Short‐term Effects of Ambient Gaseous Pollutants and Particulate Matter on Daily Mortality in Shanghai, China

Association Between Nitrogen Dioxide Pollution and Cause-Specific Mortality in China: Cross-Sectional Time Series Study

BACKGROUND

Nitrogen dioxide (NO2) has been frequently linked to a range of diseases and associated with high rates of mortality and morbidity worldwide. However, there is limited evidence regarding the risk of NO2 on a spectrum of causes of mortality. Moreover, adjustment for potential confounders in NO2 analysis has been insufficient, and the spatial resolution of exposure assessment has been limited.

OBJECTIVE

This study aimed to quantitatively assess the relationship between short-term NO2 exposure and death from a range of causes by adjusting for potential confounders in Guangzhou, China, and determine the modifying effect of gender and age.

METHODS

A time series study was conducted on 413,703 deaths that occurred in Guangzhou during the period of 2010 to 2018. The causes of death were classified into 10 categories and 26 subcategories. We utilized a generalized additive model with quasi-Poisson regression analysis using a natural cubic splines function with lag structure of 0 to 4 days to estimate the potential lag effect of NO2 on cause-specific mortality. We estimated the percentage change in cause-specific mortality rates per 10 μg/m3 increase in NO2 levels. We stratified meteorological factors such as temperature, humidity, wind speed, and air pressure into high and low levels with the median as the critical value and analyzed the effects of NO2 on various death-causing diseases at those high and low levels. To further identify potentially vulnerable subpopulations, we analyzed groups stratified by gender and age.

RESULTS

A significant association existed between NO2 exposure and deaths from multiple causes. Each 10 μg/m3 increment in NO2 density at a lag of 0 to 4 days increased the risks of all-cause mortality by 1.73% (95% CI 1.36%-2.09%) and mortality due to nonaccidental causes, cardiovascular disease, respiratory disease, endocrine disease, and neoplasms by 1.75% (95% CI 1.38%-2.12%), 2.06% (95% CI 1.54%-2.59%), 2.32% (95% CI 1.51%-3.13%), 2.40% (95% CI 0.84%-3.98%), and 1.18% (95% CI 0.59%-1.78%), respectively. Among the 26 subcategories, mortality risk was associated with 16, including intentional self-harm, hypertensive disease, and ischemic stroke disease. Relatively higher effect estimates of NO2 on mortality existed for low levels of temperature, relative humidity, wind speed, and air pressure than with high levels, except a relatively higher effect estimate was present for endocrine disease at a high air pressure level. Most of the differences between subgroups were not statistically significant. The effect estimates for NO2 were similar by gender. There were significant differences between the age groups for mortality due to all causes, nonaccidental causes, and cardiovascular disease.

CONCLUSIONS

Short-term NO2 exposure may increase the risk of mortality due to a spectrum of causes, especially in potentially vulnerable populations. These findings may be important for predicting and modifying guidelines for NO2 exposure in China.

Exploring the impact of particulate matter on mortality in coastal Mediterranean environments

Air pollution is one of the most important problems the world is facing nowadays, adversely affecting public health and causing millions of deaths every year. Particulate matter is a criteria pollutant that has been linked to increased morbidity, as well as all-cause and cause-specific mortality. However, this association remains under-investigated in smaller-size cities in the Eastern Mediterranean, which are also frequently affected by heat waves and dust storms. This study explores the impact of particulate matter with an aerodynamic diameter ≤ 10 μm (PM₁₀) and ≤ 2.5 μm (PM_2.5) on mortality (all-cause, cardiovascular, respiratory) in two coastal cities in the Eastern Mediterranean; Thessaloniki, Greece and Limassol, Cyprus. Generalized additive Poisson models were used to explore overall and gender-specific associations, controlling for long- and short-term patterns, day of week and the effect of weather variables. Moreover, the effect of different lags, season, co-pollutants and dust storms on primary associations was investigated. A 10 μg/m³ increase in PM_2.5 resulted in 1.10 % (95 % CI: -0.13, 2.34) increase in cardiovascular mortality in Thessaloniki, and in 3.07 % (95 % CI: -0.90, 7.20) increase in all-cause mortality in Limassol on the same day. Additionally, significant positive associations were observed between PM_2.5 as well as PM₁₀ and mortality at different lags up to seven days. Interestingly, an association with dust storms was observed only in Thessaloniki, having a protective effect, while the gender-specific analysis revealed significant associations only for the males in both cities. The outcome of this study highlights the need of city- or county-specific public health interventions to address the impact of climate, population lifestyle behaviour and other socioeconomic factors that affect the exposure to air pollution and other synergistic effects that alter the effect of PM on population health.

Observed causative impact of fine particulate matter on acute upper respiratory disease: a comparative study in two typical cities in China

Association between fine particulate matter (PM_2.5) and respiratory health has attracted great concern in China. Substantial epidemiological evidences confirm the correlational relationship between PM_2.5 and respiratory disease in many Chinese cities. However, the causative impact of PM_2.5 on respiratory disease remains uncertain and comparative analysis is limited. This study aims to explore and compare the correlational relationship as well as the causal connection between PM_2.5 and upper respiratory tract infection (URTI) in two typical cities (Beijing, Shenzhen) with rather different ambient air environment conditions. The distributed lag nonlinear model (DLNM) was used to detect the correlational relationship between PM_2.5 and URTI by revealing the lag effect pattern of PM_2.5 on URTI. The convergent cross mapping (CCM) method was applied to explore the causal connection between PM_2.5 and URTI. The results from DLNM indicate that an increase of 10 μg/m³ in PM_2.5 concentration is associated with an increase of 1.86% (95% confidence interval: 0.74%-2.99%) in URTI at a lag of 13 days in Beijing, compared with 2.68% (95% confidence interval: 0.99-4.39%) at a lag of 1 day in Shenzhen. The causality detection with CCM quantitatively demonstrates the significant causative influence of PM_2.5 on URTI in both two cities. Findings from the two methods consistently show that people living in low-concentration areas (Shenzhen) are less tolerant to PM_2.5 exposure than those in high-concentration areas (Beijing). In general, our study highlights the adverse health effects of PM_2.5 pollution on the general public in cities with various PM_2.5 levels and emphasizes the needs for the government to provide appropriate solutions to control PM_2.5 pollution, even in cities with low PM_2.5 concentration.

