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At least 19 records

Local pollutants go global: The impacts of intercontinental air pollution from China on air quality and morbidity in California

Highlights: • Heavy sandstorms are a major pollution source in China. • Trans-Pacific air pollution from sandstorms in China affect health in California. • Policymakers could plan for worsened air quality in California following sandstorms. China is among the greatest emitters of air pollution in the world and one concern is the effects of intercontinental air pollution traveling across the Pacific Ocean from China to the U.S. We exploit a natural experiment by observing the effects of changes in intercontinental air pollution associated with Chinese New Year, a 7-day national holiday, and sandstorms from China on air quality and morbidity in California. The timing of these events are unlikely correlated to other factors affecting air quality and health in California. Chinese New Year follows the Lunar New Year which varies each traditional calendar year while sandstorms are a naturally occurring phenomenon. We examine effects on morbidity using restricted emergency department and inpatient hospitalization data for the universe of patients with respiratory and heart disease between 2005 and 2012 in California. This is the first study to use patient-level data to examine the effects of trans-Pacific air pollution from China on morbidity in the U.S. We show that heavy sandstorms are associated with a modest increase in acute respiratory disease per capita, representing 0.5–4.6% of average weekly hospitalizations. However, we find no significant effect on morbidity in California from Chinese New Year. Results suggest that policymakers could prepare for changes in air quality following major sandstorms in China.

54 ENVIRONMENTAL SCIENCES↗

Spatiotemporal dynamics of nitrogen dioxide pollution and urban development: Satellite observations over China, 2005–2016

China experienced rapid urbanization and industrialization in recent years, which resulted in large increases of nitrogen dioxide (NO2), particularly in urban areas. We analyze the spatiotemporal variations of the vertical column densities (VCDs) of tropospheric NO2 with the level of urban development across China during the period 2005-2016. Nighttime light (NTL) data are applied as a proxy for urban development to investigate the relationship between NO, pollution and urban development. Both NO2 column data and NTL data are observed by satellite measurements. The annual mean of NO2 VCDs is presented on a grid basis. The average annual variations of NO2 VCDs and NTL value are detected for all 341 prefectural cities. Two-thirds of the cities reached their peak NO2 pollution level around 2010-2012, and decreased afterward. About 10% of the western cities kept on increasing their NO2 levels until 2016. All cities are classified into four categories with respect to the average annual variations of NO2/NTL in 2005-2010, and 2011-2016. Approximately 62% of the cities turned the average annual variations of NO2/NTL from positive to negative. 19% of the cities are in the positive-positive category and 11% of the cities are in the negative-negative category. The remaining 8% of the cities changed their ratios from negative to positive. We summarize the national air pollution regulations, and our results show the effectiveness of the regulations for most eastern China cities. This work can help to design more efficient regional emission reduction policies with sustainable development.

nighttime light data↗

Photocatalytic degradation of organic pollutants coupled with simultaneous photocatalytic H 2 evolution over graphene quantum dots/Mn-N-TiO 2 /g-C 3 N 4 composite catalysts: Performance and mechanism

Graphene quantum dots/Mn-N-TiO 2 /g-C 3 N 4 (GQDs/TCN) composite photocatalysts have been designed, synthesized and characterized by XRD, SEM, TEM, Raman, BET, and XPS. The photodegradation of organic pollutants (p-nitrophenol, diethyl phthalate and ciprofloxacin, called as 4-NP, CIP and DEP, respectively) coupled with simultaneous photocatalytic production of hydrogen was successfully achieved using the GQDs/TCN catalysts. The 5%GQDs/TCN-0.4 sample shows the best photocatalytic hydrogen production and organic pollutant degradation rate under simulated solar irradiation in the simultaneous photocatalytic oxidation and reduction system. Furthermore, the photocatalytic H 2 evolution rates in the solution of 4-NP, CIP and DEP are all larger than that in pure water system over the 5%GQDs/TCN-0.4 catalyst. And the H 2 evolution rate in the solution of 4-NP is smaller than that in the solutions of CIP and DEP. Accordingly, the photodegradation rate of 4-NP is larger than that of CIP and DEP. The analyses of density functional theory and liquid chromatography mass spectrometry indicate that some photogenerated electrons were used in the photodegradation process of 4-NP but not in that of CIP and DEP. And it leads to the photocatalytic rate of H 2 evolution in the 4-NP solution smaller than that in the solution of CIP and DEP. For the first time, the present work illuminates the photocatalytic enhancement of the GQDs/TCN-0.4 catalyst and the mechanism of the effect of different organic pollutants on photocatalytic H 2 evolution.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Efficient Nighttime Biogenic SOA Formation in a Polluted Residual Layer

