 1.788 (95 % CI 1.687–1.889) μg/m3. The ASMR of diabetes attributable to ambient PM2.5 increased from 1.57 per 100,000 population in 1990 to 2.47 per 100.000 population in 2019 (AAPC = 1.569 [95 % CI 1.42–1.718]). Most regions and countries had an increase of SEV of ambient PM2.5 and ASMR of diabetes attributable to ambient PM2.5. The largest increase of SEV of ambient PM2.5 was observed in South Asia (AAPC = 3.556 [95 % CI 3.329–3.875]), while the largest increase of ASMR of diabetes was in Central Asia (AAPC = 5.170 [95%CI 4.696–5.647]). Moreover, the increase of SEV of ambient PM2.5 and ASMR of diabetes attributable to it were positively associated with SDI in low SDI countries (SDI < 0.46), whereas the opposite result was observed when SDI ≥ 0.46. ConclusionFrom 1990 to 2019, the population's exposure to ambient PM2.5 and ASMR of diabetes attributable to it increased generally, especially in low-middle SDI regions. Ambient PM2.5 remains a threat to global health. Greater investment in ambient PM2.5 and the mortality attributable to it are needed.

Inter-regional environmental inequality under lasting pandemic exacerbated by residential response

Pandemics greatly affect transportation, economic and household activities and their associated air pollutant emissions. In less affluent regions, household energy use is often the dominant pollution source and is sensitive to the affluence change caused by a persisting pandemic. Air quality studies on COVID-19 have shown declines in pollution levels over industrialized regions as an immediate response to pandemic-caused lockdown and weakened economy. Yet few have considered the response of residential emissions to altered household affluence and energy choice supplemented by social distancing. Here we quantify the potential effects of long-term pandemics on ambient fine particulate matter pollution (PM2.5) and resulting premature mortality worldwide, by comprehensively considering the changes in transportation, economic production and household energy use. We find that a persisting COVID-like pandemic would reduce the global gross domestic product by 10.9 % and premature mortality related to black carbon, primary organic aerosols and secondary inorganic aerosols by 9.5 %. The global mortality decline would reach 13.0 % had the response of residential emissions been excluded. Among the 13 aggregated regions worldwide, the least affluent regions exhibit the greatest fractional economic losses with no comparable magnitudes of mortality reduction. This is because their weakened affluence would cause switch to more polluting household energy types on top of longer stay-at-home time, largely offsetting the effect of reduced transportation and economic production. International financial, technological and vaccine aids could reduce such environmental inequality.

Risk-benefit analysis of the association of ambient fine particulate matter pollution and physical activity with age-related cataract: A prospective cohort study

The aim of this study was to examine the associations of fine particulate matter (PM2.5) and physical activity (PA) with age-related cataract and its subtypes, and to explore potential interactions between PM2.5 and PA. A total of 291,627 participants enrolled in the UK Biobank cohort during 2006–2010 was included. The annual mean concentration of PM2.5 at each participant's residential address was estimated using Land Use Regression models. PA was measured using the International Physical Activity Questionnaire. Cox proportional hazards model was used to examine the associations of PM2.5 and PA with incident age-related cataract, and to assess their interactions on additive and multiplicative scales. We identified 12,826 incident cases of age-related cataract, including 7686 cases of nuclear cataract and 5140 cases of non-nuclear cataract. Higher PM2.5 exposure was associated with a higher risk of age-related cataract [HR = 1.140; 95% CI: 1.105, 1.177; per 1 μg/m3 increase], and the association was stronger for non-nuclear cataract than for nuclear cataract. There was a negative association between PA and cataract [HR = 0.925; 95% CI: 0.879, 0.974; comparing high to low level]. No clear evidence of the interactions between PM2.5 and PA was found. Our findings indicated that high PM2.5 exposure and low levels of PA were independently associated with increased risks of incident age-related cataract.

