Necessity of stirring for outdoor microalgal-bacterial granular sludge process.

As a green process, microalgal-bacterial granular sludge (MBGS) process shows talents in achieving pollutant removal, resource recovery and carbon neutralization. However, when it comes to application, the adequate mixing of MBGS and substrate should be adopted theoretically. Therefore, this study devoted to address the necessity of stirring for MBGS in municipal wastewater treatment. Outdoor performances showed that stirring significantly enhanced both of the photosynthetic efficiency and biomass productivity of MBGS with almost 2-fold increase as compared to non-stirred MBGS, while the average pore size and microalgae-to-bacteria ratio also increased. Consequently, stirring acted as a pivotal role in accelerating pollutants removal, with removals of organics (89.89% COD) and nutrients (99.22% NH4+-N, 92.15% PO43--P) reaching peak levels at 2 h and 6 h, respectively, while removals of organics (87.50% COD) and nutrients (86.11% NH4+-N, 86.76% PO43--P) removal peaked at 8 h for non-stirred MBGS. The improved granule characteristics and microbial compositions due to the stirring were found to be favorable for MBGS to adapting to the changeable weather. Based on the above results, the possible underlying mechanisms of stirring for improving MBGS were illustrated. Overall, stirring positively impacted the photosynthetic efficiency, biomass productivity, pollutant removal and microbial structure for MBGS. This study gains knowledge on stirred MBGS process under outdoor conditions for its future practical application.

Effects of Ultrasound Contrast Agent-Mediated Nerve Growth Factor on Apoptosis of Retinal Ganglion Cells in Mice with Glaucoma.

With an increasing incidence in recent years, glaucoma (GL) has gradually become a global public health problem for humans of all ages. Nerve growth factor (NGF) eye drops, with well-documented stable effect in the treatment of GL, can be potentiated by the administration of NGF drugs via ultrasound contrast agent (UCA). This study analyzed the efficacy of NGF+UCA on GL mice and the influencing mechanism on retinal ganglion cells and further explored the pathological changes of GL mice under different UCA irradiation duration. In this study, we established GL mouse models and treated the mouse with NGF+UCA. The effect of NGF+UCA on intraocular pressure in mice was observed; the flash visual evoked potential of mice was compared; the changes of retinal structure, inflammation index, and oxidative stress index were observed, and autophagic protein levels were tested. Finally, the influence of UCA irradiation duration on GL symptoms was observed. The results showed that the intraocular pressure of mice decreased greatly, while their flash visual evoked potential and nervous layer of retina increased, and their ganglion cells showed stronger proliferation activity and weaker apoptosis and autophagy, indicating that UCA-mediated NGF can strongly improve the pathological condition of GL mice. In addition, PI3K/AKT pathway-associated proteins were inhibited in retina under the intervention of NGF+UCA, which further suggests that the influence of UCA-mediated NGF on GL is achieved by inhibiting autophagy of retinal ganglion cells and enhancing their apoptosis via the PI3K/AKT signaling pathway. Moreover, we found that in the treatment of GL, three weeks of UCA irradiation and six weeks caused no significant difference in the pathological manifestations and ganglion cells of mice, while after six weeks of irradiation, the level of NLRP3 in mice increased. In conclusion, UCA-mediated NGF can significantly improve the pathological condition of GL mice and improve the apoptosis of retinal ganglion cells by inhibiting autophagy, which is associated with the inhibition of the PI3K/AKT signal pathway. In terms of selection of UCA irradiation duration, three weeks of irradiation is enough to yield good clinical results.

Trifocal diffractive intraocular lens implantation in patients after previous corneal refractive laser surgery for myopia.

