Estimating the effect of air pollution on road safety using atmospheric temperature inversions

Does air quality influence road safety? We estimate the effect of increased air pollution on the number of road traffic accidents in the United Kingdom between 2009 and 2014. To address concerns of spurious correlation we exploit atmospheric temperature inversions as a source of plausibly exogenous variation in daily air pollution levels. We find an increase of 0.3–0.6% in the number of vehicles involved in accidents per day for each additional 1 μg/m³ of PM_2.5. The finding suggests that less safe roads may present a large and previously overlooked cost of air pollution. The results are robust to a number of specifications and across various sub-samples.     

Environmental regulation as a double-edged sword for housing markets: Evidence from the NOx Budget Trading Program

We investigate the effects of environmental regulations on housing markets using a quasi-experimental setting—the NO_x Budget Trading Program (NBP). Hedonic theory predicts that house prices should rise as pollution levels decrease. However, environmental regulations may also affect labor markets, and thus housing demand. Employing a difference-in-differences framework, we find that house prices shifted up in the regulated areas with low manufacturing intensity, whereas in the areas with high manufacturing intensity, housing markets were weakened. We also find that in high-manufacturing-intensity areas, loan application volume declined, rejection rate augmented, and the probability of loan default increased.     

The effect of pollution on crime: Evidence from data on particulate matter and ozone

We estimate the effect of short-term air pollution exposure (PM_2.5 and ozone) on several categories of crime, with a particular emphasis on aggressive behavior. To identify this relationship, we combine detailed daily data on crime, air pollution, and weather for an eight-year period across the United States. Our primary identification strategy employs extremely high dimensional fixed effects and we perform a series of robustness checks to address confounding variation between temperature and air pollution. We find a robust positive effect of increased air pollution on violent crimes, and specifically assaults, but no relationship between increases in air pollution and property crimes. The effects are present in and out of the home, at levels well below Ambient Air Pollution Standards, and PM_2.5 effects are strongest at lower temperatures. The results suggest that a 10% reduction in daily PM_2.5 and ozone could save $1.4 billion in crime costs per year, a previously overlooked cost associated with pollution.     

Air pollution as a cause of sleeplessness: Social media evidence from a panel of Chinese cities

We provide first evidence of a link from daily air pollution exposure to sleep loss in a panel of Chinese cities. We develop a social media-based, city-level metric for sleeplessness, and bolster causal claims by instrumenting for pollution with plausibly exogenous variations in wind patterns. Estimates of effect sizes are substantial and robust. In our preferred specification a one standard deviation increase in AQI causes an 11.6% increase in sleeplessness, and for PM_2.5 is 12.8%. The results sustain qualitatively under OLS estimation but are attenuated. The analysis provides a previously unaccounted for benefit of more stringent air quality regulation. It also offers a candidate mechanism in support of recent research that links daily air quality to diminished workplace productivity, cognitive performance, school absence, traffic accidents, and other detrimental outcomes.     

‘Effortless Perfection:’ Do Chinese cities manipulate air pollution data?

This paper uses unique data on daily air pollution concentrations over the period 2001–2010 to test for manipulation in self-reported data by Chinese cities. First, we employ a discontinuity test to detect evidence consistent with data manipulation. Then, we propose a panel matching approach to identify the conditions under which irregularities may occur. We find that about 50% of cities reported dubious PM₁₀ pollution levels that led to a discontinuity at the cut-off. Suspicious data reporting tends to occur on days when the anomaly is least detectable. Our findings indicate that the official daily air pollution data are not well behaved, which provides suggestive evidence of manipulation.     

