A New Air Quality Perception Scale for Global Assessment of Air Pollution Health Effects

Despite improvements in air quality in developed countries, air pollution remains a major public health issue. To fully assess the health impact, we must consider that air pollution exposure has both physical and psychological effects; this latter dimension, less documented, is more difficult to measure and subjective indicators constitute an appropriate alternative. In this context, this work presents the methodological development of a new scale to measure the perception of air quality, useful as an exposure or risk appraisal metric in public health contexts. On the basis of the responses from 2,522 subjects in eight French cities, psychometric methods are used to construct the scale from 22 items that assess risk perception (anxiety about health and quality of life) and the extent to which air pollution is a nuisance (sensorial perception and symptoms). The scale is robust, reproducible, and discriminates between subpopulations more susceptible to poor air pollution perception. The individual risk factors of poor air pollution perception are coherent with those findings in the risk perception literature. Perception of air pollution by the general public is a key issue in the development of comprehensive risk assessment studies as well as in air pollution risk management and policy. This study offers a useful new tool to measure such efforts and to help set priorities for air quality improvements in combination with air quality measurements.     

Acculturation,Ethnicity, and Air Pollution Perceptions

A globalizing world increases immigration between nations, raising the question of how acculturation (or its lack) of immigrants and their descendants to host societies affects risk perceptions. A survey of Paterson, New Jersey, residents tested acculturation's associations with attitudes to air pollution and its management, and knowledge of and self‐reported behaviors concerning air pollution. Linguistic and temporal proxy measures for acculturation were independent variables along with ethnicity, plus controls for gender, age, education, and income in multivariate analyses. About one‐fifth of contrasts between non‐Hispanic whites, non‐Hispanic blacks, English‐interviewed Hispanics, and Spanish‐interviewed Hispanics were statistically significant (Bonferroni‐corrected) and of medium or higher affect size, with most featuring the Spanish‐interviewed Hispanics. Knowledge variables featured the most significant differences. Specifically, Spanish‐interviewed Hispanics reported less concern, familiarity with pollution, recognition of high pollution, and vigorous outdoor activity, and greater belief that government overregulates pollution than English‐interviewed Hispanics (and than the other two groups on most of these variables too). English‐interviewed Hispanics did not differ from non‐Hispanic whites, but did on several variables from non‐Hispanic blacks. Temporal proxies of acculturation among the foreign‐born were far less significant, but concern and familiarity with air pollution increased with time spent in the United States, while belief in overregulation and a positive trend in New Jersey pollution increased with time in the nation of origin. Implications of these acculturation and ethnicity findings for risk perception/communication research and practice are discussed.     

Gender and Race in Beliefs about Outdoor Air Pollution

Universal need for, or reactions to, risk communications should not be assumed; potential differences across demographic groups in environmental risk beliefs, attitudes, and behaviors could affect risk levels or opportunities for risk reduction. This article reports relevant findings from a survey experiment involving 1,100 potential jurors in Philadelphia concerning public responses to outdoor air pollution and air quality information. Flynn et al. (1994) and Finucane et al. (2000) found significant differences in risk ratings for multiple hazards, and in generic risk beliefs, between white men (or a subset) and all others (white women, nonwhite men, and nonwhite women). This study examined whether white men had significantly different responses to air pollution and air pollution information. An opportunity sample of volunteers from those awaiting potential jury duty in city courts (matching census estimates for white versus nonwhite proportions, but more female than the city's adult population and more likely to have children) filled out questionnaires distributed quasi-randomly. On most measures there were no statistically significant differences among white men (N = 192), white women (N = 269), nonwhite men (N = 165), and nonwhite women (N = 272). Nonwhites overall (particularly women) reported more concern about and sensitivity to air pollution than whites, and were more concerned by (even overly sensitive to) air pollution information provided as part of the experiment. Nonwhites also were more likely (within-gender comparisons) to report being active outdoors for at least four hours a day, a measure of potential exposure to air pollution, and to report intentions to reduce such outdoor activity after reading air pollution information. Differences between men and women were less frequent than between whites and nonwhites; the most distinctive group was nonwhite women, followed by white men. Flynn et al. (1994) and Finucane et al. (2000) found a far larger proportion of significant differences, with white men as most distinctive, probably due to use of different measures, study design, and population samples. However, all three studies broadly confirm the existence of gender and race interactions in risk beliefs and attitudes (particularly for white men and nonwhite women) that deserve more attention from researchers.     