Abstract Organic nitrates formed from nighttime reaction between anthropogenic nitrate radicals (NO3) and biogenic volatile organic compounds (BVOCs) are potentially an important but highly uncertain source of secondary organic aerosol (SOA). Here we report on the enhanced nighttime biogenic SOA formation observed in a polluted residual layer over Sacramento, California, the morning of 15 June 2010 during the Carbonaceous Aerosols and Radiative Effects Study (CARES). Trajectory analysis showed that the residual layer air, containing trace amounts of isoprene and monoterpenes left over after nighttime oxidation, was influenced by the San Francisco Bay Area emissions the previous evening. The residual layer aerosol was also enriched in nitrate, with about 64% of it estimated to be in the form of organic nitrates. The nitrate:organic mass ratio of the SOA was about 0.47±0.044, which corresponds to the range typically found in isoprene mononitrates. Assuming the SOA was composed of organic mononitrates, its nominal molecular weight was estimated at 186±11 g mol-1, consistent with the highly functionalized isoprene hydroxynitrates that have been observed in the particle phase in the southeast United States. Overall, our findings show that the efficiency of nighttime biogenic SOA formation, expressed as the change in organic aerosol mass relative to carbon monoxide (?OA/?CO), was about 100 µg m-3 ppmv, which falls in the range 77-157 µg m-3 ppmv previously estimated for enhanced daytime SOA formation from mixed anthropogenic and biogenic emissions during CARES.

Zaveri, Rahul A.↗

Air pollution and the fetal origin of disease: A systematic review of the molecular signatures of air pollution exposure in human placenta

Fetal development is a crucial window of susceptibility in which exposure-related alterations can be induced on the molecular level, leading to potential changes in metabolism and development. The placenta serves as a gatekeeper between mother and fetus, and is in contact with environmental stressors throughout pregnancy. This makes the placenta as a temporary organ an informative non-invasive matrix suitable to investigate omics-related aberrations in association with in utero exposures such as ambient air pollution.

54 ENVIRONMENTAL SCIENCES↗

Efficient electrocatalytic valorization of chlorinated organic water pollutant to ethylene

Electrochemistry can provide an efficient and sustainable way to treat environmental waters polluted by chlorinated organic compounds. However, the electrochemical valorization of 1,2-dichloroethane (DCA) is currently challenged by the lack of a catalyst that can selectively convert DCA in aqueous solutions into ethylene. Here, in this work, we report a catalyst comprising cobalt phthalocyanine molecules assembled on multiwalled carbon nanotubes that can electrochemically decompose aqueous DCA with high current and energy efficiencies. Ethylene is produced at high rates with unprecedented ~100% Faradaic efficiency across wide electrode potential and reactant concentration ranges. Kinetic studies and density functional theory calculations reveal that the rate-determining step is the first C–Cl bond breaking, which does not involve protons—a key mechanistic feature that enables cobalt phthalocyanine/carbon nanotube to efficiently catalyse DCA dechlorination and suppress the hydrogen evolution reaction. The nanotubular structure of the catalyst enables us to shape it into a flow-through electrified membrane, which we have used to demonstrate >95% DCA removal from simulated water samples with environmentally relevant DCA and electrolyte concentrations.

Choi, Chungseok↗

Role of climate goals and clean-air policies on reducing future air pollution deaths in China: a modelling study

Over 3 million people still die every year from diseases caused by exposure to outdoor PM 2.5 air pollution, and more than a quarter of these premature deaths occur in China. In addition to clean air policies that target pollution emissions, climate policies aimed at reducing fossil-fuel CO 2 emissions (e.g., to avoid 1.5°C of warming) may also dramatically improve air quality and public health. Yet there has been no comprehensive accounting of public health outcomes under different energy pathways and local clean air management decisions in China. In particular, further research is needed to understand the relationships among climate and clean air polices and future health burdens in China, where an aging population will further exacerbate the impacts of air pollution. Using a China-focused integrated assessment model (GCAM-China) and a dynamic emission projection model (DPEC), we project future Chinese air quality in scenarios spanning a range of global climate targets (i.e. 1.5°0C, 2°C, NDC, unambitious, baseline, and 4.5°C) as well as national clean air actions (i.e. 2015-pollution, current-pollution, and ambitious-pollution). We then evaluate the health impacts of PM2·5 air pollution of scenario matrix using the chemical transport model WRF-CMAQ and the latest epidemiological concentration–response (C-R) functions (i.e. GBD2019). We find that, without ambitious climate mitigation (e.g., under current NDC pledges), Chinese deaths related the PM2.5 air pollution do not substantially decrease—and often grow—by mid-century, regardless of clean air policies and air quality improvements. For example, in scenarios that track China’s current NDC pledge and deploy best-available pollution control technologies, PM 2.5 -related deaths in China decrease slightly by 2030 (to 1.2 million per year) but no further by mid-century (Ambitious-pollution-NDC-goals; 1.2 million deaths in 2050) despite substantial and continuous improvements in population-weighted air quality (27.2 to 16.0 µg/m 3 from 2030 to 2050). The contrary trends of improving air quality and increasing PM 2·5 -related deaths in many of our scenarios reveals the extent to which extra efforts are needed to compensate for the established fact of increasing age of China’s population in future. Substantial decreases in China’s PM 2.5 -related deaths and age-standardized death rates (e.g., decreasing by 0.3–0.5 million deaths and 10.2–14.2 per 100,000 population age-standardized death rates per year) thus require the sort of large-scale transition in energy sources entailed by scenarios that meet international climate goals to avoid 1.5°C and 2°C of warming (Ambitious-pollution-2°C- and 1.5°C-goals).

