Societal costs of air pollution-related health hazards: A review of methods and results

How does air pollution threaten mental health? Protocol for a machine-learning enhanced systematic map

INTRODUCTION

Air pollution exposure has influenced a broad range of mental health conditions. It has attracted research from multiple disciplines such as biomedical sciences, epidemiology, neurological science, and social science due to its importance for public health, with implications for environmental policies. Establishing and identifying the causal and moderator effects is challenging and is particularly concerning considering the different mental health measurements, study designs and data collection strategies (eg, surveys, interviews) in different disciplines. This has created a fragmented research landscape which hinders efforts to integrate key insights from different niches, and makes it difficult to identify current research trends and gaps.

METHOD AND ANALYSIS

This systematic map will follow the Collaboration for Environmental Evidence's guidelines and standards and Reporting Standards for Systematic Evidence Syntheses guidelines. Different databases and relevant web-based search engines will be used to collect the relevant literature. The time period of search strategies is conducted from the inception of the database until November 2022. Citation tracing and backward references snowballing will be used to identify additional studies. Data will be extracted by combining of literature mining and manual correction. Data coding for each article will be completed by two independent reviewers and conflicts will be reconciled between them. Machine learning technology will be applied throughout the systematic mapping process. Literature mining will rapidly screen and code the numerous available articles, enabling the breadth and diversity of the expanding literature base to be considered. The systematic map output will be provided as a publicly available database.

ETHICS AND DISSEMINATION

Primary data will not be collected and ethical approval is not required in this study. The findings of this study will be disseminated through a peer-reviewed scientific journal and academic conference presentations.

Alkylperoxy radicals are responsible for the formation of oxygenated primary organic aerosol

Organic aerosol (OA) is an air pollutant ubiquitous in urban atmospheres. Urban OA is usually apportioned into primary OA (POA), mostly emitted by mobile sources, and secondary OA (SOA), which forms in the atmosphere due to oxidation of gas-phase precursors from anthropogenic and biogenic sources. By performing coordinated measurements in the particle phase and the gas phase, we show that the alkylperoxy radical chemistry that is responsible for low-temperature ignition also leads to the formation of oxygenated POA (OxyPOA). OxyPOA is distinct from POA emitted during high-temperature ignition and is chemically similar to SOA. We present evidence for the prevalence of OxyPOA in emissions of a spark-ignition engine and a next-generation advanced compression-ignition engine, highlighting the importance of understanding OxyPOA for predicting urban air pollution patterns in current and future atmospheres.

Air pollution and hospitalization in megacities: empirical evidence from Pakistan

Air pollution has become a threat to human health in urban settlements, ultimately leading to negative impacts on overall economic system as well. Already developed nations and still developing countries both are at the risk of air pollution globally. In this scenario, this work aims to investigate the associations of asthma (AS) and acute upper respiratory infection (ARI) patients with satellite-based aerosol optical depth (AOD) and meteorological factors, i.e., relative humidity (RH), temperature (TEMP), and wind speed (WS). We applied second-generation unit root tests to provide empirical evidence. Two sets of unit root tests confirmed mix order of integration, and the other Westerlund co-integration test further showed strong linkages between estimated variables. Fully modified ordinary least square (FMOLS) and dynamic ordinary least square (DOLS) tests were applied, only to explore that TEMP and WS lower the number of AS and ARI patients, but RH and AOD increase the number of patients. Therefore, in accordance with these findings, our study provides some important policy instruments to improve the health status in megacities of Pakistan.

Annual dementia incidence and monetary burden attributable to fine particulate matter (PM2.5) exposure in Sweden

BACKGROUND

Alzheimer's disease (AD) and other dementias currently represent the fifth most common cause of death in the world, according to the World Health Organization, with a projected future increase as the proportion of the elderly in the population is growing. Air pollution has emerged as a plausible risk factor for AD, but studies estimating dementia cases attributable to exposure to fine particulate matter (PM_2.5) air pollution and resulting monetary estimates are lacking.

METHODS

We used data on average population-weighted exposure to ambient PM_2.5 for the entire population of Sweden above 30 years of age. To estimate the annual number of dementia cases attributable to air pollution in the Swedish population above 60 years of age, we used the latest concentration response functions (CRF) between PM_2.5 exposure and dementia incidence, based on ten longitudinal cohort studies, for the population above 60 years of age. To estimate the monetary burden of attributable cases, we calculated total costs related to dementia, including direct and indirect lifetime costs and intangible costs by including quality-adjusted life years (QALYs) lost. Two different monetary valuations of QALYs in Sweden were used to estimate the monetary value of reduced quality-of-life from two different payer perspectives.

