Ozone-related Mortality Research Articles

Strong increase in mortality attributable to ozone pollution under a climate change and demographic scenario

Long-term exposure to ambient ozone (O3) is associated with excess respiratory mortality. Pollution emissions, demographic, and climate changes are expected to drive future ozone-related mortality. Here, we assess global mortality attributable to ozone according to an Intergovernmental Panel on Climate Change (IPCC) Shared Socioeconomic Pathway (SSP) scenario applied in Coupled Model Intercomparison Project Phase 6 (CMIP6) models, projecting a temperature increase of about 3.6 °C by the end of the century. We estimated ozone-related mortality on a global scale up to 2090 following the Global Burden of Disease (GBD) 2019 approach, using bias-corrected simulations from three CMIP6 Earth System Models (ESMs) under the SSP3-7.0 emissions scenario. Based on the three ESMs simulations, global ozone-related mortality by 2090 will amount to 2.79 M [95% CI 0.97 M–5.23 M] to 3.12 M [95% CI 1.11 M–5.75 M] per year, approximately ninefold that of the 327 K [95% CI 103 K–652 K] deaths per year in 2000. Climate change alone may lead to an increase of ozone-related mortality in 2090 between 42 K [95% CI −37 K–122 K] and 217 K [95% CI 68 K–367 K] per year. Population growth and ageing are associated with an increase in global ozone-related mortality by a factor of 5.34, while the increase by ozone trends alone ranges between factors of 1.48 and 1.7. Ambient ozone pollution under the high-emissions SSP3-7.0 scenario is projected to become a significant human health risk factor. Yet, optimizing living conditions and healthcare standards worldwide to the optimal ones today (application of minimum baseline mortality rates) will help mitigate the adverse consequences associated with population growth and ageing, and ozone increases caused by pollution emissions and climate change.

The Social Cost of Ozone-Related Mortality Impacts From Methane Emissions.

Atmospheric methane directly affects surface temperatures and indirectly affects ozone, impacting human welfare, the economy, and environment. The social cost of methane (SC-CH4) metric estimates the costs associated with an additional marginal metric ton of emissions. Current SC-CH4 estimates do not consider the indirect impacts associated with ozone production from changes in methane. We use global model simulations and a new BenMAP webtool to estimate respiratory-related deaths associated with increases in ozone from a pulse of methane emissions in 2020. By using an approach consistent with the current SC-CH4 framework, we monetize and discount annual damages back to present day values. We estimate that the methane-ozone mechanism is attributable to 760 (95% CI: 330-1200) respiratory-related deaths per million metric tons of methane globally, for a global net present damage of $1800/mT (95% CI: $760-$2800/Mt CH4; 2% Ramsey discount rate); this would double the current SC-CH4 if included. These physical impacts are consistent with recent studies, but comparing direct costs is challenging. Economic damages are sensitive to uncertainties in the exposure and health risks associated with tropospheric ozone, assumptions about future projections of NOx emissions, socioeconomic conditions, and mortality rates, monetization parameters, and other factors. Our estimates are highly sensitive to uncertainties in ozone health risks. We also develop a reduced form model to test sensitivities to other parameters. The reduced form tool runs with a user-supplied emissions pulse, as well as socioeconomic and precursor projections, enabling future integration of the methane-ozone mechanism into the SC-CH4 modeling framework.

Health impacts under different ozone mitigation pathways in Beijing-Tianjin-Hebei and its surroundings

