Abstract  BACKGROUND: Living close to major roads or highways has been suggested to almost double the risk of dying from cardiopulmonary causes. We assessed whether long-term exposure to air pollution originating from motorized traffic and industrial sources is associated with total and cause-specific mortality in a cohort of women living in North Rhine-Westphalia, Germany. METHODS: The study was a follow-up of a series of cross-sectional studies carried out during the 1980s and 1990s on the health of women (age 50-59 years). Approximately 4800 women were followed up for vital status and migration. Exposure to air pollution was defined by distance to major roads calculated from Geographic Information System data and by 1- and 5-year average nitrogen dioxide (NO2) and particle (PM10) concentrations calculated from air monitoring station data. We analyzed associations between exposure and mortality using Cox's proportional hazards models adjusting for confounders. Relative risks (RRs) refer to an interquartile range increase in exposure (16 microg/m for NO2; 7 microg/m for PM10). RESULTS: During the follow-up period, 8% of the women died, 3% from cardiopulmonary causes. Cardiopulmonary mortality was associated with living within a 50-meter radius of a major road (adjusted RR = 1.70; 95% confidence interval = 1.02-2.81), with NO2 (1.57; 1.23-2.00 for 1-year average), and with PM10 (1.34; 1.06-1.71 for 1-year average). Exposure to NO2 was also associated with all-cause mortality (1.17; 1.02-1.34). No association was seen with noncardiopulmonary nonlung cancer mortality. CONCLUSIONS: Living close to major roads and chronic exposure to NO2 and PM10 may be associated with an increased mortality due to cardiopulmonary causes.

Abstract  Since January 2002, the European Commission is funding a large project, 'Protection against Allergy--Study in Rural Environments' (PASTURE; contract no. QLK4-2001-00250), under the Fifth Framework Program in the field of epidemiology of allergic diseases. The aim of this paper was to describe the background and design as well as the aims of the project. Asthma and allergic disorders are a major public health problem in many Western countries. The aetiology of asthma and allergic disease remains poorly understood despite considerable research. Epidemiology has the potential to add greatly to the understanding by elucidating the risk factors for asthma and allergic disease and thereby suggesting productive avenues for research into causation and prevention. Several risk factors for the development of asthma and atopic disease in children such as passive smoke exposure during pregnancy and infancy, low birth weight or high body mass index later in life have been described. Furthermore, there is consistent evidence that the prevalence of atopy increases with higher socio-economic status. Levels of air pollution such as ozone, NO2, SO2 and particles are likely to provoke acute exacerbations of pre-existent respiratory disease. Their role in the inception of asthma and allergies remains to be clarified. Allergen exposure has been linked to the development of atopic sensitization to that particular allergen in children as well as in adults with occupational exposures. Exposure to house dust mite or cat allergen is, however, unlikely to contribute to the development of childhood asthma. In turn, pet keeping in the first year of life, particularly, dog keeping, has been inversely related to the development of wheeze and atopic illnesses. Several prospective birth cohort studies found a decreased prevalence of atopic disease in children having daily contact to pets, in particular to cats and dogs, during early infancy. The protective effect might be attributable to allergen or other exposures associated with pet ownership, but may also in part be because of the removal of pets in families with sensitized or symptomatic children or in families with a positive history for atopy at the time the child was born.

Abstract  In the past few years many studies on air pollution and health based on time series have been carried out. Yet, this approach does not assess exposure to air pollution at an individual level but it is based on ambient concentrations measured by air quality monitoring networks. Questions on the estimates of exposure to pollutants have been raised, in particular the fact that background measuring stations only have been considered in the set up of pollution indicators. To assess the impact of exposure indicator characteristics on the results of time series analysis, two series (black smoke and sulfur dioxide, respectively) of exposure indicators to urban air pollution were set up taking into account a growing part of proximity measures (industrial sources) available in the studied urban area (Le Havre, France). For each pollutant, indicators distributions were almost similar, especially for black smoke. Whatever the pollutant, the most obvious heterogeneity could be observed between the 100% background indicator and the indicator including the arithmetic mean for all the stations (50% background stations and 50% proximity stations). Then the sensitivity of the associations between mortality and air pollution to these indicators was studied. These indicators did not show statistically significant differences in the estimated excess risk. Yet, confidence intervals were more statistically significant as the contribution of proximity stations was more substantial, in particular for SO2. To conclude, the use of proximity measurements did not influence dramatically on the mean estimates of the association between air pollution and mortality indicators in Le Havre. Therefore it does not seem relevant to include the data provided by the proximity stations in the urban exposure indicators within the context of the epidemiology monitoring system.