Short-term exposure to nitrogen dioxide and mortality: A systematic review and meta-analysis

BACKGROUND

Ambient air pollution has been characterized as a leading cause of mortality worldwide and has been associated with cardiovascular and respiratory diseases. There is increasing evidence that short-term exposure to nitrogen dioxide (NO₂), is related to adverse health effects and mortality.

METHODS

We conducted a systematic review of short-term NO₂ and daily mortality, which were indexed in PubMed and Embase up to June 2021. We calculated random-effects estimates by different continents and globally, and tested for heterogeneity and publication bias.

RESULTS

We included 87 articles in our quantitative analysis. NO₂ and all-cause as well as cause-specific mortality were positively associated in the main analysis. For all-cause mortality, a 10 ppb increase in NO₂ was associated with a 1.58% (95%CI 1.28%-1.88%, I² = 96.3%, Eggers' test p < 0.01, N = 57) increase in the risk of death. For cause-specific mortality, a 10 ppb increase in NO₂ was associated with a 1.72% (95%CI 1.41%-2.04%, I² = 87.4%, Eggers' test p < 0.01, N = 42) increase in cardiovascular mortality and a 2.05% (95%CI 1.52%-2.59%, I² = 78.5%, Eggers' test p < 0.01, N = 38) increase in respiratory mortality. In the sensitivity analysis, the meta-estimates for all-cause mortality, cardiovascular and respiratory mortality were nearly identical. The heterogeneity would decline to varying degrees through regional and study-design stratification.

CONCLUSIONS

This study provides evidence of an association between short-term exposure to NO₂, a proxy for traffic-sourced air pollutants, and all-cause, cardiovascular and respiratory mortality.

The Influence of Air Pollutants and Meteorological Conditions on the Hospitalization for Respiratory Diseases in Shenzhen City, China

Air pollutants have significant direct and indirect adverse effects on public health. To explore the relationship between air pollutants and meteorological conditions on the hospitalization for respiratory diseases, we collected a whole year of daily major air pollutants’ concentrations from Shenzhen city in 2013, including Particulate Matter (PM₁₀, PM_2.5), Nitrogen dioxide (NO₂), Ozone (O₃), Sulphur dioxide (SO₂), and Carbon monoxide (CO). Meanwhile, we also gained meteorological data. This study collected 109,927 patients cases with diseases of the respiratory system from 98 hospitals. We investigated the influence of meteorological factors on air pollution by Spearman correlation analysis. Then, we tested the short-term correlation between significant air pollutants and respiratory diseases’ hospitalization by Distributed Lag Non-linear Model (DLNM). There was a significant negative correlation between the north wind and NO₂ and a significant negative correlation between the south wind and six pollutants. Except for CO, other air pollutants were significantly correlated with the number of hospitalized patients during the lag period. Most of the pollutants reached maximum Relative Risk (RR) with a lag of five days. When the time lag was five days, the annual average of PM₁₀, PM_2.5, SO₂, NO₂, and O₃ increased by 10%, and the risk of hospitalization for the respiratory system increased by 0.29%, 0.23%, 0.22%, 0.25%, and 0.22%, respectively. All the pollutants except CO impact the respiratory system’s hospitalization in a short period, and PM10 has the most significant impact. The results are helpful for pollution control from a public health perspective.

Short-term exposure to particulate matter (PM10 and PM2.5), nitrogen dioxide (NO2), and ozone (O3) and all-cause and cause-specific mortality: Systematic review and meta-analysis

BACKGROUND

Air pollution is a leading cause of mortality and morbidity worldwide. Short-term exposure (from one hour to days) to selected air pollutants has been associated with human mortality. This systematic review was conducted to analyse the evidence on the effects of short-term exposure to particulate matter with aerodynamic diameters less or equal than 10 and 2.5 µm (PM_10, PM_2.5), nitrogen dioxide (NO₂), and ozone (O₃), on all-cause mortality, and PM₁₀ and PM_2.5 on cardiovascular, respiratory, and cerebrovascular mortality.

METHODS

We included studies on human populations exposed to outdoor air pollution from any source, excluding occupational exposures. Relative risks (RRs) per 10 µg/m³ increase in air pollutants concentrations were used as the effect estimates. Heterogeneity between studies was assessed using 80% prediction intervals. Risk of bias (RoB) in individual studies was analysed using a new domain-based assessment tool, developed by a working group convened by the World Health Organization and designed specifically to evaluate RoB within eligible air pollution studies included in systematic reviews. We conducted subgroup and sensitivity analyses by age, sex, continent, study design, single or multicity studies, time lag, and RoB. The certainty of evidence was assessed for each exposure-outcome combination. The protocol for this review was registered with PROSPERO (CRD42018087749).

RESULTS

We included 196 articles in quantitative analysis. All combinations of pollutants and all-cause and cause-specific mortality were positively associated in the main analysis, and in a wide range of sensitivity analyses. The only exception was NO₂, but when considering a 1-hour maximum exposure. We found positive associations between pollutants and all-cause mortality for PM₁₀ (RR: 1.0041; 95% CI: 1.0034-1.0049), PM_2.5 (RR: 1.0065; 95% CI: 1.0044-1.0086), NO₂ (24-hour average) (RR: 1.0072; 95% CI: 1.0059-1.0085), and O₃ (RR: 1.0043; 95% CI: 1.0034-1.0052). PM₁₀ and PM_2.5 were also positively associated with cardiovascular, respiratory, and cerebrovascular mortality. We found some degree of heterogeneity between studies in three exposure-outcome combinations, and this heterogeneity could not be explained after subgroup analysis. RoB was low or moderate in the majority of articles. The certainty of evidence was judged as high in 10 out of 11 combinations, and moderate in one combination.

CONCLUSIONS

This study found evidence of a positive association between short-term exposure to PM₁₀, PM_2.5, NO₂, and O₃ and all-cause mortality, and between PM₁₀ and PM_2.5 and cardiovascular, respiratory and cerebrovascular mortality. These results were robust through several sensitivity analyses. In general, the level of evidence was high, meaning that we can be confident in the associations found in this study.

