Air Pollution Control Programs Research Articles

Environmental regulation and worker earnings: Evidence from city-level air quality standards in China

This study delves into the influence of environmental regulations on worker earnings, employing China's City Air Pollution Prevention and Control Program (CAPPCP) as a quasi-experimental framework. We employ a difference-in-differences (DD) approach and match two unique firm-level data sets that include information on firm's economic indicators, and various emissions and abatement equipment. The results show that CAPPCP causes an average of 3.2% reduction in worker earnings, which amounts to CNY 6.1 billion (USD 803.4 million) in forgone earnings. The estimated result is less than that of comparable US studies. In addition, the reduction in earning tends to be attributed at bonuses rather than regular wages, and firms pay more unemployment insurance for employees. In the channel test, CAPPCP leads to an increase of 4.7% in firm's pollution abatement equipment and 6.4% in pollution treatment capacity, which significantly increase firm's production costs. We also find different types of firm responses to the regulations, where high-polluting, smaller, labor-intensive and non-SOE firms show a higher reduction in worker earnings than their counterparts. A cost-benefit analysis suggests that the health benefits gained through CAPPCP significantly outweigh that of earning losses.

A Dataset on Population Activity Patterns in Typical Regions of North China

This data article describes the "Typical Regional Activity Patterns" (TRAP) dataset, which is based on the Tackling Key Problems in Air Pollution Control Program. In order to explore the interaction between air pollution and physical activity, we collected activity patterns of 9,221 residents with different occupations and lifestyles for three consecutive days in typical regions (Jinan and Baoding) where air pollutant concentrations were higher than those in neighboring areas. The TRAP dataset consists of two aspects of information: demographic indicators (personal information, occupation, personal habits, and living situation) and physical activity pattern data (activity location and intensity); additionally, the exposure measures of physical activity patterns are included, which data users can match to various endpoints for their specific purpose. This dataset provides evidence for exploring the attributes of activity patterns of residents in northern China and for interdisciplinary researchers to develop strategies and measures for health education and health promotion.

Adaptive Governance or Status Quo? Unpacking the City of Jakarta's Approach to the Air Pollution Control Program

In recent years, Jakarta has experienced an increase in air pollution which has the potential to have a significant impact on Jakarta residents not only in terms of health, but socio-cultural and productivity. This encourages the need for effective governance strategies to overcome air pollution problems. This study seeks to critically analyze the approach used by the city of Jakarta in dealing with air pollution to find out whether the city of Jakarta's air pollution control policy has led to innovative, flexible and adaptive governance, or is still more inclined towards maintaining the status quo. Based on qualitative data, including in-depth interviews, policy analysis, and consultation with stakeholders, this research examines Jakarta's policy mechanisms, community participation pathways, and inter-agency coordination in controlling air quality and dealing with pollution. The research results show a lack of alignment between progressive policy frameworks and implementation challenges, thus underscoring the need for a more adaptive and dynamic approach. The approach adopted in Jakarta appears to be dominated by a top-down, government-led model, where policies and decisions are primarily formulated and implemented with minimal participation from non-governmental institutions. Such models, while ensuring efficient decision making, may exclude valuable insights of other stakeholders and hinder innovative and context-specific solutions. Additionally, these rigid structures appear to lack the flexibility and responsiveness that are hallmarks of adaptive governance, potentially reducing cities' ability to effectively address air pollution challenges. This research underscores the need for a more inclusive and adaptive governance framework in managing air pollution in Jakarta.