Abstract  Until recently, urban air quality modelling has been based on operational models of an integral nature. The use of computational fluid dynamics (CFD) models to address the same problems is increasing rapidly. Operational models e.g. OSPM, AERMOD, ADMS-Urban have undergone many comprehensive formal evaluations as to their "fitness for purpose" while CFD models do not have such an evaluation record in the urban air quality context. This paper looks at the application of both approaches to common problems. In particular, pollutant dispersion from point and line sources in the simplest neutral atmospheric boundary layer and line sources placed within different regular building geometries is studied with the CFD code FLUENT and the atmospheric dispersion model ADMS-Urban. Both the effect of street canyons of different aspect ratios and various obstacle array configurations consisting of cubical buildings are investigated. The standard k-epsilon turbulence model and the advection-diffusion (AD) method (in contrast to the Lagrangian particle tracking method) are used for the CFD simulations. Results from the two approaches are compared. Overall CFD simulations with the appropriate choice of coefficients produce similar concentration fields to those predicted by the integral approach. However, some quantitative differences are observed. These differences can be explained by investigating the role of the Schmidt number in the CFD simulations. A further interpretation of the differences between the two approaches is given by quantifying the exchange velocities linked to the mass fluxes between the in-canopy and above-canopy layers. (c) 2007 Elsevier Ltd. All rights reserved.

Abstract  The widely used source apportionment model, positive matrix factorization (PMF2), has been applied to various air pollution data. Recently, U.S. Environmental Protection Agency (EPA) developed EPA positive matrix factorization (PMF), a version of PMF that will be freely distributed by EPA. The objectives of this study were to conduct source apportionment studies for particulate matter less than 2.5 mu m in aerodynamic diameter (PM2.5) speciation data using PMF2 and EPA PMF (version 1.1) and to compare identified sources between the two models. In the present study, ambient PM2.5 compositional datasets of 24-hr integrated samples collected at EPA Speciation Trends Network monitoring sites in Chicago, IL, and Portland, OR, were analyzed. Both PMF2 and EPA PMF extracted eight sources for the Chicago data and 10 sources for the Portland data. The model-resolved source profiles were similar between two models for both datasets. However, in several sources, the average contributions did not agree well and the time series contributions were not highly correlated. The differences between PMF2 and EPA PMF solutions were caused by the different least-square algorithm and the different nonnegativity constraints. Most of the average source contributions resolved by both models were within 5-95% uncertainty provided by EPA PMF, indicating that the sources resolved by both models were reproducible.

Abstract  We use the fractional aerosol optical depth (AOD) values derived from Multiangle Imaging Spectroradiometer (MISR) aerosol component measurements, along with aerosol transport model constraints, to estimate ground-level concentrations of fine particulate matter (PM2.5) mass and its major constituents in the continental United States. Regression models using fractional AODs predict PM2.5 mass and sulfate (SO4) concentrations in both the eastern and western United States, and nitrate (NO3) concentrations in the western United States reasonably well, compared with the available ground-level U.S. Environment Protection Agency (EPA) measurements. These models show substantially improved predictive power when compared with similar models using total-column AOD as a single predictor, especially in the western United States. The relative contributions of the MISR aerosol components in these regression models are used to estimate size distributions of EPA PM2.5 species. This method captures the overall shapes of the size distributions of PM2.5 mass and SO4 particles in the east and west, and NO3 particles in the west. However, the estimated PM2.5 and SO4 mode diameters are smaller than those previously reported by monitoring studies conducted at ground level. This is likely due to the satellite sampling bias caused by the inability to retrieve aerosols through cloud cover, and the impact of particle hygroscopicity on measured particle size distributions at ground level.