BACKGROUND: With the difficulties in IOL power calculation and the potential side effects occurring postoperatively, multifocal IOL implantation after previous corneal refractive surgery are rarely reported especially for the trifocal IOL. Herein we report the clinical observation of trifocal IOL implantation in patients with previous myopia excimer laser correction. In this study, a multi-formula average method was performed for the IOLs power calculation to improve the accuracy. Visual and refractive outcomes were analyzed, and the subjective quality of patients' life was evaluated by questionnaires survey. METHODS: This retrospective case series included patients with previous myopia excimer laser correction who underwent femtosecond laser assisted phacoemulsification and trifocal IOL (AT LISA tri 839 MP) implantation. Follow-up was done at 1-day, 1-month and 3-month to assess the visual outcomes. Outcome measures were uncorrected distance, intermediate and near visual acuity (UDVA, UIVA, UNVA), manifest refraction, defocus curve, and subjective quality of vision. RESULTS: Twenty-one Eyes from sixteen patients (14 eyes with previous laser in situ keratomileusis and 7 eyes with previous photorefractive keratectomy) were included. Mean postoperative spherical equivalent (SE) at 3-month was - 0.56 D ± 0.49 SD, wherein, 10 eyes (47.6%) were within ±0.50 D of the desired emmetropia and 19 eyes (90.5%) were within ±1.0 D. Mean monocular UDVA, UIVA and UNVA (logMAR) at last visit were 0.02 ± 0.07, 0.10 ± 0.10, and 0.15 ± 0.11 respectively. Three patients (19%) reported halos and glare in postoperative 3 months, two of them needed to use spectacles to improve the intermediate visual acuity. Fifteen patients (94%) reported a satisfaction score of ≥3.5 out of 4.0, without any difficulty in daily activity. Thirteen patients (81%) did not need spectacles at all distances, while the other 3 patients (19%) used spectacles for near-distance related visual activity. Mean composite score of the VF-14 questionnaire was 95.00 ± 7.29 out of 100. CONCLUSIONS: Trifocal IOL implantation after myopia excimer laser correction could restore good distance, intermediate visual acuity and acceptable near visual acuity, and provide accurate refractive outcomes as well as high spectacles independence rate.

Health benefits of improving air quality in Taiyuan, China.

Since 2000, the government in Shanxi province has mounted several initiatives and mandated factory shutdowns with the goal of reducing coal burning emissions and the environmental impacts of industrialization. We estimated the health benefits associated with air quality improvement from 2001 to 2010 in Taiyuan, Shanxi Province, using disability-adjusted life years (DALYs) and monetized the health benefits using value of statistical life (VOSL). Data were collected on annual average concentrations of particulate matter less than 10 µm in aerodynamic diameter (PM10) and relevant health outcomes in Taiyuan from 2001 to 2010. Selected exposure-response functions were used to calculate the cases of death or disease attributable to PM10 annually over a 10-year period. These were summed to calculate the DALYs lost and their monetary value associated with PM10 each year between 2001 and 2010. Air quality improvement from 2001 to 2010 was estimated to have prevented 2810 premature deaths, 951 new cases of chronic bronchitis, 141,457 cases of outpatient visits, 969 cases of emergency-room visits and 31,810 cases of hospital admissions. The DALYs (VOSL) decreased by 56.92% (52.68%) from 52,937 (7274 million Yuan) in 2001 to 22,807 (3442 million Yuan) in 2010. Premature deaths accounted for almost 95% of the total DALYs. Our analysis demonstrates that air pollution abatement during the last decade in Taiyuan has generated substantial health benefits.

Size-fractionated particle number concentrations and daily mortality in a Chinese city.

BACKGROUND: Associations between airborne particles and health outcomes have been documented worldwide; however, there is limited information regarding health effects associated with different particle sizes. OBJECTIVES: We explored the association between size-fractionated particle number concentrations (PNCs) and daily mortality in Shenyang, China. METHODS: We collected daily data on cause-specific mortality and PNCs for particles measuring 0.25-10 µm in diameter between 1 December 2006 and 30 November 2008. We used quasi-Poisson regression generalized additive models to estimate associations between PNCs and mortality, and we used natural spline smoothing functions to adjust for time-varying covariates and long-term and seasonal trends. RESULTS: Mean numbers of daily deaths were 67, 32, and 7 for all natural causes, cardiovascular diseases, and respiratory diseases, respectively. Interquartile range (IQR) increases in PNCs for particles measuring 0.25-0.50 µm were significantly associated with total and cardiovascular mortality, but not respiratory mortality. Effect estimates were larger for PNCs during the warm season than the cool season, and increased with decreasing particle size. IQR increases in PNCs of 0.25-0.28 µm, 0.35-0.40 µm, and 0.45-0.50 µm particles were associated with 2.41% (95% CI: 1.23, 3.58%), 1.31% (95% CI: 0.52, 2.09%), and 0.45% (95% CI: 0.04, 0.87%) higher total mortality, respectively. Associations were generally stable after adjustment for mass concentrations of ambient particles and gaseous pollutants. CONCLUSIONS: Our findings suggest that particles < 0.5 µm in diameter may be most responsible for adverse health effects of particulate air pollution and that adverse health effects may increase with decreasing particle size.