Validation of a Novel Air Toxic Risk Model with Air Monitoring

Three modeling systems were used to estimate human health risks from air pollution: two versions of MNRiskS (for Minnesota Risk Screening), and the USEPA National Air Toxics Assessment (NATA). MNRiskS is a unique cumulative risk modeling system used to assess risks from multiple air toxics, sources, and pathways on a local to a state‐wide scale. In addition, ambient outdoor air monitoring data were available for estimation of risks and comparison with the modeled estimates of air concentrations. Highest air concentrations and estimated risks were generally found in the Minneapolis‐St. Paul metropolitan area and lowest risks in undeveloped rural areas. Emissions from mobile and area (nonpoint) sources created greater estimated risks than emissions from point sources. Highest cancer risks were via ingestion pathway exposures to dioxins and related compounds. Diesel particles, acrolein, and formaldehyde created the highest estimated inhalation health impacts. Model‐estimated air concentrations were generally highest for NATA and lowest for the AERMOD version of MNRiskS. This validation study showed reasonable agreement between available measurements and model predictions, although results varied among pollutants, and predictions were often lower than measurements. The results increased confidence in identifying pollutants, pathways, geographic areas, sources, and receptors of potential concern, and thus provide a basis for informing pollution reduction strategies and focusing efforts on specific pollutants (diesel particles, acrolein, and formaldehyde), geographic areas (urban centers), and source categories (nonpoint sources). The results heighten concerns about risks from food chain exposures to dioxins and PAHs. Risk estimates were sensitive to variations in methodologies for treating emissions, dispersion, deposition, exposure, and toxicity.     

Chronic Effects of Air Pollution are Probably Overestimated

Inappropriate measures of exposure, including inadequate consideration of latency in the analysis of chronic effects of air pollution, may lead to overestimation of the impact of air pollution on health effects. A relatively simple way to check the plausibility of results on chronic effects of air pollution would be to report in parallel the smoking‐associated risks.     

Expert Elicitation of the Value per Statistical Life in an Air Pollution Context

The monetized value of avoided premature mortality typically dominates the calculated benefits of air pollution regulations; therefore, characterization of the uncertainty surrounding these estimates is key to good policymaking. Formal expert judgment elicitation methods are one means of characterizing this uncertainty. They have been applied to characterize uncertainty in the mortality concentration‐response function, but have yet to be used to characterize uncertainty in the economic values placed on avoided mortality. We report the findings of a pilot expert judgment study for Health Canada designed to elicit quantitative probabilistic judgments of uncertainties in Value‐per‐Statistical‐Life (VSL) estimates for use in an air pollution context. The two‐stage elicitation addressed uncertainties in both a base case VSL for a reduction in mortality risk from traumatic accidents and in benefits transfer‐related adjustments to the base case for an air quality application (e.g., adjustments for age, income, and health status). Results for each expert were integrated to develop example quantitative probabilistic uncertainty distributions for VSL that could be incorporated into air quality models.     

The Risk Screening for Indoor Air Pollution Chemicals in Japan

In recent years, public health problems caused by indoor air pollution have been drawing strong public concern in Japan. After conducting extensive exposure assessment, governmental agencies have taken effective measures to solve the problem; for instance, "Guidelines for indoor air quality (IAQ)" of 13 chemicals, for example, formaldehyde, toluene, and xylene, has been established. Thousands of chemicals have been identified in the indoor environment. Priority rating of those chemicals, however, was not based on the health risk level. We developed a risk-screening scheme for indoor air pollution chemicals and analyzed the current status of the risk levels of those chemicals in Japan. We researched scientific knowledge of health hazards and exposure surveys of indoor air pollution chemicals in Japan, and classified those chemicals based on the health risk level estimated from the scheme. The risk levels of 93 chemicals were characterized and six chemicals (formaldehyde, acrolein, 1,4-dichlorobenzene, benzene, tetrachloroethylene, and benzo(a)pyrene) were classified in the highest risk category.     