To evaluate the effects of the various ozone (O3) control approaches on environmental health and health inequalities, 121 reduction scenarios for nitrogen oxides (NOx) and volatile organic compounds (VOCs) were developed, and their environmental health impacts were calculated. With the target of achieving the 90th percentile of the daily maximum 8 h mean O3 concentration (MDA8-90th) of 160 μg/m3 in Beijing-Tianjin-Hebei and its surroundings (“2 + 26” cities), three typical scenarios namely, High-NOx reduction ratio (HN, NOx/VOCs = 6:1), High-VOCs reduction ratio (HV, NOx/VOCs = 3:7), and Balanced reduction ratio (Balanced, NOx/VOCs = 1:1) were investigated. The results show that O3 formation is currently NOx-limited at the regional scale, while some developed cities are VOC-limited, indicating that NOx mitigation should be the core for achieving the targeted concentration (160 μg/m3) at the regional scale, whereas cities such as Beijing in the short term should focus on VOCs mitigation. The population-weighted O3 concentrations in the HN, Balanced, and HV scenarios were 159.19, 159.19, and 158.44 μg/m3, respectively. In addition, the O3-related premature mortality was 41,320 in “2 + 26” cities; control measures under HN, Balanced, and HV could potentially decrease O3-related premature deaths by 59.94 %, 60.25 %, and 71.48 %, respectively. The HV scenario has been found to be more advantageous in lowering the O3-related environmental health impacts than the HN and Balanced scenarios. It was further found that premature deaths avoided by the HN scenario were mainly concentrated in economically unadvanced regions, whereas those prevented by the HV scenario were mainly concentrated in developed cities. This may lead to geographical inequities in environmental health. As ozone pollution in large cities with high population density is primarily VOC-limited, decrease in VOCs should be focused on in the short term to avoid more O3-related premature deaths, whereas NOx control may be more important in decreasing ozone concentrations and ozone-related mortality in the future.

Increases in ozone-related mortality in China over 2013–2030 attributed to historical ozone deterioration and future population aging

We systematically examine historical and future changes in premature respiratory mortalities attributable to ozone (O3) exposure (O3-mortality) in China and identify the leading cause of respective change for the first time. The historical assessment for 2013–2019 is based on gridded O3 concentrations generated by a multi-source-data-fusion algorithm; the future prediction for 2019–2030 uses gridded O3 concentrations projected by four Coupled Model Intercomparison Project Phase 6 (CMIP6) models under three Shared Socioeconomic Pathways (SSP) scenarios. During 2013–2019, national annual O3-mortality is 176.3 thousand (95%CI: 123.5–224.0 thousand) averaged over 2013–2019 with an increasing trend of 14.1 thousand yr−1 (95%CI: 10.2–17.4 thousand yr−1); sensitivity experiments show that the O3-mortality varies at a rate of +12.7 (95%CI: 9.2–15.6), +5.8 (95%CI: 4.0–7.4), +1.0 (95%CI: 0.7–1.2), −5.4 (95%CI: −6.9 to −3.7) thousand yr−1, owing to changes in O3 concentration, population age structure, population size, mortality rate for respiratory disease, respectively. The deterioration of O3 air quality, shown as significant increase in O3 concentration, is identified as the primary factor which contributes 90.1 % of 2013–2019 O3-mortality rise. Compared with O3-mortality estimated in this study, the widely-used O3-mortality assessment method based on urban-site-dominant O3 measurements generates close national O3-mortality but overestimates (underestimates) provincial O3-mortality in coastal (central) provinces. From 2019 to 2030, national O3-mortality is projected to increase by 50.4–103.7 thousand under different SSP scenarios. The change in age structure (i.e. population aging) alone will result in significant O3-mortality rises of 137.9–160.5 thousand. Compared with 2013–2019 rapid O3 increase (+2.5 μg m−3 yr−1 at national level), O3 concentrations are projected to increase at a lower rate (+0.4 μg m−3 yr−1 in SSP5–8.5) or even decrease (−0.7 μg m−3 yr−1 in SSP1-2.6) from 2019 to 2030. Therefore, population aging, in place of O3 air quality deterioration, will become the leading cause of future O3-mortality rises during the coming decade.