Impact of energy structure adjustment on air quality: a case study in Beijing, China

Energy consumption is a major cause of air pollution in Beijing, and the adjustment of the energy structure is of strategic importance to the reduction of carbon intensity and the improvement of air quality. In this paper, we explored the future trend of energy structure adjustment in Beijing till 2020, designed five energy scenarios focusing on the fuel substitution in power plants and heating sectors, established emission inventories, and utilized the Mesoscale Modeling System Generation 5 (MM5) and the Models-3/Community Multiscale Air Quality Model (CMAQ) to evaluate the impact of these measures on air quality. By implementing this systematic energy structure adjustment, the emissions of PM₁₀, PM_2.5, SO₂, NO _x , and non-methane volatile organic compounds (NMVOCs) will decrease distinctly by 34.0%, 53.2%, 78.3%, 47.0%, and 30.6% respectively in the most coalintensive scenario of 2020 compared with 2005. Correspondingly, MM5-Models-3/CMAQ simulations indicate significant reduction in the concentrations of major pollutants, implying that energy structure adjustment can play an important role in improving Beijing??s air quality. By fuel substitution for power plants and heating boilers, PM₁₀, PM_2.5, SO₂, NO _x , and NMVOCs will be reduced further, but slightly by 1.7%, 4.5%, 11.4%, 13.5%, and 8.8% respectively in the least coal-intensive scenario. The air quality impacts of different scenarios in 2020 resemble each other, indicating that the potential of air quality improvement due to structure adjustment in power plants and heating sectors is limited. However, the CO₂ emission is 10.0% lower in the least coal-intensive scenario than in the most coal-intensive one, contributing to Beijing??s ambition to build a low carbon city. Except for energy structure adjustment, it is necessary to take further measures to ensure the attainment of air quality standards.     

Does subway expansion improve air quality?

Major cities in China and many other fast-growing economies are expanding their subway systems in order to address worsening air pollution and traffic congestion. This paper quantifies the impact of subway expansion on air quality by leveraging fine-scale air quality data and the rapid build-out of 14 new subway lines and 252 stations in Beijing from 2008 to 2016. Our main empirical framework examines how the density of the subway network affects air quality across different locations in the city during this period. To address the potential endogenous location of subway stations, we construct an instrument based on historical subway planning, long before air pollution and traffic congestion were of concern. Our analysis shows that an increase in subway density by one standard deviation improves air quality by two percent and the result is robust to a variety of alternative specifications including the distance-based difference-in-differences method. The total discounted health benefit during a 20-year period from reduced mortality and morbidity as a result of 14 new subway lines amounts to $1.0–3.1 billion, or only 1.4–4.4 percent of the total construction and operating cost.     

城市化对北京霾日数影响统计分析

近年来,随着超大城市/城市群大气灰霾等复合污染加剧,引起人们对区域生态环境与及公共健康问题越来越多的关注。应用北京地区1980—2012年气候资料及同期城市发展统计指标,统计分析了城、郊区间霾日数的变化特征,并在此基础上探讨了北京城市化及局地气候差异对霾日数的影响。分析表明：北京城区霾日数要明显多于郊区,在2007年以前城、郊区站点均有相似的波动增长趋势,但城区站霾日数增加速率（约21 d/10 a）要远大于郊区站（约7.2 d/10 a）;北京各地霾日数与主要城市发展指数之间的相关系数均超过0.001显著性水平,随着城市化而迅速增加的能源消耗和机动车尾气排放是导致北京地区灰霾天气逐渐增多的主要污染源,污染源的不均匀分布是导致城、郊霾日数差异的主要因素。分析还发现,城市化导致的区域气候差异对局地灰霾亦有较明显的影响。伴随着城市化的快速发展,城、郊区气候差异逐渐变大,城市下垫面粗糙度增加导致近地面层风速减小。大城市热岛效应背景下,更容易出现较厚的逆温层,这将阻碍空气垂直方向的对流输送。此外,城区气温持续上升,相对湿度下降,平均风速减小,小风频率增加,也会阻碍空气的水平流通,使得城市排放颗粒污染物的扩散难以扩散,有利于霾日增加。这表明北京地区城市气候效应对区域生态环境具有不可忽视的影响。     