大气污染协同治理能促进污染物减排吗?--基于城市的三重差分研究

大气污染具有流动性,跨区域特征明显,协同治理至关重要。基于2010-2015年275个城市的面板数据,运用三重差分法(DDD)研究了大气污染协同治理对污染物减排的影响。从全样本分析结果来看,大气污染协同治理降低了工业二氧化硫排放量和工业烟(粉)尘排放量,而此结果并没有通过显著性检验。从子样本分析结果来看,大气污染协同治理显著降低了工业二氧化硫排放量,但对工业烟(粉)尘排放量没有产生显著影响。城市在促进不同污染物减排时存在差异,减排难度较低的污染物往往被优先完成。从时间效应来看,大气污染协同治理对污染物减排的影响存在时滞性,而且这种时滞性在不同污染物减排之间存在差异。     

Assessment of Inhalation Exposures and Potential Health Risks to the General Population that Resulted from the Collapse of the World Trade Center Towers

In the days following the collapse of the World Trade Center (WTC) towers on September 11, 2001 (9/11), the U.S. Environmental Protection Agency (EPA) initiated numerous air monitoring activities to better understand the ongoing impact of emissions from that disaster. Using these data, EPA conducted an inhalation exposure and human health risk assessment to the general population. This assessment does not address exposures and potential impacts that could have occurred to rescue workers, firefighters, and other site workers, nor does it address exposures that could have occurred in the indoor environment. Contaminants evaluated include particulate matter (PM), metals, polychlorinated biphenyls, dioxins, asbestos, volatile organic compounds, particle-bound polycyclic aromatic hydrocarbons, silica, and synthetic vitreous fibers (SVFs). This evaluation yielded three principal findings. (1) Persons exposed to extremely high levels of ambient PM and its components, SVFs, and other contaminants during the collapse of the WTC towers, and for several hours afterward, were likely to be at risk for acute and potentially chronic respiratory effects. (2) Available data suggest that contaminant concentrations within and near ground zero (GZ) remained significantly elevated above background levels for a few days after 9/11. Because only limited data on these critical few days were available, exposures and potential health impacts could not be evaluated with certainty for this time period. (3) Except for inhalation exposures that may have occurred on 9/11 and a few days afterward, the ambient air concentration data suggest that persons in the general population were unlikely to suffer short-term or long-term adverse health effects caused by inhalation exposures. While this analysis by EPA evaluated the potential for health impacts based on measured air concentrations, epidemiological studies conducted by organizations other than EPA have attempted to identify actual impacts. Such studies have identified respiratory effects in worker and general populations, and developmental effects in newborns whose mothers were near GZ on 9/11 or shortly thereafter. While researchers are not able to identify specific times and even exactly which contaminants are the cause of these effects, they have nonetheless concluded that exposure to WTC contaminants (and/or maternal stress, in the case of developmental effects) resulted in these effects, and have identified the time period including 9/11 itself and the days and few weeks afterward as a period of most concern based on high concentrations of key pollutants in the air and dust.     

Technical Uncertainty in Quantitative Policy Analysis — A Sulfur Air Pollution Example

Expert judgments expressed as subjective probability distributions provide an appropriate means of incorporating technical uncertainty in some quantitative policy studies. Judgments and distributions obtained from several experts allow one to explore the extent to which the conclusions reached in such a study depend on which expert one talks to. For the case of sulfur air pollution from coal-fired power plants, estimates of sulfur mass balance as a function of plume flight time are shown to vary little across the range of opinions of leading atmospheric scientists while estimates of possible health impacts are shown to vary widely across the range of opinions of leading scientists in air pollution health effects.     