Historical transboundary ozone health impact linked to affluence

Ozone pollution is a major transboundary threat to global health. Systematic improvement of mitigation strategy for transboundary ozone requires a socioeconomic understanding of historical lessons in countries at different affluence levels. Here, we explore the changes in transboundary ozone related premature deaths over 1951–2019 driven by anthropogenic emissions of four country groups categorized by income level. By integrating global emission datasets, a chemical transport model (GEOS-Chem), in situ ozone measurements worldwide and an ozone exposure-response model, we find that mortality caused by transboundary anthropogenic ozone increases by 27 times from 1951 to 2019, and on average contributes about 27% of global anthropogenic ozone related deaths. All groups exert and suffer from substantial transboundary ozone related mortality. The high-income and upper middle groups have each experienced an inverted U-shaped relationship between its affluence and per-million-people contribution to mortality caused by transboundary ozone, with the turning point around 23 000 USD and 6300 USD, respectively. The lower middle group has gradually matched the growth pathway of the upper middle group with a turning point less clear. Concerted efforts to ensure early turning points in less affluent countries will have considerable global health benefits.

Short-term exposure to ozone and economic burden of premature mortality in Italy: A nationwide observation study

Italy is among the countries with the highest ozone concentration in Europe. However, the mortality burden of ozone and related economic loss has not been fully characterized. This study aimed to estimate the ozone-mortality association in Italy and evaluate attributable mortality burden and related economic loss in 2015–2019. We collected daily all-cause mortality data stratified by age and sex from 2015 to 2019 in 107 provinces of Italy. A two-stage time-series framework was applied to estimate the association between daily maximum eight-hour average ozone and mortality as well as economic loss. An overall increase in the risk of mortality (RR=1.0043, 95% CI: 1.0029, 1.0057) was associated with every 10 µg/m3 increase in ozone. Generally, a total of 70,060 deaths and $65 billion economic loss were attributed to ozone exposure, corresponding to 3.11% of mortality and about 0.5% of the national GDP during the study period, respectively. The highest ozone-related mortality burden (30,910 deaths) and economic loss ($29.24 billion) were observed in the hot season. This nationwide study suggested considerable mortality burden and economic loss were associated with exposure to ozone. More actions and policies should be proposed to reduce ozone levels and help the public protect their health.

Ozone-related Co-benefits of China's Climate mitigation Policy

China has demonstrated great commitment to take more vigorous and effective approaches to peak carbon emissions by 2030 and achieve carbon neutrality by 2060. China's actions to mitigate CO2 emissions are expected to simultaneously reduce co-emitted air pollutants and reduce premature deaths. This study investigates the future changes in international and regional ozone and associated health and economic benefits of stringent climate mitigation policy in China by 2050. Results show that China's stringent mitigation policy positively impacts air quality and public health in China and its downwind transboundary regions, Japan and South Korea. More specifically, approximately 15,800 and 35,550 ozone-related premature deaths will be avoided globally in 2030 and 2050 worldwide, with 78% and 76% happening in China. The avoided ozone-related mortality could save 3 billion USD in 2030 and 10 billion USD in 2050 based on the willingness to pay method.

Burning embers: synthesis of the health risks of climate change

Since 2001, a synthesizing element in Intergovernmental Panel on Climate Change assessment reports has been a summary of how risks in a particular system could change with additional warming above pre-industrial levels, generally accompanied by a figure called the burning embers. We present a first effort to develop burning embers for climate change risks for heat-related morbidity and mortality, ozone-related mortality, malaria, diseases carried by Aedes sp., Lyme disease, and West Nile fever. We used an evidence-based approach to construct the embers based on a comprehensive global literature review. Projected risks for these health outcomes under 1.5 °C, 2 °C, and >2 °C of warming were used to estimate at what temperatures risk levels increased from undetectable to medium, high, and very high, from the pre-industrial baseline, under three adaptation scenarios. Recent climate change has likely increased risks from undetectable to moderate for heat-related morbidity and mortality, ozone-related mortality, dengue, and Lyme disease. Recent climate change also was assessed as likely beginning to affect the burden of West Nile fever. A detectable impact of climate change on malaria is not yet apparent but is expected to occur with additional warming. The risk for each climate-sensitive health outcome is projected to increase as global mean surface temperature increases above pre-industrial levels, with the extent and pace of adaptation expected to affect the timing and magnitude of risks. The embers may be an effective tool for informing efforts to build climate-resilient health systems including through vulnerability, capacity, and adaptation assessments and the development of national adaptation plans. The embers also can be used to raise awareness of future threats from climate change and advocate for mitigation actions to reduce the overall magnitude of health risks later this century and to expand current adaptation efforts to protect populations now.