Exposure levels of environmental endocrine disruptors in mother-newborn pairs in China and their placental transfer characteristics.

There is a growing concern about the potential health effects of exposure to various environmental chemicals during pregnancy and infancy. The placenta is expected to be an effective barrier protecting the developing embryo against some endocrine disruptors (EDs) circulating in maternal blood. The current study was designed to assess in utero exposure levels of non-persistent organic pollutants (non-POPs) and persistent organic pollutants (POPs) in Chinese newborns and potential role of placenta barrier against fetal exposure to these commonly-used environmental endocrine disruptors. A total of 230 newborn-mother pairs were enrolled during 2010-2011, 201 pairs of which were recruited from Shanghai, and the other 29 pairs came from Wenzhou. Maternal blood, cord blood, and meconium specimens were collected in the subject population from Shanghai and analyzed for non-POPs, including mono-2-ethylhexyl phthalate (MEHP), octylphenol (OP) and 4-nonylphenol (4-NP). A total of 19 polybrominated diphenyl ethers (PBDEs) congeners, which belong to POPs, were detected in maternal and cord blood specimens from the other 29 pairs. Fetal-maternal ratios (F-M ratios) and regression coefficients were presented to assess potential function of placenta on barricading the mother/fetal transfer of these EDs. Concentrations of the detected non-POPs in cord blood samples were approximately 20% lower than those in maternal blood, and regression coefficients of which were all over 0.80. In contrast, PBDEs levels in cord blood samples were significantly higher than those in maternal blood. MEHP levels in meconium were much higher than those in cord blood samples, and highly correlated. Therefore, observations demonstrated that the placental barrier slightly decreased the fetal exposure to most non-POPs, while PBDEs seemed to be totally transferred across the placenta and finally reached the fetus. For in utero exposure assessment of Di-2-ethylhexyl phthalate (DEHP), MEHP level in meconium may be a useful biomarker.

Seasonal variation in the acute effect of particulate air pollution on mortality in the China Air Pollution and Health Effects Study (CAPES).

Epidemiological findings concerning the seasonal variation in the acute effect of particulate matter (PM) are inconsistent. We investigated the seasonality in the association between PM with an aerodynamic diameter of less than 10 µm (PM10) and daily mortality in 17 Chinese cities. We fitted the "main" time-series model after adjustment for time-varying confounders using smooth functions with natural splines. We established a "seasonal" model to obtain the season-specific effect estimates of PM10, and a "harmonic" model to show the seasonal pattern that allows PM10 effects to vary smoothly with the day in a year. At the national level, a 10 µg/m(3) increase in the two-day moving average concentrations (lag 01) of PM10 was associated with 0.45% [95% posterior interval (PI), 0.15% to 0.76%], 0.17% (95% PI, -0.09% to 0.43%), 0.55% (95% PI, 0.15% to 0.96%) and 0.25% (95%PI, -0.05% to 0.56%) increases in total mortality for winter, spring, summer and fall, respectively. For the smoothly-varying plots of seasonality, we identified a two-peak pattern in winter and summer. The observed seasonal pattern was generally insensitive to model specifications. Our analyses suggest that the acute effect of particulate air pollution could vary by seasons with the largest effect in winter and summer in China. To our knowledge, this is the first multicity study in developing countries to analyze the seasonal variations of PM-related health effects.

Communicating air pollution-related health risks to the public: an application of the Air Quality Health Index in Shanghai, China.

