Doug Brugge

Near-highway pollutants in motor vehicle exhaust: A review of epidemiologic evidence of cardiac and pulmonary health risks

There is growing evidence of a distinct set of freshly-emitted air pollutants downwind from major highways, motorways, and freeways that include elevated levels of ultrafine particulates (UFP), black carbon (BC), oxides of nitrogen (NOx), and carbon monoxide (CO). People living or otherwise spending substantial time within about 200 m of highways are exposed to these pollutants more so than persons living at a greater distance, even compared to living on busy urban streets. Evidence of the health hazards of these pollutants arises from studies that assess proximity to highways, actual exposure to the pollutants, or both. Taken as a whole, the health studies show elevated risk for development of asthma and reduced lung function in children who live near major highways. Studies of particulate matter (PM) that show associations with cardiac and pulmonary mortality also appear to indicate increasing risk as smaller geographic areas are studied, suggesting localized sources that likely include major highways. Although less work has tested the association between lung cancer and highways, the existing studies suggest an association as well. While the evidence is substantial for a link between near-highway exposures and adverse health outcomes, considerable work remains to understand the exact nature and magnitude of the risks.

Exposure Pathways and Health Effects Associated with Chemical and Radiological Toxicity of Natural Uranium: A Review

Natural uranium exposure derives from the mining, milling, and processing of uranium ore, as well as from ingestion of groundwater that is naturally contaminated with uranium. Ingestion and inhalation are the primary routes of entry into the body. Absorption of uranium from the lungs or digestive track is typically low but can vary depending on compound specific solubility. From the blood, two-thirds of the uranium is excreted in urine over the first 24 hours and up to 80% to 90% of uranium deposited in the bone leaves the body within 1.5 years. The primary health outcomes of concern documented with respect to uranium are renal, developmental, reproductive, diminished bone growth, and DNA damage. The reported health effects derive from experimental animal studies and human epidemiology. The Lowest Observed Adverse Effect Level (LOAEL) derived from animal studies is 50 microg/m3 for inhalation and 60 ug/kg body weight/day for ingestion. The current respiratory standard of the Occupational Safety and Health Administration (OSHA), 50 microg/m3, affords no margin of safety. Considering the safety factors for species and individual variation, the ingestion LOAEL corresponds to the daily consumption set by the World Health Organization Drinking Water Standard at 2 microg/L. Based on economic considerations, the United States Environmental Protection Agency maximum contaminant level is 30 microg/L. Further research is needed, with particular attention on the impact of uranium on indigenous populations, on routes of exposure in communities near uranium sites, on the combined exposures present at many uranium sites, on human developmental defects, and on health effects at or below established exposure standards.

The History of Uranium Mining and the Navajo People

From World War II until 1971, the government was the sole purchaser of uranium ore in the United States. Uranium mining occurred mostly in the southwestern United States and drew many Native Americans and others into work in the mines and mills. Despite a long and well-developed understanding, based on the European experience earlier in the century, that uranium mining led to high rates of lung cancer, few protections were provided for US miners before 1962 and their adoption after that time was slow and incomplete. The resulting high rates of illness among miners led in 1990 to passage of the Radiation Exposure Compensation Act.

Health effects of uranium: new research findings.

Abstract Recent plans for a nuclear renaissance in both established and emerging economies have prompted increased interest in uranium mining. With the potential for more uranium mining worldwide and a growth in the literature on the toxicology and epidemiology of uranium and uranium mining, we found it timely to review the current state of knowledge. Here, we present a review of the health effects of uranium mining, with an emphasis on newer findings (2005–2011). Uranium mining can contaminate air, water, and soil. The chemical toxicity of the metal constitutes the primary environmental health hazard, with the radioactivity of uranium a secondary concern. The update of the toxicologic evidence on uranium adds to the established findings regarding nephrotoxicity, genotoxicity, and developmental defects. Additional novel toxicologic findings, including some at the molecular level, are now emerging that raise the biological plausibility of adverse effects on the brain, on reproduction, including estrogenic effects, on gene expression, and on uranium metabolism. Historically, most epidemiology on uranium mining has focused on mine workers and radon exposure. Although that situation is still overwhelmingly true, a smaller emerging literature has begun to form around environmental exposure in residential areas near uranium mining and processing facilities. We present and critique such studies. Clearly, more epidemiologic research is needed to contribute to causal inference. As much damage is irreversible, and possibly cumulative, present efforts must be vigorous to limit environmental uranium contamination and exposure.

