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1.
J Environ Manage ; 261: 110174, 2020 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-32148264

RESUMEN

Rapid industrialization and urbanization are often accompanied by deteriorating air quality that imposes substantial health and productivity costs on the local population. However, existing studies have generally found low marginal willingness to pay (WTP) for mitigating such damages. To understand the determinants and the extent of WTP for air quality improvements, we collected comprehensive socio-demographic and stated preference information from more than 3000 random respondents in three cities in China. Combining the survey data with air quality data from ground-level monitoring stations, we find that exposure to persistent air pollution is a significant determinant of the extent individuals are willing to pay for cleaner air. On average, urban residents are willing to pay 65 CNY (~10 USD) each year to improve air quality to World Health Organization standards. Males and individuals that are younger and more educated tend to have higher WTP. We also find that individuals with more knowledge of sustainability and who engage in more pro-environmental behaviors are willing to pay more. Compared to existing government monetary incentives to reduce air pollution, the public's total WTP for cleaner air is much higher. Overall, these results highlight the potential welfare gain for policymakers to implement more stringent air quality regulations to reduce pollution.


Asunto(s)
Contaminación del Aire , China , Ciudades , Contaminación Ambiental , Humanos , Masculino , Encuestas y Cuestionarios , Urbanización
2.
J Environ Manage ; 261: 110207, 2020 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-32148277

RESUMEN

Over the past few decades, the pollutant emissions trading policies in China have undergone significant innovation and exploration. It is considered as a market-based approach that became integrated with command-and-control mechanisms such as total emissions control or pollution permits. This study is the first to provide systematic, reflective thinking that tracks the regional initiatives of pollutant emissions trading systems in China. In this article, we divided China's emissions trading practices into three stages and conducted a comparative qualitative analysis of the country's eleven provincial emissions trading pilots. We found that provincial pilots are highly diverse and complex regarding the pollutants that can be traded, the industrial sectors involved, the design of trading administration and processes, and the implementation of trading practices such as allowance, pricing and platforms. We also identified four main challenges: legislation setup, monitoring and verification, administrative interference, and the technical quantification of pollutant hotspots. We conclude the article by providing policy implications so that emissions trading policies can be integrated with the newly developed pollution permitting system.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Contaminantes Ambientales , China , Industrias
4.
Environ Sci Technol ; 54(5): 2859-2868, 2020 03 03.
Artículo en Inglés | MEDLINE | ID: mdl-32022552

RESUMEN

Both ozone exposure and extreme temperatures are found to be significantly associated with mortality; however, inconsistent results have been obtained on the modification effects of temperature on the ozone-mortality association. In the present study, we conducted a nationwide time-series analysis in 128 counties from 2013-2018 to examine whether temperature modifies the association between short-term ozone exposure with nonaccidental and cause-specific mortality in China. First, we analyzed the effects of ozone exposure on mortality at different temperature levels. Then, we calculated the pooled effects through a meta-analysis across China. We found that high-temperature conditions (>75th percentile in each county) significantly enhanced the effects of ozone on nonaccidental, cardiovascular, and respiratory mortality, with increases of 0.44% (95% confidence interval (CI): 0.36 and 0.51%), 0.42% (95% CI: 0.32 and 0.51%) and 0.50% (95% CI: 0.31 and 0.68%), respectively, for a 10 µg/m3 increase in ozone at high temperatures. Stronger effects on nonaccidental and cardiovascular mortality were observed at high temperatures among elderly individuals aged 65 years and older compared with the younger people. Our findings provide evidence that health damage because of ozone may be influenced by the impacts of increasing temperatures, which point to the importance of mitigating ozone exposure in China under the context of climate change to further reduce the public health burden.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Enfermedades Cardiovasculares , Ozono , Anciano , China , Calor , Humanos , Mortalidad , Temperatura Ambiental
5.
Environ Monit Assess ; 192(3): 175, 2020 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-32055978

