Traffic-related particulate matter and acute respiratory symptoms among New York City area adolescents.

BACKGROUND: Exposure to traffic-related particulate matter (PM) has been associated with adverse respiratory health outcomes in children. Diesel exhaust particles (DEPs) are a local driver of urban fine PM [aerodynamic diameter < or = 2.5 microm (PM(2.5))]; however, evidence linking ambient DEP exposure to acute respiratory symptoms is relatively sparse, and susceptibilities of urban and asthmatic children are inadequately characterized. OBJECTIVES: We examined associations of daily ambient black carbon (BC) concentrations, a DEP indicator, with daily respiratory symptoms among asthmatic and nonasthmatic adolescents in New York City (NYC) and a nearby suburban community. METHODS: BC and PM(2.5) were monitored continuously outside three NYC high schools and one suburban high school for 4-6 weeks, and daily symptom data were obtained from 249 subjects (57 asthmatics, 192 nonasthmatics) using diaries. Associations between pollutants and symptoms were characterized using multilevel generalized linear mixed models, and modification by urban residence and asthma status were examined. RESULTS: Increases in BC were associated with increased wheeze, shortness of breath, and chest tightness. Multiple lags of nitrogen dioxide (NO(2)) exposure were associated with symptoms. For several symptoms, associations with BC and NO(2) were significantly larger in magnitude among urban subjects and asthmatics compared with suburban subjects and nonasthmatics, respectively. PM(2.5) was not consistently associated with increases in symptoms. CONCLUSIONS: Acute exposures to traffic-related pollutants such as DEPs and/or NO(2) may contribute to increased respiratory morbidity among adolescents, and urban residents and asthmatics may be at increased risk. The findings provide support for developing additional strategies to reduce diesel emissions further, especially in populations susceptible because of environment or underlying respiratory disease.

Spatial and Temporal Variations in Traffic-related Particulate Matter at New York City High Schools.

Relatively little is known about exposures to traffic-related particulate matter at schools located in dense urban areas. The purpose of this study was to examine the influences of diesel traffic proximity and intensity on ambient concentrations of fine particulate matter (PM(2.5)) and black carbon (BC), an indicator of diesel exhaust particles, at New York City (NYC) high schools. Outdoor PM(2.5) and BC were monitored continuously for 4-6 weeks at each of 3 NYC schools and 1 suburban school located 20 kilometers upwind of the city. Traffic count data were obtained using an automated traffic counter or video camera. BC concentrations were 2-3 fold higher at urban schools compared with the suburban school, and among the 3 urban schools, BC concentrations were higher at schools located adjacent to highways. PM(2.5) concentrations were significantly higher at urban schools than at the suburban school, but concentrations did not vary significantly among urban schools. Both hourly average counts of trucks and buses and meteorological factors such as wind direction, wind speed, and humidity were significantly associated with hourly average ambient BC and PM(2.5) concentrations in multivariate regression models. An increase of 443 trucks/buses per hour was associated with a 0.62 mug/m(3) increase in hourly average BC at a NYC school located adjacent to a major interstate highway. Car traffic counts were not associated with BC. The results suggest that local diesel vehicle traffic may be important sources of airborne fine particles in dense urban areas and consequently may contribute to local variations in PM(2.5) concentrations. In urban areas with higher levels of diesel traffic, local, neighborhood-scale monitoring of pollutants such as BC, which compared to PM(2.5), is a more specific indicator of diesel exhaust particles, may more accurately represent population exposures.

Pesticide sales in low-income, minority neighborhoods.

The US EPA has phased-out residential use of two organophosphate pesticides commonly used to control cockroaches-retail sales of chlorpyrifos were scheduled to end on 12/31/01, and diazinon on 12/31/02. In light of recent findings highlighting the associations between pests, pesticides and health, we surveyed stores in low-income, minority neighborhoods in New York City to determine whether the phase-outs have been effective and to assess the availability of alternatives to spray pesticides. In summer 2002, when sales of chlorpyrifos were illegal and diazinon still legal, we surveyed 106 stores selling pesticides. Four percent sold products containing chlorpyrifos and 40 percent sold products containing diazinon. One year later, when sales of both pesticides were to have ended, we surveyed 109 stores selling pesticides in the same neighborhoods and found chlorpyrifos in only one store and diazinon in 18 percent of stores, including 80 percent of supermarkets surveyed. At least one form of lower toxicity pesticides, including gels, bait stations and boric acid was available in 69 percent of stores in 2002. However sprays were most widely available, found in 94 percent of stores in 2002 and less expensive than lower toxicity baits and gels. In a separate survey of storekeeper recommendations conducted in 2002, storekeepers recommended lower toxicity pesticides as the best way to control cockroaches 79% of the time. The EPA's phase-outs have nearly eliminated sales of chlorpyrifos, but the diazinon phase-out appears to be less effective.