Abstract  Our meta-analysis of 126 nitrogen addition experiments evaluated nitrogen (N) limitation of net primary production (NPP) in terrestrial ecosystems. We tested the hypothesis that N limitation is widespread among biomes and influenced by geography and climate. We used the response ratio (R approximately equal ANPP(N)/ANPP(ctrl)) of aboveground plant growth in fertilized to control plots and found that most ecosystems are nitrogen limited with an average 29% growth response to nitrogen (i.e., R = 1.29). The response ratio was significant within temperate forests (R = 1.19), tropical forests (R = 1.60), temperate grasslands (R = 1.53), tropical grasslands (R = 1.26), wetlands (R = 1.16), and tundra (R = 1.35), but not deserts. Eight tropical forest studies had been conducted on very young volcanic soils in Hawaii, and this subgroup was strongly N limited (R = 2.13), which resulted in a negative correlation between forest R and latitude. The degree of N limitation in the remainder of the tropical forest studies (R = 1.20) was comparable to that of temperate forests, and when the young Hawaiian subgroup was excluded, forest R did not vary with latitude. Grassland response increased with latitude, but was independent of temperature and precipitation. These results suggest that the global N and C cycles interact strongly and that geography can mediate ecosystem response to N within certain biome types.

Abstract  The primary emission source contributions to fine organic carbon (OC) and fine particulate matter (PM2.5) mass concentrations on a daily basis in Atlanta, GA, are quantified for a summer (July 3 to August 4, 2001) and a winter (January 2-31, 2002) month. Thirty-one organic compounds in PM2.5 were identified and quantified by gas chromatography/mass spectrometry. These organic tracers, along with elemental carbon, aluminum, and silicon, were used in a chemical mass balance (CMB) receptor model. CMB source apportionment results revealed that major contributors to identified fine OC concentrations include meat cooking (7-68%; average: 36%), gasoline exhaust (7-45%; average: 21%), and diesel exhaust (6-41%; average: 20%) for the summer month, and wood combustion (0-77%; average: 50%); gasoline exhaust (14-69%; average: 33%), meat cooking (1-14%; average: 5%), and diesel exhaust (0-13%; average: 4%) for the winter month. Primary sources, as well as secondary ions, including sulfate, nitrate, and ammonium, accounted for 86 +/- 13% and 112 +/- 15% of the measured PM2.5 mass in summer and winter, respectively.

Abstract  Particulate air pollution is a serious problem in Beijing. The annual concentration of particulate matter with aerodynamic diameter less than 10 microm (PM(10)), ranging from 141 to 166 microg m(-3) in 2000-2004, could be very harmful to human health. In this paper, we presented the mortality and morbidity effects of PM(10) pollution based on statistical data and the epidemiological exposure-response function. The economic costs to health during the 5 years were estimated to lie between US$1670 and $3655 million annually, accounting for about 6.55% of Beijing's gross domestic product each year. The total costs were apportioned into two parts caused by: the local emissions and long-range transported pollution. The contribution from local emissions dominated the total costs, accounting on average for 3.60% of GDP. However, the contributions from transported pollution cannot be neglected, and the relative percentage to the total costs from the other regions could account for about 45%. An energy policy and effective measures should be proposed to reduce particulate matter, especially PM(2.5) pollution in Beijing to protect public health. The Beijing government also needs to cooperate with the other local governments to reduce high background level of particulate air pollution.

Abstract  Objective: It is still unknown whether specific components in fine particles are associated with heart rate variability (HRV) reduction. Methods: We recruited 46 patients with or at risk for cardiovascular diseases to measure 24-hour HRV by ambulatory electrocardiographic monitoring. Fixed-site air-monitoring stations were used to represent participants' exposures to particles with aerodynamic diameters less than 10 ?m (PM10) and 2.5 ?m (PM2.5), and particulate components of sulfate, nitrate, organic carbon (OC) and elemental carbon, and gaseous pollutants. Results: We found that HRV reduction was associated with sulfate, OC, and PM2. 5 but not with the other five pollutants in single-pollutant models. Sulfate was found to remain in significant association with HRV reduction adjusting for OC and PM2.5 in three-pollutant models. Conclusions: Exposures to sulfate and OC in PM2.5were associated with HRV reduction in patients with or at risk for cardiovascular diseases.