Identification and contribution of potential sources to atmospheric lead pollution in a typical megacity: Insights from isotope analysis and the Bayesian mixing model

Atmospheric particulate matter (PM) enriched with lead (Pb) has severe irreversible effects on human health. Therefore, identifying the contribution of Pb emission sources is essential for protecting the health of residents. Using the Pb isotopic tracer method, this study explored the seasonal characteristics and primary anthropogenic Pb sources for atmospheric PM in Tianjin in 2019. We calculated the contribution of Pb sources using the end-member and MixSIAR models. The results showed that Pb loaded in PM10 was more abundant in January than in July, and was strongly influenced by meteorological conditions and anthropogenic emissions. The primary Pb sources of the aerosol samples originated from coal combustion and vehicle and steel plant emissions, mainly originating from local Pb emission sources in Tianjin. The PM10-bond Pb in January was influenced by regional transportation and local sources. The MixSIAS model calculated the contribution of coal combustion as approximately 50 %. Compared with that in January, the contribution of coal combustion decreased by 9.6 % in July. Our results indicate that some of the benefits of phased-out leaded gasoline have been short-lived, whereas other industrial activities releasing Pb have increased. Furthermore, the results emphasise the practicability of the Pb isotope tracer source approach for identifying and distinguishing between different anthropogenic Pb inputs. Based on this study, scientific and effective air pollution prevention and control programs can be formulated to provide decision support for the guidance and control of air pollutant emissions.

Update of Ambient Air Pollution Monitoring Programs within Regional-Level Implementation of National Projects

Introduction: The Federal Clean Air Project has been developed and is now implemented with the purpose of improving both ambient air quality and the quality of life of the population in 12 pilot cities, including Bratsk. An adequate air pollution control program, priority pollutant monitoring, and health risk management can facilitate improvement of the quality of human life and achievement of the targets of government projects. Objective: To update and streamline the ambient air quality monitoring program in Bratsk within implementation of national and federal projects at the regional level. Materials and methods: The updated air quality control program in Bratsk was based on the results of dispersion modeling verified by instrumental measurements of 34 pollutants at five monitoring stations of the Federal Service for Hydrometeorology and Environmental Monitoring (Roshydromet) and three stations of the Federal Service for Surveillance on Consumer Rights Protection and Human Wellbeing (Rospotrebnadzor). The consolidated database included 2,202 sources emitting 112 chemicals, with total emissions approaching 127,207 tons per year. Hygienic analysis and health risk assessment were performed according to conventional procedures. Results: We established that airborne levels of 29 pollutants exceeded their maximum allowable concentrations (MAC), i.e. were up to 7.0 times higher than short-term MAC, 13.8 and 60 times higher than the average daily and annual MAC, respectively. We also found that 19 air contaminants posed unacceptable health risks for the local population (CR up to 1.82×10–3, HQac up to 113.2, HQcr up to 211.1). Cluster analysis of the results of health risk assessment allowed us to distinguish three clusters within the urban area. We substantiated cutting down the number of monitoring stations to one and its optimal location in Cluster 1, the expediency of moving the station in Cluster 2 and adding a station in Cluster 3 at the point of concern. Optimization of the air quality control program involves reducing the number of monitored pollutants to 8–15 chemicals that are not covered by Roshydromet air monitoring plan. Conclusions: Given the changing sanitary and epidemiological situation, streamlining of air quality monitoring programs will provide relevant and timely information, thus contributing to elaboration of effective health risk management activities.

Citizens’ Assessment of the Environmental Management Programs Delivered by the Local Government Unit of Lezo, Aklan

The performance in the delivery of environmental management programs of the local government of Lezo, Aklan, Philippines was evaluated in this study. Through the Multi-Stage Random Probability Sampling technique, 150 respondents from barangays’ share in the municipal population were determined based on the Philippine Statistical Authority’s Data on Census Population and Housing for the 2015. The probability respondents were selected using the Kish Grid where female respondents were given even numbered questionnaires while male respondents were assigned odd numbers. The four major core concepts namely awareness, availment, satisfaction and need for action were used in measuring the ratings presented in frequency and percentage distributions. Interview was also conducted to gather reasons for their ratings. The study inferred that majority of the respondents were highly aware of the community-based greening project. However, low awareness was attained on projects such as air pollution control program and waste-water management. A high percentage of respondents have availed the environmental management programs except for solid waste management. Overall, majority of the respondents were satisfied of the environmental management programs rendered by the local government unit and therefore needs less action. It is recommended that the local government unit strengthen air pollution control program.