RESUMEN

This study aimed to assess the air quality, the prevalence of child respiratory morbidity, and the association between them, in urban areas where concentrations of pollutants are expected to be below national limits. The monitoring of PM10, NO2 and O3 was performed in five schools, during 9 months. Information about respiratory diseases and associated symptoms were collected from each student using a questionnaire based on the International Study of Asthma and Allergies in Childhood. The PM10 and NO2 concentrations were higher at points closer to roads and avenues with intense vehicle flow and lower at the point closer to a park, with dense vegetation. All sampling points exceeded the annual limit established by WHO for PM10. Some maximum PM10 concentrations recorded close to the road was six times higher than the international limit. In total, 340 answered questionnaires were collected (68% response rate). Respiratory symptoms such as wheezing, sneezing, running nose, tearing, and itchy eyes had positive and strong correlation to the primary pollutants (0.70 to 0.87), but the frequency of some symptoms was lower close to the urban forest. Therefore, our results confirm the importance of creating and maintaining green areas in urban space, considering all ecosystem services provided by them, especially the improvement of air quality. In addition, a continuous program to monitor and control atmospheric pollution is required in mid-sized counties located nearby important roads, with growing fleets of vehicles.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Contaminantes Atmosféricos/toxicidad , Niño , Ecosistema , Exposición a Riesgos Ambientales , Monitoreo del Ambiente , Bosques , Humanos , Emisiones de Vehículos
6.
Environ Monit Assess ; 192(3): 195, 2020 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-32086616

RESUMEN

With air quality issues in urban areas garnering increasing media attention, concerned citizens are beginning to engage with the technology as a means of identifying and responding to the environmental risks posed. However, while much has been written about the accuracy of the units, little research has been conducted into its effects on users. As such, this research deploys coping theory to explore the specific ways in which portable air quality sensors influence user behaviour. This is done using a qualitative exploratory design, targeting parents and carers of children on the school run. Drawing from survey and interview responses, the article illustrates the decision-making pathways underpinning engagement with monitors and the ways in which they influence behaviour and disrupt misconceptions around air pollution. The study demonstrates that personal environmental monitors can play a role in protecting children from air pollution on the school run. They can raise awareness about air pollution and disrupt misconceptions about where does and does not occur. They can also encourage the public to change their behaviour in an attempt to mitigate and manage risks. However, the findings additionally reveal that sensor technology does not generate a simple binary response among users, of behavioural change or not. When attempts at behavioural change fail to reduce risk, resulting negative feelings can lead to inaction. Hence, the relationship between the technology and the individual is entwined with various social circumstances often beyond a parent or carer's control. Thus, top-down support aimed at tackling air pollution at source is essential if this bottom-up technology is to fulfil its full potential.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Instituciones Académicas , Contaminantes Atmosféricos/toxicidad , Contaminación del Aire/prevención & control , Niño , Monitoreo del Ambiente , Humanos , Encuestas y Cuestionarios , Estados Unidos , United States Environmental Protection Agency
7.
J Environ Manage ; 260: 109851, 2020 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-32090792

RESUMEN

The Clean Air Action implemented in China between 2013 and 2017 strengthened air pollution regulation to an unprecedented level, advancing the country's war against pollution. Although its effect on air quality improvement has been witnessed and evaluated, its influence on employment, which determines the overall desirability and efficiency of the policy, has remained unaddressed with reliable empirical evidence. We provide causal estimates of the aggregate effect of the Clean Air Action, one of the largest and most recent environmental programs in China, on labor demand. Utilizing the cross-city variations in regulatory stringency measured by the air quality targets, we adopt the difference-in-differences propensity score matching method to estimate the effect. We find that during the program's first two years, the Clean Air Action did not bring significant negative impacts on economy-wide employment or labor demand in the primary, secondary, and tertiary sectors. It also did not reduce employment in the more disaggregated sectors of mining, manufacturing, and utilities supply. These findings are robust across different econometric specifications. To explain our results, we examine the output effect and the substitution effect, and find that on the aggregate levels, the Action did not cause significant changes in the inputs of labor and capital as well as the elasticity of substitution but led to a significant drop in the total output. Possible explanations for these findings are discussed. Our study empirically reveals that the short-term negative impacts on the macro economy from the latest air pollution regulation in China are characterized by output reduction rather than employment shocks. It also potentially contributes to the timely evaluation of the causal effects of environmental policies in China and provides evidence-based suggestions for the adjustment of the ongoing regulation to achieve higher social welfare.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , China , Ciudades , Empleo , Contaminación Ambiental
8.
J Environ Manage ; 260: 109978, 2020 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-32090795