Abstract  The National Children's Study is considering a wide spectrum of airborne pollutants that are hypothesized to potentially influence pregnancy outcomes, neurodevelopment, asthma, atopy, immune development, obesity, and pubertal development. In this article we summarize six applicable exposure assessment lessons learned from the Centers for Children's Environmental Health and Disease Prevention Research that may enhance the National Children's Study: a) Selecting individual study subjects with a wide range of pollution exposure profiles maximizes spatial-scale exposure contrasts for key pollutants of study interest. b) In studies with large sample sizes, long duration, and diverse outcomes and exposures, exposure assessment efforts should rely on modeling to provide estimates for the entire cohort, supported by subject-derived questionnaire data. c) Assessment of some exposures of interest requires individual measurements of exposures using snapshots of personal and microenvironmental exposures over short periods and/or in selected microenvironments. d) Understanding issues of spatial-temporal correlations of air pollutants, the surrogacy of specific pollutants for components of the complex mixture, and the exposure misclassification inherent in exposure estimates is critical in analysis and interpretation. e) "Usual" temporal, spatial, and physical patterns of activity can be used as modifiers of the exposure/outcome relationships. f) Biomarkers of exposure are useful for evaluation of specific exposures that have multiple routes of exposure. If these lessons are applied, the National Children's Study offers a unique opportunity to assess the adverse effects of air pollution on interrelated health outcomes during the critical early life period.

Abstract  The term 'air pollution' is used to describe the presence of chemicals or materials in the atmosphere that produce poor air quality. Air pollutants may be classified into four principal categories which include anthropogenic (man-made; e.g. combustion products), biogenic (biological; e.g. pollen, allergens), technogenic (technology; e.g. metal aerosols or smelter) and geogenic (geological; e.g. erosion of earth, i.e. minerals, volcanic ash). From these categories are derived the seven main pollutants of human health concern, i.e. carbon monoxide, nitrogen dioxide, ozone, sulphur dioxide, hydrocarbons, lead, and particulate matter (PM). The common provenance of all these emissions is from the combustion of fossil fuels (e.g. coal, petrol and diesel), biomass (e.g. cooking) and tobacco smoke. PM is now considered to be the most precarious of pollutants, with the combustion-derived nano-particles being linked to a myriad of premature and excess deaths world-wide; especially for persons with pre-existing cardiovascular disorders. This meeting intended to bring together scientists from a host of disciplines (toxicologists, biologists, chemists, physicists and material scientists) that work at the bio-particulate interface. It aimed to present and discuss, via topical 'break-out' sessions, the current thoughts on the 'burden to human health' following exposure to and harm from combustion-derived particles. Furthermore, strategies for 'harm reduction' were another feature of this cross-disciplinary meeting. The final objectives were to identify biomarkers of exposure and harm to these inhalation hazards. All topics covered sought to find biomarker indices for human health effects.

Abstract  Several studies have documented potential health effects due to agricultural burning smoke. However, there is a paucity of literature characterizing community residents exposure to agricultural burning smoke. This study assesses personal exposures to particulate matter (PM) with aerodynamic diameters <2.5 mu m (PM sub(2.5)) from agriculture burning smoke (E sub(b)) for 33 asthmatic adults in Pullman, WA. PM sub(2.5) concentrations were measured on 16 subjects, inside of all but four residences, outside of 6 residences, and at a central site. The mean+/-standard deviation of personal exposure to PM sub(2.5) was 13.8+/-11.1 mu g m super(-3), which was on average 8.0 mu g m super(-3) higher during the agricultural burning episodes (19.0+/-11.8 mu g m super(-3)) than non-episodes (11.0+/-9.7 mu g m super(-3)). The levoglucosan (LG, a unique marker for biomass burning PM) on personal filter samples also was higher during the episodes than non-episodes (0.026+/-0.030 vs. 0.010+/-0.012 mu g m super(-3)). We applied the random component superposition model on central-site and home indoor PM measurements, and estimated a central-site infiltration factor between 0.21 and 2.05 for residences with good modeling performance. We combined the source apportionment and total exposure modeling results to estimate individual E sub(b), which ranged from 1.2 to 6.7 mu g m super(-3) and correlated with personal LG with an r of 0.51. The sensitivity analysis of applying the infiltration efficiency estimated from the recursive model showed that the E sub(b) (range: 1.3-4.3 mu g m super(-3)) obtained from this approach have a higher correlation with personal LG (r=0.75). Nevertheless, the small sample size of personal LG measurements prevents a comparative and conclusive assessment of the model performance. We found a significant between-subject variation between episodes and non-episodes in both the E sub(b) estimates and subjects activity patterns. This suggests that the LG measurements at the central site may not always represent individual exposures to agricultural burning smoke. We recommend collecting more microenvironmental samples to model the E sub(b) and more personal samples to validate the E sub(b) estimates.