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.

Pedestrian road traffic injuries in urban Peruvian children and adolescents: case control analyses of personal and environmental risk factors

Background Child pedestrian road traffic injuries (RTIs) are an important cause of death and disability in poorer nations, however RTI prevention strategies in those countries largely draw upon studies conducted in wealthier countries. This research investigated personal and environmental risk factors for child pedestrian RTIs relevant to an urban, developing world setting. Methods This is a case control study of personal and environmental risk factors for child pedestrian RTIs in San Juan de Miraflores, Lima, Perú. The analysis of personal risk factors included 100 cases of serious pedestrian RTIs and 200 age and gender matched controls. Demographic, socioeconomic, and injury data were collected. The environmental risk factor study evaluated vehicle and pedestrian movement and infrastructure at the sites in which 40 of the above case RTIs occurred and 80 control sites. Findings After adjustment, factors associated with increased risk of child pedestrian RTIs included high vehicle volume (OR 7·88, 95%CI 1·97–31·52), absent lane demarcations (OR 6·59, 95% CI 1·65–26·26), high vehicle speed (OR 5·35, 95%CI 1·55–18·54), high street vendor density (OR 1·25, 95%CI 1·01–1·55), and more children living in the home (OR 1·25, 95%CI 1·00–1·56). Protective factors included more hours/day spent in school (OR 0·52, 95%CI 0·33–0·82) and years of family residence in the same home (OR 0·97, 95%CI 0·95–0·99). Conclusion Reducing traffic volumes and speeds, limiting the number of street vendors on a given stretch of road, and improving lane demarcation should be evaluated as components of child pedestrian RTI interventions in poorer countries.

Native and foreign born as predictors of pediatric asthma in an Asian immigrant population: a cross sectional survey

BackgroundAsthma prevalence is lower in less developed countries and among some recent immigrant populations in the US, but the reasons for this are not clear. One possibility is that early childhood infections are protective against asthma.MethodsWe surveyed Asian immigrant children (n = 204; age 4–18) to assess the relationship between asthma and native or foreign place of birth. We included questions about environmental exposures, demographic variables and family history of asthma to test whether they might explain effects of place of birth on asthma.ResultsThe native and foreign born groups were similar in most respects. Analysis of association with diagnosed asthma for all ages together resulted in two logistic regression models. Both retained born in the US (ORs were 3.2 and 4.3; p < 0.01) and family history of asthma (ORs were 6.4 and 7.2; p < 0.001). One model retained living near heavy motor traffic (OR = 2.6; p = 0.012). The other retained language (OR = 3.2; p = 0.003). However, for older children (11–18 years of age) being born in the US lost some of its predictive power.ConclusionOur findings are consistent with early childhood infections that are prevalent outside the US protecting against asthma.

An hourly regression model for ultrafine particles in a near-highway urban area.

Estimating ultrafine particle number concentrations (PNC) near highways for exposure assessment in chronic health studies requires models capable of capturing PNC spatial and temporal variations over the course of a full year. The objectives of this work were to describe the relationship between near-highway PNC and potential predictors, and to build and validate hourly log-linear regression models. PNC was measured near Interstate 93 (I-93) in Somerville, MA using a mobile monitoring platform driven for 234 h on 43 days between August 2009 and September 2010. Compared to urban background, PNC levels were consistently elevated within 100-200 m of I-93, with gradients impacted by meteorological and traffic conditions. Temporal and spatial variables including wind speed and direction, temperature, highway traffic, and distance to I-93 and major roads contributed significantly to the full regression model. Cross-validated model R(2) values ranged from 0.38 to 0.47, with higher values achieved (0.43 to 0.53) when short-duration PNC spikes were removed. The model predicts highest PNC near major roads and on cold days with low wind speeds. The model allows estimation of hourly ambient PNC at 20-m resolution in a near-highway neighborhood.