RESUMEN

This is an evidence from a high-income economy in Southeast Asia and a support for scientific planning of the energy sector in ensuring air pollution and climate change mitigation. A comparative analysis of the energy options for electricity generation in the nation was made considering availability, cost and greenhouse gases emission - CO2, N2O and CH4, using a two-stage method comprising multi-objective optimization and TOPSIS. The renewable (RE) and non-renewable energy (NRE) options available were assessed through the lifecycle approach to determine the lifecycle greenhouse gas emission (LCGHG) and levelized cost of energy (LCOE) per MWh of electricity. Considering historical electricity consumption, annual GDP and population growth from 1965, energy consumption for the year 2035 was forecasted using support vector machine regressor in Weka. Future plans in energy diversification pathways were examined through various scenario multi-objective optimizations with a constraint on resource availability and energy target using genetic algorithm in MATLAB. The outputs were ranked using TOPSIS method. Results showed that greenhouse gases emission could be reduced by 10.3 percent compared to business as usual scenario while the energy mix could attain 10 percent renewable energy in the grid at a relatively lower generation cost.


Asunto(s)
Contaminación del Aire , Gases de Efecto Invernadero , Cambio Climático , Electricidad , Efecto Invernadero , Energía Renovable
9.
J Environ Manage ; 260: 110031, 2020 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-32090802

RESUMEN

This study summarized the history of ambient air quality monitoring and air pollution prevention and control, and it analyzed the spatiotemporal patterns of ambient air pollutants during 1981-2017 in China. The results showed that monitoring of ambient air quality has changed dramatically in terms of determinants, sampling methods, monitoring extent, and evaluation basis during the previous four decades. Annual average concentrations of total suspended particulates, PM10 and SO2 have shown obvious decreasing trends during the studied period. These improvements have been closely related to the considerable efforts and various approaches undertaken to prevent and control air pollution. However, although policy implementation has been decisive and, at least in part, it has been enforced effectively, significant challenges remain. Air pollution control cannot be accomplished without a long-term strategy designed to achieve clean air in all parts of China.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , China , Polvo , Monitoreo del Ambiente , Material Particulado
10.
J Environ Manage ; 260: 110069, 2020 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-32090813

RESUMEN

Understanding the air pollution emission abatement potential and associated control cost is a prerequisite to design cost efficient control policies. In this study, a linear programming algorithm model, International Control Cost Estimate Tool, was updated with cost data for applications of 56 types of end-of-pipe technologies and five types of renewable energy in 10 major sectors namely power generation, industry combustion, cement production, iron and steel production, other industry processes, domestic combustion, transportation, solvent use, livestock rearing, and fertilizer use. The updated model was implemented to estimate the abatement potential and marginal cost of multiple pollutants in China. The total maximum abatement potentials of sulfur dioxide (SO2), nitrogen oxides (NOx), primary particulate matter (PM2.5), non-volatile organic compounds (NMVOCs), and ammonia (NH3) in China were estimated to be 19.2, 20.8, 9.1, 17.2 and 8.6 Mt, respectively, which accounted for 89.7%, 89.9%, 94.6%, 74.0%, and 80.2% of their total emissions in 2014, respectively. The associated control cost of such reductions was estimated as 92.5, 469.7, 75.7, 449.0, and 361.8 billion CNY in SO2, NOx, primary PM2.5, NMVOCs and NH3, respectively. Shandong, Jiangsu, Henan, Zhejiang, and Guangdong provinces exhibited large abatement potentials for all pollutants. Provincial disparity analysis shows that high GDP regions tend to have higher reduction potential and total abatement costs. End-of-pipe technologies tended be a cost-efficient way to control pollution in industries processes (i.e., cement plants, iron and steel plants, lime production, building ceramic production, glass and brick production), whereas such technologies were less cost-effective in fossil fuel-related sectors (i.e., power plants, industry combustion, domestic combustion, and transportation) compared with renewable energy. The abatement potentials and marginal abatement cost curves developed in this study can further be used as a crucial component in an integrated model to design optimized cost-efficient control policies.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , China , Monitoreo del Ambiente , Material Particulado , Dióxido de Azufre
12.
BMJ ; 368: m108, 2020 02 10.
Artículo en Inglés | MEDLINE | ID: mdl-32041707