Abstract  Scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDX) of particulate matter on lichen transplant thalli (Hypogymnia physodes) was assessed as a complementary technique to wet chemical analysis for source apportionment of airborne contaminants. Transplants (2 month exposure) stationed in the Cu smelter and former mining town of Karabash were compared with those from a control site 30 km south. Particulate matter in Karabash samples (715 analyses) showed higher levels of S, Pb, Cu, Sn and Zn compared with the control (598 analyses). Complex element associations among the particles confounded detailed mineralogical identifications, and therefore a simplified particle classification scheme was devised for source apportionment. Karabash samples contained high levels of particles classified as mining-related (MRP), and these were also identified in control samples, indicating wide spatial dispersion from the smelter and highlighting the sensitivity of the method. It was noted that MRP -2.5-mm diameter were poorly represented on lichen surfaces suggesting this may limit the usefulness of Hypogymnia transplants as proxies when assessing human health impacts from airborne particulates. Analyses of the lichen thallus surface (away from surface particulates) revealed high levels of Cu, Zn, Fe and Pb associated with organics in the Karabash samples compared with the control, with a proportionate loss of K, interpreted as being due to a stress-related increase in cell membrane permeability. This type of analysis may provide a novel SEM-EDXbased method for assessing lichen vitality. The techniques developed are presented and further implications of the study are discussed.

Abstract  Recent papers have reported that Asian dust events have been associated with increased risks of all-cause mortality and rates of respiratory illness. The current study was designed to estimate the relative risk of mortality associated with Asian dust events. We used the daily counts of non-accidental deaths, air pollution and meteorological data in Seoul, Korea from 2000 to 2004. We divided all days during the study period into two groups according to the presence or absence of Asian dust events. For each group, we conducted time-series analysis to estimate the relative risk of total non-accidental death when the concentration of each air pollutant increased by the inter-quartile range (IQR). The average concentrations of every air pollutant on the days without a dust event were lower than those on the days with such an event. We found that the effect sizes of air pollution on daily death rates in the model without Asian dust events were larger than those in the model with Asian dust events, and were statistically significant for all air pollutants (PM10, CO, NO2, and SO2) except for O-3. Our results Suggest that we are likely to underestimate the risk of urban air particles if we analyze the effect size of air pollution on daily mortality during Asian dust events. We hypothesize that the real health effect is much larger than previous results suggested.

Abstract  There is a paradox in that some types of nanoparticles (a generic term for particles less than approximately 100 nm in diameter) are used in nanomedicine for imaging and therapy, whereas other types of nanoparticles produced by combustion are thought by many scientists to be responsible for the adverse health effects of air pollution. In addition, the nanotechnology industry is in the process of producing new nanoparticles whose hazard and potential for human exposure are not yet determined. Medicinal nanoparticles are being designed and tested on a case-by-case basis using testing procedures derived from biomaterials and drug safety and with due regard to risk-benefit. There are considerable differences in physical and chemical properties between medicinal nanoparticles and the industrial and combustion-derived nanoparticles studied by particle toxicologists, a recognized branch of toxicology that studies particles. Medical nanoparticles tend to be composed of materials that are similar to biological molecules and they are generally biodegradable. By contrast, combustion-derived nanoparticles are carbon-centered and contaminated with metals and organics, with a biopersistent core. To fully address the paradox that nanoparticles can be both beneficial and harmful, there is a need, over the next 10 years, to advance our understanding of the characteristics that determine acute and chronic toxicity, translocation, biodegradation and elimination of all types of nanoparticles likely to gain access to the human body.

Abstract  A detailed analysis is provided for the meteorological conditions that prevailed during the Pacific 2001 Air Quality Field Study (13-31 August 2001). The general region of interest is the Georgia Basin with a focus on the Lower Fraser Valley of British Columbia. The study period can be broken into three distinct periods: dry, wet and unsettled. Particular attention is paid to synoptic scale conditions, low-level flow, back trajectory analyses and stability conditions associated with the dry and unsettled periods. A pressure slope index, based on sea-level pressure, was developed to characterise the sea breeze-land breeze signal. This index proved useful in describing the low-level flow over the valley for time resolutions on the order of one hour. Indeed, the index highlighted two periods where a prominent sea breeze-land breeze cycle had prevailed. Back trajectory output from multiple models along with observed winds provided a detailed description of pollutant source regions and the flow pattern in the lower troposphere during the field study. Finally, approaches to calculating the mixing height based on radiosonde data were introduced. The spatial and temporal variability of this data combined with the flow diagnosis illustrated the relationship between the mixing height and the sea breeze-land breeze cycle. (C) 2004 Elsevier Ltd. All rights reserved.