The relationship between air quality and MODIS aerosol optical depth in major cities of the Yangtze River Delta

The AOD derived from the MODIS deep blue(DB) algorithm and AQI were used to investigate the correlation between AOD and AQI in seven major cities of Yangtze River Delta (YRD) from January to December 2019. The accuracy of MODIS AOD was validated by AERONET. Moreover, the AOD and AQI were studied to explore the annual and seasonal distribution characteristics, and the correlation analysis was carried out using five regression models. It was found: Ⅰ) There was a significant correlation between AOD and AERONET data (R2 ˃ 0.80, RMSE = 0.106, and MAE = 0.089). Ⅱ) The highest AQI was observed in winter (83), followed by spring (76), autumn (74), and summer (72). Ⅲ) The monthly average AOD showed noticeable seasonal variations, which reached the highest in summer (0.91) and the lowest in winter (0.69), followed by spring and autumn. Ⅳ) Among the five models, the cubic model obtained the best results with R2 ˃ 0.55. In the sub-seasonal regression model, the cubic model outperformed other models in spring (R2 ˃ 0.57), summer (R2 ˃ 0.76) and autumn (R2 ˃ 0.38). However, in winter the composite model outperformed others (R2 ˃ 0.68). Ⅴ) Considering annual data, the AOD can predict over 70% of the variations in AQI (0.41＜R2 ＜0.81). These results demonstrate the feasibility of AOD derived from the MODIS DB algorithm in AQI prediction. The method used in this study can be applied as an aid for air pollution control programs in different regions.

Spatio-temporal variation of ozone pollution risk and its influencing factors in China based on Geodetector and Geospatial models.

Ozone (O3) has become the primary pollutant in many cities, and high concentrations of O3 cause significant harm to the ecological environment and human health. This study investigated the spatiotemporal distribution of surface concentrations of ozone over entire China and analyzed the influencing factors based on the geographical detector technique. Moreover, the Pearson correlation analysis was used to analyze the influence of various meteorological factors on ozone concentrations. The results showed that, on the national scale, the daily average O3 concentration in the cities of China in 2019 was 92.441μg/m3 and the nonattainment rate of daily average ozone was 7.98%. However, the ozone nonattainment rate was 33.33% in heavily polluted regions. The highest O3 concentration was observed in summer, and the lowest was observed in spring. The O3 concentrations in cities across the country showed significant spatial distribution characteristics. Among the five pollutants, the highest correlation was observed between O3 and PM2.5 and the lowest was observed between O3 and SO2. Among the metrological factors, wind speed and solar radiation are the most influencing factors, and showed positive correlation. Moreover, the annual precipitation is negatively correlated with O3-8h concentrations. The methods and findings of this paper can be used as an aid for air pollution control programs in different regions for diminishing the risk of exposure to various air pollutants.

Impact of Environmental Regulation on Firm Exports: Evidence from a Quasi-Natural Experiment in China

ABSTRACT To estimate the short term effect of environmental regulation on firm exports, this study considers China’s 2003 City Air Pollution Prevention and Control Program (CAPPCP) in a quasi-natural experiment with microdata from 2000–2007. Using the difference-in-differences (DID) and matching DID methods, our findings indicate that CAPPCP reduced firm exports by 6.2% and 12.3%, respectively. A mechanism analysis examines the three channels through which CAPPCP affects firm exports: total factor productivity, production costs, and factor endowments. Furthermore, a heterogeneity analysis reveals that non-state-owned firms, small-scale firms, and firms in highly polluting industries have stronger negative responses to environmental regulations.

Biomonitoring of air pollution: a dichotomous key for lichen species identification

Biomonitoring has been seen as complementary analysis to physicochemical methods and as a low-cost alternative, mainly for regions lacking air pollution control programs. Despite being the most widely used bioindicator for this type of pollution, lichens are not easily identified and this methodology is restricted to groups of expert researchers. Accordingly, the aim of the present study was to analyze lichen diversity in urban and industrial areas, in order to elaborate a dichotomous key to identify the listed species, based on easily visualized features. Lichens with leaf stalks belonging to family Parmeliaceae and genus Parmotrema were the most abundant, which are known for their resistance to air pollution. The study sites generally presented low lichen diversity, which may also have been influenced by the degree of vegetation around them. This result reinforces the importance of green areas for mitigating air pollution in urban environment. The dichotomous key elaborated for the lichen species found aims to support research, environmental education and management activities, and may expand the use of lichens as air-quality bioindicators.