RESUMEN

OBJECTIVE: To assess short term mortality risks and excess mortality associated with exposure to ozone in several cities worldwide. DESIGN: Two stage time series analysis. SETTING: 406 cities in 20 countries, with overlapping periods between 1985 and 2015, collected from the database of Multi-City Multi-Country Collaborative Research Network. POPULATION: Deaths for all causes or for external causes only registered in each city within the study period. MAIN OUTCOME MEASURES: Daily total mortality (all or non-external causes only). RESULTS: A total of 45 165 171 deaths were analysed in the 406 cities. On average, a 10 µg/m3 increase in ozone during the current and previous day was associated with an overall relative risk of mortality of 1.0018 (95% confidence interval 1.0012 to 1.0024). Some heterogeneity was found across countries, with estimates ranging from greater than 1.0020 in the United Kingdom, South Africa, Estonia, and Canada to less than 1.0008 in Mexico and Spain. Short term excess mortality in association with exposure to ozone higher than maximum background levels (70 µg/m3) was 0.26% (95% confidence interval 0.24% to 0.28%), corresponding to 8203 annual excess deaths (95% confidence interval 3525 to 12 840) across the 406 cities studied. The excess remained at 0.20% (0.18% to 0.22%) when restricting to days above the WHO guideline (100 µg/m3), corresponding to 6262 annual excess deaths (1413 to 11 065). Above more lenient thresholds for air quality standards in Europe, America, and China, excess mortality was 0.14%, 0.09%, and 0.05%, respectively. CONCLUSIONS: Results suggest that ozone related mortality could be potentially reduced under stricter air quality standards. These findings have relevance for the implementation of efficient clean air interventions and mitigation strategies designed within national and international climate policies.


Asunto(s)
Contaminación del Aire/efectos adversos , Exposición a Riesgos Ambientales/efectos adversos , Salud Global/estadística & datos numéricos , Mortalidad , Ozono/efectos adversos , Contaminación del Aire/análisis , Ciudades/estadística & datos numéricos , Cambio Climático/mortalidad , Exposición a Riesgos Ambientales/normas , Política Ambiental , Humanos , Cooperación Internacional , Ozono/análisis , Estaciones del Año
13.
J Environ Manage ; 258: 110036, 2020 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-31929069

RESUMEN

The Clean Air Action is considered an important measure to control air pollution. Despite extensive studies on the benefits or the cost of the Clean Air Action, the overall effect of such an action on green development is largely unknown. This paper tries to fill this gap. Based on panel data of 278 Chinese cities, this paper begins with the construction of a comprehensive indicator, namely green production efficiency, to reflect the green development over the period 2011 to 2016, we then implement the quasi-difference-in-differences framework to identify the policy effect of the Clean Air Action on green development. The following findings are obtained: (1) The Clean Air Action has enhanced the green development of Chinese cities, especially in areas with relatively high reduction target and rich resource endowment; (2) The dynamic analysis reveals that the positive effect of the Clean Air Action on green development presents an intensifying trend with time. This paper provides new insights to understand the Clean Air Action, based on these findings, we propose that future policies should focus on the transformation of overall green development and take full account of regional heterogeneity.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Ciudades , Políticas
14.
J Environ Manage ; 258: 110035, 2020 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-31929070