Abstract  Polycyclic aromatic hydrocarbons (PAHs) are becoming a major component of atmospheric toxic pollutants (ATPs) in Guangzhou city, China. Studies showed that ATPs may have adverse health effect in urban area. An investigation on particulate- and vapor-phase distribution of n-alkanes and PAHs in urban atmosphere has been conducted. In LiWan district, 24h sampling for three consecutive days was performed in April and July 2001 at ground level. For comparison, samples were also collected on a nine-story building, ca. 25 m above ground level. The ambient concentrations of Sigman-alkanes and SigmaPAHs, compositional variations including molecular diagnostic ratios, natural biogenic and investigated. (C) 2002 Elsevier Science Ltd. All rights reserved.

Abstract  [1] Estimates of global mean direct climate forcing by absorbing aerosols located above boundary layer clouds are large, uncertain, and almost entirely unconstrained by observations. Spaceborne lidar offers a new opportunity for global constraints. Here we examine techniques for using liquid water clouds as lidar targets, allowing aerosol optical depth and Angstrom exponent to be deduced directly from aerosol effects on light transmission. Two such techniques are examined using data from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO). The first is a previously reported method based on measurements of cloud depolarization ratio (DR) at 532-nm wavelength. The second is a new method using measurements of cloud color ratio (CR), which is the ratio of the signal from the cloud at 1064 nm to that at 532 nm. Optical depth retrievals from these two methods compare favorably over the eastern tropical Atlantic Ocean during August 2006, when biomass burning aerosols are frequently advected over marine stratiform clouds. The CR technique is mainly sensitive to fine-mode aerosols and essentially insensitive to clouds and coarse-mode dust. Because anthropogenic aerosol is predominantly found in the fine mode, the CR technique can be used to help identify situations where anthropogenic cloudy-sky direct radiative forcing is occurring. We demonstrate this capability using 6 months data over the eastern tropical Atlantic Ocean.

Abstract  Laden et al. (2000)recently reported results of applying factor analysis to data taken in six cities from 1979 to 1988, identifying airborne particle sources potentially affecting daily mortality. These authors sought relationships between source groups and risk measures using source tracer elements, Se (coal combustion), Pb (light-duty motor vehicle sources), and Si (crustal-soil dispersion). Combined data analyses of this kind may overlook the complexity of source contributions, which have common tracer elements. In one of the cities, Boston, for example, the authors found coal combustion was an important source of mortality risk. For the city of Boston, the authors attribute coal combustion largely to distant upwind regional sources. The emphasis on coal combustion is confounded by the presence of major local sources of residual oil combustion, which contribute V, Se, and S (sulfur as sulfate) to the source apportionment. Evaluation of the source identification using single-element tracer analysis indicates that the detailed chemical composition or profile of major local sources needs to be taken into account in these investigations to minimize misclassification of airborne particle sources with potential adverse health effects.

Abstract  Inner-city, minority populations are high-risk groups for adverse birth outcomes and also are more likely to be exposed to environmental contaminants, including environmental tobacco smoke (ETS), benzo[a]pyrene (BaP), and other polycyclic aromatic hydrocarbons (PAHs) found in urban air. In a sample of nonsmoking African-American and Dominican women, we evaluated the effects on birth outcomes of prenatal exposure to ETS, using questionnaire data and plasma cotinine as a biomarker of exposure, and environmental PAHs using BaP-DNA adducts as a molecular dosimeter. We previously reported that among African Americans, high prenatal exposure to PAHs estimated by prenatal personal air monitoring was associated with lower birth weight (p = 0.003) and smaller head circumference (p = 0.01) after adjusting for potential confounders. In the present analysis, self-reported ETS was associated with decreased head circumference (p = 0.04). BaP-DNA adducts were not correlated with ETS or dietary PAHs. There was no main effect of BaP-DNA adducts on birth outcomes. However, there was a significant interaction between the two pollutants such that the combined exposure to high ETS and high adducts had a significant multiplicative effect on birth weight (p = 0.04) and head circumference (p = 0.01) after adjusting for ethnicity, sex of newborns, maternal body mass index, dietary PAHs, and gestational age. This study provides evidence that combined exposure to environmental pollutants at levels currently encountered in New York City adversely affects fetal development.