Ozone pollution in China: Background and transboundary contributions to ozone concentration & related health effects across the country

China experiences high ozone concentrations with highest annual 8-hour maximum concentration in eastern China of 78 μg/m3 and was followed by southern (73 μg/m3), north-western (69 μg/m3), northern (68 μg/m3), central (67 μg/m3), north eastern (65 μg/m3) and south-western China (59 μg/m3). Ozone concentration peaked in spring season in 4 (eastern, northern, north eastern & central) of 7 regions across China while lowest concentration in most regions across China was experienced in winter season with central and southern China being the only exceptions. Regions outside Asia contributed ozone to all regions across China with highest contributions in 4 (East, Central, North & Northeast) of the 7 regions. South-western China had the largest ozone contribution from outside (23%) and was followed by 16.39% outside ozone contribution in north-western China, 11.64% contribution in north eastern China, 11% contribution in northern China, 7.85% contribution in southern China, 5.28% contribution in central China while 4.56% contribution in eastern China. Policy relevant background (PRB) concentration was above 47 μg/m3 in all regions across China and contributed about 71–94% to total ozone concentration with highest PRB concentration of 65.25 μg/m3 recorded in north-west China. China recorded 93,351 (95%CI: 11001–169,898) ozone related premature mortality in 2015 with 42,673 (95%CI: 11001–69,586) respiratory mortality and 50,678 (95%CI: 0–100,312) cardiovascular mortality. Northern and eastern China recorded high ozone related mortality with 18,230 (95%CI: 4700–29,727) & 12,261 (95%CI: 3161–19,993) respiratory and 21,662 (95%CI: 0–42,877) & 14,528 (95%CI: 0–28,757) cardiovascular deaths respectively. In terms of foreign contributions, premature mortality due to ozone from outside Asia contributed the most to China with 1070 (95%CI: 276–1746) respiratory mortality and 1270 (95%CI: 0–2515) cardiovascular mortality. East Asia contributed to about 419 (95%CI: 109–679) respiratory deaths and 501 (95%CI: 0–989) cardiovascular deaths while North Asia contributed to 220 (95%CI: 56–358) respiratory mortality and 260 (95%CI, 0–515) cardiovascular mortality.

Spatial and temporal trends in the mortality burden of ozone pollution in China: 2005-2017

Introduction: While recent assessments have quantified the burden of ozone pollution at the national scale in China, air quality managers would benefit from assessments that disaggregate health impacts over regions and over time. Taking advantage of a new daily maximum 8-hour averaged (MDA8) ozone concentration dataset, we analyze spatial and temporal trends of ozone-related mortality burden in China from 2005 to 2017. Methods: Population weighted exposure (PWE) was calculated by overlapping ozone concentrations and population maps. MDA8 ozone concentrations at 10 km resolution from 2005-2017 were from a nationwide prediction model that was based on the XGBoost algorithm and trained by MDA8 ozone observations from 2013 to 2017 combining with concurrent meteorological parameters and land use data. Population data are from Landscan Global Population Database. Using non-accidental total (NAT) deaths as target outcomes, we further calculated the excess deaths by applying exposure response functions from 272 Chinese cities. Results and Discussion: During 2005-2017, MDA8 ozone PWE fluctuated from 87.2 μg/m3 to 92.2 μg/m3, with no obvious upward or downward trends. National PWE are higher than the national average ozone concentration, indicating that the overlap of dense population areas and heavy polluted areas aggravated the mortality burdens. National ozone related NAT deaths increased from approximately 145,000 (95% confidence interval (CI): 70,000-213,000) cases in 2005 to 167,000 (95% CI: 80,000-245,000) cases in 2017. The mortality burden exhibited strong spatial variations, with high excess deaths concentrated in Beijing-Tianjin Metropolitan Region, North China Plain, Yangtze River Delta, Pearl River Delta, Sichuan Basin, Wuhan Metropolitan Region, and Changsha-Zhuzhou-Xiangtan. Hotspots of mortality burden have not expanded significantly over time, that is to say, the regions with heavy mortality burdens appear to be the ones with rapid growth. This undoubtedly makes the health risk of ozone in these areas more severe.