RESUMEN

We have analyzed trends in ambient fine (PM2.5) and coarse (PM2.5-10) particulate matter in Santiago, Chile, for the last 30 years. PM2.5 has monotonously decreased between 67% and 72% at those sites. Trends varied between -2.0 and -2.7 (µg/m3/year) between 1989 and late 90's, and between -0.7 and -1.1 (µg/m3/year) afterwards. This slowing down is likely a consequence of fast increase of motor vehicles in the city, which have become a dominant source of ambient PM2.5. Annual ambient PM2.5 concentrations are still above 20 (µg/m3), so more regulation is needed to bring them down. Coarse particles have changed little in 30 years, decreasing between 0% and 12%; particle concentrations have evolved in a non-linear way: first increasing in 1989-1995, then decreasing until 2003, and with a flat trend afterwards. We ascribe these trends to a combination of a) public works implemented throughout the city, b) fugitive dust controls like street sweeping programs and emission offsets for PM10 and c) increasing numbers of motor vehicles in the city. Further initiatives are needed to curb down coarse particles as well. By considering interaction between trend and seasonality, we have found that ambient PM2.5 has monotonously decreased all year long at all monitoring sites with similar patterns; this is characteristic of a regional-scale pollution. For ambient PM2.5-10 trend and season have a more complex, site-specific interaction, suggesting local sources and site location in the basin are relevant in determining ambient concentrations of coarse particles. A limitation of this study is that no quantitative link between ambient concentrations trends and atmospheric emissions could be established with the analyses carried out. A strength of the study is the long period analyzed with measurements conducted with the same gravimetric methodology.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Animales , Chile , Ciudades , Monitoreo del Ambiente , Tamaño de la Partícula , Material Particulado
15.
J Environ Manage ; 258: 110052, 2020 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-31929078

RESUMEN

The atmospheric pollution has been the public attention in recent years. In order to better coordinate economic development and atmospheric environmental management, China introduced the concept of atmospheric environmental capacity (AEC). The remaining atmospheric environmental capacity (RAEC) calculated by existing atmospheric pollution sources and AEC is an important basis for regional development and environmental protection. The RAEC of the high-pollution risk suburb of Chengdu in 2015 was estimated by the single-box model and analyzed on multiple time scales. The results show that the RAEC of SO2 and NO2 in this region is 3299 t/a and 2849 t/a, respectively under the annual time scale. However, in the daily time scale, the RAEC of NO2 is negative for 3 days, that is, there are 3 days with serious air pollution. Therefore, it is not appropriate to plan the industrial area only by relying on annual RAEC. Especially, RAEC displays inter-seasonal and monthly variability. On the one hand, in plain areas with low wind speed and little change in wind direction, achieving the prediction of atmospheric mixing layer height could give early warning of atmospheric pollution events. On the other hand, different management measures are taken on different time scales. On a long timescale, the regional energy structure should be optimized. On seasonal and monthly time scales, the production plans should be adapted to RAEC. On the daily time scale, it mainly deals with the serious atmospheric pollution accident timely.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , China , Monitoreo del Ambiente , Material Particulado , Estaciones del Año
16.
Environ Monit Assess ; 192(2): 90, 2020 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-31902018

RESUMEN

Owing to the rise in population, lifestyle changes, high traffic rates in urban areas and environmental pollution, respiratory diseases have become much more prevalent on both regional and urban scales. Respiratory diseases affect over 300 million people worldwide and are thus among the major threats to humans' general well-being. The identification of underlying factors and the specification of accompanying risk areas for the temporal exacerbation of respiratory diseases are effective steps in managing the damage caused by such disorders. Here, we demonstrate a strategy for modelling the risk zone of respiratory diseases temporally, using a location-based social network (LBSN) and an artificial neural network (ANN). The main contribution of this paper is to consider the environmental and infrastructural factors and identify their relationships with the geographical locations of respiratory attacks. The study also utilizes Telegram, which is the most popular and conventional social media platform, in order to observe temporal changes in the location of respiratory attacks in Iran, in the form of a developed Telegram bot known as @respiratoryassociation. The relations between the factors behind and the location of respiratory attacks are determined using a multilayer perceptron (MLP) ANN. All the required data have been collected on a daily basis over a 5-year period from December 2013 to December 2018 in Tehran, Iran. The results indicated air pollution, especially pollution from carbon monoxide (CO) and suspended particulate matter (PM) as the most decisive factors. Following air pollution, the amount of exposure to the polluted area was determined as the second most decisive factor, which in turn increased as a result of escalations in traffic jams. Land use was determined as the third most decisive factor. Furthermore, the results revealed that the ANN performed satisfactorily, implying that the model can be used to examine the spatio-temporal behaviour of the time series of respiratory diseases with respect to environmental and infrastructural factors.