Abstract  We investigated the occurrence of color vision loss in 75 styrene-exposed workers and in 60 referents. Color vision was evaluated by adopting the Lanthony D 15 desaturated panel, a teat specifically suited to detect mild acquired dyschromatopsia. The results of the test were expressed as Color Confusion Index. Styrene exposure was evaluated with both environmental and biological monitoring. Airborne levels of the solvent were 3.2 to 549.5 mg/m3. In styrene-exposed workers color vision was significantly impaired when compared with referents matched for age. A significative correlation was found between environmental and urinary levels of styrene and Color Confusion Index excluding the influence of age in multiple regression analysis, indicating the possibility of a dose-effect relationship. The findings suggest that styrene can induce an early appearance of a dose-dependent color vision loss.

Abstract  #The health risk associated with low-level air pollution exposure is still uncertain. The association between exposure and pulmonary function was assessed with personal sampling. Small, portable multipollutant samplers were used to assess personal exposure to particulate matter. Thirty-six asthmatic subjects participated in the study for up to 20 d in both summer (n = 10 d) and winter (n = 10 d); pulmonary function was assessed at the beginning and end of each sampling day, and medication use was recorded. A within-individual longitudinal analysis of the relationship between pulmonary function and particulate matter revealed an effect of season. In winter, pulmonary function increased as particulate exposure increased, which was explained by a confounding effect of medication use. Therefore, in addition to exposure, season of the year and medication use are factors that must be considered.

Abstract  U.S. Environmental Protection Agency; National Institute of Environmental Health Sciences. #Previously we reported that fine particle mass (particulate matter <= 2.5 "mu"m; PM2.5), which is primarily from combustion sources, but not coarse particle mass, which is primarily from crustal sources, was associated with daily mortality in six eastern U.S. cities (1). In this study, we used the elemental composition of size-fractionated particles to identify several distinct source-related fractions of fine particles and examined the association of these fractions with daily mortality in each of the six cities. Using specific rotation factor analysis for each city, we identified a silicon factor classified as soil and crustal material, a lead factor classified as motor vehicle exhaust, a selenium factor representing coal combustion, and up to two additional factors. We extracted daily counts of deaths from National Center for Health Statistics records and estimated city-specific associations of mortality with each source factor by Poisson regression, adjusting for time trends, weather, and the other source factors. Combined effect estimates were calculated as the inverse variance weighted mean of the city-specific estimates. In the combined analysis, a 10 "mu"g/m3 increase in PM2.5 from mobile sources accounted for a 3.4% increase in daily mortality [95% confidence interval (CI), 1.7-5.2%], and the equivalent increase in fine particles from coal combustion sources accounted for a 1.1% increase [CI, 0.3-2.0%). PM2.5 crustal particles were not associated with daily mortality. These results indicate that combustion particles in the fine fraction from mobile and coal combustion sources, but not fine crustal particles, are associated with increased mortality.

Abstract  SUMMARY The effect of lead exposure on neurobehavioral performance is modified by age. Whether educational achievement can serve as an effect modifier on the lead-cognitive performance relationship is examined. The Mini-Mental State Examination (MMSE) and the reading section of the Wide Range Achievement Test-Revised (WRAT-R), a measure of educational achievement, were administered to 256 lead smelter workers. The workers had a mean (standard deviation) age of 41 (7.9) years, education of 10 (2.8) years, employment duration of 17 (8.1) years, current blood lead of 28 (8.8) Ág/dL, and working lifetime integrated blood lead index (IBL) of 725 (434) Ág-yr/dL. The median (range) MMSE score was 29 (19 to 30). Multiple linear regression assessed the contribution of age, WRAT-R, education, alcohol intake, cigarette use, IBL, and IBL x WRAT-R on MMSE performance. A significant IBL x WRAT-R interaction examined by stratification found a significant dose-effect relationship between IBL and MMSE, but only in the 78 workers with a WRAT-R reading grade level below 6 years. Workers with higher educational achievement compensated for the effect of lead on cognitive performance. (J Occup Environ Med. 2002;44:574-578)