Environmental Regulation and Worker Benefits: Evidence from City-Level Air Quality Standards in China

This study identifies the effect of environmental regulation on worker earnings using China’s “City Air Pollution Prevention and Control Program” (CAPPCP), which is a new city-level air quality, as a quasi-experiment. CAPPCP provides variations in regulatory intensity across years and cities for polluting firms, we use a difference-in-differences (DD) strategy to examine this variation and to compare the earnings in polluting firms before and after the program’s implementation. We match two unique firm-level datasets that include information on firm’s economic indicators, various emissions and abatement equipment. CAPPCP did not significantly decrease firm employment but caused an average of 3% reduction in worker earnings, which amounts to CNY 6.63 billion (USD 871.99 million) in forgone earnings. The estimated result is less than that of comparable US studies. In addition, the reduction in earning tends to be attributed at bonuses rather than regular wages, and firms pay more unemployment insurance for employees. In the channel test, CAPPCP led to an increase of 5.9% in firm’s pollution abatement equipment and 6.3% in pollution treatment capacity, which significantly increased firm’s production costs. We also find different types of firm responses to the regulations, where high-polluting, smaller, labor-intensive, low-tech, non-SOE, non-exporting firms and firms without labor union show a higher reduction in worker earnings than their counterparts. A cost-benefit analysis suggests that the health benefits gained through CAPPCP significantly outweigh that of earning losses.

Assessing the effectiveness of air pollution control programs in Tehran using air quality trend analysis

سابقه و هدف: رشد جمعیت، ترافیک و گسترش صنعتی سبب ایجاد آلودگی هوا در کلانشهرها مانند تهران شده است. با توجه به این واقعیت که آلودگی هوا می تواند صدمه جدی به سلامت شهروندان وارد آورد، مطالعات مختلفی در سطوح ملی و بین المللی انجام گرفته است. بدون شک یکی از مهمترین راه های کاهش آلودگی محیطی، استفاده از برنامه های کنترلی و اقدام ­های کاهشی است. لذا این تحقیق با هدف بررسی اثربخشی برخی طرح ها و برنامه های کاهش آلودگی هوا در کلان شهر تهران انجام شده است. مواد و روش ها: به منظور بررسی تغییرپذیری­ های سالانه آلاینده های هوا (CO، PM10، O3، SOX، NO2، NO) ، غلظت این پارامترها از سال 2005 تا 2012 در تهران مورد بررسی قرار گرفت و از تجزیه و تحلیل همبستگی پیرسون، رگرسیون گام به گام (نرم افزار SAS) برای ارزیابی رابطه بین آلودگی هوا، تعداد وسیله ­های نقلیه و مصرف سوخت در تهران استفاده شد. نتایج و بحث: از سال 2005 تا 2012، غلظت سالانه منوکسید کربن کاهش یافته است. بیشترین غلظت این آلاینده در سال 2006 در حدود 5 میلی گرم بر لیتر و کمترین مقدار آن در سال 2011 در حدود 2 میلی گرم بر لیتر بود. در طول همان دوره، روند سالانه ذرات معلق از 100 تا 140 میکروگرم بر متر مکعب افزایش و در این سال ها، روند سالانه تغییر غلظت ازن از 0.03 میلی گرم در لیتر به 0.02 میلی گرم در لیتر کاهش یافت. در همین زمان غلظت سالانه دی اکسید گوگرد از 0.055به 0.03 میلی گرم در لیتر کاهش و روند نیتروژن دی اکسید نیتروژن و غلظت منوکسید نیتروژن در طول سال های 1390-1384 از 10.07 به 0.2 میلی گرم در لیتر و از 0.05. به 0.01 میلی گرم در لیتر کاهش یافت. نتیجه­ گیری: نتایج نشان می دهد که روند تغییر غلظت سالانه آلاینده­ ها در سال­های1390-1384 برای همه­ ی آلاینده­ ها به غیر از ذرات معلق کاهشی است و حذف وسیله ­های نقلیه فرسوده، استفاده از وسیله­ های نقلیه هیبریدی و افزایش مصرف خودروهای گاز سوز نقش مهمی در کاهش آلودگی هوای تهران دارد. همچنین با توجه به نتایج تجزیه همبستگی و معنی­ دار بودن اثر خروج خودروهای فرسوده بر آلاینده­ های اتمسفری، تاثیر اجرای این سیاست در کاهش آلاینده­ ها موثر بوده است. نتایج تجزیه رگرسیون گام به گام در طول سال‌های1390-1384 نشان می­ دهد که خروج خودروهای فرسوده و جایگزینی با سواری دوگانه سوز بیشترین اثر را در کاهش انتشار گاز منوکسید کربن در سطح شهر تهران داشته است.

