Search PubMed⌕ Search

Biomedical subjects

Jonathan I Levy

Publications and source records attributed to Jonathan I Levy.

At least 19 recordsLinked to original sources
PubMed2007

Determinants of allergen concentrations in apartments of asthmatic children living in public housing.

There is growing evidence linking poor housing conditions and respiratory diseases, including asthma. The association between housing conditions and asthma in the inner city has been attributed in part to cockroach and mouse infestation and the resulting allergen exposures. Multiple social and behavioral factors can influence environmental exposures and health conditions, necessitating a thorough examination of such factors. As part of the Healthy Public Housing Initiative, we evaluated the association between physical and household characteristics and pest-related allergen levels in three public housing developments in Boston, MA. We detected cockroach allergens (Bla g 1 and Bla g 2) in bedroom air, bed, and especially high concentrations in kitchen samples. In multivariate Tobit regressions controlling for development and season, clutter and lack of cleanliness in the apartment were associated with a tenfold increase in Bla g 1 concentration in the air, a sevenfold increase in Bla g 1 and an eightfold increase in Bla g 2 concentrations in the bed, and an 11-fold increase in Bla g 2 in the kitchen (p<0.05 for all). Holes in the wall/ceiling were associated with a six- to 11-fold increase in kitchen cockroach allergen concentrations (p<0.05). Occupancy in an apartment unit of 2 years or more was also associated with increased cockroach allergen concentrations. In contrast, there were low concentrations of mouse urinary protein in this population. In conclusion, these results suggest that interventions in these homes should focus on reducing cockroach allergen concentrations and that building-wide interventions should be supplemented with targeted efforts focused on high-risk units.

Adolescent↗
PubMed2006

Measured concentrations of VOCs in several non-residential microenvironments in the United States.

Individuals spend about 25% of their time in non-residential indoor microenvironments. For some of these microenvironments, particularly stores and restaurants, exposures to volatile organic compounds (VOCs), have not been well characterized. In the Boston Exposure Assessment in Microenvironments (BEAM) study, sampling using scripted activities was conducted in stores, restaurants, and transportation in the summer of 2003 and winters of 2004 and 2005. A suite of VOCs including hydrocarbons, several chlorinated compounds, and aldehydes was analyzed. Nine store types were sampled using a composite design to enable a greater number of stores to be visited. Stores had higher concentrations of formaldehyde, toluene, ethylbenzene, xylenes, and styrene than other microenvironments, particularly in certain store types. Geometric mean formaldehyde levels were highest in the housewares stores, at 53 microg/m3 (95% CI = 43, 66). Geometric mean toluene levels were highest in multipurpose stores, at 76 microg/m3 (95% CI = 50, 118). The levels observed in stores were several times higherthan levels found in transportation microenvironments, and indicate strong indoor sources. In contrast, benzene did not have significantly higher levels in stores than typically found outdoors. Concentrations of formaldehyde and benzene, ethylbenzene, xylenes, and styrene were strongly influenced by the presence of smoking in the dining microenvironment. Chloroform levels were higher in restaurants than in other microenvironments, with a geometric mean of 1.1 microg/m3 (95% CI = 0.7, 1.8). The VOC concentrations found in stores and restaurants in this study are a potentially important source of exposure for sensitive individuals or people who work in these microenvironments.

Air Pollution, Indoor↗
PubMed2006

Predictors of concentrations of nitrogen dioxide, fine particulate matter, and particle constituents inside of lower socioeconomic status urban homes.