Short- and intermediate-term exposure to NO2 and mortality: A multi-county analysis in China

Nitrogen dioxide (NO2) is a well-established traffic emissions tracer and has been associated with multiple adverse health outcomes. Short- and long-term exposure to NO2 has been studied and is well-documented in existing literature, but information on intermediate-term NO2 effects and mortality is lacking, despite biological plausibility. We obtained daily NO2 and mortality data from 42 counties in China from 2013 to 2015. Distributed-lag non-linear models were employed to investigate the relationship between non-accidental mortality and NO2 up to 30 days before the event, including PM2.5, temperature, relative humidity, and holidays as covariates in a random effects meta-analysis pooling county-specific estimates. We repeated the analysis for cardiovascular- and respiratory-related mortality, and explored sex-stratified associations. Per 10 μg/m3 increase in NO2, we estimated a 0.13% (95%CI: 0.03, 0.23%), 0.57% (95%CI: -0.04, 1.18%), and -0.14% (95%CI: -1.63, 1.37%) change in non-accidental mortality for same-day and previous-day NO2 (lag0-1 cumulated), in the preceding 7 days (lag0-7 cumulated), and in the preceding 30 days (lag0-30 cumulated), respectively. The strongest estimate was observed for respiratory-related mortality in the lag0-30 cumulated effect for women (3.12%; 95%CI: -1.66, 8.13%). We observed a trend of higher effect estimates of intermediate-term NO2 exposure on respiratory mortality compared to that of the short-term, although the differences were not statistically significant. Our results at longer lags for all-cause and cardiovascular mortality were sensitive to modeling choices. Future work should further investigate intermediate-term air pollution exposure given their potential biological relevance, but in larger scale settings.

Association between PM2.5 and mortality of stomach and colorectal cancer in Xi'an: a time-series study

Globally, fine particulate matter has been associated with several health problems including cancer. However, most studies focused mainly on lung cancer. Stomach and colorectal cancers play significant roles in increasing public health's cancer globally. This study focused on investigating a possible significant association between exposure to fine particulate matter (PM_2.5) and mortality due to stomach and colorectal cancer in Xi'an from 2014 to 2016. Using time-series analysis, the study applied both single and multi-pollutant(s) approaches for investigations; PM_2.5 was the pollutant of interest. Generalized additive model (GAM) was the core statistical method used with the addition of distributed lag model (DLM) to observe delayed effects. As a single pollutant, PM_2.5 was significantly associated with stomach cancer mortality only RR (95%CI): 1.0003 (1.0001, 1.002). For the multi-pollutant analysis, PM_2.5 combinations with NO₂ were significantly associated with both stomach and colorectal cancer mortality RR (95%CI): 1.0103 (1.009, 1.021) and 1.054 (1.0324, 1.0667), respectively. Also, PM_2.5 combination with O₃ was significantly associated with colorectal cancer mortality, RR (95%CI): 1.0151 (1.0091, 1.0172), but no association was noted for combination with SO₂. Though this study has reported significant associations, it will be beneficial for the public's health if more studies further investigate the relationship between exposure to PM_2.5 and other cancer mortality.

Distribution characteristics and noncarcinogenic risk assessment of culturable airborne bacteria and fungi during winter in Xinxiang, China

Bioaerosols are an important component of particulate matter in the atmosphere and are harmful to human health. In this study, the concentration, size distribution, and factors influencing culturable airborne bacteria and fungi in the atmosphere were investigated using a six-stage impactor device in the city of Xinxiang, China, during the winter season. The results revealed that the concentration of culturable airborne bacteria and fungi varied significantly during the sampling period: 4595 ± 3410 and 6358 ± 5032 CFU/m³, respectively. The particle sizes of the bioaerosols were mainly within stage V (1.1-2.1 μm), and fine particulate matter accounted for 45.9% ± 18.9% of airborne bacteria and 52.0% ± 18.5% of airborne fungi, respectively. With the deterioration of air quality, the concentration of airborne fungi gradually increased, and that of airborne bacteria increased when the air quality index was lower than 200 and decreased when it was higher than 200. With respect to the diurnal variation pattern of bioaerosol concentration, the highest and lowest concentrations were registered at night and noon, respectively, probably because of changes in ultraviolet radiation intensity. Bioaerosol concentration positively correlated with humidity, concentration of PM_2.5, PM₁₀, SO₂, and NO₂ and negatively correlated with O₃ concentration. The risk of exposure of humans to the airborne bacteria was primarily associated with the respiratory inhalation pathway, and the risk of skin exposure was negligible. These results should improve our understanding of the threat of bioaerosols to public health.

A comprehensive evaluation of the association between ambient air pollution and adverse health outcomes of major organ systems: a systematic review with a worldwide approach

Ambient air pollution is nowadays one of the most crucial contributors to deteriorating health status worldwide. The components of air pollution include PM_2.5 and PM₁₀, NO₂, SO₂, CO, O₃, and organic compounds. They are attributed to several health outcomes, for instance, cardiovascular diseases (CVD), respiratory diseases, birth outcomes, neurologic diseases, and psychiatric diseases. The objective of this study is to evaluate the association between different ambient air pollutants and the above-mentioned health outcomes. In this systematic review, a total of 76 articles was ultimately selected from 2653 articles, through multiple screening steps by the aid of a set of exclusion criteria as non-English articles, indoor air pollution assessment, work-related, occupational and home-attributed pollution, animal studies, tobacco smoking effects, letters to editors, commentaries, animal experiments, reviews, case reports and case series, out of 19,862 published articles through a systematic search in PubMed, Web of Science, and Scopus. Then, the associations between air pollution and different health outcomes were measured as relative risks and odds ratios. The association between air pollutants, PM_2.5 and PM₁₀, NO₂, SO₂, CO, O₃, and VOC with major organ systems health was investigated through the gathered studies. Relative risks and/or odds ratios attributed to each air pollutant/outcome were ultimately reported. In this study, a thorough and comprehensive discussion of all aspects of the contribution of ambient air pollutants in health outcomes was proposed. To our knowledge up to now, there is no such comprehensive outlook on this issue. Growing concerns in concert with air pollution-induced health risks impose a great danger on the life of billions of people worldwide. Should we propose ideas and schemes to reduce ambient air pollutant, there will be dramatic reductions in the prevalence and occurrence of health-threatening conditions.