Is China's air pollution control policy effective? Evidence from Yangtze River Delta cities

Abstract: China is currently facing the threat of serious air pollution and has adopted a series of governance policies. However, the fact that PM2.5 indicator in some regions often reached far higher than the official threshold since 2015 has reflected that China's current Air Quality Index system for measuring and evaluating air quality is still not perfect. Therefore, this paper extended the current air quality indicator system officially used by China. Using improved Entropy-weighted Factor Method and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) Method, we calculated the air quality scores of 26 cities in China's most economically developed region - the Yangtze River Delta region based on their daily average concentration numbers of main air pollutants from February 2015 to January 2018. Based on the air quality calculation result, we further studied the effectiveness of air pollution control policies of this region by using the Box-Jenkins Model with fuzzy strategy parameter adjustment. Our findings are: the pollution control policy is more effective to Shanghai, Jiangsu and Zhejiang. The air quality score of Shanghai has improved by 51.07% compared with its level before the policy. Meanwhile, the air quality improvement in Zhejiang province has shown the characteristics of “Campaign-style Governance” right before the G20 Summit, especially that in Hangzhou, the host city of the Summit. On the other hand, maybe due to late start of air pollution control programs, the cities of Anhui province haven't shown obvious improvements in air quality, and some cities have even seen deterioration in air quality scores during our study period.

Natural gas and electricity: Two perspective technologies of substituting coal‐burning stoves for rural heating and cooking in Hebei Province of China

AbstractCoal not only powers the household, social and global economy development but also emits large pollutants. Natural gas and electricity can be promising solutions to the energy supply and environmental pollution dilemma in Hebei Province of China. Currently, this coal‐dependent province has launched the Hebei Air Pollution Prevention and Control Program to curb air pollution by replacing residential coal consumption with natural gas and electricity for space heating in winter. Approximately 2.53 million households have completed the switch from coal‐burning stoves to natural gas or electricity stoves in rural areas surrounding Beijing and Tianjin since 2017. However, the contribution of this clean heating replacement on provincial emission reduction remains unclear. This study aimed to determine emission factors, energy efficiency, and economic profits of traditional coal‐burning stoves, as well as cleaner natural gas and electricity stoves by laboratory simulation and field tests. The results indicated a significant reduction after clean replacement for PM2.5, CO, CO2, NOX, SO2, CH4, and 16 types of U.S. EPA priority polycyclic aromatic hydrocarbons (PAHs). The emission of PM2.5 can be reduced by 99% and 95% for natural gas and electricity switch. Toxic equivalent quantity value of PAHs was also decreased from 4.89 (coal) to 0.03 (natural gas) and 0.07 μg/MJnet (electricity). When comprehensively considering the upstream pollutants emissions from power plant, natural gas switching performed better than coal‐fired electricity. Moreover, the government supported the clean heating replacement project with extensive financial subsidy for purchasing clean stoves and using clean energy within 3 years in rural areas. A relatively cheaper price on an energy basic of natural gas and electricity use can be obtained after this subsidy compared to coal.

