Abstract  The aim of the present review was to provide an up-to-date overview of the biological and epidemiological evidence of the role of oxidative stress as a major underlying feature of the toxic effect of air pollutants, and the potential role of dietary supplementation in enhancing antioxidant defences. A bibliographic search was conducted through PubMed. The keywords used in the search were "air pollutant", "oxidative stress", "inflammation", "antioxidant polyunsaturated fatty acids" and "genetics". In addition, the authors also searched for biomarkers of oxidative stress and nutrients. The review presents the most recent data on: the biological and epidemiological evidence of the oxidative stress response to air pollutants; the role of dietary supplementation as a modulator of these effects; and factors of inter-individual variation in human response. The methodology for further epidemiological studies will be discussed in order to improve the current understanding on how nutritional factors may act. There is substantial evidence that air pollution exposure results in increased oxidative stress and that dietary supplementation may play a modulating role on the acute effect of air pollutants. Further epidemiological studies should address the impact of supplementation strategies in the prevention of air-pollution-related long-term effects in areas where people are destined to be exposed for the distant future.

Abstract  Epidemiologic studies have revealed that pollution by ambient particulates is associated with respiratory and cardiovascular diseases, particularly in older people. Toxicologic sensitivity of nanoparticles in different ages was investigated for the first time to demonstrate and explain an age-related difference in response to manufactured nanoparticles. Young, adult, and old rats physiologically inhaled air containing aerosol of manufactured SiO(2) nanoparticles (24.1 mg/m(3); 40 min/day) for four weeks. Changes in serum biomarkers, hemorheologic, pulmonary inflammation, heart injury, and pathology in rats of different ages and their corresponding controls were compared. Inhalation of SiO(2) nanoparticles under identical conditions caused pulmonary and cardiovascular alterations in old rats, yet less change in young and adult rats, including pulmonary inflammation, myocardial ischernic damage, atrio-ventricular blockage, and increase in fibrinogen concentration and blood viscosity. Old individuals were more sensitive to nanoparticle exposure than the young and adult rats. The risk of causing pulmonary damages was: old > young > adult. The risk of cardiovascular disorder was observed only in old age. Our results suggest that different ages may require different biomarkers for identifying pulmonary toxicity during inhalation of nanoparticles.

Abstract  To evaluate the respiratory effects of long-term exposure to air pollution, schoolchildren (ages 8 to 12 years) from two districts in Hong Kong with contrasting air quality were studied. Parents of 1660 children completed questionnaires on respiratory symptoms, and 1294 children had their ventilatory function tested with a spirometer. After adjustment for relevant covariates, children living in the more polluted district had increased odds ratios for frequent cough (1.74), frequent sputum (1.87), chronic sputum (1.84), and doctor-diagnosed asthma (1.98). Children of both sexes in the more polluted district had significantly poorer lung function, and the differences among girls were more marked. The study provides additional evidence for the adverse effects of long-term exposure to relatively low-level air pollution.

Abstract  With the rapid economic development occurring in the last decade in many countries of Asia, the level of air pollution has increased from both industrial and motor vehicle emissions. Compared with Europe and North America, the potential health effects of this increasing air pollution in Asia remain largely unmeasured. Recent data published by the Health Effects Institute from some major cities in India and China reveal that a 10 µg/m(3) increase in PM(10) was associated with an increase in mortality of 0.6% in daily all-natural cause mortality, with higher risks being found at extremes of high temperatures and in the lowest economically advantaged population. Other Asian studies have confirmed the link between hospital admissions for the worsening of COPD and the increase in asthma prevalence to levels of outdoor air pollutants. Although potential health effects appear to be similar to already-published Western data, it is important that further studies be carried out in Asia that will inform the public and the authorities of the necessity to curb levels of outdoor air pollutants to acceptable levels.

Abstract  The health burden of environmental exposures, including ambient air pollution and climate-change-related health impacts, is not equally distributed between or within regions and countries. These inequalities are currently receiving increased attention in environmental research as well as enhanced appreciation in environmental policy, where calls for environmental equity are more frequently heard. The World Health Organization (WHO) 2006 Global Update of the Air Quality Guidelines attempted to address the global-scale inequalities in exposures to air pollution and the burden of diseases due to air pollution. The guidelines stop short, however, of addressing explicitly the inequalities in exposure and adverse health effects within countries and urban areas due to differential distribution of sources of air pollution such as motor vehicles and local industry, and differences in susceptibility to the adverse health effects attributed to air pollution. These inequalities, may, however, be addressed in local air quality and land use management decisions. Locally, community-based participatory research can play an important role in documenting potential inequities and fostering corrective action. Research on environmental inequities will also benefit from current efforts to (1) better understand social determinants of health and (2) apply research evidence to reduce health disparities. Similarly, future research and policy action will benefit from stronger linkages between equity concerns related to health consequences of both air pollution exposure and climate change, since combustion products are important contributors to both of these environmental problems.