The Air Quality Health Index (AQHI) was originally developed in Canada. However, little is known about its validity in communicating morbidity risks. We aimed to establish the AQHI in Shanghai, China, and to compare the associations of AQHI and existing Air Pollution Index (API) with daily mortality and morbidity. We constructed the AQHI as the sum of excess total mortality associated with individual air pollutants, and then adjusted it to an arbitrary scale (0-10), according to a time-series analysis of air pollution and mortality in Shanghai from 2001 to 2008. We examined the associations of AQHI with daily mortality and morbidity, and compared these associations with API from 2005 to 2008. The coefficients of short-term associations of total mortality with particulate matter with an aerodynamic diameter less than 10 µm (PM(10)), PM(2.5) and nitrogen dioxide (NO(2)) were used in the establishment of AQHI. During 2005-2008, the AQHI showed linear non-threshold positive associations with daily mortality and morbidity. A unit increase of the PM(10)-AQHI was associated with a 0.90% [95% (confidence interval, CI), 0.43 to 1.37], 1.04% (95%CI, 0.04 to 2.04), 1.62% (95%CI, 0.39 to 2.85) and 0.51% (95%CI, 0.09 to 0.93) increase of current-day total mortality, hospital admissions, outpatient visits and emergency room visits, respectively. The PM(2.5)-AQHI showed quite similar effect estimates with the PM(10)-AQHI. In contrast, the associations for API were much weaker and generally statistically insignificant. The AQHI, compared with the existing API, provided a more effective tool to communicate the air pollution-related health risks to the public.

[The establishment and application of Shanghai air quality health index].

OBJECTIVE: This work aimed to construct Shanghai air quality health index (SAQHI) and to grade the air quality in Shanghai. METHODS: Daily average concentrations of particulate matter with aerodynamic diameter less than 10 micrometer (PM(10)), SO(2) and NO(2) from 2001 to 2008 in the central urban areas of Shanghai were collected from Shanghai Environmental Monitoring Center. Contemporaneous data of daily average temperature and relative humidity were obtained from Shanghai Meteorological Bureau. Contemporaneous daily non-accidental mortality of registered residents in central urban areas of Shanghai were obtained from Shanghai Municipal CDC, respectively. Time-series analysis was conducted to estimate the association between air pollution and daily non-accidental mortality in the central urban areas of Shanghai. SAQHI was then established and applied to grade the air quality in Shanghai. RESULTS: On average, there were 122 non-accidental daily deaths in the central urban areas of Shanghai from 2001 to 2008. The contemporaneous daily average concentrations of PM(10), SO(2) and NO(2) for the same period were (97.3 ± 59.5), (50.1 ± 27.8) and (64.7 ± 23.9) µg/m(3), respectively. Daily average temperature was (17.7 ± 8.8)°C, and daily average relative humidity was (71.4 ± 11.8)%. Based on results of time series analysis, formula for SAQHI was SAQHI = 10/17× (exp (0.000 153×PM(10))-1+exp (0.000 662×NO(2))-1)×100. Air quality in Shanghai was graded according to SAQHI values as low health risk (SAQHI: 0 ∼ 3), moderate health risk (SAQHI: 4-6), high health risk (SAQHI: 7-10) and very high health risk (SAQHI: > 10). CONCLUSION: SAQHI could be applied in grading air quality in Shanghai, and reflect the effects of the overall air quality on health.

Short-term exposure to sulfur dioxide and daily mortality in 17 Chinese cities: the China air pollution and health effects study (CAPES).

Sulfur dioxide (SO(2)) is a major air pollutant and has significant impacts upon human health. Few multi-city studies in Asia have examined the acute health effects of SO(2). As part of the China Air Pollution and Health Effects Study (CAPES), this study aimed at investigating the short-term association between SO(2) and daily mortality in 17 Chinese cities. We applied two-stage Bayesian hierarchical models to obtain city-specific and national average estimates for SO(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. As a result, the combined analysis showed that an increase of 10 µg/m(3) of two-day moving averaged SO(2) was associated with 0.75% [95% posterior interval (PI), 0.47 to 1.02], 0.83% (0.95% PI, 0.47 to 1.19) and 1.25% (95% PI, 0.78 to 1.73) increase of total, cardiovascular and respiratory mortality, respectively. The effects of SO(2) appeared more evident among the elderly. These associations were generally independent of particles with aerodynamic diameter <10 µm (PM(10)) but did not persist after adjustment for nitrogen dioxide (NO(2)). In conclusions, this largest epidemiologic study of air pollution in China to date suggests that short-term exposure to SO(2) is associated with increased mortality risk; however, these associations may be attributable to SO(2) serving as a surrogate of other substances. Further studies are needed to tackle the independent health effect of SO(2).