Sleep disturbance exacerbates the cardiac conduction abnormalities induced by persistent heavy ambient fine particulate matter pollution: A multi-center cross-sectional study

Fine particulate matter (PM2.5) exposure and sleep disturbance have been significantly associated with adverse cardiovascular outcomes, however, the combined effects of these two factors are still unclear. We conducted a multi-center cross-sectional study from November 2018 to May 2019 in the Beijing–Tianjin–Hebei region in China to investigate the potential modifying effects of sleep disturbance on associations between cardiac conduction abnormalities and PM2.5 exposure, as well as the combined effects of sleep disturbance and heavy pollution episodes, which were defined based on the PM2.5 mass concentration (≥75 μg/m3, falling in the 75th/90th percentile) and duration (1 day and ≥2 days). The sleep quality and sleep duration of all participants were evaluated using the Pittsburgh Sleep Quality Index. Standard 12-lead electrocardiogram (ECG) test was performed to measure the heart rate (HR), QRS duration (time taken for ventricular depolarization), HR corrected QT interval (time for ventricular depolarization and repolarization) and PR interval (time for atrioventricular conduction). Multivariable linear regression models were performed to evaluate the associations of PM2.5 and heavy pollution events on ECG parameters and the joint effects with sleep disturbance. We found PM2.5 exposure was independently associated with prolonged QRS and QTc intervals. Association between PM2.5 and the QTc interval was significantly stronger in participants with poor sleep quality. For each 10-μg/m3 increase in PM2.5 concentration, the QTc interval in the participants with poor sleep quality increased by 0.41 % (95 % confidence interval: 0.19, 0.64). In addition, heavy PM2.5 pollution episodes, especially extremely heavy pollution of long duration, were found to have synergistic effects with sleep disturbance on ECG parameters. Our findings provide evidence that PM2.5 exposure, especially heavy pollution episodes, may increase abnormal cardiac conduction and have a synergistic effect with sleep disturbance. Improving sleep hygiene is crucial to protect the heart health of the general population.

Impact of Exposure to Ambient Fine Particulate Matter Pollution on Adults with Knee Osteoarthritis.

The impact of exposure to fine particulate matter (PM2.5) on the incidence of knee osteoarthritis is unclear, especially in Beijing which is a highly polluted city. We conducted a time-series study to examine the correlation between PM2.5 exposure and outpatient visits for knee osteoarthritis in Beijing. Changes (in percentage) in the number of outpatient visits corresponding to every 10-μg/m3 increase in the PM2.5 concentration were determined using a generalized additive quasi-Poisson model. There were records of 9,797,446 outpatient visits for knee osteoarthritis in the study period from 1 January 2010 to 31 December 2017. The daily concentration of PM2.5 was 86.8 (74.3) μg/m3 over this period. A 10-μg/m3 increase in PM2.5 concentrations on lag days 0–3 was associated with a 1.41% (95% confidence interval: 1.40–1.41%) increase in outpatient visits for knee osteoarthritis. Females and patients aged above 65 years were more sensitive to the adverse effects of PM2.5 exposure. The present findings demonstrate that short-term exposure to PM2.5 resulted in an increase in the number of outpatient visits for knee osteoarthritis in Beijing. The findings shed light on the effects of air pollution on knee osteoarthritis and could guide risk-mitigating strategies in cities such as Beijing.

Global burden of lung cancer attributable to ambient fine particulate matter pollution in 204 countries and territories, 1990–2019