Abstract  The goal of this study is to describe linkages between the National Health Interview Survey (NHIS) and Environmental Protection Agency (EPA) air monitoring data, specifically how the linkage method affects characteristics and exposure estimates of study samples and estimated associations between exposure and health. In the USA, nationally representative health data are collected in the NHIS and annual air quality data are collected by the EPA. The linkage of these data for research is not straightforward and the choices made may introduce bias into results. The 2000-2003 NHIS and air quality data for six air pollutants were linked by residential block group and monitor location, which differ by pollutants. For each pollutant, three annual exposure variables were assigned to respondents: (1) average of all monitors in the county, (2) of monitors within a 5-mile radius of the distance between block group and monitor, and (3) within a 20-mile radius. Exposure estimates, study sample characteristics, and association between fine particle exposure and respondent-reported health status were compared for different geographic linkage methods. The results showed that study sample characteristics varied by geographic linkage method and pollutant linked. Generally, the fewer the NHIS respondents linked, the higher is the pollution exposure and lower is the percentage of non-Hispanic whites. After adjustment for sociodemographic and geographic factors, associations between fine particles and health status were generally comparable across study samples. Because exposure information is not available for all potential participants in an epidemiological study, selection effects should be considered when drawing inferences about air quality-health associations. With the current monitoring data system, the study sample is substantially reduced when linkage to multiple pollutants is performed.

Abstract  Motor vehicle traffic is an important source of particulate pollution in cities of the developing world, where rapid growth, coupled with a lack of effective transport and land use planning, may result in harmful levels of fine particles (PM(2.5)) in the air. However, a lack of air monitoring data hinders health impact assessments and the development of transportation and land use policies that could reduce health burdens due to outdoor air pollution. To address this important need, a study of traffic-related PM(2.5) was carried out in the city of Nairobi, Kenya, a model city for sub-Saharan Africa, in July 2009. Sampling was carried out using portable filter-based air samplers carried in backpacks by technicians on weekdays over two weeks at several sites in and around Nairobi ranging from high-traffic roadways to rural background. Mean daytime concentrations of PM(2.5) ranged from 10.7 at the rural background site to 98.1 μg/m(3) on a sidewalk in the central business district. Horizontal dispersion measurements demonstrated a decrease in PM(2.5) concentration from 128.7 to 18.7 μg/m(3) over 100 meters downwind of a major intersection in Nairobi. A vertical dispersion experiment revealed a decrease from 119.5 μg/m(3) at street level to 42.8 μg/m(3) on a third-floor rooftop in the central business district. Though not directly comparable to air quality guidelines, which are based on 24-hour or annual averages, the urban concentrations we observed raise concern with regard to public health and related policy. Taken together with survey data on commuting patterns within Nairobi, these results suggest that many Nairobi residents are exposed on a regular basis to elevated concentrations of fine particle air pollution, with potentially serious long-term implications for health.

Abstract  The aim of the study was to determine whether the area of Tanggu, Tianjin Binhai New Economic Developing Area, China, is subject to similar effects of ambient particulate matter less than 10 micrometres in aerodynamic diameter (PM10) similar to other areas of China. This study was designed to investigate cause-specific mortality risks associated with air pollution in this geographical region. The present study used a time-series analysis to explore the relationship between PM10 and the cause-specific mortalities for non-accidental, cardiovascular, and cardiopulmonary mortality from 1 January 2006 to 31 December 2010. A 10 μg/m(3) increment of PM10 was associated with a 1.02% (95% confidence interval (CI): 0.48, 1.56) increase in cardiovascular mortality, and a 0.88% (95% CI: 0.36, 1.39) increase in cardiopulmonary mortality. In addition, the effects from PM10 appear to be consistent with multi-pollutant models. The results show that there are strong associations between daily cardiovascular and cardiopulmonary mortality and ambient PM10 exposure.

Abstract  The results from a number of studies suggest that children living close to busy roads may have impaired respiratory health. The study reported here was designed specifically to test the hypothesis that exhaust from traffic has an impact on indoor air quality and children's respiratory health. Children living at three different locations in a suburban area in India were enrolled in the study, and the concentrations of indoor air quality parameters were measured at selected households during the period March 2006-February 2007 using portable air quality monitors. Respiratory symptoms were identified by means of a questionnaire completed by parents and from the results of a pulmonary function test (PFT) carried out using an electronic Spiro Meter. The logistic regression model revealed associations between respiratory symptoms and traffic-related indoor air pollutants among our study population. The prevalence of respiratory disorders was greater among children living in close proximity to traffic sources than among those living more distant from these sources, even after the adjustment of confounding factors. We also found intra-urban variability of indoor air quality and associated differences in respiratory symptoms. Our findings support the hypothesis that traffic has an impact on indoor air quality and that it is associated with children's health. The findings from this study have important policy and program implications, including the need for public information campaigns designed to inform people about the risks of exposure to traffic exhausts.