Air pollution exposure patterns may contribute to known spatial patterning of asthma morbidity within urban areas. While studies have evaluated the relationship between traffic and outdoor concentrations, few have considered indoor exposure patterns within low socioeconomic status (SES) urban communities. In this study, part of a prospective birth cohort study assessing asthma etiology in urban Boston, we collected indoor and outdoor 3-4 day samples of nitrogen dioxide (NO2) and fine particulate matter (PM2.5) in 43 residences across multiple seasons from 2003 to 2005. Homes were chosen to represent low SES households, including both cohort and non-cohort residences in similar neighborhoods, and consisted almost entirely of multiunit residences. Reflectance analysis and X-ray fluorescence spectroscopy were performed on the particle filters to determine elemental carbon (EC) and trace element concentrations, respectively. Additionally, information on home characteristics (e.g. type, age, stove fuel) and occupant behaviors (e.g. smoking, cooking, cleaning) were collected via a standardized questionnaire. The contributions of outdoor and indoor sources to indoor concentrations were quantified with regression analyses using mass balance principles. For NO2 and most particle constituents (except outdoor-dominated constituents like sulfur and vanadium), the addition of selected indoor source terms improved the model's predictive power. Cooking time, gas stove usage, occupant density, and humidifiers were identified as important contributors to indoor levels of various pollutants. A comparison between cohort and non-cohort participants provided another means to determine the influence of occupant activity patterns on indoor-outdoor ratios. Although the groups had similar housing characteristics and were located in similar neighborhoods, cohort members had significantly higher indoor concentrations of PM2.5 and NO2, associated with indoor activities. We conclude that the effect of indoor sources may be more pronounced in high-density multiunit dwellings, and that future epidemiological studies in these populations should explicitly consider these sources in assigning exposures.

Female↗
PubMed2006

A community-based participatory research study of multifaceted in-home environmental interventions for pediatric asthmatics in public housing.

Pest infestation is a major problem in urban, low-income housing and may contribute to elevated asthma prevalence and exacerbation rates in such communities. However, there is poor understanding of the effectiveness of integrated pest management (IPM) efforts in controlling pediatric asthma, or of the interactions among various interventions and risk factors in these settings. As part of the Boston-based Healthy Public Housing Initiative, we conducted a longitudinal, single-cohort community-based participatory research intervention study. Fifty asthmatic children aged 4-17 from three public housing developments in Boston, Massachusetts, USA successfully completed interventions and detailed environmental, medical, social, and health outcome data collection. Interventions primarily consisted of IPM and related cleaning and educational efforts, but also included limited case management and support from trained community health advocates. In pre-post analyses, we found significant reductions in a 2-week recall respiratory symptom score (from 2.6 to 1.5 on an 8-point scale, p = 0.0002) and in the frequency of wheeze/cough, slowing down or stopping play, and waking at night. Longitudinal analyses of asthma-related quality of life similarly document significant improvements, with a suggestion of some improvements prior to environmental interventions with an increased rate of improvement subsequent to pest management activities. Analyses of potential explanatory factors demonstrated significant between-development differences in symptom improvements and suggested some potential contributions of allergen reductions, increased peak flow meter usage, and improved social support, but not medication changes. In spite of limitations with pre-post comparisons, our results are consistent with aggressive pest management and other allergen reduction efforts having a positive impact on clinical health outcomes associated with asthma. Our findings reinforce the multifactorial nature of urban asthma and suggest a need for further study of the relative contributions of and possible synergies between environmental and social factors in asthma intervention programs.

Adolescent↗
PubMed2006

The air quality impacts of road closures associated with the 2004 Democratic National Convention in Boston.

BACKGROUND: The Democratic National Convention (DNC) in Boston, Massachusetts in 2004 provided an opportunity to evaluate the impacts of a localized and short-term but potentially significant change in traffic patterns on air quality, and to determine the optimal monitoring approach to address events of this nature. It was anticipated that the road closures associated with the DNC would both influence the overall air pollution level and the distribution of concentrations across the city, through shifts in traffic patterns. METHODS: To capture these effects, we placed passive nitrogen dioxide badges at 40 sites around metropolitan Boston before, during, and after the DNC, with the goal of capturing the array of hypothesized impacts. In addition, we continuously measured elemental carbon at three sites, and gathered continuous air pollution data from US EPA fixed-site monitors and traffic count data from the Massachusetts Highway Department. RESULTS: There were significant reductions in traffic volume on the highway with closures north of Boston, with relatively little change along other highways, indicating a more isolated traffic reduction rather than an across-the-board decrease. For our nitrogen dioxide samples, while there was a relatively small change in mean concentrations, there was significant heterogeneity across sites, which corresponded with our a priori classifications of road segments. The median ratio of nitrogen dioxide concentrations during the DNC relative to non-DNC sampling periods was 0.58 at sites with hypothesized traffic reductions, versus 0.88 for sites with no changes hypothesized and 1.15 for sites with hypothesized traffic increases. Continuous monitors measured slightly lower concentrations of elemental carbon and nitrogen dioxide during road closure periods at monitors proximate to closed highway segments, but not for PM2.5 or further from major highways. CONCLUSION: We conclude that there was a small but measurable influence of DNC-related road closures on air quality patterns in the Boston area, and that a low-cost monitoring study combining passive badges for spatial heterogeneity and continuous monitors for temporal heterogeneity can provide useful insight for community air quality assessments.