IntroductionUnderstanding the latest global spatio-temporal pattern of lung cancer burden attributable to ambient fine particulate matter pollution (PM2.5) is crucial to prioritize global lung cancer prevention, as well as environment improvement. MethodsData on lung cancer attributable to ambient PM2.5 were downloaded from the Global Burden of Disease Study (GBD) 2019. The numbers and age-standardized rates on lung cancer mortality (ASMR) and disability-adjusted life years (ASDR) were estimated by age, sex, region, and country. We used estimated annual percentage change (EAPC) to quantify the temporal trends of ASMR and ASDR from 1990 to 2019. ResultsIn 2019, the number of global lung cancer deaths and DALYs attributable to ambient PM2.5 was approximately 0.31 million and 7.02 million respectively, among which more deaths and DALYs occurred in males. At GBD region level, the heaviest burden occurred in East Asia, accounting for over 50% worldwide, with China ranked first worldwide. The number of ambient PM2.5 attributable lung cancer deaths and DALYs has over doubled from 1990 to 2019, but high sociodemographic index (SDI) region had a rapid decrease, with EAPC -2.21 in ASMR (95% CI: −2.32, −2.09). The age-specific mortality rate or DALY rate has increased in all age groups in low to middle SDI regions from 1990 to 2019. The ASMR or ASDR showed an inverted V-shaped association with SDI. The EAPC in ASMR or ASDR was highly negatively correlated with ASMR or ASDR in 1990 and SDI in 2019, with coefficients around 0.70. ConclusionsThe number of ambient PM2.5-related lung cancer deaths and DALYs has largely increased because of the increase of exposure to PM2.5, population growth, and aging. Local governments should do economic activities under the consideration of public health, especially in high-burden areas.

Engagement in outdoor physical activity under ambient fine particulate matter pollution: A risk-benefit analysis

BackgroundOutdoor physical activity (PA) brings important health benefits, but exposure to polluted air increases health risks. This study aimed to quantify the tradeoff of PA under fine particulate matter (PM2.5) air pollution by estimating the optimal PA duration under various pollution levels. MethodsA risk-benefit analysis was performed to estimate the optimal outdoor moderate-intensity PA (MPA) duration under varying PM2.5 concentrations. ResultsAn inverse nonlinear relationship was identified between optimal MPA duration and background PM2.5 concentration levels. When background PM2.5 concentration increased to 186 µg/m3, the optimal outdoor MPA duration decreased to 2.5 h/week, the minimum level recommended by current PA guidelines. When background PM2.5 concentration further increased to 235 µg/m3, the optimal outdoor MPA duration decreased to 1 h/week. The relationship between optimal MPA duration and background PM2.5 concentration levels was stronger when exercising at a location closer to a source of air pollution. Compared to the general adult population, adults aged 60 years and older had substantially steeper curves—the optimal outdoor MPA duration decreased to 2.5 h/week when background PM2.5 concentration reached 45 µg/m3. ConclusionThe health benefit of outdoor MPA by far outweighs the health risk of PM2.5 pollution for the global average urban background concentration (22 μg/m3). This modeling study examined a single type of air pollutant and suffered from measurement errors and estimation uncertainties. Future research should examine other air pollutants and indoor PA, incorporate short- and mid-term health effects of MPA and air pollution into the risk-benefit analysis, and provide estimates specific for high-risk subgroups.

Ambient fine particulate matter pollution and years of life lost from cardiovascular diseases in 48 large Chinese cities: Association, effect modification, and additional life gain

Existing evidence on the associations between fine particulate matter (PM2.5) and years of life lost (YLL) from cardiovascular diseases (CVD) is limited and inconclusive, and the role of potential modifiers, especially those at city-level, is not fully understood. In this study, a time-series study was conducted in 48 large Chinese cities from 2013 to 2017. Generalized additive model coupled with random effects model were used to estimate national-average associations of PM2.5 with YLL. Effect modification by individual- and city-level characteristics obtained by linking with China Chronic Disease and Risk Factors Surveillance was explored. Moreover, additional life gain was evaluated under scenario where PM2.5 concentration would be reduced. For 10 μg/m3 increase in PM2.5 concentration at lag01 day, the relative increment of YLL was 0.22% from CVD, 0.20% from ischemic heart disease, 0.26% from stroke, 0.23% from hemorrhagic stroke, and 0.31% from ischemic stroke. Some associations were stronger in elder and less educated people, warm season, as well as cities characterized by higher temperature and prevalence of binge drinking and excess red meat intake, or lower PM2.5 and prevalence of usual exercise. Additional life gain attributable to avoidable YLL from CVD was estimated to be 0.08 year if PM2.5 concentration could fall to the standard recommended by World Health Organization (25 μg/m3). This large epidemiological investigation demonstrated robust evidence of short-term associations between PM2.5 exposure and YLL from CVD. Potential modifiers should be considered to develop efficient intervention strategies. Implementation of more stringent standard is beneficial to alleviate YLL caused by PM2.5.