Abstract  SETTING: Although there are proven risk factors related to air pollution, the prevalent situation in low-income countries is not well known.

OBJECTIVE: To quantify the health impacts associated with particulate air pollution in the city of Algiers.

DESIGN: Descriptive study to evaluate a health impact assessment (HIA) approach based on a dose-response curve from the literature. A study area was defined around an air quality monitoring site in Algiers. Daily health data were obtained from a network of physicians practising in out-patient health centres.

RESULTS: Over the period studied, the number of consultations for respiratory reasons attributable to PM10 exposure was 439, representing 4.5% of all health events observed. Different scenarios were examined, showing that a reduction in ambient levels of PM10 would be accompanied by important public health gains.

CONCLUSION: The study allowed us to test the applicability of the HIA approach in a low-income country and to confirm the interest of the approach. Although the estimation of dose-response functions obeys a complex methodology, the HIA is an alternative that constitutes an important decision-making tool.

Abstract  An experimental model was designed to test the possibility that inhalation of a noxious air pollutant may facilitate the blood-borne cancer cell metastasis to the lungs. Animals were exposed to inhalation of air containing 0.8 ppm of nitrogen dioxide for 12 weeks. After this period, animals were infused intravenously with melanoma cells, and 3 weeks later lungs were examined for metastases. The results indicate that NO2exposed animals develop significantly higher number of lung metastases (P less than 0.0025) than the controls. Such results raise the possibility that the inhalation of NO2 from ambient air may facilitate the seeding and proliferation of blood-borne cancer cells in the human lung.

Abstract  STUDY OBJECTIVE: To examine the risk of fatal stroke in relation to smoking habits in men screened for the Oslo study.

DESIGN: The Oslo study is a prospective, cohort study of the epidemiology and preventive aspects of cardiovascular diseases in middle aged men. Screening started in May 1972 and results after 18 years of follow up are reported.

PARTICIPANTS: There were 16209 men aged 40-49 years, of whom 16173 had no stroke history. Eighty five men died from stroke, of whom 48 were daily cigarettes smokers, 7 were pipe and cigar smokers, 15 smoked cigarettes and pipe or cigars daily, 11 were previous cigarette smokers, and 4 had never smoked cigarettes.

MAIN RESULTS: Results of proportional hazards regression analysis adjusted for age, diastolic blood pressure, and glucose concentration showed the following rate ratios (RR) (95% confidence interval) of smoking groups compared with those who had never smoked or had previously smoked: combined cigarette and cigar or pipe smokers, RR = 6.1 (3.0, 12.5); cigarettes only, RR = 4.1 (2.3,7.4); and pipe and/or cigars only RR = 2.2 (0.9,5.5). The overall, age adjusted risk of smoking cigarettes daily was 3.5 and was found to increase with increasing cigarette consumption. Regardless of their smoking group, stroke cases had increased diastolic (DBP) and systolic blood pressure (SBP) when compared with men who had not had a stroke. The absolute differences in DBP and SBP between stroke cases and others for never and previous cigarette smokers versus daily smokers were twice as large: DBP, 12.1 mmHg versus 6.5 mmHg respectively and SBP, 16.0 mmHg versus 7.1 mmHg respectively. A high BMI increased the risk of fatal stroke of never and previous cigarette smokers. Men being treated for hypertension at the time of screening had three times the crude risk of fatal stroke of men who were not taking hypertensive treatment.

CONCLUSIONS: Daily cigarette smoking increased the risk of fatal stroke three and a half times. Combined cigarette and pipe or cigar smoking had a higher risk than smoking cigarettes only. An increased risk was found in relation to increased daily cigarette consumption.