Air Pollutants↗
PubMed2006

Incorporating concepts of inequality and inequity into health benefits analysis.

BACKGROUND: Although environmental policy decisions are often based in part on both risk assessment information and environmental justice concerns, formalized approaches for addressing inequality or inequity when estimating the health benefits of pollution control have been lacking. Inequality indicators that fulfill basic axioms and agree with relevant definitions and concepts in health benefits analysis and environmental justice analysis can allow for quantitative examination of efficiency-equality tradeoffs in pollution control policies. METHODS: To develop appropriate inequality indicators for health benefits analysis, we provide relevant definitions from the fields of risk assessment and environmental justice and consider the implications. We evaluate axioms proposed in past studies of inequality indicators and develop additional axioms relevant to this context. We survey the literature on previous applications of inequality indicators and evaluate five candidate indicators in reference to our proposed axioms. We present an illustrative pollution control example to determine whether our selected indicators provide interpretable information. RESULTS AND CONCLUSIONS: We conclude that an inequality indicator for health benefits analysis should not decrease when risk is transferred from a low-risk to high-risk person, and that it should decrease when risk is transferred from a high-risk to low-risk person (Pigou-Dalton transfer principle), and that it should be able to have total inequality divided into its constituent parts (subgroup decomposability). We additionally propose that an ideal indicator should avoid value judgments about the relative importance of transfers at different percentiles of the risk distribution, incorporate health risk with evidence about differential susceptibility, include baseline distributions of risk, use appropriate geographic resolution and scope, and consider multiple competing policy alternatives. Given these criteria, we select the Atkinson index as the single indicator most appropriate for health benefits analysis, with other indicators useful for sensitivity analysis. Our illustrative pollution control example demonstrates how these indices can help a policy maker determine control strategies that are dominated from an efficiency and equality standpoint, those that are dominated for some but not all societal viewpoints on inequality averseness, and those that are on the optimal efficiency-equality frontier, allowing for more informed pollution control policies.

Journal Article↗
PubMed2006

Challenges of conducting community-based participatory research in Boston's neighborhoods to reduce disparities in asthma.

Boston is one of the preeminent health care and research centers in the world, but for much of its urban core, these resources are largely out of reach. Community Based Participatory Research (CBPR) provides a model with the potential to bridge the gaps between its research prominence and the health of its residents. We report here two case studies of major research projects that were partnerships between universities in Boston and community based organizations and city agencies. The Healthy Public Housing Initiative (HPHI) and the Asthma Center on Community Environment and Social Stress (ACCESS) are projects that provide numerous lessons about the potential and challenges of conducting CBPR. Ensuring that the projects were true partnerships emerged as key issues in both, especially with respect to funding mechanisms and distribution of resources, although the nature of the challenges differed substantially in the two projects. We note that both academic and community partners may harbor stereotypes about the other and that generalizations about broad populations, academics or community members, may not apply well to everyone. Aligning objectives and expectations emerged as another key lesson. In HPHI, tension between service delivery and research was both a source of conflict and a source of creative development that led to divergent but interesting outcomes. In ACCESS, the tensions revolved more around community capacity building while attempting to build and maintain a large cohort for epidemiological investigations. We conclude that open and frank discussion and a transparent process upfront about project direction, finances, expectations, and other dimensions are necessary but not sufficient to address the inherent challenges in CBPR, and that even so, there are likely to be differences in perspective in such partnerships that require honest negotiation throughout the process of the project.