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.

Stroke burden and mortality attributable to ambient fine particulate matter pollution in 195 countries and territories and trend analysis from 1990 to 2017

BackgroundFine particulate matter (PM2.5) exposure is associated with stroke incidence and mortality. However, the global distribution and trends of stroke burden and mortality attributable to PM2.5 are rarely studied. We estimated the spatial patterns and temporal trends of PM2.5-attributable stroke burden in 195 countries and territories from 1990 to 2017. MethodsDetailed data on stroke burden attributable to PM2.5 were extracted from the Global Burden of Disease Study (GBD) 2017. The numbers and age-standardized rates of stroke disability-adjusted life years (DALYs) and mortality (ASDR and ASMR) were estimated by age, sex, subtype, region, and country. Temporal trends in ASDR and ASMR were analyzed using estimated annual percentage change (EAPC). ResultsGlobally, in 2017, 10.5 million DALYs and 0.4 million deaths related to stroke were attributable to PM2.5. The corresponding ASDR and ASMR increased with age, were highest in males and for intracerebral hemorrhage, and varied greatly across countries, with the largest burden in high-middle sociodemographic index (SDI) regions and East Asia. The global ASDR and ASMR decreased by 7.2% and 12.2% from 1990 to 2017, with EAPCs of −0.42 (95% confidence interval [CI]: -0.55, −0.28) and −0.57 (95% CI: -0.72, −0.42), respectively. Age-specific stroke burden rates declined significantly, except in the middle-aged population. The decrease was more pronounced in women and for subarachnoid hemorrhage, while proportions of ischemic stroke burden increased globally and in all SDI regions. Most geographic regions achieved significant declines in ASDR and ASMR since 1990; however, Asia and approximately 30% of countries and territories, especially in low-income countries, showed undesirable increasing trends. ConclusionsThe patterns and trends were heterogeneous across countries. Strengthened and tailored approaches for stroke prevention and air pollution management are still needed to reduce the disease burden associated with PM2.5, particularly in males, middle-age populations, and low-income countries and for ischemic stroke.

Potential gains in life expectancy by attaining daily ambient fine particulate matter pollution standards in mainland China: A modeling study based on nationwide data.

Ambient fine particulate matter pollution (PM2.5) is one leading cause of disease burden, but no study has quantified the association between daily PM2.5 exposure and life expectancy. We aimed to assess the potential benefits in life expectancy by attaining the daily PM2.5 standards in 72 cities of China during 2013-2016. We applied a two-stage approach for the analysis. At the first stage, we used a generalized additive model (GAM) with a Gaussian link to examine the city-specific short-term association between daily PM2.5 and years of life lost (YLL); at the second stage, a random-effects meta-analysis was used to generate the regional and national estimations. We further estimated the potential gains in life expectancy (PGLE) by assuming that ambient PM2.5 has met the Chinese National Ambient Air Quality Standard (NAAQS, 75 μg/m3) or the ambient air quality guideline (AQG) of the World Health Organization (WHO) (25 μg/m3). We also calculated the attributable fraction (AF), which denoted the proportion of YLL attributable to a higher-than-standards daily mean PM2.5 concentration. During the period from January 18, 2013 to December 31, 2016, we recorded 1,226,849 nonaccidental deaths in the study area. We observed significant associations between daily PM2.5 and YLL: each 10 μg/m3 increase in three-day-averaged (lag02) PM2.5 concentrations corresponded to an increment of 0.43 years of life lost (95% CI: 0.29-0.57). We estimated that 168,065.18 (95% CI: 114,144.91-221,985.45) and 68,684.95 (95% CI: 46,648.79-90,721.11) years of life lost can be avoided by achieving WHO's AQG and Chinese NAAQS in the study area, which corresponded to 0.14 (95% CI: 0.09-0.18) and 0.06 (95% CI: 0.04-0.07) years of gain in life expectancy for each death in these cities. We observed differential regional estimates across the 7 regions, with the highest gains in the Northwest region (0.28 years of gain [95% CI: 0.06-0.49]) and the lowest in the North region (0.08 [95% CI: 0.02-0.15]). Furthermore, using WHO's AQG and Chinese NAAQS as the references, we estimated that 1.00% (95% CI: 0.68%-1.32%) and 0.41% (95% CI: 0.28%-0.54%) of YLL could be attributable to the PM2.5 exposure at the national level. Findings from this study were mainly limited by the unavailability of data on individual PM2.5 exposure. This study indicates that significantly longer life expectancy could be achieved by a reduction in the ambient PM2.5 concentrations. It also highlights the need to formulate a stricter ambient PM2.5 standard at both national and regional levels of China to protect the population's health.