Asunto(s)
Exposición a Riesgos Ambientales/estadística & datos numéricos , Enfermedades Respiratorias/epidemiología , Contaminación del Aire/análisis , Contaminación del Aire/estadística & datos numéricos , Monóxido de Carbono , Progresión de la Enfermedad , Monitoreo del Ambiente , Contaminantes Ambientales , Humanos , Irán , Material Particulado/análisis , Prevalencia
17.
Environ Monit Assess ; 192(2): 116, 2020 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-31942665

RESUMEN

Serious air pollution motivates governments to take control measures. However, specific emission reduction effects of various temporary emission reduction policies are difficult to evaluate. During the Asia-Pacific Economic Cooperation meeting in Beijing in 2014, the Chinese government implemented a number of emergency emission control measures in the Beijing-Tianjin-Hebei area to maintain the air quality in this region. This gave us an opportunity to quantify the effectiveness of the emission reduction measures separately and identify the efficient policy combinations for the reduction of major pollutants. In this study, we evaluated the impacts of specific emission reduction measures on the concentrations of two major air pollutants (PM2.5 and O3) under eight policy scenarios using the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem). Comparing these scenarios, we found that the control policies against the primary PM2.5 emission achieved the most significant results. Meanwhile, all the emission control measures raised the ozone concentrations in different degrees, which might be partly attributed to the changes of PM2.5 concentration and the ratio of NOx and VOCs caused by the emission control measures. Our results suggest that, in VOC-sensitive areas like Beijing, emergency control measures focusing on primary PM2.5 emission could lead to significant PM2.5 reduction and relatively small ozone increase, and should be considered as a priority policy. Joint emission control at the regional scale is also important especially under unfavorable meteorological conditions.


Asunto(s)
Contaminantes Atmosféricos/análisis , Contaminación del Aire/prevención & control , Política Ambiental , Contaminación del Aire/análisis , Contaminación del Aire/estadística & datos numéricos , Asia , Beijing , China , Monitoreo del Ambiente , Ozono/análisis , Material Particulado/análisis
18.
Environ Sci Technol ; 54(5): 2585-2594, 2020 03 03.
Artículo en Inglés | MEDLINE | ID: mdl-31951123

RESUMEN

To illustrate the major sources responsible for the redox activity of ambient fine particles during the 2014 Asia-Pacific Economic Cooperation (APEC) conference in Beijing, 3 months of daytime (8:00-19:30 LST) and nighttime (20:00-7:30 LST) particulate kmatter (PM2.5) was collected in Huairou, Beijing from November 3, 2014 through January 31, 2015. PM2.5 compositions were analyzed, including elements, organic carbon, elemental carbon, water-soluble ions, organics, and redox activities measured by both the dithiothreitol and the macrophage reactive oxygen species (ROS) assays. The mass-normalized redox activity was approximately constant during the noncontrol period (NCP) and control period (CP). The absolute value of the volume-normalized redox activity was about 4 times higher during NCP than that during CP, indicating the effectiveness of the control measures. The statistical analysis results showed that an interquartile range increase in PM2.5 mass, chemicals, and sources (µg/m3) was associated with the 1-3% increase in redox activity, indicating that the successful control did make a significant reduction in redox activity but did not elucidate that some source controls (i.e., vehicle emissions) could be more effective at reducing redox activity than other control programs (i.e., dust source). This study demonstrated that combustion particles from both solid fuels and liquid fuels could contribute to ROS generation. Furthermore, ROS could be formed in the atmosphere via photochemical reactions, which highlights the need to further research on their formation pathways. A better understanding of the relevant mechanistic pathways and different source contributors to ROS will help to guide strategies for targeted mitigation of the atmospheric oxidation potential and will also help to reduce the great disease stress caused by exposure to air pollution.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Asia , Beijing , China , Monitoreo del Ambiente , Oxidación-Reducción , Material Particulado
19.
Environ Sci Technol ; 54(4): 2133-2142, 2020 02 18.
Artículo en Inglés | MEDLINE | ID: mdl-31995368

