The short-term effect of ambient ozone on mortality is modified by temperature in Guangzhou, China

Zhou

et al. 2017

Environmental Research

Background Few multicity studies have addressed the health effects of ozone in China due to the scarcity of ozone monitoring data. A critical scientific and policy-relevant question is whether a threshold exists in the ozone-mortality relationship. Methods Using a generalized additive model and a univariate random-effects meta-analysis, this research evaluated the relationship between short-term ozone exposure and daily total mortality in seven cities of Jiangsu Province, China during 2013–2014. Spline, subset, and threshold models were applied to further evaluate whether a safe threshold level exists. Results This study found strong evidence that short-term ozone exposure is significantly associated with premature total mortality. A 10 μg/m3 increase in the average of the current and previous days’ maximum 8-h average ozone concentration was associated with a 0.55% (95% posterior interval: 0.34%, 0.76%) increase of total mortality. This finding is robust when considering the confounding effect of PM2.5, PM10, NO2, and SO2. No consistent evidence was found for a threshold in the ozone-mortality concentration-response relationship down to concentrations well below the current Chinese Ambient Air Quality Standard (CAAQS) level 2 standard (160 μg/m3). Conclusions Our findings suggest that ozone concentrations below the current CAAQS level 2 standard could still induce increased mortality risks in Jiangsu Province, China. Continuous air pollution control measures could yield important health benefits in Jiangsu Province, China, even in cities that meet the current CAAQS level 2 standard.

Section: Introductionmentioning

confidence: 85%

Acute effect of ozone exposure on daily mortality in seven cities of Jiangsu Province, China: No clear evidence for threshold

Zhou

et al. 2017

Environmental Research

“…In addition to the net downward transport of O 3 by eddy diffusion from the stratosphere aloft, tropospheric O 3 is a well-known secondary gaseous pollutant, and it is formed through the photochemical oxidation of volatile organic compounds (VOCs) and NO x under the irradiation of sunlight (Logan, 1985;Roelofs and Lelieveld, 1997). These chemicals have both received extensive attention either due to their harmful impact on human health (Pope and Dockery, 1999;Shao et al, 2006;Streets et al, 2007;Liu et al, 2013) and vegetation (Feng et al, 2014) or significant effects on climate change (Seinfeld et al, 2004;IPCC, 2007;Mercado et al, 2009). Moreover, some critical interactions have been verified to exist between the gaseous pollutants and/or particulate matter Cheng et al, 2016).…”

Section: Introductionmentioning

confidence: 99%

Characterization of atmospheric trace gases and particulate matter in Hangzhou, China

Zhang

et al. 2018

Atmos. Chem. Phys.

Abstract. The Yangtze River Delta (YRD) is one of the most densely populated regions in China with severe air quality issues that have not been fully understood. Thus, in this study, based on 1-year (2013) continuous measurement at a National Reference Climatological Station (NRCS, 30.22 • N, 120.17 • E; 41.7 m a.s.l.) in the center of Hangzhou in the YRD, we investigated the seasonal characteristics, interspecies relationships, and the local emissions and the regional potential source contributions of trace gases (including O 3 , NO x , NO y , SO 2 , and CO) and particulate matter (PM 2.5 and PM 10 ). Results revealed that severe two-tier air pollution (photochemical and haze pollution) occurred in this region, with frequent exceedances in O 3 (38 days) and PM 2.5 (62 days). O 3 and PM 2.5 both exhibited distinct seasonal variations with reversed patterns: O 3 reaching a maximum in warm seasons (May and July) but PM 2.5 reaching a maximum in cold seasons (November to January). The overall results from interspecies correlation indicated a strong local photochemistry favoring the O 3 production under a volatile organic compound (VOC)-limited regime, whereas it moved towards an optimum O 3 production zone during warm seasons, accompanied by the formation of secondary fine particulates under high O 3 . The emission maps of PM 2.5 , CO, NO x , and SO 2 demonstrated that local emissions were significant for these species on a seasonal scale. The contributions from the regional transport among inland cities (Zhejiang, Jiangsu, Anhui, and Jiangxi Province) on a seasonal scale were further confirmed to be crucial to air pollution at the NRCS site by using backward trajectory simulations. Air masses transported from the offshore areas of the Yellow Sea, East Sea, and South Sea were also found to be highly relevant to the elevated O 3 at the NRCS site through the analysis of potential source contribution function (PSCF). Case studies of photochemical pollution (O 3 ) and haze (PM 2.5 ) episodes both suggested the combined importance of local atmospheric photochemistry and synoptic conditions during the accumulation (related with anticyclones) and dilution process (related with cyclones). Apart from supplementing a general picture of the air pollution state in the city of Hangzhou in the YRD region, this study specifically elucidates the role of local emission and regional transport, and it interprets the physical and photochemical processes during haze and photochemical pollution episodes. Moreover, this work suggests that cross-regional control measures are crucial to improve air quality in the YRD region, and it further emphasizes the importance of local thermally induced circulation for air quality.