RESULTS

The annual number of dementia cases attributable to PM_2.5 exposure was estimated to be 820, which represents 5% of the annual dementia cases in Sweden. Direct and indirect lifetime average cost per dementia case was estimated to correspond € 213,000. A reduction of PM_2.5 by 1 μg/m³ was estimated to yield 101 fewer cases of dementia incidences annually, resulting in an estimated monetary benefit ranging up to 0.01% of the Swedish GDP in 2019.

CONCLUSION

This study estimated that 5% of annual dementia cases could be attributed to PM_2.5 exposure, and that the resulting monetary burden is substantial. These findings suggest the need to consider airborne toxic pollutants associated with dementia incidence in public health policy decisions.

Long-Term Ambient Air Pollutant Exposure and Risk of Recurrent Headache in Children: A 12-Year Cohort Study

Although studies have suggested environmental factors to be triggers of headache, the contribution of long-term air pollution exposure to recurrent headaches is poorly understood. Hence, we executed this nationwide cohort study to investigate associations between levels of ambient air pollutants and risks of recurrent headaches in children in Taiwan from 2000 to 2012. We used data from the Taiwan National Health Insurance Research Database and linked them to the Taiwan Air Quality Monitoring Database. Overall, 218,008 children aged < 18 were identified from 1 January 2000, and then followed until they were diagnosed by a physician for ≥3 times with recurrent headaches or until 31 December 2012. We categorized the annual average concentration of each air pollutant (fine particulate matter, total hydrocarbon, methane, sulfur dioxide, and nitrogen dioxide) into quartiles (Q1–Q4). We measured the incidence rate, hazard ratios (HRs), and the corresponding 95% confidence intervals for recurrent headaches. stratified by the quartiles. A total of 28,037 children (12.9%) were identified with recurrent headaches. The incidence rate and adjusted HR for recurrent headaches increased with higher-level exposure of air pollutants, except sulfur dioxide. We herein demonstrate that long-term ambient air pollutant exposure might be a risk factor for childhood recurrent headaches.

Perfluorooctanoic acid in indoor particulate matter triggers oxidative stress and inflammation in corneal and retinal cells

To investigate the particle size distribution of particulate matter and the concentration of specific perfluorinated compounds in indoor dust samples from several locations. Then, we used cell-based assays to investigate the effect of perfluorinated compounds on human corneal epithelial (HCEpiC), endothelial cells (HCEC) and retinal pigment epithelial cells (RPE). Indoor dust samples were collected at five different locations and PM_50–10, PM_10–2.5, and PM_2.5–1 were fractionized. The presence and levels of 8:2 fluorotelomer alcohol, 10:2 fluorotelomer alcohol, and perfluorooctanoic acid were detected by gas chromatography–mass spectrometry. The effect of perfluorooctanoic acid on the activation of reactive oxygen species, transepithelial resistance as well as the expression of interleukin (IL)-6 and IL-8 were determined. The basolateral media of human corneal epithelial or human corneal endothelial cells were used to treat human corneal endothelial or retinal pigment epithelial cells, respectively to indicate the potential of ocular surface inflammation may result in retinal inflammation. Among perfluorinated compounds, only perfluorooctanoic acid was detected in all indoor dust samples. Perfluorooctanoic acid had the highest concentration among all perfluorinated compounds in the samples. Exposure to perfluorooctanoic acid impaired tight junction sealing and increased the levels of reactive oxygen species in human corneal epithelial cells. In human corneal epithelial cells, secretion of IL-6 and IL-8 in both apical and basolateral media was promoted significantly by perfluorooctanoic acid treatment. Stimulation with the basolateral media from perfluorooctanoic acid-treated human corneal epithelial cells induced inflammation in human corneal endothelial cells. The treatment of retinal pigment epithelial cells with the basolateral media from stimulated human corneal endothelial cells also elicited the secretion of proinflammatory cytokines. The results indicate that perfluorooctanoic acid exposure impaired the tight junction of corneal cells and caused inflammatory reactions in the retina. Exposure of the cornea to perfluorooctanoic acid contained in particulate matter might induce oxidative stress and inflammation in the retina and represent a risk factor for age-related macular degeneration.