Asthma↗
PubMed2006

The health benefits of reduced tropospheric ozone in California.

Californians are exposed daily to concentrations of ozone (O3) that are among the highest in the United States. Recently, the state adopted a new 8-hr ambient standard of 0.070 ppm, more stringent than the current federal standard. The new standard is based on controlled human studies and on dozens of epidemiologic studies reporting associations between O3 at current ambient levels and a wide range of adverse health outcomes. Clearly, the new O3 standards will require further reductions in the precursor pollutants and additional expenditures for pollution control. Therefore, it is important to quantify the incremental health benefits of moving from current conditions to the new California standard. In this paper, a standard methodology is applied to quantify the health benefits associated with O3 concentration reductions in California. O3 concentration reductions are estimated using ambient monitoring data and a proportional rollback approach in which changes are specific to each air basin, and control strategies may impact concentrations both below and above the standard. Health impacts are based on published epidemiologic studies, including O3-related mortality and morbidity, and economic values are assigned to these outcomes based on willingness-to-pay and cost-of-illness studies. Central estimates of this research indicate that attaining the California 8-hr standard, relative to current concentrations, would result in annual reductions of 630 cases of premature mortality, 4200 respiratory hospital admissions, 660 pediatric emergency room visits for asthma, 4.7 million days of school loss, and 3.1 million minor restricted activity days, with a median estimated economic value of dollar 4.5 billion. Sensitivity analyses indicate that these findings are robust with respect to exposure assessment methods but are influenced by assumptions about the slope of the concentration-response function in threshold models and the magnitude of the O3-mortality relationship. Although uncertainties exist for several components of the methodology, these results indicate that the benefits of reducing O3 to the California standard may be substantial and that further research on the shape of the O3-mortality concentration-response function and economic value of O3-related mortality would best reduce these uncertainties.

Air Pollution↗
PubMed2006

Does living near a Superfund site contribute to higher polychlorinated biphenyl (PCB) exposure?

We assessed determinants of cord serum polychlorinated biphenyl (PCB) levels among 720 infants born between 1993 and 1998 to mothers living near a PCB-contaminated Superfund site in Massachusetts, measuring the sum of 51 PCB congeners (capital sigmaPCB) and ascertaining maternal address, diet, sociodemographics, and exposure risk factors. Addresses were geocoded to obtain distance to the Superfund site and neighborhood characteristics. We modeled log10(capital sigmaPCB) as a function of potential individual and neighborhood risk factors, mapping model residuals to assess spatial correlates of PCB exposure. Similar analyses were performed for light (mono-tetra) and heavy (penta-deca) PCBs to assess potential differences in exposure pathways as a function of relative volatility. PCB-118 (relatively prevalent in site sediments and cord serum) was assessed separately. The geometric mean of capital sigmaPCB levels was 0.40 (range, 0.068-18.14) ng/g serum. Maternal age and birthplace were the strongest predictors of capital sigmaPCB levels. Maternal consumption of organ meat and local dairy products was associated with higher and smoking and previous lactation with lower capital sigmaPCB levels. Infants born later in the study had lower capital sigmaPCB levels, likely due to temporal declines in exposure and site remediation in 1994-1995. No association was found between capital sigmaPCB levels and residential distance from the Superfund site. Similar results were found with light and heavy PCBs and PCB-118. Previously reported demographic (age) and other (lactation, smoking, diet) correlates of PCB exposure, as well as local factors (consumption of local dairy products and Superfund site dredging) but not residential proximity to the site, were important determinants of cord serum PCB levels in the study community.

Adult↗
PubMed2005

The influence of geographic location on population exposure to emissions from power plants throughout China.