Exploring the association between short-term exposure to ambient fine particulate matter pollution and emergency admissions for peptic ulcer bleeding in Beijing, China

BackgroundAir pollution affects the pathophysiology of gastrointestinal tract and has been linked to several gastrointestinal diseases in recent years. However, little is known about the association of air pollution with peptic ulcer bleeding (PUB). We aimed to conduct a time-series study to examine the association between short-term exposure to fine particulate matter (PM2.5) and emergency admissions for PUB in Beijing, China. MethodsData on emergency admissions for PUB between January 1, 2010, and June 30, 2012 were obtained from the Beijing Medical Claim Data for Employees. Measurements of PM2.5 concentration were obtained from the United States Embassy air-monitoring station. A generalized additive Poisson model was applied to explore the association between PM2.5 concentrations and emergency admissions for PUB, with stratification by gender and age. ResultsA total of 5123 emergency admissions for PUB were identified. Short-term exposure to outdoor PM2.5 was significantly associated with increased emergency admissions for PUB at lag0 day. A 10 μg/m3 increase in PM2.5 concentration at lag0 day corresponded to a 0.56% (95% confidence interval (CI) 0.04%–1.08%; P = 0.035) increase in emergency admissions for PUB. There was a clear concentration-response association between PM2.5 concentrations and emergency admissions for PUB. The PM2.5 effect estimates were greater in elderly people (≥65 years old) with the difference approaching statistical significance (percentage change 0.78, 95% CI 0.03%–1.54% in patients ≥65 years old; percentage change 0.32, 95% CI -0.38%–1.03% in patients <65 years old; P = 0.073), but the difference between men and women was not significant (percentage change 0.75, 95% CI 0.08%–1.43% in man; percentage change 0.27, 95% CI -0.51%–1.07% in woman; P = 0.368). ConclusionShort-term elevation in outdoor PM2.5 concentrations was associated with increased emergency admissions for PUB, particularly in elderly people. Future studies are warranted to confirm the findings and elucidate the mechanisms underlying the association.

Mo1272 – Short-Term Effects of Ambient Fine Particulate Matter Pollution on Emergency Admissions for Peptic Ulcer Bleeding in Beijing, China

Mo1272 – Short-Term Effects of Ambient Fine Particulate Matter Pollution on Emergency Admissions for Peptic Ulcer Bleeding in Beijing, China

Short-term effects of ambient fine particulate matter pollution on hospital visits for chronic obstructive pulmonary disease in Beijing, China