Air pollution and hospitalization: an autoregressive distributed lag (ARDL) approach

Air pollution is one of the biggest global environmental problems in urban regions. This study aimed to investigate the validity of the relationship between air pollution and respiratory and cardiovascular hospitalization using time series methods. This time series study was conducted in Isfahan, Iran. We used data of hospitalized cases in three main university hospitals (Alzahra, Noor, Chamran) and air pollution data from 2014 to 2016. We applied the autoregressive distributed lag (ARDL) bounds testing approach of cointegration to examine the relationship between the air pollution and hospitalizations of respiratory and cardiovascular diseases. The results of air quality assessment on the number of respiratory and cardiovascular hospitalization demonstrate that in the case of cardiovascular disease, both in the long run and in the short run, the air quality index has a significant impact on men and women with a bigger impact in the long run compared to the short run. The value of the long-run coefficient indicates the relationship between air pollution index and cardiovascular hospitalization is stronger than respiratory hospitalizations. In the long term, the effect of the air quality index (AQI) on the number of hospitalizations is more than that in the short term. Based on the results, a 10-unit increase in AQI leads to 5.3% increase in the number of respiratory hospitalization. Accordingly, a 10-unit increase in AQI will result in 7.3% increase in the number of cardiovascular hospitalizations.

Health benefits on cardiocerebrovascular disease of reducing exposure to ambient fine particulate matter in Tianjin, China

With the development of the industrialization level in China, high concentrations of fine particulate matter (≤ 2.5 μg/m³ in aerodynamic diameter (PM_2.5)) could have a great impact on the health of the population. Our study is to quantify the health benefits on cardiocerebrovascular disease of reducing exposure to PM_2.5 in Tianjin, China. We obtained the data on cardiovascular disease (CVD), ischemic heart disease (IHD), and cerebrovascular disease (CD) mortalities to quantify the association between CVD, CD, and IHD mortalities and PM_2.5 and calculate health and economic benefits when the annual average concentration of PM_2.5 was reduced to National Ambient Air Quality Standard (NAAQS) and World Health Organization (WHO) guidelines by using our concentration response (C-R) functions. There were 435.22 (95% CI 253.86 to 616.57) all-cause, 130.22 (95% CI 66.34 to194.09) IHD, and 204.07 (95% CI 111.66 to 296.47) CD deaths attributed to PM_2.5 and the economic benefits obtained by preventing all-cause, IHD, and CD mortalities were equivalent to be 2.79%, 0.83%, and 1.31% of Baodi's GDP in Tianjin in 2017, respectively. PM_2.5 concentration was positive with all-cause, IHD, and CD mortalities in rural, suburban, and urban area of Tianjin, China. Meanwhile, the number of avoidable deaths and economic cost of reducing PM_2.5 concentrations to NAAQS and WHO guidelines was highest in the rural area.

PM2.5 and NOx exposure promote myopia: clinical evidence and experimental proof

Myopia is caused by complex genetic and environmental factors. However, information regarding the effect of long-term exposure to air pollutants on the risk of development of myopia is lacking. We collected data from two linked databases: the Taiwan National Health Insurance Research Database (NHIRD) and the Taiwan Air Quality-Monitoring Database (TAQMD). A total of 15,822 children (16.3%) were diagnosed with myopia within the cohort. The incidence rate of myopia increased with exposure to increasing concentrations of particulate matter (PM2.5) and nitrogen oxides (NOx), increasing from 15.8 to 24.5 and from 13.7 to 34.4, per 1000 person-years, respectively. The adjusted hazard ratio for myopia increased with elevated PM2.5 and NOx exposure concentrations in Q4 to 1.57 and 2.60, respectively, compared to those exposed to the corresponding concentrations in Q1. In the animal experiments, PM2.5 induced myopia in hamsters by enhancing inflammation and was inhibited by resveratrol treatment compared to the control group. The change in axial length in the PM2.5 group was 0.386 ± 0.069 mm versus 0.287 ± 0.086 mm in the control group and 0.257 ± 0.059 mm in the PM2.5 + resveratrol group. We provide both clinical and experimental correlations that exposure to ambient air pollutants is associated with the pathogenesis of myopia.