58 GEOSCIENCES↗

Does the air pollution model influence the evidence of socio-economic disparities in exposure and susceptibility?

Highlights: • Daily exposure to ozone may vary across air pollution models, considerably. • The exposure model influenced disparity of exposure across socio-economic strata. • The air pollution model does not affect disparity of susceptibility. • Multiple air pollution models should be used to assess socio-economic disparities. Studies assessing socio-economic disparities in air pollution exposure and susceptibility are usually based on a single air pollution model. A time stratified case-crossover study was designed to assess the impact of the type of model on differential exposure and on the differential susceptibility in the relationship between ozone exposure and daily mortality by socio-economic strata (SES) in Montreal. Non-accidental deaths along with deaths from cardiovascular and respiratory causes on the island of Montreal for the period 1991–2002 were included as cases. Daily ozone concentration estimates at partictaipants’ residence were obtained from the five following air pollution models: Average value (AV), Nearest station model (NS), Inverse-distance weighting interpolation (IDW), Land-use regression model with back-extrapolation (LUR-BE) and Bayesian maximum entropy model combined with a land-use regression (BME-LUR). The prevalence of a low household income (< 20,000/year) was used as socio-economic variable, divided into two categories as a proxy for deprivation. Multivariable conditional logistic regressions were used considering 3-day average concentrations. Multiplicative and additive interactions (using Relative Excess Risk due to Interaction) as well as Cochran's tests were calculated and results were compared across the different air pollution models. Heterogeneity of susceptibility and exposure according to socio-economic status (SES) were found. Ratio of exposure across SES groups means ranged from 0.75 [0.74–0.76] to 1.01 [1.00–1.02], respectively for the LUR-BE and the BME-LUR models. Ratio of mortality odds ratios ranged from 1.01 [0.96–1.05] to 1.02 [0.97–1.08], respectively for the IDW and LUR-BE models. Cochran's test of heterogeneity between the air pollution models showed important heterogeneity regarding the differential exposure by SES, but the air pollution model was not found to influence heterogeneity regarding the differential susceptibility. The study showed air pollution models can influence the assessment of disparities in exposure according to SES in Montreal but not that of disparities in susceptibility.

54 ENVIRONMENTAL SCIENCES↗

The burden of ischemic heart disease related to ambient air pollution exposure in a coastal city in South China

Highlights: • Burden of ischemic heart disease related to PM{sub 2.5}, SO{sub 2} and NO{sub 2} were estimated. • Stronger impacts of gaseous pollutants versus particulate matter were found. • SO{sub 2} exposure was positively associated with YLL in widowed group. Air pollution is considered one of the most important risk factors for ischemic heart disease (IHD), which is a major public health concern. The disease burden of IHD has continued to rise in China in the past two decades. However, epidemiological studies examining the associations between air pollution and IHD have been scarce in China, and the only studies were conducted in severe air pollution areas, where air pollution levels seriously exceed the World Health Organization Air Quality Guidelines. Whether the influence of air pollution on IHD in areas with relatively low levels of air pollution differs from the influence of high pollution levels in heavily studied areas was unknown until now. Furthermore, the estimation of the disease burden of IHD related to air pollution has been very limited.