Air Pollution and Human Health: Perspectives for the '90s and Beyond

This paper considers the health effects of air pollution from three perspectives: historical, statistical, and public policy, and also as depicted by the recent epidemiology, primarily mortality studies. The historical perspectives establish the reality of population-based health effects, and they provide data with which to evaluate more recent evidence. Statistical perspectives imply that, while there is strong evidence that associations between air quality and health persist, many details of these relationships remain obscure, especially as to the existence of concentration thresholds that might define safe exposure levels. Additional major questions include the effects of uncertainties in actual pollution exposures, the degree of prematurity of "excess" deaths, and whether the development of new cases of chronic disease is associated with air pollution. Public policy issues center around interpreting the new epidemiological studies in the light of these uncertainties and the analysis and management of the concomitant health risks.     

Air Pollution and Mortality: Quantification and Valuation of Years of Life Lost

To analyze the loss of life expectancy (LLE) due to air pollution and the associated social cost, a dynamic model was developed that took into account the decrease of risk after the termination of an exposure to pollution. A key parameter was the time constant for the decrease of risk, for which estimates from studies of smoking were used. A sensitivity analysis showed that the precise value of the time constant(s) was not critical for the resulting LLE. An interesting aspect of the model was that the relation between population total LLE and PM2.5 concentration was numerically almost indistinguishable from a straight line, even though the functional dependence was nonlinear. This essentially linear behavior implies that the detailed history of a change in concentration does not matter, except for the effects of discounting. This model was used to correct the data of the largest study of chronic mortality for variations in past exposure, performed by Pope et al. in 1995; the correction factor was shown to depend on assumptions about the relative toxicity of the components of PM2.5. In the European Union, an increment of 1 microg/m3 of PM2.5 for 1 year implies an average LLE of 0.22 days per person. With regard to the social cost of an air pollution pulse, it was found that for typical discount rates (3% to 8% real) the cost was reduced by a factor of about 0.4 to 0.6 relative to the case with zero discount rate, if the value of a life year was taken as given; if the value of a life year was calculated from the "value of statistical life" by assuming the latter as a series of discounted annual values, the cost varied by at most +/-20% relative to the case with zero discount rate. To assess the uncertainties, this study also examined how the LLE depended on the demographics (mortality and age pyramid) of a population, and how it would change if the relative risk varied with age, in the manner suggested by smoking studies. These points were found to have a relatively small effect (compared to the epidemiological uncertainties) on the calculated LLE.     

Estimating the Risks of Smoking, Air Pollution, and Passive Smoke on Acute Respiratory Conditions

Five years of the annual Health Interview Survey, conducted by the National Center for Health Statistics, are used to estimate the effects of air pollution, smoking, and environmental tobacco smoke on respiratory restrictions in activity for adults, and bed disability for children. After adjusting for several socioeconomic factors, the multiple regression estimates indicate that an independent and statistically significant association exists between these three forms of air pollution and respiratory morbidity. The comparative risks of these exposures are computed and the plausibility of the relative risks is examined by comparing the equivalent doses with actual measurements of exposure taken in the homes of smokers. The results indicate that: (1) smokers will have a 55-75% excess in days with respiratory conditions severe enough to cause reductions in normal activity; (2) a 1 microgram increase in fine particulate matter air pollution is associated with a 3% excess in acute respiratory disease; and (3) a pack-a-day smoker will increase respiratory restricted days for a nonsmoking spouse by 20% and increase the number of bed disability days for young children living in the household by 20%. The results also indicate that the estimates of the effects of secondhand smoking on children are improved when the mother's work status is known and incorporated into the exposure estimate.     

The Influence of Uncertain Map Features on Risk Beliefs and Perceived Ambiguity for Maps of Modeled Cancer Risk from Air Pollution