Public health benefits of reducing exposure to ambient fine particulate matter in South Africa

Air pollution is a growing problem in developing countries, and there exists a wide range of evidence documenting the large health and productivity losses associated with high concentrations of pollutants. South Africa is a developing country with high levels of air pollution in some regions, and the costs of air pollution on human health and economic growth in South Africa are still uncertain. The environmental Benefits Mapping and Analysis Program (BenMAP) model was applied to South Africa using local data on population, mortality rates, and concentrations of fine particulate matter (PM_2.5), as well as mortality risk coefficients from the epidemiological literature. BenMAP estimates the number of premature deaths that would likely have been avoided if South African air quality levels met the existing annual National Ambient Air Quality Standard (NAAQS) of 20 μg m^-3, and the more stringent World Health Organization (WHO) guideline for annual average PM_2.5 of 10 μg m^-3. We estimate 14,000 avoided premature mortalities in 2012 if all of South Africa met the existing NAAQS annual average standard for PM_2.5. These avoided cases of mortality have an estimated monetary value of $14.0 billion (US2011$), which is equivalent to 2.2% of South Africa's 2012 GDP (PPP, US2011$). We estimate 28,000 avoided premature mortalities if the more stringent WHO guideline for annual average PM_2.5 is met across South Africa, which when expressed as a national burden is equivalent to 6% of all deaths in South Africa being attributable to PM_2.5 exposure. These avoided cases of mortality have an estimated monetary value of $29.1 billion, which is equivalent to 4.5% of South Africa's 2012 GDP. These results show that there are significant public health benefits to lowering PM_2.5 concentrations across South Africa, with correspondingly high economic benefits.

Health benefits and control costs of tightening particulate matter emissions standards for coal power plants - The case of Northeast Brazil

Exposure to ambient particulate matter (PM) caused an estimated 4.2 million deaths worldwide in 2015. However, PM emission standards for power plants vary widely. To explore if the current levels of these standards are sufficiently stringent in a simple cost-benefit framework, we compared the health benefits (avoided monetized health costs) with the control costs of tightening PM emission standards for coal-fired power plants in Northeast (NE) Brazil, where ambient PM concentrations are below World Health Organization (WHO) guidelines. We considered three Brazilian PM₁₀ (PM_x refers to PM with a diameter under x micrometers) emission standards and a stricter U.S. EPA standard for recent power plants. Our integrated methodology simulates hourly electricity grid dispatch from utility-scale power plants, disperses the resulting PM_2.5, and estimates selected human health impacts from PM_2.5 exposure using the latest integrated exposure-response model. Since the emissions inventories required to model secondary PM are not available in our study area, we modeled only primary PM so our benefit estimates are conservative. We found that tightening existing PM₁₀ emission standards yields health benefits that are over 60 times greater than emissions control costs in all the scenarios we considered. The monetary value of avoided hospital admissions alone is at least four times as large as the corresponding control costs. These results provide strong arguments for considering tightening PM emission standards for coal-fired power plants worldwide, including in regions that meet WHO guidelines and in developing countries.

Building Evidence for Health: Green Buildings, Current Science, and Future Challenges

Civilizational challenges have questioned the status quo of energy and material consumption by humans. From the built environment perspective, a response to these challenges was the creation of green buildings. Although the revolutionary capacity of the green building movement has elevated the expectations of new commercial construction, its rate of implementation has secluded the majority of the population from its benefits. Beyond reductions in energy usage and increases in market value, the main strength of green buildings may be the procurement of healthier building environments. Further pursuing the right to healthy indoor environments could help the green building movement to attain its full potential as a transformational public health tool. On the basis of 40 years of research on indoor environmental quality, we present a summary of nine environment elements that are foundational to human health. We posit the role of green buildings as a critical research platform within a novel sustainability framework based on social-environmental capital assets.

Valuing the Air Quality Effects of Biochar Reductions on Soil NO Emissions

While it is clear that biochar can alter soil N₂O emissions, data on NO impacts are scarce. Reports range from 0 to 67% soil NO emission reductions postbiochar amendment. We use regional air quality and health cost models to assess how these soil NO reductions could influence U.S. air quality and health costs. We find that at 67% soil NO reduction, widespread application of biochar to fertilized agricultural soils could reduce O₃ by up to 2.4 ppb and PM_2.5 by up to 0.15 μg/m³ in some regions. Modeled biochar-mediated health benefits are up to $4.3 million/county in 2011, with impacts focused in the Midwest and Southwest. These potential air quality and health cobenefits of biochar use highlight the need for an improved understanding of biochar's impacts on soil NO emissions. The benefits reported here should be included with estimates of other biochar benefits, such as crop yield increase, soil water management, and N₂O reductions.

Cost saving potential in cardiovascular hospital costs due to reduction in air pollution

OBJECTIVE

We describe a methodological framework to estimate potential cost savings in Belgium for a decrease in cardiovascular emergency admissions (ischemic heart disease (IHD), heart rhythm disturbances (HRD), and heart failure) due to a reduction in air pollution.