54 ENVIRONMENTAL SCIENCES↗

An Overview of Policies Influencing Air Pollution from the Electricity Sector in Central Asia

The electricity sector is a substantial source of air pollution and associated health problems in Central Asia and elsewhere. Fossil-fueled power plants emit a wide variety of harmful pollutants and their chemical precursors. The pollutants with the greatest health impacts are particulate matter and ozone. Once released into the atmosphere, there is no practical way to remove air pollutants, which means that policies designed to improve air quality have to limit the pollutants before release. However, tackling such pollution is challenging, particularly in developing economies, due to the need to provide electricity as a basic necessity for citizens and as an engine of economic growth. This report provides examples of policies impacting air pollution from the electricity sector in the Central Asian countries of Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan. It is a partner publication to an earlier report that addressed policies in South Asia. As with the South Asia report, information on policies in some countries was difficult to locate; therefore, this is not a comprehensive study, but rather an overview or "scan" of the sector that includes examples of: (1) policies that directly regulate air quality by limiting emissions from specific point sources (by restricting operating hours, for instance); and (2) indirect policies that incentivize or disincentivize polluting activities, such as policies to encourage fuel switching to or from cleaner renewable resources. Note that this report was prepared before the Russia-Ukraine conflict and therefore doesn't address consequences of that war for Central Asia. The report finds: (1) That Central Asian countries typically have relatively few policy instruments available for regulating national air emissions; (2) That many countries, especially those that have a mismatch between seasonal demand and resource availability, could improve energy security and reduce air pollution through increased cross-border electricity trade; (3) That some countries have seemingly contradictory policies (promoting both coal and renewables, for instance). This report is also available in Russian: https://www.nrel.gov/docs/fy23osti/85192.pdf.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Long-term exposure to ambient air pollution (including PM1) and metabolic syndrome: The 33 Communities Chinese Health Study (33CCHS)

Highlights: • Associations of ambient air pollution with metabolic syndrome were scarcely studied. • Data from 15,477 Chinese adults were analyzed. • Long-term exposure to air pollution was associated with metabolic syndrome. • Demographic and lifestyle factors modified the association between metabolic syndrome and air pollution. Little evidence exists about the effects of long-term exposure to ambient air pollution on metabolic syndrome (MetS). This study aimed to determine the association between long-term ambient air pollution and MetS in China. A total of 15,477 adults who participated in the 33 Communities Chinese Health Study (33CCHS) in 2009 were evaluated. MetS was defined based on the recommendation by the Joint Interim Societies. Exposure to air pollutants was assessed using data from monitoring stations and a spatial statistical model (including particles with diameters ≤ 1.0 µm (PM{sub 1}), ≤ 2.5 µm (PM{sub 2.5}), and ≤ 10 µm (PM{sub 10}), sulfur dioxide (SO{sub 2}), nitrogen dioxide (NO{sub 2}), and ozone (O{sub 3})). Two-level logistic regression analyses were utilized to assess the associations between air pollutants and MetS. The prevalence of MetS was 30.37%. The adjusted odds ratio of MetS per 10 µg/m{sup 3} increase in PM{sub 1}, PM{sub 2.5}, PM{sub 10}, SO{sub 2}, NO{sub 2}, and O{sub 3} were 1.12 (95% CI = 1.00–1.24), 1.09 (95% CI = 1.00–1.18), 1.13 (95% CI = 1.08–1.19), 1.10 (95% CI = 1.02–1.18), 1.33 (95% CI = 1.12–1.57), and 1.10 (95% CI = 1.01–1.18), respectively. Stratified analyses indicated that the above associations were stronger in participants with the demographic variables of males, < 50 years of age, and higher income, as well as with the behavioral characteristics of smoking, drinking, and consuming sugar-sweetened soft drinks frequently. This study indicates that long-term exposure to ambient air pollutants may increase the risk of MetS, especially among males, the young to middle aged, those of low income, and those with unhealthy lifestyles.

54 ENVIRONMENTAL SCIENCES↗

Inequity in consumption of goods and services adds to racial–ethnic disparities in air pollution exposure

Fine particulate matter (PM 2.5 ) air pollution exposure is the largest environmental health risk factor in the United States. Here, we link PM 2.5 exposure to the human activities responsible for PM 2.5 pollution. We use these results to explore “pollution inequity”: the difference between the environmental health damage caused by a racial–ethnic group and the damage that group experiences. We show that, in the United States, PM 2.5 exposure is disproportionately caused by consumption of goods and services mainly by the non-Hispanic white majority, but disproportionately inhaled by black and Hispanic minorities. On average, non-Hispanic whites experience a “pollution advantage”: They experience ∼17% less air pollution exposure than is caused by their consumption. Blacks and Hispanics on average bear a “pollution burden” of 56% and 63% excess exposure, respectively, relative to the exposure caused by their consumption. The total disparity is caused as much by how much people consume as by how much pollution they breathe. Differences in the types of goods and services consumed by each group are less important. PM 2.5 exposures declined ∼50% during 2002–2015 for all three racial–ethnic groups, but pollution inequity has remained high.