A tensor product quasi-Poisson model for estimating health effects of multiple ambient pollutants on mortality

BACKGROUND

People are exposed to mixtures of highly correlated gaseous, liquid and solid pollutants. However, in previous studies, the assessment of air pollution effects was mainly based on single-pollutant models or was simultaneously included as multiple pollutants in a model. It is essential to develop appropriate methods to accurately estimate the health effects of multiple pollutants in the presence of a high correlation between pollutants.

METHODS

The flexible tensor product smooths of multiple pollutants was applied for the first time in a quasi-Poisson model to estimate the health effects of SO₂, NO₂ and PM₁₀ on daily all-cause deaths during 2005-2012 in Guangzhou, China. The results were compared with those from three other conventional models, including the single-pollutant model and the three-pollutant model with and without first-order interactions.

RESULTS

The tensor product model revealed a complex interaction among three pollutants and significant combined effects of PM₁₀, NO₂ and SO₂, which revealed a 2.53% (95%CI: 1.03-4.01%) increase in mortality associated with an interquartile-range (IQR) increase in the concentrations of all three pollutants. The combined effect estimated by the single-pollutant model was 5.63% (95% CI: 3.96-7.34%). Although the conventional three-pollutant models produced combined effect estimates (2.20, 95%CI, 1.18-3.23%; 2.78, 95%CI: 1.35-4.23%) similar to those of the tensor product model, they distorted the estimates and inflated the variances of the estimates when attributing the combined health effects to individual pollutants.

CONCLUSIONS

The single-pollutant model or conventional multi-pollutant model may yield misleading results in the presence of collinearity. The tensor product quasi-Poisson regression provides a novel approach to the assessment of the health impacts of multiple pollutants by flexibly fitting the interaction effects and avoiding the collinearity problem.

Association between Atmospheric Particulate Pollutants and Mortality for Cardio-Cerebrovascular Diseases in Chinese Korean Population: A Case-Crossover Study

Background: Air pollution in large Chinese cities has led to recent studies that highlighted the relationship between particulate matters (PM) and elevated risk of cardio-cerebrovascular mortality. However, it is unclear as to whether: (1) The same adverse relations exist in cities with relatively low levels of air pollution; and (2) the relationship between the two are similar across ethnic groups. Methods: We collected data of PM_2.5 (PM with an aerodynamic diameter ≤ 2.5 µm) and PM₁₀ (aerodynamic diameter ≤ 10 µm) in the Yanbian Korean Autonomous Prefecture between 1 January 2015 and 31 December 2016. Using a time-stratified case-crossover design, we investigated whether levels of particulate pollutants influence the risk of cardio-cerebrovascular disease mortality among ethnic Korean vs. ethnic Han residents residing in the Yanbian Korean Autonomous Prefecture. Results: Under the single air pollutant model, the odds ratios (ORs) of cardio-cerebrovascular disease were 1.025 (1.024–1.026) for each 10 μg/m³ increase in PM_2.5 at lag0 day, 1.012 (1.011–1.013) for each 10 μg/m³ increase in PM₁₀ at lag1 day. In the multi-pollutant model adjusted by PM₁₀, SO₂, and NO₂, the ORs of cardio-cerebrovascular disease were 1.150 (1.145–1.155) for ethnic Koreans and 1.154 (1.149–1.158) for ethnic Hans for each 10 μg/m³ increase in PM_2.5. In the multi-pollutant model adjusted by PM_2.5, SO₂, and NO₂, the ORs of cardio-cerebrovascular disease were 1.050 (1.047–1.053) for ethnic Koreans and 1.041 (1.039–1.043) for ethnic Hans for each 10 μg/m³ increase in PM₁₀. Conclusion: This study showed that PM_2.5 and PM₁₀ were associated with increased risks of acute death events in residential cardio-cerebrovascular disease in Yanbian, China.

Short-term effect of air pollution on asthma patient visits in Shanghai area and assessment of economic costs

BACKGROUNDS

Shanghai, in China, is one of the highest incidence cities for asthma morbidity. However, few studies have systemically explored the association of ambient air pollutants and asthma patients with economic costs.

OBJECTIVES

The study researched the link of short-term ambient air pollutants exposure and asthma patients in Shanghai. Furthermore, the economic cost was also assessed.

METHODS

We applied the generalized addictive model (GAM) to analyze the association between ambient air pollutants and asthma patients with economic costs assessment.

RESULTS

We investigated a total of 7200 asthma patient visits (inhabitant in Shanghai). A 10 µg m^-3 increase in the current day concentrations of SO₂, CO, NO₂, PM₁₀, O₃ and PM_2.5 corresponded to increase of 3.79% [95% CI: 0.84%, 6.83%], 0.27% [95% CI: 0.14%, 0.40%], 0.63% [95% CI: - 0.81%, 2.10%], 1.11% [95% CI: 0.38%, 1.85%], 0.23% [95% CI: 0.31%, 078%] and 1.27% [95% CI: 0.29%, 2.26%] in daily asthma patient visits. In economic cost level, the economic cost of asthma patients were attributed to ambient air pollutants (SO₂, CO, NO₂, PM₁₀, O₃ and PM_2.5) with 197 million USD losses per year. Among, the economic cost of asthma patient visits were attributed to SO₂, CO, NO₂, PM₁₀, O₃ and PM_2.5 with 101.30, 7.46, 17.15, 30.18, 6.39 and 34.50 million USD loss per year, respectively.

CONCLUSIONS

Short-term exposure to SO₂, CO, NO₂, PM₁₀, O₃ and PM_2.5 were linked to asthma patient visits increase in Shanghai areas. The economic cost of asthma patient visits were attributed to ambient air pollutants (SO₂, CO, O₃, PM₁₀, NO₂ and PM_2.5) with 197 million USD losses per year. The study strengthen our fundamental comprehending of impacts of ambient air pollutants on human health and economy burden.