METHODS

Hospital discharge data on emergency admissions from an academic hospital were used to identify cases, derive risk functions, and estimate hospital costs. Risk functions were derived with case-crossover analyses with weekly average PM10, PM2.5, and NO2 exposures. The risk functions were subsequently used in a micro-costing analysis approach. Annual hospital cost savings for Belgium were estimated for two scenarios on the decrease of air pollution: 1) 10% reduction in each of the pollutants and 2) reduction towards annual WHO guidelines.

RESULTS

Emergency admissions for IHD and HRD were significantly associated with PM10, PM2.5, and NO2 exposures the week before admission. The estimated risk reduction for IHD admissions was 2.44% [95% confidence interval (CI): 0.33%-4.50%], 2.34% [95% CI: 0.62%-4.03%], and 3.93% [95% CI: 1.14%-6.65%] for a 10% reduction in PM10, PM2.5, and NO2 respectively. For Belgium, the associated annual cost savings were estimated at € 5.2 million, € 5.0 million, and € 8.4 million respectively. For HRD, admission risk could be reduced by 2.16% [95% CI: 0.14%-4.15%], 2.08% [95% CI: 0.42%-3.70%], and 3.46% [95% CI: 0.84%-6.01%] for a 10% reduction in PM10, PM2.5, and NO2 respectively. This corresponds with a potential annual hospital cost saving in Belgium of € 3.7 million, € 3.6 million, and € 5.9 million respectively. If WHO annual guidelines for PM10 and PM2.5 are met, more than triple these amounts would be saved.

DISCUSSION

This study demonstrates that a model chain of case-crossover and micro-costing analyses can be applied in order to obtain estimates on the impact of air pollution on hospital costs.

A study on the direct and indirect costs of multiple sclerosis based on expanded disability status scale score in khuzestan, iran

BACKGROUND

Multiple sclerosis is a common and chronic neurologic disorder. This disorder imposes physical, economic, and psychosocial burden on individuals, their families and society. This study aims to analyze the costs of multiple sclerosis disease based on the severity of disability.

METHODS

We performed a cross-sectional cost of illness study. This study was conducted in 332 patients of Khuzestan province of Iran. Data were included: Patient's characteristics, disability status, medical, and nonmedical costs and were gathered by using the questionnaire during 3 months period. Costs analysis was performed in the basis of expanded disability status scale (EDSS). Data were analyzed by using SPSS 18 software.

RESULTS

Mean age of the patients was 33.5 (standard deviation [SD]: 9.1) and 70.5% of patients were female. Mean EDSS score of the patients was 2.2 (SD: 1.6). Most patients (92.1%) had relapsing remitting multiple sclerosis (MS) form of the disease. Costs mean per patients was 8.6 ± 7.9 million Rial. The direct and indirect costs were 93.1% and 6.9% of total costs, respectively. The major cost of the disease belongs to the pharmaceutical treatment (22% of costs). The majority costs (approximately 62%) attributed to EDSS of 6-7 and >7. Furthermore, there was strong significant relationship between cost of illness and disability severity of patients (P < 0.05).

CONCLUSIONS

Cost mean per MS patients was relatively high. Furthermore, the results showed that cost of disease had positive and significant relationships with EDSS score that is, progression of disability increase costs of patients.

Peak expiratory flow, breath rate and blood pressure in adults with changes in particulate matter air pollution during the Beijing Olympics: a panel study

OBJECTIVES

This study aims to examine whether changes in short-term exposures to particulate matter are associated with changes in lung function, breath rate, and blood pressure among healthy adults and whether smoking status modifies the association.

METHODS

We took advantage of the artificially controlled changes in air pollution levels that occurred during the 2008 Olympic Games in Beijing, China and conducted a panel study of 201 Beijing residents. Data were collected before, during, and after the Olympics, respectively. Linear mixed-effect models and generalized estimating equation models were used to compare measurements of peak expiratory flow, breath rate and blood pressure across three time points.

RESULTS

The mean values of peak expiratory flow were 346.0 L/min, 399.3 L/min, and 364.1L/min over the three study periods. Peak expiratory flow levels increased in 78% of the participants when comparing the during- with pre- Olympics time points, while peak expiratory flow levels decreased in 80% of participants for the post- and during-Olympic periods comparison. In subgroup analyses comparing the during-Olympic to pre-Olympic time points, we found a larger percentage change in peak expiratory flow (+17%) among female, younger and non-smoking participants than among male, elderly and smoking participants (+12%). The percentage of participants with a fast breath rate (>20/min) changed from 9.7% to 4.9% to 30.1% among females, and from 7.9% to 2.6% to 27.3% among males over the three time points. The changes in blood pressure over the three study periods were not very clear, although there is an increase in diastolic pressure and a decrease in pulse pressure among males during the games.