Air pollution control and the occurrence of acute respiratory illness in school children of Quito, Ecuador

Because of air quality management and control, traffic-related air pollution has declined in Quito, Ecuador. We evaluated the effect of a city-wide 5-year air pollution control program on the occurrence of acute respiratory illness (ARI). We compared two studies conducted at the same location in Quito: in 2000, 2 years before the policy to control vehicle emission was introduced, and in 2007. Each study involved ~ 730 children aged 6–12 years, observed for 15 weeks. We examined associations between carboxyhemoglobin (COHb) serum concentration—an exposure proxy for carbon monoxide (CO)—ambient CO, and ARI in both cohorts. In 2007, we found a 48% reduction in the ARI incidence (RR 0.52; 95% CI 0.45–0.62, p < 0.0001), and 92% decrease in the percentage of children with COHb > 2.5% as compared to the 2000 study. We found no association between COHb concentrations above the safe level of 2.5% and the ARI incidence (p = 0.736). The decline in air pollution due to vehicle emissions control was associated with a lower incidence of respiratory illness in school children.

Comparison of Ground-Based PM2.5 and PM10 Concentrations in China, India, and the U.S.

Urbanization and industrialization have spurred air pollution, making it a global problem. An understanding of the spatiotemporal characteristics of PM2.5 and PM10 concentrations (particulate matter with an aerodynamic diameter of less than 2.5 μm and 10 μm, respectively) is necessary to mitigate air pollution. We compared the characteristics of PM2.5 and PM10 concentrations and their trends of China, India, and the U.S. from 2014 to 2017. Particulate matter levels were lowest in the U.S., while China showed higher concentrations, and India showed the highest. Interestingly, significant declines in PM2.5 and PM10 concentrations were found in some of the most polluted regions in China as well as the U.S. No comparable decline was observed in India. A strong seasonal trend was observed in China and India, with the highest values occurring in winter and the lowest in summer. The opposite trend was noted for the U.S. PM2.5 was highly correlated with PM10 for both China and India, but the correlation was poor for the U.S. With regard to reducing particulate matter pollutant concentrations, developing countries can learn from the experiences of developed nations and benefit by establishing and implementing joint regional air pollution control programs.

Long-term particulate matter modeling for health effect studies in California – Part 2: Concentrations and sources of ultrafine organic aerosols

Abstract. Organic aerosol (OA) is a major constituent of ultrafine particulate matter (PM0. 1). Recent epidemiological studies have identified associations between PM0. 1 OA and premature mortality and low birth weight. In this study, the source-oriented UCD/CIT model was used to simulate the concentrations and sources of primary organic aerosols (POA) and secondary organic aerosols (SOA) in PM0. 1 in California for a 9-year (2000–2008) modeling period with 4 km horizontal resolution to provide more insights about PM0. 1 OA for health effect studies. As a related quality control, predicted monthly average concentrations of fine particulate matter (PM2. 5) total organic carbon at six major urban sites had mean fractional bias of −0.31 to 0.19 and mean fractional errors of 0.4 to 0.59. The predicted ratio of PM2. 5 SOA ∕ OA was lower than estimates derived from chemical mass balance (CMB) calculations by a factor of 2–3, which suggests the potential effects of processes such as POA volatility, additional SOA formation mechanism, and missing sources. OA in PM0. 1, the focus size fraction of this study, is dominated by POA. Wood smoke is found to be the single biggest source of PM0. 1 OA in winter in California, while meat cooking, mobile emissions (gasoline and diesel engines), and other anthropogenic sources (mainly solvent usage and waste disposal) are the most important sources in summer. Biogenic emissions are predicted to be the largest PM0. 1 SOA source, followed by mobile sources and other anthropogenic sources, but these rankings are sensitive to the SOA model used in the calculation. Air pollution control programs aiming to reduce the PM0. 1 OA concentrations should consider controlling solvent usage, waste disposal, and mobile emissions in California, but these findings should be revisited after the latest science is incorporated into the SOA exposure calculations. The spatial distributions of SOA associated with different sources are not sensitive to the choice of SOA model, although the absolute amount of SOA can change significantly. Therefore, the spatial distributions of PM0. 1 POA and SOA over the 9-year study period provide useful information for epidemiological studies to further investigate the associations with health outcomes.