Cardiorespiratory health effects of gaseous ambient air pollution exposure in low and middle income countries: a systematic review and meta-analysis

BACKGROUND

Lack of research on the effects of gaseous pollutants (nitrogen oxides [NO_x], sulfur dioxide [SO₂], carbon monoxide [CO] and ozone [O₃]) in the ambient environment on health outcomes from within low and middle income countries (LMICs) is leading to reliance on results from studies performed within high income countries (HICs). This systematic review and meta-analysis examines the cardiorespiratory health effects of gaseous pollutants in LMICs exclusively.

METHODS

Systematic searching was carried out and estimates pooled by pollutant, lag and outcome, and presented as excess relative risk per 10 μg/m³ (NO_x, SO₂, O₃) or 1 ppm (CO) increase pollutant. Sub-group analysis was performed examining estimates by specific outcomes, city and co-pollutant adjustment.

RESULTS

Sixty studies met the inclusion criteria, most (44) from the East Asia and Pacific region. A 10 μg/m³ increase in same day NOx was associated with 0.92% (95% CI: 0.44, 1.39), and 0.70% (0.01, 1.40) increases in cardiovascular and respiratory mortality respectively, same day NO_x was not associated with morbidity. Same day sulfur dioxide was associated with 0.73% (0.04, 1.42) and 0.50% (0.01, 1.00) increases in respiratory morbidity and in cardiovascular mortality respectively.

CONCLUSIONS

Acute exposure to gaseous ambient air pollution (AAP) is associated with increases in morbidity and mortality in LMICs, with greatest associations observed for cardiorespiratory mortality.

Cardiorespiratory health effects of particulate ambient air pollution exposure in low-income and middle-income countries: a systematic review and meta-analysis

BACKGROUND

Most prospective studies on the health effects of particulate ambient air pollution exposure have focused on high-income countries, which have much lower pollutant concentrations than low-income and middle-income countries (LMICs) and different sources of pollution. We aimed to investigate the cardiorespiratory health effects of particulate ambient air pollution exposure in LMICs exclusively.

METHODS

For this systematic review and meta-analysis, we searched PubMed, Web of Science, Embase, LILACS, Global Health, and Proquest for studies published between database inception and Nov 28, 2016, investigating the cardiorespiratory health effects of particulate ambient air pollution exposure in LMICs. Data were extracted from published studies by one author, and then checked and verified by all authors independently. We pooled estimates by pollutant type (particulate matter with a diameter of <2·5 μm [PM_2·5] or 2·5-10 μm [PM₁₀]), lag, and outcome, and presented them as excess relative risk per 10 μg/m³ increase in particulate ambient air pollution. We used a random-effects model to derive overall excess risk. The study protocol is registered with PROSPERO, number CRD42016051733.

FINDINGS

Of 1553 studies identified, 91 met the full eligibility criteria. Only four long-term exposure studies from China were identified and not included in the meta-analysis. A 10 μg/m³ increase in same-day PM_2·5 was associated with a 0·47% (95% CI 0·34-0·61) increase in cardiovascular mortality and a 0·57% (0·28-0·86) increase in respiratory mortality. A 10 μg/m³ increase in same-day PM₁₀ was associated with a 0·27% (0·11-0·44) increase in cardiovascular mortality and a 0·56% (0·24-0·87) increase in respiratory mortality.

INTERPRETATION

Short-term exposure to particulate ambient air pollution is associated with increases in cardiorespiratory morbidity and mortality in LMIC's, with apparent regional-specific variations.

FUNDING

None.

Seasonal Effect on Association between Atmospheric Pollutants and Hospital Emergency Room Visit for Stroke

BACKGROUND

The relationship between air pollution and stroke is conflicting. This study was conducted to document the relationship between daily changes in atmospheric pollutants and hospital emergency room visits (ERVs) for stroke.

METHODS

Data of daily hospital ERVs for stroke and atmospheric pollutants in Changsha city between 2008 and 2009 were collected. Using a time-stratified bidirectional case-crossover design, we analyzed the association between atmospheric pollutants and stroke incidence in 4 seasons.

RESULTS

In the single-pollutant model, we found changes in sulfur dioxide (SO₂), nitrogen dioxide (NO₂), and particulate matters (PM₁₀) were significantly associated with cerebral hemorrhage and cerebral infarction (P < .05) in lags of 0-2 days in autumn. A 10-µg/m³ increase in SO₂ in autumn was significantly associated with ERVs for both cerebral hemorrhage (odds ratio [OR], 1.166; 95% confidence interval [CI], 1.012-1.343) and cerebral infarction (OR, 1.214; 95% CI, 1.018-1.448). NO₂ in autumn was significantly associated with ERVs for cerebral hemorrhage and infarction with OR = 1.162 (95% CI, 1.005-1.344) and OR = 1.137 (95% CI, 1.011-1.279), respectively. PM₁₀ in autumn was significantly associated with ERVs for cerebral hemorrhage and infarction with OR = 1.147 (95% CI, 1.045-1.259) and OR = 1.091 (95% CI, 1.019-1.168), respectively. Results of the multipollutant model showed that in autumn after PM₁₀ and NO₂ adjustment, only a 10-µg/m³ increase in SO₂ was significantly associated with ERVs for cerebral infarction (OR, 1.158; 95% CI, 1.006-1.333; P < .05). SO₂, NO₂, and PM₁₀ were not associated with ERVs for cerebral hemorrhage (P > .05).

CONCLUSIONS

This study demonstrates that the change in atmospheric SO₂ levels in Changsha is significantly associated with the stroke incidence in autumn.

The Association between Air Pollution and Population Health Risk for Respiratory Infection: A Case Study of Shenzhen, China

Nowadays, most of the research on air pollution and its adverse effects on public health in China has focused on megacities and heavily-polluted regions. Fewer studies have focused on cities that are slightly polluted. Shenzhen used to have a favorable air environment, but its air quality has deteriorated gradually as a result of development in recent years. So far, no systematic investigations have been conducted on the adverse effects of air pollution on public health in Shenzhen. This research has applied a time series analysis model to study the possible association between different types of air pollution and respiratory hospital admission in Shenzhen in 2013. Respiratory hospital admission was divided into two categories for comparison analysis among various population groups: acute upper respiratory infection and acute lower respiratory infection. The results showed that short-term exposure to ambient air pollution was significantly associated with acute respiratory infection hospital admission in Shenzhen in 2013. Children under 14 years old were the main susceptible population of acute respiratory infection due to air pollution. PM₁₀, PM_2.5 and NO₂ were the primary air pollutants threatening respiratory health in Shenzhen. Though air pollution level is generally relatively low in Shenzhen, it will benefit public health to control the pollution of particulate matter as well as other gaseous pollutants.