CONCLUSIONS

The results suggest that exposure to different air pollution levels has significant effects on respiratory function. Smoking, age and gender appear to modify participants' biological response to changes in air quality.

Mercury policy in the Great Lakes states: past successes and future opportunities

While mercury (Hg) releases to air and water within the Great Lakes states have declined significantly, concentrations of mercury in fish remain a cause for concern regarding human and ecosystem health in the Great Lakes Basin. This paper assesses the priority that Hg source reduction ought to have in relation to some other environmental concerns, and explores the relative costs of various Hg reduction policies. Long-range transport of atmospheric mercury creates a collective action problem for states, since most of the mercury emitted within any given state deposits outside that state's borders, and since most of the mercury deposited within a state originated outside that state. This paper discusses some of the mechanisms that policy makers in the Great Lakes states employed to get beyond the collective action problem, including: providing an example for others to follow; using cross-jurisdiction cooperation to leverage the benefits of leadership on Hg reduction and control; and, promoting voluntary actions. Recommendations for future opportunities include: focusing reduction efforts on sources with the highest total mass of emissions rather than solely focusing on reduction of local deposition and utilizing all tools available in the clean air and clean water acts.

Real noise from the urban environment: how ambient community noise affects health and what can be done about it

The increasing interest in the potential effects of the community environment on individual health has so far excluded those of the acoustic environment. Yet it has long been recognized that continued exposure to elevated sound levels leads to noise-induced hearing loss. Noise is defined as unwanted sound that disturbs communication and speech intelligibility and interferes with sleep and mental tasks. Evidence points to numerous psychophysiologic outcomes of sustained exposure, including annoyance, reduced performance, aggressive behavior, and increased risk of myocardial infarction. Populated areas have experienced a steady rise in outdoor ambient noise resulting from increases in vehicular traffic and the ubiquitous use of machinery. In 2000, the WHO produced guidelines on occupational and community noise. The European Union mandated noise surveillance and abatement programs in cities. In the U.S., a few cities have revised their noise ordinances, but proactive noise reduction initiatives remain confined to new transportation infrastructure projects, thus leaving a large portion of the population at risk. Adding community noise to the public health agenda seems timely. Research needs to measure population-wide health effects of involuntary long-term exposure to ambient noise. Further study of the range and severity of co-morbidities will help refine the thresholds used to protect health. Policies and interventions, including health impact assessments, will require detailed data on actual ambient noise levels. Reducing noise at the source will likely require new road standards and lower allowable engine noise levels. Finally, noise abatement programs have an environmental justice dimension and need to target the at-risk population.

Annoyance and health symptoms and their influencing factors: a population-based air pollution intervention study

OBJECTIVES

Interventions for reducing air pollution are important means for improving public health. The role of psychological factors in understanding annoyance and health symptoms due to air pollution is limited and further investigation is required. This study aimed to investigate the effects of an intervention to reduce air pollution (predominantly dust and soot) with respect to perceived pollution, risk perception, annoyance and health symptoms. Another objective was to test a model that describes inter-relations between air pollution, perceived pollution, health risk perception, annoyance and health symptoms.

STUDY DESIGN

An interventional, population-based questionnaire study.

METHODS

Surveys were performed before (pre-test) and after (post-test) closure of a sinter plant. Instead, pellets were shipped to the community's harbour for steel production. Individuals in the community aged 18-75 years were selected at random for participation in the pre-test (n=738; 74% of the sample participated) and post-test (n=684; 68% of the sample participated). The two samples were representative of the populations at the two points in time, and thus not identical.

RESULTS

After the sinter plant was closed, the environment was perceived as being less dusty, the residents were more positive in their risk perception, and they reported less annoyance due to dust, soot and odorous substances. No difference was found for health symptoms between the pre-test and the post-test. Based on path analyses, a model is proposed of inter-relations between air pollution, perceived pollution, health risk perception, annoyance and health symptoms.

CONCLUSION

The intervention was successful with respect to perceived dust and soot pollution; to annoyance attributed to dust, soot and odorous substances; and to risk perception. The path analyses suggest that perceived pollution and health risk perception play important roles in understanding and predicting environmentally induced annoyance and health symptoms.