BackgroundLittle is known about the effect of ambient fine particulate matter (PM2.5) on chronic obstructive pulmonary disease (COPD) in China. The objective of this study was to explore the short-term effects of PM2.5 on outpatient and inpatient visits for COPD in Beijing, China.MethodsA total of 3,503,313 outpatient visits and 126,982 inpatient visits for COPD between January 1, 2010, and June 30, 2012, were identified from the Beijing Medical Claim Data for Employees. A generalized additive Poisson model was applied to estimate the percentage change with 95% confidence interval (CI) in hospital visits for COPD in relation to an interquartile range (IQR) (90.8 μg/m3) increase in PM2.5 concentrations.ResultsShort-term exposure to PM2.5 was significantly associated with increased use of COPD-related health services. There were clear exposure–response associations of PM2.5 with COPD outpatient and inpatient visits. An IQR increase in the concurrent day PM2.5 concentrations was significantly associated with a 2.38% (95% CI, 2.22%–2.53%) and 6.03% (95% CI, 5.19%–6.87%) increase in daily outpatient visits and inpatient visits, respectively. Elderly people were more sensitive to the adverse effects. The estimated risk was higher during the warm season compared to the cool season.ConclusionsShort-term exposure to PM2.5 was associated with increased risk of hospital visits for COPD. Our findings contributed to the limited evidence concerning the effects of ambient PM2.5 on COPD morbidity in developing countries.

Research round-up

With data from a prospective cohort study, Lin and colleagues examine the effects of air pollution and smoking on depression. Data were analysed for 41 785 individuals from 6 low and middle income countries. Analysis showed an association between air pollution and risk of depression: for each 10μg/m3 increase in ambient fine particulate matter pollution, the adjusted odds ratio (OR) for depression was 1·10 (95% CI 1·02–1·19). Tobacco smoking was also linked with increased risk of depressive symptoms (>8 cigarettes per day: OR 1·27 [95% CI 1·13–1·43]). There was some evidence that the combined effects of air pollution and tobacco consumption were greater than the added effects of the individual components, although the association was not significant when a multiplicative model was used.

Exposure to air pollution and tobacco smoking and their combined effects on depression in six low- and middle-income countries.

BackgroundLittle is known about the joint mental health effects of air pollution and tobacco smoking in low- and middle-income countries.AimsTo investigate the effects of exposure to ambient fine particulate matter pollution (PM2.5) and smoking and their combined (interactive) effects on depression.MethodMultilevel logistic regression analysis of baseline data of a prospective cohort study (n = 41 785). The 3-year average concentrations of PM2.5 were estimated using US National Aeronautics and Space Administration satellite data, and depression was diagnosed using a standardised questionnaire. Three-level logistic regression models were applied to examine the associations with depression.ResultsThe odds ratio (OR) for depression was 1.09 (95% C11.01-1.17) per 10 μg/m3 increase in ambient PM2.5, and the association remained after adjusting for potential confounding factors (adjusted OR = 1.10, 95% CI 1.02-1.19). Tobacco smoking (smoking status, frequency, duration and amount) was also significantly associated with depression. There appeared to be a synergistic interaction between ambient PM2.5 and smoking on depression in the additive model, but the interaction was not statistically significant in the multiplicative model.ConclusionsOur study suggests that exposure to ambient PM2.5 may increase the risk of depression, and smoking may enhance this effect.

Using daily excessive concentration hours to explore the short-term mortality effects of ambient PM2.5 in Hong Kong

We developed a novel indicator, daily excessive concentration hours (DECH), to explore the acute mortality impacts of ambient fine particulate matter pollution (PM2.5) in Hong Kong. The DECH of PM2.5 was calculated as daily concentration-hours >25 μg/m3. We applied a generalized additive models to quantify the association between DECH and mortality with adjustment for potential confounders. The results showed that the DECH was significantly associated with mortality. The excess mortality risk for an interquartile range (565 μg/m3*hours) increase in DECH of PM2.5 was 1.65% (95% CI: 1.05%, 2.26%) for all natural mortality at lag 02 day, 2.01% (95% CI: 0.82%, 3.21%) for cardiovascular mortality at lag 03 days, and 1.41% (95% CI: 0.34%, 2.49%) for respiratory mortality at lag 2 day. The associations remained consistent after adjustment for gaseous air pollutants (daily mean concentration of SO2, NO2 and O3) and in alternative model specifications. When compared to the mortality burden of daily mean PM2.5, DECH was found to be a relatively conservative indicator. This study adds to the evidence by showing that daily excessive concentration hours of PM2.5 might be a new predictor of mortality in Hong Kong.