This analysis seeks to evaluate the influence of emission source location on population exposure in China to fine particles and sulfur dioxide. We use the concept of intake fraction, defined as the fraction of material or its precursor released from a source that is eventually inhaled or ingested by a population. We select 29 power-plant sites throughout China and estimate annual average intake fractions at each site, using identical source characteristics to isolate the influence of geographic location. In addition, we develop regression models to interpret the intake fraction values and allow for extrapolation to other sites. To model the concentration increase due to emissions from selected power plants, we used a detailed long-range atmospheric dispersion model, CALPUFF. Primary fine particles have the highest average intake fraction (1 x 0(-5)), followed by sulfur dioxide (5 x 10(-6)), sulfate from sulfur dioxide (4 x 10(-6)), and nitrate from nitrogen oxides (4 x 10(-6)). For all pollutants, the intake fractions span approximately an order of magnitude across sites. In the regression analysis, the independent variables are meteorological proxies (such as climate region and precipitation) and population at various distances from the source. We find that population terms can explain a substantial percentage of variability in the intake fraction for all pollutants (R(2) between 0.86 and 0.95 across pollutants), with a significant modifying influence of meteorological regime. Near-source population is more important for primary coarse particles while population at medium to long distance is more important for primary fine particles and secondary particles. A significant portion of intake fraction (especially for secondary particles and primary fine particles) occurs beyond 500 km of the source, emphasizing the need for detailed long-range dispersion modeling. These findings demonstrate that intake fractions for power plants in China can be estimated with reasonable precision and summarized using simple regression models. The results should be useful for informing future decisions about power-plant locations and controls.

Air Pollutants↗
PubMed2005

Ozone exposure and mortality: an empiric bayes metaregression analysis.

BACKGROUND: Results from time-series epidemiologic studies evaluating the relationship between ambient ozone concentrations and premature mortality vary in their conclusions about the magnitude of this relationship, if any, making it difficult to estimate public health benefits of air pollution control measures. We conducted an empiric Bayes metaregression to estimate the ozone effect on mortality, and to assess whether this effect varies as a function of hypothesized confounders or effect modifiers. METHODS: We gathered 71 time-series studies relating ozone to all-cause mortality, and we selected 48 estimates from 28 studies for the metaregression. Metaregression covariates included the relationship between ozone concentrations and concentrations of other air pollutants, proxies for personal exposure-ambient concentration relationships, and the statistical methods used in the studies. For our metaregression, we applied a hierarchical linear model with known level-1 variances. RESULTS: We estimated a grand mean of a 0.21% increase (95% confidence interval = 0.16-0.26%) in mortality per 10-microg/m increase of 1-hour maximum ozone (0.41% increase per 10 ppb) without controlling for other air pollutants. In the metaregression, air-conditioning prevalence and lag time were the strongest predictors of between-study variability. Air pollution covariates yielded inconsistent findings in regression models, although correlation analyses indicated a potential influence of summertime PM2.5. CONCLUSIONS: These findings, coupled with a greater relative risk of ozone in the summer versus the winter, demonstrate that geographic and seasonal heterogeneity in ozone relative risk should be anticipated, but that the observed relationship between ozone and mortality should be considered for future regulatory impact analyses.

Air Pollutants↗
PubMed2004

Lung function, asthma symptoms, and quality of life for children in public housing in Boston: a case-series analysis.

BACKGROUND: Children in urban public housing are at high risk for asthma, given elevated environmental and social exposures and suboptimal medical care. For a multifactorial disease like asthma, design of intervention studies can be influenced by the relative prevalence of key risk factors. To better understand risk factors for asthma morbidity in the context of an environmental intervention study, we conducted a detailed baseline evaluation of 78 children (aged 4-17 years) from three public housing developments in Boston. METHODS: Asthmatic children and their caregivers were recruited between April 2002 and January 2003. We conducted intake interviews that captured a detailed family and medical history, including questions regarding asthma symptom severity, access to health care, medication usage, and psychological stress. Quality of life was evaluated for both the child and caregiver with an asthma-specific scale. Pulmonary function was measured with a portable spirometer, and allergy testing for common indoor and outdoor allergens was conducted with skin testing using the prick puncture method. Exploratory linear and logistic regression models evaluating predictors of respiratory symptoms, quality of life, and pulmonary function were conducted using SAS. RESULTS: We found high rates of obesity (56%) and allergies to indoor contaminants such as cockroaches (59%) and dust mites (59%). Only 36% of children with persistent asthma reported being prescribed any daily controller medication, and most did not have an asthma action plan or a peak flow meter. One-time lung function measures were poorly correlated with respiratory symptoms or quality of life, which were significantly correlated with each other. In multivariate regression models, household size, body mass index, and environmental tobacco smoke exposure were positively associated with respiratory symptom severity (p < 0.10). Symptom severity was negatively associated with asthma-related quality of life for the child and the caregiver, with caregiver (but not child) quality of life significantly influenced by caregiver stress and whether the child was in the intensive care unit at birth. CONCLUSION: Given the elevated prevalence of multiple risk factors, coordinated improvements in the social environment, the built environment, and in medical management would likely yield the greatest health benefits in this high-risk population.