RESUMEN

Diverse urban air pollution sources contribute to spatially variable atmospheric concentrations, with important public health implications. Mobile monitoring shows promise for understanding spatial pollutant patterns, yet it is unclear whether uncertainties associated with temporally sparse sampling and instrument performance limit our ability to identify locations of elevated pollution. To address this question, we analyze 9 months of repeated weekday daytime on-road mobile measurements of black carbon (BC), particle number (PN), and nitrogen oxide (NO, NO2) concentrations within 24 census tracts across Houston, Texas. We quantify persistently elevated, intermittent, and extreme concentration behaviors at 50 m road segments on surface streets and 90 m segments on highways relative to median statistics across the entire sampling domain. We find elevated concentrations above uncertainty levels (±40%) within portions of every census tract, with median concentration increases ranging from 2 to 3× for NO2, and >9× for NO. In contrast, PN exhibits elevated concentrations of 1.5-2× the domain-wide median and distinct spatial patterns relative to other pollutants. Co-located elevated concentrations of primary combustion tracers (BC and NOx) near 30% of metal recycling and concrete batch plant facilities within our sampled census tracts are comparable to those measured within 200 m of highways. Our results demonstrate how extensive mobile monitoring across multiple census tracts can quantitatively characterize urban air pollution source patterns and are applicable to developing effective source mitigation policies.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Contaminantes Ambientales , Monitoreo del Ambiente , Material Particulado , Texas
20.
Matern Child Health J ; 24(Suppl 1): 48-56, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31981064

RESUMEN

INTRODUCTION: Childhood pneumonia is a major cause of mortality worldwide while household air pollution (HAP) is a major contributor to childhood pneumonia in low and middle-income countries. This paper presents the prevalence trend of childhood pneumonia in Nepal and assesses its association with household air pollution. METHODS: The study analysed data from the 2006, 2011 and 2016 Nepal Demographic Health Surveys (NDHS). It calculated the prevalence of childhood pneumonia and the factors that cause household air pollution. The association of childhood pneumonia and HAP was assessed using univariate and multi-variate analysis. The population attributable fraction (PAF) of indoor pollution for causing pneumonia was calculated using 2016 NDHS data to assess the burden of pneumonia attributable to HAP factors. RESULTS: The prevalence of childhood pneumonia decreased in Nepal between 2006 and 2016 and was higher among households using polluting cooking fuels. There was a higher risk of childhood pneumonia among children who lived in households with no separate kitchens in 2011 [Adjusted risk ratio (ARR) 1.40, 95% CI 1.01-1.97] and in 2016 (ARR 1.93, 95% CI 1.14-3.28). In 2016, the risk of children contracting pneumonia in households using polluting fuels was double (ARR 1.98, 95% CI 1.01-3.92) that of children from households using clean fuels. Based on the 2016 data, the PAF for pneumonia was calculated as 30.9% for not having a separate kitchen room and 39.8% for using polluting cooking fuel. DISCUSSION FOR PRACTICE: Although the occurrence of childhood pneumonia in Nepal has decreased, the level of its association with HAP remained high.


Asunto(s)
Contaminación del Aire Interior/efectos adversos , Culinaria , Vivienda , Neumonía/epidemiología , Adolescente , Adulto , Contaminación del Aire/análisis , Contaminación del Aire Interior/estadística & datos numéricos , Preescolar , Composición Familiar , Femenino , Humanos , Masculino , Nepal/epidemiología , Prevalencia , Adulto Joven
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