Oxidative Capacity of the PM10 and PM2.5 in Beijing During 2014 APEC

In order to evaluate the effect of the joint air pollution prevention and control program on the toxicity of the airborne particles in Beijing during the APEC conference, we collected the PM10 and PM2.5 (particulate matter with aerodynamic diameters of less than 10 μm and 2.5 μm respectively) from October to December in the urban district of Beijing, and analyzed the oxidative capacity of the particles by plasmid scission assay. The results indicated that the oxidative capacity of PM10 was higher than that of PM2.5 during the APEC conference, and that the damage rate of supercoiled DNA by the samples increased with their experimental dose levels. The TD30 (toxic dose of PM causing 30% of plasmid DNA damage, unit: μg·mL-1) was used to indicate the oxidative capacity and the lower TD30 values indicated higher oxidative capacity. The TD30 values of the PM samples before, during, and after APEC conference displayed a descending order of during APEC (November) >before APEC (October) >after APEC (December), which indicated a decreasing order of the PM oxidative capacity of after APEC (November) >before APEC (October) >during APEC. The TI (toxic index) was further introduced to represent the human exposure risk of particles, which was represented by the product of the mass concentration of PM (μg·m-3) and the DNA damage percentages under the PM dose of 250 μg·mL-1 (%). Compared with the TI values of previous years, the TI value of the 2014 APEC PM was lower than that of 2004, but higher than that of the 2008 Olypic Games, suggesting that the exposure risk of airborne particles decreased obviously with the increase of policy control strength.

How Can Urban Policies Improve Air Quality and Help Mitigate Global Climate Change: a Systematic Mapping Review.

Tackling climate change at the global level is central to a growing field of scientific research on topics such as environmental health, disease burden, and its resulting economic impacts. At the local level, cities constitute an important hub of atmospheric pollution due to the large amount of pollutants that they emit. As the world population shifts to urban centers, cities will increasingly concentrate more exposed populations. Yet, there is still significant progress to be made in understanding the contribution of urban pollutants other than CO2, such as vehicle emissions, to global climate change. It is therefore particularly important to study how local governments are managing urban air pollution. This paper presents an overview of local air pollution control policies and programs that aim to reduce air pollution levels in megacities. It also presents evidence measuring their efficacy. The paper argues that local air pollution policies are not only beneficial for cities but are also important for mitigating and adapting to global climate change. The results systematize several policy approaches used around the world and suggest the need for more in-depth cross-city studies with the potential to highlight best practices both locally and globally. Finally, it calls for the inclusion of a more human rights-based approach as a mean of guaranteeing of clean air for all and reducing factors that exacerbate climate change.

Can the Golden State Catch a Greenhouse Waiver?

In 2004, California adopted the nation's first regulations limiting the emission of greenhouse gases from new motor vehicles. Before these regulations can take effect, however, California must obtain a waiver of preemption under the Clean Air Act from the U.S. Environmental Protection Agency. California has sought, and received, numerous waivers of preemption for air pollution control programs in the past. EPA approval of this waiver request is not automatic, however. This essay provides an overview of the distinct legal and policy issues raised by California's request for a waiver of federal preemption of its new greenhouse gas emission regulations. After summarizing the legal requirements for obtaining a waiver of preemption under the Clean Air Act, this essay explains why it may be more difficult for California to obtain a waiver for greenhouse gas emission regulations than it has been for prior state regulations governing traditional air pollutants. The essay then considers how California's waiver request fits into a broader policy framework dividing responsibility for environmental protection between the federal and state governments. Accepting there are strong arguments for greater state flexibility in environmental law, this essay assesses the relative strength of California's demand for greater freedom to set its own greenhouse gas emission control policies.