Exposure assessment of phthalates in non-occupational populations in China.

Phthalates have been used worldwide and are ubiquitous in environmental media and human bodies. Based on existing data on phthalate concentrations, distributions of phthalates in the environment and their exposure assessment to non-occupational populations in China can be evaluated. Fifty-three studies, published from January 2000 to October 2010, were reviewed and their data were analyzed in this study. Geographic information system (GIS) was used in mapping the published data of phthalate concentrations and their distributions in environmental media, while scatter diagrams were applied to show the time trends for phthalate concentrations in various environmental media. Results showed that there was a time-dependent increase in ∑phthalates (total phthalates) and DEHP concentrations in air during the past 10 years; phthalate concentrations varied in different areas, among which Guangdong and northeast China were the most polluted. Using Clark's equations, daily intake of ∑phthalates and DEHP in the Pearl River Delta and the Yangtze River Delta was estimated from consumption of contaminated food, water and air. Results showed that daily intake of ∑phthalates and DEHP was 128.63 and 61.29 µg/kg BW/d for adults in the Pearl River Delta, which is significantly higher than those residing in the Yangtze River Delta (33.87 and 24.68 µg/kg BW/d).

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.

Association of particulate air pollution with daily mortality: the China Air Pollution and Health Effects Study.

China is one of the few countries with some of the highest particulate matter levels in the world. However, only a small number of particulate matter health studies have been conducted in China. The study objective was to examine the association of particulate matter with an aerodynamic diameter of less than 10 µm (PM(10)) with daily mortality in 16 Chinese cities between 1996 and 2008. Two-stage Bayesian hierarchical models were applied to obtain city-specific and national average estimates. Poisson regression models incorporating natural spline smoothing functions were used to adjust for long-term and seasonal trends of mortality, as well as other time-varying covariates. The averaged daily concentrations of PM(10) in the 16 Chinese cities ranged from 52 µg/m(3) to 156 µg/m(3). The 16-city combined analysis showed significant associations of PM(10) with mortality: A 10-µg/m(3) increase in 2-day moving-average PM(10) was associated with a 0.35% (95% posterior interval (PI): 0.18, 0.52) increase of total mortality, 0.44% (95% PI: 0.23, 0.64) increase of cardiovascular mortality, and 0.56% (95% PI: 0.31, 0.81) increase of respiratory mortality. Females, older people, and residents with low educational attainment appeared to be more vulnerable to PM(10) exposure. Conclusively, this largest epidemiologic study of particulate air pollution in China suggests that short-term exposure to PM(10) is associated with increased mortality risk.

Fine particulate matter constituents and cardiopulmonary mortality in a heavily polluted Chinese city.