Short term association between ozone and mortality: global two stage time series study in 406 locations in 20 countries

ObjectiveTo assess short term mortality risks and excess mortality associated with exposure to ozone in several cities worldwide.DesignTwo stage time series analysis.Setting406 cities in 20 countries, with overlapping periods between...

Ozone and heat-related mortality in Europe in 2050 significantly affected by changes in climate, population and greenhouse gas emission

Climate change is expected to increase to extreme temperatures and lead to more intense formation of near-surface ozone. Higher temperatures can cause heat stress and ozone is a highly oxidative pollutant; both increase cardiorespiratory mortality. Using greenhouse gas and ozone precursor emission scenarios, global and regional climate and chemistry-transport models, epidemiological data, and population projections, we projected ozone- and heat-related health risks under a changing climate. European near-surface temperature was modelled with the regional climate model (RCA4), forced by the greenhouse gas emission scenario RCP4.5 and the global climate model EC-EARTH, and near-surface ozone was modelled with the Multi-scale Atmospheric Transport and Chemistry (MATCH) model. Two periods were compared: recent climate in 1991–2000 and future climate in 2046–2055, projecting around a 2° increase in global temperatures by that time. Projections of premature mortality considered future climate, future population, and future emissions separately and jointly to understand the relative importance of their contributions. Ozone currently causes 55 000 premature deaths annually in Europe due to long-term exposure, including a proportion of the estimated 26 000 deaths per year due to short-term exposures. When only taking into account the impact of a changing climate, up to an 11% increase in ozone-associated mortality is expected in some countries in Central and Southern Europe in 2050. However, projected decreases in ozone precursor emissions are expected to result in a decrease in ozone-related mortality (−30% as EU average). Due to aging and increasingly susceptible populations, the decrease in 2050 would be smaller, up to −24%. During summer months, ozone risks could combine with increasing temperatures, especially during the hottest periods and in densely populated urban areas. While the heat burden is currently of the same order of magnitude as ozone, due to increasing temperatures and decreasing ozone precursor emissions, heat-related mortality could be twice as large as ozone-related mortality in 2050.

A Multi-Country Study on Ozone-Related Mortality

Back&aim: Many studies have characterized the short-term association between ozone and mortality in different settings, but mostly across limited geographical areas and using different methodological approaches. In this study, we aimed at comprehensively assessing short-term ozone-related mortality associations in a multi-country analysis.Method: We collected daily mortality and air pollution data (ozone, O3, and particulate matter, PM10) from 245 locations in 16 countries (Australia, Brazil, Canada, Chile, Columbia, France, Japan, South Korea, Mexico, Portugal, Spain, Sweden, Switzerland, Taiwan, Thailand, and United States), included in the Multi-City Multi-Country Collaborative Research Network. We applied a two-stage time-series design. First, we modelled mortality-ozone associations across 21 days of lag using quasi-Poisson regression and distributed lag linear models (DLMs). Second, we performed a multilevel multivariate meta-regression to obtain pooled associations across locations nested within country. Best linear unbiased predictions (BLUPs) were derived at both location and country levels. We estimated season-specific ozone-related mortality through time-varying interaction DLMs.Results: On average, an increase in 10 μg/m3 in ozone was associated with a 0.6% increase in mortality risk [95%CI: 0.3 to 0.8%]. The positive association was lagged and persisted during the following 7 days. Country-specific BLUPs ranged between 0.2%[-0.05 to 0.5] in Brazil to 0.8%[0.5 to 1.2] in the US. The ozone-related mortality association was significantly larger in winter [0.8%, 0.5 to 1.0] vs summer [0.5%, 0.4 to 0.7]. Results were robust to sensitivity analyses, such as multi-pollutant models.Conclusion: This represents the largest epidemiological study on health effects of ozone. By using a common advanced statistical framework, we provide robust evidence on the association with all-cause mortality in different locations across the globe.On behalf of the MCC Network

Future ozone-related acute excess mortality under climate and population change scenarios in China: A modeling study.