The effect of particulate matter size on cardiovascular health in Taipei Basin, Taiwan

BACKGROUND

Although the overall effect of particulate matter (PM) on cardiovascular disease (CVD) has been previously documented, the effect of different PM sizes (PM₁₀, PM_2.5-10 and PM_2.5) has not been well studied. This study estimates the effect of different PM sizes on the incidence of CVD in Taipei, Taiwan.

METHODS

We collected outpatients with CVD from 2006 to 2010 and data on the concentrations of air pollutants such as PM₁₀, PM_2.5-10, PM_2.5, sulfur dioxide, carbon monoxide, nitrogen dioxide, and ozone. A Distributed Lag Non-linear Model (DLNM) was used to explore the effect of different PM sizes on CVD risk.

RESULTS

In high air pollution events, PM_2.5 was significantly associated with elevated risk (4.9%) [95% confidence interval (CI): 1.010-1.089] for CVD with increasing interquartile range (IQR) in single air pollutant model. PM_2.5-10 and PM₁₀ did not show a significant positive association with CVD in this study. After adjusting for other air pollutants such as SO₂, CO, NO₂, and O₃, the estimated effect of PM_2.5 only decreased 0.2%. Moreover, patients under 40 years old did not show a significant association between PM_2.5 and CVD.

CONCLUSION

This study demonstrates that only PM_2.5 is significantly positively correlated with the number of daily outpatient visits for CVD during high air pollution events.

Community health risk assessment of primary aluminum smelter emissions

OBJECTIVE

Primary aluminum production is an industrial process with high potential health risk for workers. We consider in this article how to assess community health risks associated with primary aluminum smelter emissions.

METHODS

We reviewed the literature on health effects, community exposure data, and dose-response relationships of the principal hazardous agents emitted.

RESULTS

On the basis of representative measured community exposure levels, we were able to make rough estimates on health risks associated with specific agents and categorize these as none, low, medium, or high.

CONCLUSIONS

It is possible to undertake a rough-estimate community Health Risk Assessment for individual smelters on the basis of information available in the epidemiological literature and local community exposure data.

A review on human health perspective of air pollution with respect to allergies and asthma

The increase in cases of asthma and allergies has become an important health issue throughout the globe. Although these ailments were not common diseases a few short decades ago, they are now affecting a large part of the population in many regions. Exposure to environmental (both outdoor and indoor) pollutants may partially account for the prevalence of such diseases. In this review, we provide a multidisciplinary review based on the most up-to-date survey of literature regarding various types of airborne pollutants and their associations with asthma-allergies. The major pollutants in this respect include both chemical (nitrogen dioxide, ozone, sulfur dioxide, particulate matter, and volatile organic compounds) and biophysical parameters (dust mites, pet allergens, and mold). The analysis was extended further to describe the development of these afflictions in the human body and the subsequent impact on health. This publication is organized to offer an overview on the current state of research regarding the significance of air pollution and its linkage with allergy and asthma.

Associations between fine particle, coarse particle, black carbon and hospital visits in a Chinese city

China is one of the countries with the highest ambient particle levels in the world; however, there have been no epidemiologic studies examining the effects of fine particle (PM2.5), coarse particle (PM10-2.5) and black carbon (BC) simultaneously on morbidity outcomes. In this study, we conducted a time-series analysis to evaluate the acute effects of PM2.5, PM10-2.5, and BC on daily hospital visits in Shanghai, China. During our study period, the mean daily concentrations of PM2.5, PM10-2.5 and BC were 53.9 μg/m(3), 38.4 μg/m(3) and 3.9 μg/m(3), respectively. We found significant associations of PM2.5, PM 10-2.5, and BC with daily hospital visits. An inter-quartile range increase of the average concentrations of the current and previous days in PM2.5, PM10-2.5 and BC was associated with a 1.88% (95% CI: 0.69% to 3.06%), a 1.30% (95% CI: 0.25% to 2.34%) and a 1.33% (95% CI: 0.34% to 2.32%) increase in emergency-room visits, respectively. For outpatient visits, the corresponding estimated changes were -2.44% (95% CI: -6.62% to 1.74%), 1.09% (95% CI: -2.72% to 4.90%) and 3.34% (95% CI: 0.10% to 6.57%) respectively. The effects of BC were more robust than the effects of PM2.5 and PM10-2.5 in two-pollutant models. To our knowledge, this is the first study in China, or even in Asian developing countries, to report the effect of PM2.5, PM10-2.5, and BC simultaneously on morbidity. Our findings also suggest that BC could serve as a valuable air quality indicator that reflects the health risks of airborne particles.

Differentiating the associations of black carbon and fine particle with daily mortality in a Chinese city

There is only limited monitoring data of black carbon for epidemiologic analyses. In the current study, we used the distributed lag models to evaluate the association between mortality outcomes (both total and cause-specific) and exposure to black carbon and fine particle (PM(2.5)) in Shanghai, China. During our research period, the mean daily concentrations of black carbon and PM(2.5) were 3.9 μg/m3 and 53.9 μg/m3, respectively. The regression results showed that black carbon was significantly associated with total and cardiovascular mortality, but not with respiratory mortality. An inter-quartile range increase (2.7 μg/m3) of black carbon corresponded to a 2.3% (95% confidence interval [CI]: 0.6-4.1), 3.2% (95% CI: 0.6-5.7), and 0.6% (95% CI: -4.5 to 5.7) increase in total, cardiovascular and respiratory mortality, respectively. When adjusted for PM(2.5), the effects of black carbon increased and remained statistically significant; in contrast, the associations of PM(2.5) with daily mortality decreased and became statistically insignificant after adjustment for black carbon. To our knowledge, this is the first study in China, or even in Asian developing countries, to report the acute effect of black carbon and PM(2.5) on daily mortality simultaneously. Our findings suggest that black carbon is a valuable additional air quality indicator to evaluate the health risks of ambient particles.