BACKGROUND: Although ambient fine particulate matter (PM(2.5); particulate matter ≤ 2.5 µm in aerodynamic diameter) has been linked to adverse human health effects, the chemical constituents that cause harm are unknown. To our knowledge, the health effects of PM(2.5) constituents have not been reported for a developing country. OBJECTIVES: We examined the short-term association between PM(2.5) constituents and daily mortality in Xi'an, a heavily polluted Chinese city. METHODS: We obtained daily mortality data and daily concentrations of PM(2.5), organic carbon (OC), elemental carbon (EC), and 10 water-soluble ions for 1 January 2004 through 31 December 2008. We also measured concentrations of fifteen elements 1 January 2006 through 31 December 2008. We analyzed the data using overdispersed generalized linear Poisson models. RESULTS: During the study period, the mean daily average concentration of PM(2.5) in Xi'an was 182.2 µg/m³. Major contributors to PM(2.5) mass included OC, EC, sulfate, nitrate, and ammonium. After adjustment for PM(2.5) mass, we found significant positive associations of total, cardiovascular, or respiratory mortality with OC, EC, ammonium, nitrate, chlorine ion, chlorine, and nickel for at least one lag period. Nitrate demonstrated stronger associations with total and cardiovascular mortality than PM(2.5) mass. For a 1-day lag, interquartile range increases in PM(2.5) mass and nitrate (114.9 and 15.4 µg/m³, respectively) were associated with 1.8% [95% confidence interval (CI): 0.8%, 2.8%] and 3.8% (95% CI: 1.7%, 5.9%) increases in total mortality. CONCLUSIONS: Our findings suggest that PM(2.5) constituents from the combustion of fossil fuel may have an appreciable influence on the health effects attributable to PM(2.5) in Xi'an.

A time-stratified case-crossover study of fine particulate matter air pollution and mortality in Guangzhou, China.

OBJECTIVES: Few studies in China investigate health impact of fine particulate matter (PM(2.5)) due to lack of monitoring data and the findings are controversial. The aim of this study is to examine the short-association between PM(2.5) and daily mortality in Guangzhou, the economic center of south China. METHODS: In Guangzhou, we measured daily PM(2.5) concentrations between 2007 and 2008 and conducted a time-stratified case-crossover analysis to explore the association between PM(2.5) and daily mortality, and examine potential effect modifiers including age, sex, and education. RESULTS: The averaged PM(2.5) concentration in 2007-2008 was 70.1 µg/m(3) in Guangzhou, which was approximately seven times higher than the WHO Air Quality Guidelines for PM(2.5) (annual average: 10 µg/m(3)). Regression analysis showed that ambient PM(2.5) was associated with mortality from all causes and cardiorespiratory diseases. An increase of 10 µg/m(3) in 2-day moving average (lag01) concentration of PM(2.5) corresponds to 0.90% [95% confidence interval (CI): 0.55, 1.26%] increase of total mortality, 1.22% (95% CI: 0.63, 1.68%) increase of cardiovascular mortality, and 0.97% (95% CI: 0.16, 1.79%) increase of respiratory mortality. The associations were stronger in the elderly (aged 65 years or more), in females, and in those with low education level, but the differences were statistically insignificant. After adjustment for nitrogen dioxide (NO(2)), however, the effects of PM(2.5) decreased and became statistically insignificant. CONCLUSIONS: Our findings provided new information for the adverse health effects of PM(2.5) in China, and may have some implications for environmental policy making and standard setting in Guangzhou.

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.

Coarse particles and mortality in three Chinese cities: the China Air Pollution and Health Effects Study (CAPES).

Evidence concerning the health risks of coarse particles (PM(10-2.5)) is limited. There have been no multi-city epidemiologic studies of PM(10-2.5) in developing Asian countries. We examine the short-term association between PM(10-2.5) and daily mortality in three Chinese cities: Beijing, Shanghai, and Shenyang. PM(10-2.5) concentrations were estimated by subtracting PM(2.5) from PM(10) measurements. Data were analyzed using the over-dispersed generalized linear Poisson models. The average daily concentrations of PM(10-2.5) were 101 µg/m(3) for Beijing (2007-2008), 50 µg/m(3) for Shanghai (2004-2008), and 49 µg/m(3) for Shenyang (2006-2008). In the single-pollutant models, the three-city combined analysis showed significant associations between PM(10-2.5) and daily mortality from both total non-accidental causes and from cardiopulmonary diseases. A 10-µg/m(3) increase in 1-day lagged PM(10-2.5) was associated with a 0.25% (95% CI: 0.08 to 0.42) increase in total mortality, 0.25% (95% CI: 0.10 to 0.40) increase in cardiovascular mortality, and 0.48% (95% CI: 0.20 to 0.76) increase in respiratory mortality. However, these associations became statistically insignificant after adjustment for PM(2.5). PM(2.5) was significantly associated with mortality both before and after adjustment for PM(10-2.5). In conclusion, there were no statistically significant associations between PM(10-2.5) and daily mortality after adjustment for PM(2.5) in the three Chinese cities.