BackgroundClimate change is likely to further worsen ozone pollution in already heavily polluted areas, leading to increased ozone-related health burdens. However, little evidence exists in China, the world’s largest greenhouse gas emitter and most populated country. As China is embracing an aging population with changing population size and falling age-standardized mortality rates, the potential impact of population change on ozone-related health burdens is unclear. Moreover, little is known about the seasonal variation of ozone-related health burdens under climate change. We aimed to assess near-term (mid-21st century) future annual and seasonal excess mortality from short-term exposure to ambient ozone in 104 Chinese cities under 2 climate and emission change scenarios and 6 population change scenarios.Methods and findingsWe collected historical ambient ozone observations, population change projections, and baseline mortality rates in 104 cities across China during April 27, 2013, to October 31, 2015 (2013–2015), which included approximately 13% of the total population of mainland China. Using historical ozone monitoring data, we performed bias correction and spatially downscaled future ozone projections at a coarse spatial resolution (2.0° × 2.5°) for the period April 27, 2053, to October 31, 2055 (2053–2055), from a global chemistry–climate model to a fine spatial resolution (0.25° × 0.25°) under 2 Intergovernmental Panel on Climate Change Representative Concentration Pathways (RCPs): RCP4.5, a moderate global warming and emission scenario where global warming is between 1.5°C and 2.0°C, and RCP8.5, a high global warming and emission scenario where global warming exceeds 2.0°C. We then estimated the future annual and seasonal ozone-related acute excess mortality attributable to both climate and population changes using cause-specific, age-group-specific, and season-specific concentration–response functions (CRFs). We used Monte Carlo simulations to obtain empirical confidence intervals (eCIs), quantifying the uncertainty in CRFs and the variability across ensemble members (i.e., 3 predictions of future climate and air quality from slightly different starting conditions) of the global model. Estimates of future changes in annual ozone-related mortality are sensitive to the choice of global warming and emission scenario, decreasing under RCP4.5 (−24.0%) due to declining ozone precursor emissions but increasing under RCP8.5 (10.7%) due to warming climate in 2053–2055 relative to 2013–2015. Higher ambient ozone occurs under the high global warming and emission scenario (RCP8.5), leading to an excess 1,476 (95% eCI: 898 to 2,977) non-accidental deaths per year in 2053–2055 relative to 2013–2015. Future ozone-related acute excess mortality from cardiovascular diseases was 5–8 times greater than that from respiratory diseases. Ozone concentrations increase by 15.1 parts per billion (10−9) in colder months (November to April), contributing to a net yearly increase of 22.3% (95% eCI: 7.7% to 35.4%) in ozone-related mortality under RCP8.5. An aging population, with the proportion of the population aged 65 years and above increased from 8% in 2010 to 24%–33% in 2050, will substantially amplify future ozone-related mortality, leading to a net increase of 23,838 to 78,560 deaths (110% to 363%). Our analysis was mainly limited by using a single global chemistry–climate model and the statistical downscaling approach to project ozone changes under climate change.ConclusionsOur analysis shows increased future ozone-related acute excess mortality under the high global warming and emission scenario RCP8.5 for an aging population in China. Comparison with the lower global warming and emission scenario RCP4.5 suggests that climate change mitigation measures are needed to prevent a rising health burden from exposure to ambient ozone pollution in China.

Does temperature-confounding control influence the modifying effect of air temperature in ozone–mortality associations?