Residential Traffic Exposure, Pulse Pressure, and C-reactive Protein: Consistency and Contrast among Exposure Characterization Methods

Background Traffic exposure may increase cardiovascular disease (CVD) risk via systemic inflammation and elevated blood pressure, two important clinical markers for managing disease progression. Objectives We assessed degree and consistency of association between traffic exposure indicators as predictors of C-reactive protein (CRP) and pulse pressure (PP) in an adult U.S. Puerto Rican population (n = 1,017). Methods Cross-sectional information on health and demographics and blood data was collected. Using multiple linear regression, we tested for associations between CRP, PP, and six traffic exposure indicators including residential proximity to roads with > 20,000 vehicles/day and traffic density [vehicle miles traveled per square mile (VMT/mi2)]. Diabetes and obesity [body mass index (BMI) ≥ 30 kg/m2] were tested as effect modifiers. Results CRP was positively associated with traffic density in the total population [36% CRP difference with 95% confidence interval (CI) 2.5–81%] for residence within the highest versus lowest VMT/mi2 level. With BMI ≥ 30, CRP showed significant positive associations with five of six traffic indices including residence ≤ 200 m versus > 200 m of a roadway [22.7% CRP difference (95% CI, 3.15–46.1)] and traffic density in the third highest versus lowest VMT/mi2 level [28.1% difference (95% CI, 1.0–62.6)]. PP was positively associated with residence within ≤ 100 m of a roadway for the total population [2.2 mmHg (95% CI, 0.13–4.3 mmHg)] and persons with BMI ≥ 30 [3.8 mmHg (95% CI, 0.88–6.8)]. Effect estimates approximately doubled for residence within ≤ 200 m of two or more roadways, particularly in persons with diabetes [8.1 mmHg (95% CI, 2.2–14.1)]. Conclusions Traffic exposure at roadway volumes as low as 20,000–40,000 vehicles/day may increase CVD risk through adverse effects on blood pressure and inflammation. Individuals with elevated inflammation profiles, that is, BMI ≥ 30, may be more susceptible to the effects of traffic exposure.

Development of risk maps to minimize uranium exposures in the Navajo Churchrock mining district

BackgroundDecades of improper disposal of uranium-mining wastes on the Navajo Nation has resulted in adverse human and ecological health impacts as well as socio-cultural problems. As the Navajo people become increasingly aware of the contamination problems, there is a need to develop a risk-communication strategy to properly inform tribal members of the extent and severity of the health risks. To be most effective, this strategy needs to blend accepted risk-communication techniques with Navajo perspectives such that the strategy can be used at the community level to inform culturally- and toxicologically-relevant decisions about land and water use as well as mine-waste remediation.ObjectiveThe objective of this study was to develop GIS-based thematic maps as communication tools to clearly identify high risk exposure areas and offer alternatives to minimize public and ecological health impacts.MethodsThematic maps were produced that incorporated data derived from environmental sampling and public health surveys. The maps show the location and quality of unregulated water resources and identify regulated water sources that could be used as alternatives. In addition, the maps show the location of contaminated soil and sediment areas in which disturbance of surface deposits should be avoided. Preliminary feedback was collected from an informal Navajo working group to assess the clarity and efficacy of this proposed communication method.ResultsThe working group found the maps to be both clear and effective, and made suggestions for improvements, such as the addition of more map features. The working group predicted that once the maps are presented to the public, water hauling and soil use behaviors will change, and dialogue with chapter officials will be initiated to accelerate further risk reduction efforts.ImplicationsBecause risk communication is complicated by language barriers, lack of infrastructure, and historical mistrust of non-Navajo researchers, mapping provides an easily interpretable medium that can be objectively viewed by community members and decision makers to evaluate activities that affect toxicant exposures.