Ambient carbon monoxide and daily mortality in three Chinese cities: the China Air Pollution and Health Effects Study (CAPES).

Ambient carbon monoxide (CO) is an air pollutant primarily generated by traffic. CO has been associated with increased mortality and morbidity in developed countries, but few studies have been conducted in Asian developing countries. In the China Air Pollution and Health Effects Study (CAPES), the short-term associations between ambient CO and daily mortality were examined in three Chinese cities: Shanghai, Anshan and Taiyuan. Poisson regression models incorporating natural spline smoothing functions were used to adjust for long-term and seasonal trend of mortality, as well as other time-varying covariates. Effect estimates were obtained for each city and then for the cities combined. In both individual-city and combined analysis, significant associations of CO with both total non-accidental and cardiovascular mortality were observed. In the combined analysis, a 1 mg/m(3) increase of 2-day moving average concentrations of CO corresponded to 2.89% (95%CI: 1.68, 4.11) and 4.17% (95%CI: 2.66, 5.68) increase of total and cardiovascular mortality, respectively. CO was not significantly associated with respiratory mortality. Sensitivity analyses showed that our findings were generally insensitive to alternative model specifications. In conclusion, ambient CO was associated with increased risk of daily mortality in these three cities. Our findings suggest that the role of exposure to CO and other traffic-related air pollutants should be further investigated in China.

Fine particulate air pollution and daily mortality in Shenyang, China.

Fine particulate matter (PM2.5) is not a criteria pollutant in China, and few studies were conducted in the country to investigate the health impact of PM2.5. In this study, we did a time-stratified case-crossover analysis to examine the association between PM2.5 and daily mortality in Shenyang, an industrial center in northeast China. Daily mortality, air pollution and weather data from August 1, 2006 to December 31, 2008 in Shenyang were collected. A time-stratified case-crossover approach was used to estimate the association of PM2.5 with both total and cause-specific mortality. Controls were selected as matched days of the week in the same month. Potential effect modifiers, such as age, gender, and season, were also examined. We found significant associations between PM2.5 and daily mortality in Shenyang. A 10 µg/m³ increment in the 2-day moving average (lag 01) concentrations of PM2.5 corresponded to 0.49% (95% CI: 0.19%, 0.79%), 0.53% (95% CI: 0.09%, 0.97%), and 0.97% (95% CI: 0.01%, 1.94%) increase of total, cardiovascular, and respiratory mortality, respectively. The associations appeared to be stronger in older people (aged ≥ 75 years), in females and during the warm season. To our knowledge, this is the longest PM2.5 health study in time duration in China. Our findings provide new information on the adverse health effects of PM2.5, and may have implications for environmental policy making and standard setting in China.

Association between long-term exposure to outdoor air pollution and mortality in China: a cohort study.

No prior cohort studies exist in China examining the association of outdoor air pollution with mortality. We studied 70,947 middle-aged men and women in the China National Hypertension Survey and its follow-up study. Baseline data were obtained in 1991 using a standard protocol. The follow-up evaluation was conducted in 1999 and 2000. Annual average air pollution exposure between 1991 and 2000, including total suspended particle (TSP), sulfur dioxide (SO(2)) and nitrogen oxides (NO(x)), were estimated by linking fixed-site monitoring data with resident zip code. We examined the association of air pollution with mortality using proportional hazards regression model. We found significant associations between air pollution levels and mortality from cardiopulmonary diseases and from lung cancer. Each 10 µg/m(3) elevation of TSP, SO(2) and NO(x) was associated with a 0.9% (95%CI: 0.3%, 1.5%), 3.2% (95%CI: 2.3%, 4.0%), and 2.3% (95%CI: 0.6%, 4.1%) increased risk of cardiovascular mortality, respectively. We found significant effects of SO(2) on mortality after adjustment for TSP. Conclusively, ambient air pollution was associated with increased cardiopulmonary and lung cancer mortality in China. These data contribute to the scientific literature on long-term effects of air pollution for high exposure settings typical in developing countries.