沙尘与大雾天气对京津石空气质量影响

采用北京、天津、石家庄2001-2010年沙尘与大雾天气的统计数据以及城市空气污染指数（API）,分析北京、天津、石家庄3市空气污染指数变化特征及大雾和沙尘天气下北京、天津、石家庄3市空气质量情况,进而得出沙尘大雾天气对京津石空气质量的影响。结果表明：2001-2010年间北京、天津、石家庄3市API总体呈下降趋势,天津、石家庄相对于北京空气质量改善较为明显,且空气质量夏季〉秋季〉春冬季。沙尘天气条件下,北京、天津、石家庄3市API平均值分别为255、179和167,空气质量出现良的比率天津为24%,北京、石家庄为10%左右,出现重污染的比率北京高达50%以上,天津和石家庄均在20%左右;3市沙尘天气高频次均出现在3-5月份,但北京沙尘天气发生次数远大于天津和石家庄。大雾天气条件下,北京、天津、石家庄3市API平均值为185、130和167,空气质量出现优或良的比率：天津〉石家庄〉北京,北京和石家庄出现重污染的比率均接近30%,天津不到10%,所以大雾天气对3市空气质量影响较小,大雾天气频次的变化波动并未对该地区空气质量的年际变化造成显著影响,3市高频次大雾天气集中在10-12月份,对该时段内空气污染呈现加重趋势有一定的贡献。所以沙尘和大雾天气均对北京、天津和石家庄空气质量存在不利影响,其中对北京影响最为严重,对天津影响最轻。整体上沙尘对3市的空气质量影响较大,大雾天气影响较小。     

An initial assessment of spatial relationships between respiratory cases,soil metal content,air quality and deprivation indicators in Glasgow,Scotland, UK: relevance to the environmental justice agenda

There is growing interest in links between poor health and socio-environmental inequalities (e.g. inferior housing, crime and industrial emissions) under the environmental justice agenda. The current project assessed associations between soil metal content, air pollution (NO₂/PM₁₀) and deprivation and health (respiratory case incidence) across Glasgow. This is the first time that both chemical land quality and air pollution have been assessed citywide in the context of deprivation and health for a major UK conurbation. Based on the dataset ‘averages’ for intermediate geography areas, generalised linear modelling of respiratory cases showed significant associations with overall soil metal concentration (p = 0.0367) and with deprivation (p < 0.0448). Of the individual soil metals, only nickel showed a significant relationship with respiratory cases (p = 0.0056). Whilst these associations could simply represent concordant lower soil metal concentrations and fewer respiratory cases in the rural versus the urban environment, they are interesting given (1) possible contributions from soil to air particulate loading and (2) known associations between airborne metals like nickel and health. This study also demonstrated a statistically significant correlation (?0.213; p < 0.05) between soil metal concentration and deprivation across Glasgow. This highlights the fact that despite numerous regeneration programmes, the legacy of environmental pollution remains in post-industrial areas of Glasgow many decades after heavy industry has declined. Further epidemiological investigations would be required to determine whether there are any causal links between soil quality and population health/well-being. However, the results of this study suggest that poor soil quality warrants greater consideration in future health and socio-environmental inequality assessments.     

Did the Clean Air Act cause the remarkable decline in sulfur dioxide concentrations?

Over the last three decades, ambient concentrations of sulfur dioxide (SO₂) air pollution have declined by approximately 80%. This paper tests whether the 1970 Clean Air Act and its subsequent amendments caused this decline. The centerpiece of this legislation is the annual assignment of all counties to SO₂ nonattainment or attainment categories. Polluters face stricter regulations in nonattainment counties. There are two primary findings. First, regulators pay little attention to the statutory selection rule in their assignment of the SO₂ nonattainment designations. Second, SO₂ nonattainment status is associated with modest reductions in SO₂ air pollution, but a null hypothesis of zero effect generally cannot be rejected. This finding holds whether the estimated effect is obtained with linear adjustment or propensity score matching. Overall, the evidence suggests that the nonattainment designation played a minor role in the dramatic reduction of SO₂ concentrations over the last 30 years.     