Background: Recent epidemiological studies investigating the modifying effect of air temperature in ozone–mortality associations lack consensus as how to adjust for nonlinear and lagged temperature effect in addition to including an interaction term. Methods: We evaluated the influence of temperature confounding control on temperature-stratified ozone–mortality risks in a time series setting in eight European cities and 86 US cities, respectively. To investigate potential residual confounding, we additionally incorporated next day’s ozone in models with differing temperature control. Results: Using only a categorical variable for temperature or only controlling nonlinear effect of low temperatures yielded highly significant ozone effects at high temperatures but also significant residual confounding in both regions. Adjustment for nonlinear effect of temperature, especially high temperatures, substantially reduced ozone effects at high temperatures and residual confounding. Conclusions: Inadequate control for confounding by air temperature leads to residual confounding and an overestimation of the temperature-modifying effect in studies of ozone-related mortality.

Projection of Ozone-Related Mortality with Climate and Population Changes in Urban China

Background/Aim: China is experiencing rising ozone pollution in urban areas, but its potential future health impacts under both climate and population changes remain unclear. We examine future annual and seasonal ozone-related mortality in 347 urban counties of China under three climate and emission scenarios and six population scenarios. Methods: Ozone projections were statistically downscaled from a global chemistry-climate model to a fine spatial resolution (0.25° × 0.25°) using newly available ambient ozone monitoring data across China from 2013-2015. The attributable fraction method was then applied to estimate the daily ozone-related premature mortality in the 2010s, 2030s, 2040s, and 2050s, respectively. Results: Higher ground-level ozone occurs under an extreme warming scenario in which air pollutant emissions are held at 2005 levels (RCP8.5_WMGG), leading to an excess 4296 (95% CI: 3415 to 5169), 5181 (4213 to 6228), and 5134 (4086 to 6171) non-accidental deaths per year in 2033-2035, 2043-2045, and 2053-2055 relative to 2013-2015. Estimates of future changes in ozone-related mortality are sensitive to the choice of climate and emissions scenario, decreasing under RCP4.5 but increasing under RCP8.5 by 2043-2045 and 2053-2055 relative to 2013-2015. Population increases amplify the adverse impacts of climate change on ozone-related mortality. Deteriorating ozone air quality in colder months contributes to excess ozone-related mortality. Conclusions: Our analysis suggests that more stringent air pollution control measures will be needed, including beyond the warm season, to prevent a rising health burden of climate change via ozone pollution in urban China.

FUTURE GLOBAL MORTALITY FROM CHANGES IN AIR POLLUTION ATTRIBUTABLE TO CLIMATE CHANGE.

The effect of ozone and fine particulate matter on human health is dependent on emissions and climate change. Here the effects of climate change on air pollution mortality are isolated, with increases predicted in all regions except Africa. Ground-level ozone and fine particulate matter (PM 2.5) are associated with premature human mortality1,2,3,4; their future concentrations depend on changes in emissions, which dominate the near-term5, and on climate change6,7. Previous global studies of the air-quality-related health effects of future climate change8,9 used single atmospheric models. However, in related studies, mortality results differ among models10,11,12. Here we use an ensemble of global chemistry–climate models13 to show that premature mortality from changes in air pollution attributable to climate change, under the high greenhouse gas scenario RCP8.5 (ref. 14), is probably positive. We estimate 3,340 (−30,300 to 47,100) ozone-related deaths in 2030, relative to 2000 climate, and 43,600 (−195,000 to 237,000) in 2100 (14% of the increase in global ozone-related mortality). For PM 2.5, we estimate 55,600 (−34,300 to 164,000) deaths in 2030 and 215,000 (−76,100 to 595,000) in 2100 (countering by 16% the global decrease in PM 2.5-related mortality). Premature mortality attributable to climate change is estimated to be positive in all regions except Africa, and is greatest in India and East Asia. Most individual models yield increased mortality from climate change, but some yield decreases, suggesting caution in interpreting results from a single model. Climate change mitigation is likely to reduce air-pollution-related mortality.

Tempo-Spatial Variations of Ambient Ozone-Mortality Associations in the USA: Results from the NMMAPS Data.

