Air toxics exposure from vehicle emissions at a U.S. border crossing: Buffalo Peace Bridge Study.

The Peace Bridge in Buffalo, New York, which spans the Niagara River at the east end of Lake Erie, is one of the busiest U.S. border crossings. The Peace Bridge plaza on the U.S. side is a complex of roads, customs inspection areas, passport control areas, and duty-free shops. On average 5000 heavy-duty diesel trucks and 20,000 passenger cars traverse the border daily, making the plaza area a potential "hot spot" for emissions from mobile sources. In a series of winter and summer field campaigns, we measured air pollutants, including many compounds considered by the U.S. Environmental Protection Agency (EPA*) as mobile-source air toxics (MSATs), at three fixed sampling sites: on the shore of Lake Erie, approximately 500 m upwind (under predominant wind conditions) of the Peace Bridge plaza; immediately downwind of (adjacent to) the plaza; and 500 m farther downwind, into the community of west Buffalo. Pollutants sampled were particulate matter (PM) < or = 10 microm (PM10) and < or = 2.5 microm (PM2.5) in aerodynamic diameter, elemental carbon (EC), 28 elements, 25 volatile organic compounds (VOCs) including 3 carbonyls, 52 polycyclic aromatic hydrocarbons (PAHs), and 29 nitrogenated polycyclic aromatic hydrocarbons (NPAHs). Spatial patterns of counts of ultrafine particles (UFPs, particles < 0.1 microm in aerodynamic diameter) and of particle-bound PAH (pPAH) concentrations were assessed by mobile monitoring in the neighborhood adjacent to the Peace Bridge plaza using portable instruments and Global Positioning System (GPS) tracking. The study was designed to assess differences in upwind and downwind concentrations of MSATs, in areas near the Peace Bridge plaza on the U.S. side of the border. The Buffalo Peace Bridge Study featured good access to monitoring locations proximate to the plaza and in the community, which are downwind with the dominant winds from the direction of Lake Erie and southern Ontario. Samples from the lakeside Great Lakes Center (GLC), which is upwind of the plaza with dominant winds, were used to characterize contaminants in regional air masses. On-site meteorologic measurements and hourly truck and car counts were used to assess the role of traffic on UFP counts and pPAH concentrations. The array of parallel and perpendicular residential streets adjacent to the plaza provided a grid on which to plot the spatial patterns of UFP counts and pPAH concentrations to determine the extent to which traffic emissions from the Peace Bridge plaza might extend into the neighboring community. For lake-wind conditions (southwest to northwest) 12-hour integrated daytime samples showed clear evidence that vehicle-related emissions at the Peace Bridge plaza were responsible for elevated downwind concentrations of PM2.5, EC, and benzene, toluene, ethylbenzene, and xylenes (BTEX), as well as 1,3-butadiene and styrene. The chlorinated VOCs and aldehydes were not differentially higher at the downwind site. Several metals (aluminum, calcium, iron, copper, and antimony) were two times higher at the site adjacent to the plaza as they were at the upwind GLC site on lake-wind sampling days. Other metals (beryllium, sodium, magnesium, potassium, titanium, manganese, cobalt, strontium, tin, cesium, and lanthanum) showed significant increases downwind as well. Sulfur, arsenic, selenium, and a few other elements appeared to be markers for regional transport as their upwind and downwind concentrations were correlated, with ratios near unity. Using positive matrix factorization (PMF), we identified the sources for PAHs at the three fixed sampling sites as regional, diesel, general vehicle, and asphalt volatilization. Diesel exhaust at the Peace Bridge plaza accounted for approximately 30% of the PAHs. The NPAH sources were identified as nitrate (NO3) radical reactions, diesel, and mixed sources. Diesel exhaust at the Peace Bridge plaza accounted for 18% of the NPAHs. Further evidence for the impact of the Peace Bridge plaza on local air quality was found when the differences in 10-minute average UFP counts and pPAH concentrations were calculated between pairs of sites and displayed by wind direction. With winds from approximately 160 degrees through 220 degrees, UFP counts adjacent to the plaza were 10,000 to 20,000 particles/cm3 higher than those upwind of the plaza. A similar pattern was displayed for pPAH concentrations adjacent to the plaza, which were between 10 and 20 ng/m3 higher than those at the upwind GLC site. Regression models showed better correlation with traffic variables for pPAHs than for UFPs. For pPAHs, truck counts and car counts had significant positive correlations, with similar magnitudes for the effects of trucks and cars, despite lower truck counts. Examining all traffic variables, including traffic counts and counts divided by wind speed, the multivariate regression analysis had an adjusted coefficient of determination (R2) of 0.34 for pPAHs, with all terms significant at P < 0.002. Study staff members traversed established routes in the neighborhood while carrying instruments to record continuous UFP and pPAH values. They also carried a GPS, which was used to provide location-specific time-stamped data. Analyses using a geographic information system (GIS) demonstrated that emissions at the Peace Bridge plaza, at times, affected ambient air quality over several blocks (a few hundred meters). Under lake-wind conditions, overall spatial patterns in UFP and pPAH levels were similar for summer and winter and for morning and afternoon sampling sessions. The Buffalo Peace Bridge Study demonstrated that a concentration of motor vehicles resulted in elevated levels of mobile-source-related emissions downwind, to distances of 300 m to 600 m. The study provides a unique data set to assess interrelationships among MSATs and to ascertain the impact of heavy-duty diesel vehicles on air quality.