Maps are often used to convey information generated by models, for example, modeled cancer risk from air pollution. The concrete nature of images, such as maps, may convey more certainty than warranted for modeled information. Three map features were selected to communicate the uncertainty of modeled cancer risk: (i) map contours appeared in or out of focus, (ii) one or three colors were used, and (iii) a verbal‐relative or numeric risk expression was used in the legend. Study aims were to assess how these features influenced risk beliefs and the ambiguity of risk beliefs at four assigned map locations that varied by risk level. We applied an integrated conceptual framework to conduct this full factorial experiment with 32 maps that varied by the three dichotomous features and four risk levels; 826 university students participated. Data was analyzed using structural equation modeling. Unfocused contours and the verbal‐relative risk expression generated more ambiguity than their counterparts. Focused contours generated stronger risk beliefs for higher risk levels and weaker beliefs for lower risk levels. Number of colors had minimal influence. The magnitude of risk level, conveyed using incrementally darker shading, had a substantial dose‐response influence on the strength of risk beliefs. Personal characteristics of prior beliefs and numeracy also had substantial influences. Bottom‐up and top‐down information processing suggest why iconic visual features of incremental shading and contour focus had the strongest visual influences on risk beliefs and ambiguity. Variations in contour focus and risk expression show promise for fostering appropriate levels of ambiguity.     

Change in Public Concern and Responsive Behaviors Toward Air Pollution Under the Dome

This study evaluates the effect of the documentary Under the Dome on the concern and responsive behaviors of the public regarding air pollution in China, with two surveys conducted before and after watching the documentary. Employing difference-in-differences regression, this study answers two research questions: (1) Does Under the Dome change public concern about air pollution? (2) Does Under the Dome change public behaviors in response to air pollution, including protective behaviors (i.e., wearing face masks) and mitigation behaviors (i.e., reducing car driving)? We find that the information campaign (1) protects against the decline of public concern about air pollution in Beijing and (2) moderates the degree to which people's perceived severity, perceived susceptibility, and sense of self-efficacy influence protective behaviors and moderates the degree to which people's belief in the cooperative behaviors by others influences mitigation behaviors. This study provides evidence that information campaigns of the Under the Dome type are effective in raising public awareness; however, the information campaign did not directly influence public protective and mitigation behaviors.     

Exposure Misclassification and Threshold Concentrations in Time Series Analyses of Air Pollution Health Effects

Linear, no-threshold relationships are typically reported for time series studies of air pollution and mortality. Since regulatory standards and economic valuations typically assume some threshold level, we evaluated the fundamental question of the impact of exposure misclassification on the persistence of underlying personal-level thresholds when personal data are aggregated to the population level in the assessment of exposure-response relationships. As an example, we measured personal exposures to two particle metrics, PM2.5 and sulfate (SO4(2-)), for a sample of lung disease patients and compared these with exposures estimated from ambient measurements Previous work has shown that ambient:personal correlations for PM2.5 are much lower than for SO4(2-), suggesting that ambient PM2.5 measurements misclassify exposures to PM2.5. We then developed a method by which the measured:estimated exposure relationships for these patients were used to simulate personal exposures for a larger population and then to estimate individual-level mortality risks under different threshold assumptions. These individual risks were combined to obtain the population risk of death, thereby exhibiting the prominence (and the value) of the threshold in the relationship between risk and estimated exposure. Our results indicated that for poorly classified exposures (PM2.5 in this example) population-level thresholds were apparent at lower ambient concentrations than specified common personal thresholds, while for well-classified exposures (e.g., SO4(2-)), the apparent thresholds were similar to these underlying personal thresholds. These results demonstrate that surrogate metrics that are not highly correlated with personal exposures obscure the presence of thresholds in epidemiological studies of larger populations, while exposure indicators that are highly correlated with personal exposures can accurately reflect underlying personal thresholds.     

空气污染对重污染公司股票价格的影响:基于政策干预视角的经济价值研究

随着经济发展和产业结构调整，社会公众和政府部门对空气污染问题的原因和治理给予了更多关注。空气重污染公司聚焦度陡增，在经营业绩、发展前景和股市表现方面受到不同程度的冲击。本文利用2014—2019年全国地级市层面空气重污染公司的日度非平衡面板数据，研究政策干预视角下空气污染对股票交易的影响及其经济价值。相较人体弹性感知能力，以空气质量等级变化为触发条件的地方政府防治措施能够更精准地对空气污染做出反应，进而通过公司基本面和投资者情绪渠道影响股市交易。实证结果显示，空气质量等级恶化会对空气重污染公司的股价产生非持续性负面影响，且股价的短期下跌伴随换手率上升特点。经济意义检验表明，空气污染与股价短期关系的发现能够指导投资实践以获取经济增益，而空气质量指数具有改进股价预测的潜力。本文的研究对理解政策干预视角下空气污染对股票市场的影响、股价预测和投资组合均具有十分重要的理论和实践意义。     