Epiphytische Flechten im Wandel von Immissionen und Klima • Ergebnisse einer Vergleichskartierung 1989/2007 in Nordwestdeutschland

Epiphytic lichens as indicators for changes in air pollution and climate. Results of a comparative survey 1989/2007 in north-west Germany Background, aim, and scope Lichens growing on tree bark (epiphytic lichens) respond very sensitively to environmental effects such as chemical substances and air temperature. Therefore, they are used as biomonitors for atmospheric pollution in environmental assessments. Based on a survey of epiphytic lichens in 1989, a repetition was performed in an intensively-used agricultural area of north-west Germany in 2007. The objective of this study was to assess possible changes in air pollution and climate. Materials and methods The study is based on a comparative inventory of epiphytic lichens, growing on 335 trees at 45 monitoring sites. A simplified half quantitative survey technique of the first survey was used. Results Indeed, major changes to the epiphytic lichen flora were found. Overall, nearly all monitoring points showed an increase in the level of lichen species. A sharp decrease in acidophileous species and a sharp increase in basidophileous and nitrophileous species were detected. In addition, an increase in thermophileous species which are mainly inhabitants of southern European countries was observed, combined with decreases in boreo-montanic species. Discussion These trends correspond with supra-regional observations. They are primarily attributed to changes in air pollution involving a decrease in SO₂ and an increase in NH₃ concentrations. Clear effects from climate change are evident as well. Conclusions Changes to epiphytic lichens over a 18-year period could be demonstrated using a relatively low-cost investigation. They are relevant for assessing the changing environmental situation, which is of great importance for other organism groups and ecosystems. Recommendations and perspectives Using standardized techniques epiphytic lichens are suitable bioindicators for obtaining different types of information about the air pollution in urban areas and in intensively-used agricultural regions. Furthermore they are obviously good indicators of temperature changes in their environment. More research is needed about the suitability of epiphytic lichens for a biomonitoring of climate changes.     

A flexible spatio-temporal model for air pollution with spatial and spatio-temporal covariates

The development of models that provide accurate spatio-temporal predictions of ambient air pollution at small spatial scales is of great importance for the assessment of potential health effects of air pollution. Here we present a spatio-temporal framework that predicts ambient air pollution by combining data from several different monitoring networks and deterministic air pollution model(s) with geographic information system covariates. The model presented in this paper has been implemented in an R package, SpatioTemporal, available on CRAN. The model is used by the EPA funded Multi-Ethnic Study of Atherosclerosis and Air Pollution (MESA Air) to produce estimates of ambient air pollution; MESA Air uses the estimates to investigate the relationship between chronic exposure to air pollution and cardiovascular disease. In this paper we use the model to predict long-term average concentrations of \(\text {NO}_{x}\) in the Los Angeles area during a 10 year period. Predictions are based on measurements from the EPA Air Quality System, MESA Air specific monitoring, and output from a source dispersion model for traffic related air pollution (Caline3QHCR). Accuracy in predicting long-term average concentrations is evaluated using an elaborate cross-validation setup that accounts for a sparse spatio-temporal sampling pattern in the data, and adjusts for temporal effects. The predictive ability of the model is good with cross-validated \(R^2\) of approximately \(0.7\) at subject sites. Replacing four geographic covariate indicators of traffic density with the Caline3QHCR dispersion model output resulted in very similar prediction accuracy from a more parsimonious and more interpretable model. Adding traffic-related geographic covariates to the model that included Caline3QHCR did not further improve the prediction accuracy.     

SARS-CoV-2 variants and environmental effects of lockdowns,masks and vaccination: a review

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is continuously evolving and four variants of concern have been identified so far, including Alpha, Beta, Gamma and Delta variants. Here we review the indirect effect of preventive measures such as the implementation of lockdowns, mandatory face masks, and vaccination programs, to control the spread of the different variants of this infectious virus on the environment. We found that all these measures have a considerable environmental impact, notably on waste generation and air pollution. Waste generation is increased due to the implementation of all these preventive measures. While lockdowns decrease air pollution, unsustainable management of face mask waste and temperature-controlled supply chains of vaccination potentially increases air pollution.