Adolescent↗
PubMed2003

Estimation of primary and secondary particulate matter intake fractions for power plants in Georgia.

Air pollution benefit-cost analyses depend on dispersion models to predict population exposures to pollutants, but it is difficult to determine the reasonableness of the model estimates. This is in part because validation with field measurements is not feasible for marginal concentration changes and because few models can capture the necessary spatial and temporal domains with adequate sophistication. In this study, we use the concept of an intake fraction (the fraction of a pollutant or its precursor emitted that is eventually inhaled) to provide insight about population exposures and model performance. We apply CALPUFF, a regional-scale dispersion model common in health benefits assessments, to seven power plants in northern Georgia, considering both direct emissions of fine particulate matter (PM2.5) and secondarily formed ammonium sulfate and ammonium nitrate particles over a domain within 500 km of Atlanta. We estimate emission-weighted average intake fractions of 6 x 10(-7) for primary PM2.5, 2 x 10(-7) for ammonium sulfate from SO2, and 6 x 10(-8) for ammonium nitrate from NOx, with no effect of SO2 on ammonium nitrate. To provide insight about model strengths and limitations, we compare our findings with those from a frequently applied source-receptor (S-R) matrix. Using S-R matrix over an identical domain, the corresponding intake fractions are 5 x 10(-7), 2 x 10(-7), 3 x 10(-8), and -2 x 10(-8), respectively, with the values approximately doubling if the domain is expanded to cover the continental United States. Evaluation of model assumptions and comparison of past intake fraction estimates using these two models illustrates the importance of assumptions about the relative concentrations of ammonia, sulfate, and nitrate, which significantly influences ammonium nitrate intake fractions. These findings provide a framework for improved understanding of the factors that influence population exposures to particulate matter.

Air Pollutants↗
PubMed2003

Fuels for urban transit buses: a cost-effectiveness analysis.

Public transit agencies have begun to adopt alternative propulsion technologies to reduce urban transit bus emissions associated with conventional diesel (CD) engines. Among the most popular alternatives are emission controlled diesel buses (ECD), defined here to be buses with continuously regenerating diesel particle filters burning low-sulfur diesel fuel, and buses burning compressed natural gas (CNG). This study uses a series of simplifying assumptions to arrive at first-order estimates for the incremental cost-effectiveness (CE) of ECD and CNG relative to CD. The CE ratio numerator reflects acquisition and operating costs. The denominator reflects health losses (mortality and morbidity) due to primary particulate matter (PM), secondary PM, and ozone exposure, measured as quality adjusted life years (QALYs). We find that CNG provides larger health benefits than does ECD (nine vs six QALYs annually per 1000 buses) but that ECD is more cost-effective than CNG (dollar 270 000 per QALY for ECD vs dollar 1.7 million to dollar 2.4 million for CNG). These estimates are subject to much uncertainty. We identify assumptions that contribute most to this uncertainty and propose potential research directions to refine our estimates.

Air Pollutants↗
PubMed2003

The public health benefits of insulation retrofits in existing housing in the United States.