Associations between short-term exposure to nitrogen dioxide and mortality in 17 Chinese cities: the China Air Pollution and Health Effects Study (CAPES)

Few multi-city studies in Asian developing countries have examined the acute health effects of ambient nitrogen dioxide (NO(2)). In the China Air Pollution and Health Effects Study (CAPES), we investigated the short-term association between NO(2) and mortality in 17 Chinese cities. We applied two-stage Bayesian hierarchical models to obtain city-specific and national average estimates for NO(2). In each city, we used Poisson regression models incorporating natural spline smoothing functions to adjust for long-term and seasonal trend of mortality, as well as other time-varying covariates. We examined the associations by age, gender and education status. We combined the individual-city estimates of the concentration-response curves to get an overall NO(2)-mortality association in China. The averaged daily concentrations of NO(2) in the 17 Chinese cities ranged from 26 μg/m(3) to 67 μg/m(3). In the combined analysis, a 10-μg/m(3) increase in two-day moving averaged NO(2) was associated with a 1.63% [95% posterior interval (PI), 1.09 to 2.17], 1.80% (95% PI, 1.00 to 2.59) and 2.52% (95% PI, 1.44 to 3.59) increase of total, cardiovascular, and respiratory mortality, respectively. These associations remained significant after adjustment for ambient particles or sulfur dioxide (SO(2)). Older people appeared to be more vulnerable to NO(2) exposure. The combined concentration-response curves indicated a linear association. Conclusively, this largest epidemiologic study of NO(2) in Asian developing countries to date suggests that short-term exposure to NO(2) is associated with increased mortality risk.

Sulfur dioxide and emergency department visits for stroke and seizure

The purpose of this study was to assess an association between ambient sulfur dioxide and the number of emergency department (ED) visits for ischemic stroke and seizure. The study used data collected in a Vancouver (Canada) hospital in the years 1999–2003. Daily ED visits diagnosed as ministroke, stroke, or seizure were investigated using the case-crossover technique. Conditional logistic regression models were applied to estimate the odds ratios (ORs) and their respective 95% confidence intervals (CIs). The models included temperature and relative humidity in the form of natural splines. The results were reported for an increase in interquartile range ((IQR), IQR = 1.9 ppb for SO₂). Positive and statistically significant associations were obtained for SO₂ and ischemic stroke for all patients (OR = 1.12; CI 1.02, 1.23; lag 3) and for female patients (OR = 1.17; CI 1.01, 1.33; lag 0). In the case of ED visits for seizure, for female patients the results were also statistically significant (OR = 1.15; CI 1.02, 1.28; lag 1 and OR = 1.18; CI 1.05, 1.32; lag 2). These findings suggest that cases of ischemic cerebrovascular accidents are associated with acute exposure to ambient sulfur dioxide.

Associations between size-segregated particle number concentrations and respiratory mortality in Beijing, China

Numerous studies have described the adverse associations between particle mass and respiratory health. The aim of the study was to analyze the associations of particle properties, especially size-segregated particle number concentrations (PNC), and respiratory mortality in Beijing, P.R. China. We gathered daily values of respiratory mortality and air pollution data of the Beijing urban area. Generalized additive models were used to estimate the associations. Single pollutant models showed that delayed concentrations of SO(2), total PNCs, and PNC of 300-1000 nm were adversely associated with total respiratory mortality. There was an indication that adverse health effects of PNCs might be stronger for stagnant air masses. Two-pollutant models verified the independence of associations of total PNCs of other pollutants (SO(2), NO(2), and PM(10)). In conclusion, particle number concentrations, especially accumulation mode particles, might be factors influencing the adverse associations between particulate matter and respiratory health.

Air pollution and health studies in China--policy implications

During the rapid economic development in China, ambient air pollutants in major cities, including PM10 (particulate matter with aerodynamic diameter < or =10 microm) and SO2 have been reduced due to various measures taken to reduce or control sources of emissions, whereas NO2 is stable or slightly increased. However, air pollution levels in China are still at the higher end of the world level. Less information is available regarding changes in national levels of other pollutants such as PM2.5 and ozone. The Chinese Ministry of Environmental Protection (MOEP) set an index for "controlling/reducing total SO2 emissions" to evaluate the efficacy of air pollution control strategy in the country. Total SO2 emissions declined for the first time in 2007. Chinese epidemiologic studies evidenced adverse health effects of ambient air pollution similar to those reported from developed countries, though risk estimates on mortality/morbidity per unit increase of air pollutant are somewhat smaller than those reported in developed countries. Disease burden on health attributable to air pollution is relatively greater in China because of higher pollution levels. Improving ambient air quality has substantial and measurable public health benefits in China. It is recommended that the current Chinese air quality standards be updated/revised and the target for "controlling/reducing total SO2 emissions" be maintained and another target for "reducing total NO2 emissions" be added in view of rapid increase in motor vehicles. Continuous and persistent efforts should be taken to improve ambient air quality.

Survival analysis of long-term exposure to different sizes of airborne particulate matter and risk of infant mortality using a birth cohort in Seoul, Korea

BACKGROUND

Several studies suggest that airborne particulate matter (PM) is associated with infant mortality; however, most focused on short-term exposure to larger particles.

OBJECTIVES

We evaluated associations between long-term exposure to different sizes of particles [total suspended particles (TSP), PM ≤ 10 μm in aerodynamic diameter (PM₁₀), ≤ 10-2.5 μm (PM(10-2.5)), and ≤ 2.5 μm (PM(2.5))] and infant mortality in a cohort in Seoul, Korea, 2004-2007.

METHODS

The study includes 359,459 births with 225 deaths. We applied extended Cox proportional hazards modeling with time-dependent covariates to three mortality categories: all causes, respiratory, and sudden infant death syndrome (SIDS). We calculated exposures from birth to death (or end of eligibility for outcome at 1 year of age) and pregnancy (gestation and each trimester) and treated exposures as time-dependent variables for subjects' exposure for each pollutant. We adjusted by sex, gestational length, season of birth, maternal age and educational level, and heat index. Each cause of death and exposure time frame was analyzed separately.