Although the health effects of ambient ozone have been widely assessed, their tempo-spatial variations remain unclear. We selected 20 communities (ten each from southern and northern USA) based on the US National Morbidity, Mortality, and Air Pollution Study (NMMAPS) dataset. A generalized linear model (GLM) was used to estimate the season-specific association between each 10 ppb (lag0-2 day average) increment in daily 8 h maximum ozone concentration and mortality in every community. The results showed that in the southern communities, a 10 ppb increment in ozone was linked to an increment of mortality of −0.07%, −0.17%, 0.40% and 0.27% in spring, summer, autumn and winter, respectively. For the northern communities, the excess risks (ERs) were 0.74%, 1.21%, 0.52% and −0.65% in the spring, summer, autumn and winter seasons, respectively. City-specific ozone-related mortality effects were positively related with latitude, but negatively related with seasonal average temperature in the spring, summer and autumn seasons. However, a reverse relationship was found in the winter. We concluded that there were different seasonal patterns of ozone effects on mortality between southern and northern US communities. Latitude and seasonal average temperature were identified as modifiers of the ambient ozone-related mortality risks.

Impact of climate and emission change on ozone induced mortality in Europe with combining effect of heat

Introduction Ozone is a highly oxidative pollutant, associated with increasing mortality. All else (e.g. ozone precursors) being equal, summertime ground-level ozone will increase as temperatures increase with climate change. As a part of the ACCEPTED project we will use CO2 emission scenarios, global and regional climate and chemistry-transport models, epidemiological data and population projections to assess ozone- and heat-related health impacts under a changing climate. Methods European ozone concentrations are modelled at a grid size of 50x50 km using MATCH. Climate projections from the regional climate model, RCA4 are used. For the surface ozone and temperatures the global climate model EC-EARTH, was used as input of the regional climate model, forced by the greenhouse gas emission scenario RCP4.5. Two periods were compared: the current climate as 1991-2000 and future climate as 2046–2055. The impacts on long-term mortality due to ozone exposure from April-September and heat related premature deaths in Europe are calculated. Results When only taking into account the impact of changing climate on summertime surface ozone, up to 16% increase to the ozone-associated mortality is expected in Central- and Southern-Europe. However, projected decrease in ozone precursor emissions will cause much larger decrease in surface ozone (45% as EU average). Furthermore, due to aging Europe and increasing susceptible populations, the ozone related mortality might yet increase by 5.8%. During summer months, there is also combining effect of heat, especially during hottest periods and in densely populated urban areas. While the effects of heat are at the moment 20-25% larger compared to ozone, due to increasing temperatures and decreasing ozone precursor emission, the difference will be three times in 2050. Conclusions Climate and emission changes will substantially affect ozone and temperature related mortality and the ratio between them in the middle of this century in Europe.

Projecting ozone-related mortality in East China

BackgroundThe concentrations of ozone (O3) in China are increasing, especially in East China, but its future trends and potential health impacts remain to be explored. ObjectivesThe objective was to assess future trends in O3 concentrations and related premature death in East China between 2005 and 2030. MethodsFirst, a global chemical transport model (MIROC-ESM-CHEM) and regional chemical transport modelling system (including the Weather Research and Forecasting model and the Community Multiscale Air Quality model) were combined to estimate daily O3 concentrations in 2005 and 2030 in East China under the “current legislation” (CLE) and “maximum technically feasible reduction” (MFR) scenarios which were applied globally. O3 concentrations were then linked with population projections, mortality projections, and O3-mortality associations to estimate changes in O3-related mortality in East China. ResultsThe annual mean O3 concentration was projected to increase in East China between 2005 and 2030 under the CLE scenario, while decrease under the MFR scenario. Under the CLE scenario, O3-attributable health burden could increase by at least 40,000 premature deaths in East China, without considering the population growth. Under the MFR scenario, the health burden could decrease by up to 260,000 premature deaths as a result of the reduction in O3 concentration with a static population. However, when the population growth was considered, O3-attributable health burden could increase by up to 46,000 premature deaths in East China under the MFR scenario. ConclusionsThe results suggest that the health burden attributable to O3 may increase in East China in 2030.