Public Perceptions of How Long Air Pollution and Carbon Dioxide Remain in the Atmosphere

The atmospheric residence time of carbon dioxide is hundreds of years, many orders of magnitude longer than that of common air pollution, which is typically hours to a few days. However, randomly selected respondents in a mail survey in Allegheny County, PA (N = 119) and in a national survey conducted with MTurk (N = 1,013) judged the two to be identical (in decades), considerably overestimating the residence time of air pollution and drastically underestimating that of carbon dioxide. Moreover, while many respondents believed that action is needed today to avoid climate change (regardless of cause), roughly a quarter held the view that if climate change is real and serious, we will be able to stop it in the future when it happens, just as we did with common air pollution. In addition to assessing respondents’ understanding of how long carbon dioxide and common air pollution stay in the atmosphere, we also explored the extent to which people correctly identified causes of climate change and how their beliefs affect support for action. With climate change at the forefront of politics and mainstream media, informing discussions of policy is increasingly important. Confusion about the causes and consequences of climate change, and especially about carbon dioxide's long atmospheric residence time, could have profound implications for sustained support of policies to achieve reductions in carbon dioxide emissions and other greenhouse gases.     

Intake Fraction Variability Between Air Pollution Emission Sources Inside an Urban Area

The cost‐effective mitigation of adverse health effects caused by air pollution requires information on the contribution of different emission sources to exposure. In urban areas the exposure potential of different sources may vary significantly depending on emission height, population density, and other factors. In this study, we quantified this intraurban variability by predicting intake fraction (iF) for 3,066 emission sources in Warsaw, Poland. iF describes the fraction of the pollutant that is inhaled by people in the study area. We considered the following seven pollutants: particulate matter (PM), nitrogen oxides (NO_x), sulfur dioxide (SO₂), benzo[a] pyrene (BaP), nickel (Ni), cadmium (Cd), and lead (Pb). Emissions for these pollutants were grouped into four emission source categories (Mobile, Area, High Point, and Other Point sources). The dispersion of the pollutants was predicted with the CALPUFF dispersion model using the year 2005 emission rate data and meteorological records. The resulting annual average concentrations were combined with population data to predict the contribution of each individual source to population exposure. The iFs for different pollutant‐source category combinations varied between 51 per million (PM from Mobile sources) and 0.013 per million (sulfate PM from High Point sources). The intraurban iF variability for Mobile sources primary PM emission was from 4 per million to 100 per million with the emission‐weighted iF of 44 per million. These results propose that exposure due to intraurban air pollution emissions could be decreased more effectively by specifically targeting sources with high exposure potency rather than all sources.     

大气污染府际间合作治理联盟的达成与稳定——基于演化博弈分析

地方政府的大气污染治理模式主要有属地治理和合作治理模式,合作治理逐渐成为当前大气污染治理的共识。从演化博弈的视角,分析地方政府在大气污染治理中的行为演化路径与稳定策略,探究地方政府间达成并巩固合作治理联盟的因素。比较有中央约束和无中央政府约束下地方政府属地治理和合作治理四种演化博弈结果表明：在属地治理背景下,无论中央政府是否对地方政府进行约束,地方政府均倾向于“搭便车”行为,而中央政府对地方政府的约束在属地治理中面临失灵;在合作治理场景中,地方政府的稳定策略均向达成合作治理或均不治理的方向演进,但在中央政府约束下,地方政府的稳定策略能快速有效得向合作治理的方向演进。为实现大气污染的有效治理,地方政府间必须形成有效的合作治理联盟,合作收益是达成大气污染合作治理联盟的必要条件,而合作成本与中央政府约束的程度决定了合作治理联盟的稳定性。