RESULTS

We found a relationship between gestational exposures to PM and infant mortality from all causes or respiratory causes for normal-birth-weight infants. For total mortality (all causes), risks were 1.44 (95% confidence interval, 1.06-1.97), 1.65 (1.18-2.31), 1.53 (1.22-1.90), and 1.19 (0.83-1.70) per interquartile range increase in TSP, PM₁₀, PM(2.5), and PM(10-2.5), respectively; for respiratory mortality, risks were 3.78 (1.18-12.13), 6.20 (1.50-25.66), 3.15 (1.26-7.85), and 2.86 (0.76-10.85). For SIDS, risks were 0.92 (0.33-2.58), 1.15 (0.38-3.48), 1.42 (0.71-2.87), and 0.57 (0.16-1.96), respectively.

CONCLUSIONS

Our findings provide supportive evidence of an association of long-term exposure to PM air pollution with infant mortality.

Investigation of gene expression of MMP-2 and TIMP-2 mRNA in rat lung in inhaled nickel oxide and titanium dioxide nanoparticles

In order to investigate whether or not dispersed nanoparticles have an effect of inflammation and fibrosis on animals, we developed a nanoparticle generation system and examined the gene expression of matrix metalloproteinase (MMP) and tissue inhibitor matrix proteinase (TIMP) in rat lung containing inhaled nickel oxide (NiO) or titanium dioxide (TiO(2)) nanoparticles. In both experiments, Wistar male rats were exposed to NiO or TiO(2) nanoparticles for 4 wk (6 h/day). The geometric mean diameters of NiO and TiO(2) in the chamber were 139 ± 12 nm and 51 ± 9 nm, respectively. The average concentration of the particle number of NiO and TiO(2) was 1.0E+05 /cm(3) and 2.8E+05 /cm(3), respectively. At 4 d, 1 and 3 months after the end of the inhalation, the rats exposed to these particles were sacrificed and the gene expressions of MMP-2, TIMP-2 and type I collagen were measured using RT-PCR. Pathological finding revealed that there was minimum inflammation with nickel oxide only at 4 d and no change with titanium oxide. However, there were no changes of the gene expression of MMP-2, TIMP-2, and type I collagen in either the NiO or TiO(2) exposure groups. In this study, inhalation of nickel oxide and titanium dioxide nanoparticles did not induce the gene expression of MMP-2 and TIMP-2 mRNA in rat lungs.

Hazard assessments of manufactured nanomaterials

BACKGROUND

It has been difficult to make reliable hazard assessments of manufactured nanomaterials, because the nanomaterials form large agglomerations in both in vitro and in vivo studies.

OBJECTIVE

In the New Energy and Industrial Technology Development Organization (NEDO) Project of Japan, the physicochemical properties of many manufactured nanomaterials are being measured, and in vitro and in vivo studies are being performed to determine which endpoints are correspond to the hazards and risks of nanomaterials. Focusing on titanium dioxide, fullerenes and carbon nanotubes, we introduce findings made in inhalation and intratracheal installation studies overseas, and together with the findings made in the NEDO project, and also assess the hazards presented by manufactured nanomaterials.

RESULTS AND CONCLUSION

A project by NEDO has succeeded in ensuring the stability of dispersion (nanoscale <100 nm) of manufactured nanomaterials, and is developing hazard assessments of manufactured nanomaterials. In these interim reports, the acceptable exposure concentration of titanium dioxide and fullerene was proposed to be 1.2 mg/m(3) and 0.8 mg/m(3) respirable dust in working environment, respectively.

Ambient air pollution and hospital admission in Shanghai, China

No prior studies exist in Mainland China examining the association of outdoor air pollution with hospital admissions. In this study, we conducted a time-series analysis to examine the association of outdoor air pollutants (PM(10), SO(2), and NO(2)) with both total and cause-specific hospital admission in Shanghai, using three years of daily data (2005-2007). Hospital admission and air pollution data were collected from the Shanghai Health Insurance Bureau and Shanghai Environmental Monitoring Center. Natural spline model was used to analyze the data. We found outdoor air pollution was associated with increased risk of total and cardiovascular hospital admission in Shanghai. The effect estimates of air pollutants varied by lag (L) structures of pollutants' concentrations. For lag 5, a 10 microg/m(3) increase in concentration of PM(10), SO(2) and NO(2) corresponded to 0.18% (95% CI: -0.15%, 0.52%), 0.63% (95% CI: 0.03%, 1.23%), and 0.99% (95% CI: 0.10%, 1.88%) increase of total hospital admission; and 0.23% (95% CI: -0.03%, 0.48%), 0.65% (95% CI: 0.19%, 1.12%), and 0.80% (95% CI: 0.10%, 1.49%) increase of cardiovascular hospital admission. The associations appeared to be more evident in the cool season (from November to April) than in the warm season (from May to October). We found significant effects of gaseous pollutants (SO(2) and NO(2)) after adjustment for PM(10). Our analyses provide the first evidence in China that the current air pollution level has an effect on hospital admission and strengthen the rationale for further limiting air pollution levels in Shanghai.

Impact of ambient air pollution on public health under various traffic policies in Shanghai, China

OBJECTIVE

To investigate the potential impact of ambient air pollution on public health under various traffic policies in Shanghai.

METHODS

The exposure level of Shanghai residents to air pollution under various planned traffic scenarios was estimated, and the public health impact was assessed using concentration-response functions derived from available epidemiological studies.

RESULTS

Our results showed that ambient air pollution in relation to traffic scenarios had a significant impact on the future health status of Shanghai residents. Compared with the base case scenario, implementation of various traffic scenarios could prevent 759-1574, 1885-2420, and 2277-2650 PM10-related avoidable deaths (mean-value) in 2010, 2015, and 2020, respectively. It could also decrease the incidence of several relevant diseases.

CONCLUSION

Our findings emphasize the need to consider air pollution-related health effects as an important impact of traffic policy in Shanghai.