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTAN↗

An Overview of Policies Influencing Air Pollution from the Electricity Sector in South Asia

The electricity sector is a substantial source of air pollution and associated health problems in South Asia and elsewhere. Fossil-fueled power plants emit a wide variety of harmful pollutants. Those with the greatest health impacts are particulate matter and ozone. Once released into the atmosphere, there is no practical way to remove air pollutants, which means that policies designed to improve air quality have to limit the pollutants before release. However, tackling such pollution is challenging because developing economies also need to provide electricity as a basic necessity for their citizens and as an engine of economic growth. This report provides examples of policies impacting air pollution from the fossil-fuel electricity sector in the South Asian countries of Afghanistan, Bangladesh, Bhutan, India, the Maldives, Nepal, Pakistan, and Sri Lanka. Some of this information was difficult to locate, so this is not a comprehensive study, but rather an overview or "scan" of the sector that includes examples of (1) policies that directly regulate air quality by limiting emissions from specific point sources (by restricting operating hours, for instance), and (2) indirect policies that incentivize or disincentivize polluting activities, such as policies to encourage fuel switching, for example. The report shows (1) the great variation among the policy instruments used in each country, (2) that many countries, especially those that have a mismatch between seasonal demand and resource availability, could improve energy security and reduce air pollution through increased cross-border electricity trade, and (3) some countries have contradictory policies (promoting both coal and renewables, for instance).

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Riverine Plastic Pollution: Sampling and Analysis Methods

Riverine plastic pollution has been found in all major U.S. rivers, but the exact amount of plastic being released to the oceans has not been quantified. Field studies conducted in U.S. rivers have used a range of sampling and analysis techniques and rarely measured the mass of the plastic collected. Measurements of riverine plastic pollution are needed to calibrate and validate models used to estimate the U.S. riverine plastic emissions to the oceans. This report surveys measurement methods used to quantify riverine pollution and current estimates of U.S. riverine plastic pollution from measurements and models. Measurement methods include field sampling and laboratory analysis. Field sampling methods are described for large (macro) and small (micro) plastic particles. Laboratory analysis methods are described for macro and microplastic with an emphasis on the detailed characterization processes of microplastics. Waterborne leachate analysis is also briefly described. Three models are described that estimate plastic pollution based on mismanaged plastic waste in the river catchment basins. The models were validated and calibrated with global data sources. The data sources were predominantly outside of the U.S., where the magnitude and composition of plastic pollution is different than what is found in U.S. rivers. Comprehensive measurements of riverine plastics are needed not only to characterize the riverine plastic pollution, but also parameterize and validate models of plastic fate and transport. This report also describes five key U.S. rivers that span a range of sizes and environmental conditions that could be sampled to obtain data to support characterization and model development of plastic pollution from rivers to oceans. Sampling and analysis protocol recommendations are made to ensure the highest quality of data are collected in the five rivers.

54 ENVIRONMENTAL SCIENCES↗

Meteorological characteristics of extreme ozone pollution events in China and their future predictions

Ozone (O 3 ) has become one of the most concerning air pollutants in China in recent decades. In this study, based on surface observations, reanalysis data, global atmospheric chemistry model simulations, and multi-model future predictions, meteorological characteristics conducive to extreme O 3 pollution in various regions of China are investigated, and their historical changes and future trends are analyzed. During the most severe O 3 polluted months, the chemical production of O 3 is enhanced under the hot and dry conditions over the North China Plain (NCP) in June 2018 and the Yangtze River Delta (YRD) in July 2017, while regional transport is the main reason for the severe O3 pollution over the Sichuan Basin (SCB) in July 2015 and the Pearl River Delta (PRD) in September 2019. Over the last 4 decades, the frequencies of high-temperature and low-relative-humidity conditions increased in 2000–2019 relative to 1980–1999, indicating that O 3 pollution in both the NCP and YRD has become more frequent under historical climate change. In the SCB and PRD, the occurrence of atmospheric circulation patterns similar to those during the most polluted months increased, together with the more frequent hot and dry conditions, contributing to the increases in severe O 3 pollution in the SCB and PRD during 1980–2019. In the future (by 2100), the frequencies of months with anomalous high temperature show stronger increasing trends in the high-forcing scenario (Shared Socioeconomic Pathway (SSP5-8.5)) compared to the sustainable scenario (SSP1-2.6) in China. It suggests that high anthropogenic forcing will not only lead to slow economic growth and climate warming but also likely result in environmental pollution issues.

54 ENVIRONMENTAL SCIENCES↗