Advances in Climate Change Research

“…In low temperature conditions (days within the 25% percentile of daily mean temperature) or in the cold season (November-April), the residents' death risk increases significantly (including the daily effect and accumulated effect) with the increase in O 3 concentration. In contrast, in the warm season and in high temperature conditions, the effects of O 3 on the residents' death risk are not significant [Liu et al, 2012].…”

Section: Increases In Ozone Concentrationmentioning

confidence: 88%

“…In the city of Shenzhen, O 3 shows a significant positive correlation (r =0.658) with cases of cardiovascular dis-eases at a confidence level of 95% [Yin et al, 2009a]. Another study by Liu et al [2012] shows that temperature and O 3 have interactive effects on the death rate in Guangzhou. In low temperature conditions (days within the 25% percentile of daily mean temperature) or in the cold season (November-April), the residents' death risk increases significantly (including the daily effect and accumulated effect) with the increase in O 3 concentration.…”

Section: Increases In Ozone Concentrationmentioning

confidence: 99%

Impacts of Climate Change on Human Health and Adaptation Strategies in South China

Du¹,

Wang²,

Yang³

et al. 2013

This study reviews the impacts of climate change on human health and presents corresponding adaptation strategies in South China. The daily mean surface air temperatures above or below 26.4 • C increase the death risk for the people in Guangzhou, especially the elderly are vulnerable to variations in temperature. Heat waves can cause insomnia, fatigue, clinical exacerbation, or death from heatstroke etc., while cold spells show increases in patients with fractures. During a cold spell period, the rates of both on-site emergency rescues and non-implementable rescues increase, and the risk of non-accidental deaths and respiratory disease deaths significantly rise as well. Both time series of hazy days and ozone concentrations have significant positive correlations with the number of patients with cardiovascular diseases. Both malaria and dengue fever reach higher altitudes and mountainous areas due to climate warming. Climate change is likely to bring stronger heat waves in the future, thereby increasing heat wave-related illnesses and deaths, particularly in the metropolitan areas of the Pearl River Delta. The projected increase of continuous cold days in Guangdong province and parts of northern Guangxi province will affect residents' health in the future. The rising temperature exaggerates ozone pollution, but it is not clear whether climate change is aggravating or mitigating haze pollution. The transmission potential of malaria in South China will increase by 39%-140% and the transmission season will extend by 1-2 months with an air temperature increase of 1-2 • C. By 2050, most areas in Hainan province are projected to convert from non-endemic dengue into endemic dengue areas. The aging population will cause more vulnerable people. To mitigate the adverse impacts of climate change on human health, sound and scientific adaptation strategies must be adopted in advance, such as strengthening the surveillance of epidemic diseases in potential transmission areas, conducting timely weather forecasting for human health, evaluating health vulnerability to climate change, improving environmental and health education, and strengthening hazard management and the cooperation between meteorological and health departments.