Abstract  A case study is presented on the impact of an extensive grassland fire, at a high altitude location in Western Ghats, on the aerosol black carbon (BC) mass concentration (M-B) and concentration (CO) of carbon monoxide measured at two remote, coastal, nearby locations. Observations revealed a substantial increase shortly after the outbreak of the fire at a high altitude location (similar to 20 km away) in the concentrations of both species; while a two-fold increase occurred in the mass concentration of BC; the increase in CO though was less pronounced (by a factor of similar to 1.5). It is suggested that the sea-breeze circulation modified by the prevailing winds caused the transport of pollutants from the source region downwind to the coastal location. The impact persisted for one day after which it became insignificant. During the first maximum of these, the wind conditions were such that the pollutants emitted from the fire were transported offshore with the return flow of the sea breeze, they then sank along with the airmass and were again transported back to the coast via the sea breeze. During the second maximum (after sunset), the particles as well as the trace gases along with the airmass came directly to the regions of fire to the valley via katabatic flow and were again transported to the coast via the land breeze. This added with the nighttime confinement of pollutants near the surface caused the enhancement in nocturnal peak and it prevailed high until next day morning unlike normal days. (c) 2007 Elsevier B.V. All rights reserved.

Abstract  OBJECTIVE: To assess disease mortality among people with exposure to metal-rich particulate air pollution.

METHODS: We conducted a cohort study on mortality from 1981 to 2005 among 33,573 people living near a nickel/copper smelter in Harjavalta, Finland. Nickel concentration in soil humus was selected as an indicator for long-term exposure. Relative risks--adjusted for age, socioeconomic status, and calendar period--were calculated for three exposure zones.

RESULTS: The relative risks for diseases of the circulatory system by increasing exposure were 0.93 (95% confidence interval = 0.79 to 1.09), 1.20 (1.04 to 1.39), and 1.18 (1.00 to 1.39) among men and 1.01 (0.88 to 1.17), 1.20 (1.04 to 1.38), and 1.14 (0.97 to 1.33) among women. Exclusion of smelter workers from the cohort did not materially change the results.

CONCLUSIONS: Long-term environmental exposure to metal-rich air pollution was associated with increased mortality from circulatory diseases.

Abstract  The health of human populations living in industrial regions is negatively affected by exposure to environmental air pollutants. In this study, we investigated the impact of air pollution on a cohort of subjects living in Ostrava, a heavily polluted industrial region and compared it with a cohort of individuals from the relatively clean capital city of Prague. This study consisted of three sampling periods differing in the concentrations of major air pollutants (winter 2009, summer 2009 and winter 2010). During all sampling periods, the study subjects from Ostrava region were exposed to significantly higher concentrations of benzo[a]pyrene (B[a]P) and benzene than the subjects in Prague as measured by personal monitors. Pollution by B[a]P, particulate matter of aerodynamic diameter <2.5 µm (PM2.5) and benzene in the Ostrava region measured by stationary monitors was also higher than in Prague, with the exception of PM2.5 in summer 2009 when concentration of the pollutant was significantly elevated in Prague. To evaluate DNA damage in subjects from both locations we determined the levels of bulky DNA adducts in peripheral blood lymphocytes using the (32)P-postlabeling method. Despite higher B[a]P air pollution in the Ostrava region during all sampling periods, the levels of B[a]P-like DNA adducts per 10(8) nucleotides were significantly higher in the Ostrava subjects only in winter 2009 (mean ± SD: 0.21 ± 0.06 versus 0.28 ± 0.08 adducts/10(8) nucleotides, P < 0.001 for Prague and Ostrava subjects, respectively; P < 0.001). During the other two sampling periods, the levels of B[a]P-like DNA adducts were significantly higher in the Prague subjects (P < 0.001). Multivariate analyses conducted among subjects from Ostrava and Prague separately during all sampling periods revealed that exposure to B[a]P and PM2.5 significantly increased levels of B[a]P-like DNA adducts in the Ostrava subjects, but not in subjects from Prague.

Abstract  This paper tests factors thought to be important in explaining the choices people make in where they spend time. Three aggregate locations are analyzed: outdoors, indoors, and in-vehicles for two different sample groups: a year-long (longitudinal) sample of one individual and a cross-sectional sample of 169 individuals from the US Environmental Protection Agency's Consolidated Human Activity Database (CHAD). The cross-sectional sample consists of persons similar to the longitudinal subject in terms of age, work status, education, and residential type. The sample groups are remarkably similar in the time spent per day in the tested locations, although there are differences in participation rates: the percentage of days frequenting a particular location. Time spent outdoors exhibits the most relative variability of any location tested, with in-vehicle time being the next. The factors found to be most important in explaining daily time usage in both sample groups are: season of the year, season/temperature combinations, precipitation levels, and day-type (work/nonwork is the most distinct, but weekday/weekend is also significant). Season, season/temperature, and day-type are also important for explaining time spent indoors. None of the variables tested are consistent in explaining in-vehicle time in either the cross-sectional or longitudinal samples. Given these findings, we recommend that exposure modelers subdivide their population activity data into at least season/temperature, precipitation, and day-type "cohorts" as these factors are important discriminating variables affecting where people spend their time.