     

The abatement of major pollutants in air and water by environmental catalysis

This review reports the research progress in the abatement of major pollutants in air and water by environmental catalysis. For air pollution control, the selective catalytic reduction of NO _x (SCR) by ammonia and hydrocarbons on metal oxide and zeolite catalysts are reviewed and discussed, as is the removal of Hg from flue gas by catalysis. The oxidation of Volatile organic compounds (VOCs) by photo- and thermal-catalysis for indoor air quality improvement is reviewed. For wastewater treatment, the catalytic elimination of inorganic and organic pollutants in wastewater is presented. In addition, the mechanism for the procedure of abatement of air and water pollutants by catalysis is discussed in this review. Finally, a research orientation on environment catalysis for the treatment of air pollutants and wastewater is proposed.     

An economic analysis of air pollution from coal-fired power plants

The benefits of air pollution control techniques on a coal-fired power plant are Simulated with a scientifically based environmental model. Air pollution abatement techniques are assessed in terms of their resource cost (measured in dollars) and their effectiveness in reducing environmental damage (measured in dollars and healthy days lost). Which air pollution techniques are most efficient depend upon how much a day of health should be valued. Other factors of potential interest such as uncertainty and equity are also simulated through the model. The paper demonstrates that scientific evidence can be organized around economic principles in order to develop more rational and effective environmental policies.     

Hedonic housing prices and the demand for clean air

This paper investigates the methodological problems associated with the use of housing market data to measure the willingness to pay for clean air. With the use of a hedonic housing price model and data for the Boston metropolitan area, quantitative estimates of the willingness to pay for air quality improvements are generated. Marginal air pollution damages (as revealed in the housing market) are found to increase with the level of air pollution and with household income. The results are relatively sensitive to the specification of the hedonic housing price equation, but insensitive to the specification of the air quality demand equation.     

Too hot to handle: The effects of high temperatures during pregnancy on adult welfare outcomes

This paper studies the long-term effects of high temperatures during pregnancy on later-life outcomes for Chinese adults. Adults experienced one additional high-temperature day during in utero period, on average, attain 0.02 fewer years of schooling, increase the risk of illiteracy by 0.18%, achieve lower standardized word-test score by 0.48%, and are shorter by 0.02 cm. The impacts are greater in the first and second trimesters. Additionally, we find that income effects represent one important channel to explain the adverse effects of hot weather. Back-of-the-envelope predictions suggest that by the end of the 21st century, a 0.14–0.54 reduction in years of education and a 0.21–0.84 cm reduction in height is likely to result from climate change, ceteris paribus.     

Air quality improvement in Los Angeles—perspectives for developing cities

Air quality improvement in Los Angeles can inform air quality policies in developing cities. Emission control efforts, their results, costs and health benefits are briefly summarized. Today's developing cities face new challenges including regional pollution. Air quality issues in Beijing are briefly compared and contrasted with Los Angeles. Opportunities for co-benefits for climate and air quality improvement are identified. Air quality improvement in Los Angeles, California is reviewed with an emphasis on aspects that may inform air quality policy formulation in developing cities. In the mid-twentieth century the air quality in Los Angeles was degraded to an extent comparable to the worst found in developing cities today; ozone exceeded 600 ppb and annual average particulate matter <10 mm reached ~150 mg·m⁻³. Today's air quality is much better due to very effective emission controls; e.g., modern automobiles emit about 1% of the hydrocarbons and carbon monoxide emitted by vehicles of 50 years ago. An overview is given of the emission control efforts in Los Angeles and their impact on ambient concentrations of primary and secondary pollutants; the costs and health benefits of these controls are briefly summarized. Today's developing cities have new challenges that are discussed: the effects of regional pollution transport are much greater in countries with very high population densities; often very large current populations must be supplied with goods and services even while economic development and air quality concerns are addressed; and many of currently developing cities are located in or close to the tropics where photochemical processing of pollution is expected to be more rapid than at higher latitudes. The air quality issues of Beijing are briefly compared and contrasted with those of Los Angeles, and the opportunities for co-benefits for climate and air quality improvement are pointed out.