BACKGROUND: Methodological limitations make it difficult to quantify the public health benefits of energy efficiency programs. To address this issue, we developed a risk-based model to estimate the health benefits associated with marginal energy usage reductions and applied the model to a hypothetical case study of insulation retrofits in single-family homes in the United States. METHODS: We modeled energy savings with a regression model that extrapolated findings from an energy simulation program. Reductions of fine particulate matter (PM2.5) emissions and particle precursors (SO2 and NOx) were quantified using fuel-specific emission factors and marginal electricity analyses. Estimates of population exposure per unit emissions, varying by location and source type, were extrapolated from past dispersion model runs. Concentration-response functions for morbidity and mortality from PM2.5 were derived from the epidemiological literature, and economic values were assigned to health outcomes based on willingness to pay studies. RESULTS: In total, the insulation retrofits would save 800 TBTU (8 x 10(14) British Thermal Units) per year across 46 million homes, resulting in 3,100 fewer tons of PM2.5, 100,000 fewer tons of NOx, and 190,000 fewer tons of SO2 per year. These emission reductions are associated with outcomes including 240 fewer deaths, 6,500 fewer asthma attacks, and 110,000 fewer restricted activity days per year. At a state level, the health benefits per unit energy savings vary by an order of magnitude, illustrating that multiple factors (including population patterns and energy sources) influence health benefit estimates. The health benefits correspond to 1.3 billion dollars per year in externalities averted, compared with 5.9 billion dollars per year in economic savings. CONCLUSION: In spite of significant uncertainties related to the interpretation of PM2.5 health effects and other dimensions of the model, our analysis demonstrates that a risk-based methodology is viable for national-level energy efficiency programs.

Air Pollution, Indoor↗
PubMed2003

Influence of traffic patterns on particulate matter and polycyclic aromatic hydrocarbon concentrations in Roxbury, Massachusetts.

Vehicle emissions have been associated with adverse health effects in multiple epidemiological studies, but the sources or constituents responsible have not been established. Characterization of vehicle-related exposures requires detailed information on spatial and temporal trends of various pollutants and the ability to predict exposures in unmonitored settings. To address these issues, in the summer of 2001 we measured continuously particle-bound polycyclic aromatic hydrocarbons (PAHs), ultrafine particles, and PM(2.5) at a number of sites in Roxbury, a neighborhood of Boston, Massachusetts with significant diesel and gasoline-fueled traffic. We took measurements at the side of the road and at varying distances from the road, with simultaneous collection of traffic counts and meteorological conditions. Across all nine sites, median roadside concentrations were 8 ng/m(3) of particle-bound PAHs (range: 4-57), 16,000 ultrafine particles/cm(3) (range: 11,000-53,000), and 54 microg/m(3) of PM(2.5) as measured with a DustTrak (range: 12-86). Concentrations of all pollutants were lower at greater distances from the road, upwind, and at higher wind speeds, with greater concentration gradients for PAHs and ultrafine particles. In linear mixed effects regression models accounting for temporal autocorrelation, large diesel vehicle counts were significantly associated with roadside concentrations of PAHs (P=0.02), with a moderate association with ultrafine particles and little relation with PM(2.5). Although more comprehensive information would be needed for epidemiological applications, these data demonstrate significant spatial and temporal heterogeneity for traffic-related pollutants during the summer in an urban center, with our monitoring and analytical methodology helping to inform source attribution.

Air Pollutants↗
PubMed2003

Health, wealth, and air pollution: advancing theory and methods.

The effects of both ambient air pollution and socioeconomic position (SEP) on health are well documented. A limited number of recent studies suggest that SEP may itself play a role in the epidemiology of disease and death associated with exposure to air pollution. Together with evidence that poor and working-class communities are often more exposed to air pollution, these studies have stimulated discussion among scientists, policy makers, and the public about the differential distribution of the health impacts from air pollution. Science and public policy would benefit from additional research that integrates the theory and practice from both air pollution and social epidemiologies to gain a better understanding of this issue. In this article we aim to promote such research by introducing readers to methodologic and conceptual approaches in the fields of air pollution and social epidemiology; by proposing theories and hypotheses about how air pollution and socioeconomic factors may interact to influence health, drawing on studies conducted worldwide; by discussing methodologic issues in the design and analysis of studies to determine whether health effects of exposure to ambient air pollution are modified by SEP; and by proposing specific steps that will advance knowledge in this field, fill information gaps, and apply research results to improve public health in collaboration with affected communities.

Air Pollution↗