Local ecological factors, ultrafine particulate concentrations, and asthma prevalence rates in Buffalo, New York, neighborhoods.

Previous to this study various healthcare utilization studies and house-to-house surveys had shown that Buffalo's west side had a high utilization rate for asthma and high asthma prevalence in comparison with neighboring communities. The relative contributions of traffic-related pollution and personal and local ecological factors to the high asthma rates were still unknown. To investigate the potential roles of personal home environmental factors and local ecological factors in variations of asthma prevalence in Buffalo neighborhoods, we conducted a cross-sectional survey of a systematic random sample of 2000 households in the city of Buffalo, New York, with a response rate of 80.4%. We found that the odds of having at least one person with asthma per household on Buffalo's west side was 2.57 times [95% confidence interval (CI)=1.85-3.57] that of Buffalo's east side. There were no statistically significant differences in the odds of finding at least one person with asthma in households of other Buffalo neighborhoods. We further found no difference in the odds of having asthma on Buffalo's west side even after correcting for race/ethnicity, household triggers of asthma, and socioeconomic factors. Monitoring ultrafine particulates showed increased levels in communities downwind of the Peace Bridge Complex and major roadways supplying it. A multiple-regression model showed that asthma prevalence may be influenced by humidity and ultrafine particulate concentrations. These results suggest that increased asthma risk may be influenced by chronic exposure to personal and local ecological factors.

Risk factors for asthma prevalence and chronic respiratory illnesses among residents of different neighbourhoods in Buffalo, New York.

STUDY OBJECTIVE: The aim of this study is to identify risk factors for asthma prevalence and chronic respiratory illnesses in Buffalo's neighbourhoods after previous studies reported increased levels of asthma among residents on Buffalo's west side. DESIGN: Cross sectional surveys. SETTING: Buffalo neighbourhoods along a US-Canada border crossing point. SUBJECTS: A systematic random survey of 82% of the 2000 targeted households was conducted between January and August 2002. MAIN RESULTS: A multivariate logistic regression model shows that the risk of persons with asthma and chronic respiratory illnesses is significantly (p< or =0.05) high among children and young adults living in Buffalo's west side, newer housing units, and of Latino ethnicity. In a separate analysis of the nine risk factors, it was observed that location, gender, age, and race were significant risk factors even after adjusting for age of housing, pets, moulds, animal trigger, and smoking. CONCLUSIONS: These findings confirm the hypothesis that a considerable risk of asthma and chronic respiratory illnesses exists particularly among Buffalo's west side residents. Further evaluation of these risk factors is warranted to determine the severity of asthma and the reasons for such a significant disease burden.

Geographic clustering of adult asthma hospitalization and residential exposure to pollution at a United States-Canada border crossing.

OBJECTIVES: We conducted a case-control study of adulthood asthma and point-source respirable particulate air pollution with asthma-diagnosed case patients (n = 3717) and gastroenteritis-diagnosed control patients (n = 4129) to determine effects of particulate air pollution on public health. METHODS: We used hospitalization data from Buffalo, NY, neighborhoods for a 5-year period (1996 through 2000), geographic information systems techniques, the Diggle method, and statistical analysis to compare the locations of case patients and control patients in terms of proximity to different known pollution sources in the study area. RESULTS: We found a clustering of asthma cases in close proximity to the Peace Bridge Complex and the freeways and a dose-response relationship indicating a decreased risk of asthma prevalence the farther an individual resides from the source of exposure. CONCLUSIONS: These findings provide a basis for the development of new hypotheses relating to the spatial distribution of asthma prevalence and morbidity in this community.

Association between traffic volume and health care use for asthma among residents at a U.S.-Canadian border crossing point.

Little information is available about health impacts of the North American Free Trade Agreement (NAFTA) traffic-related pollution on residents near the major traffic corridors along the U.S.-Canadian border. Here we report on a 10 year (1991-2000) retrospective study of commercial traffic volumes across the Peace Bridge and health care use for asthma in a residential community, which serves as a conduit for traffic crossing between Fort Erie, Ontario, Canada, and Buffalo, New York. We hypothesized that commercial traffic pollution was impacting on residents in close proximity to the trade corridor. Commercial traffic volumes, hospital discharges for asthma, and outpatient visits to area hospitals and clinics were analyzed before and after implementation of NAFTA. Results showed a positive association between increased commercial traffic volume and increased health care use for asthma. Zip codes 14201 and 14213, which surround the Peace Bridge Plaza Complex (PBC), had the highest prevalence rates and health care use rates for asthma. Statistical analysis showed the findings to be significant (p < 0.05) in that residential proximity to the PBC was associated with greater hospital discharge rates for asthma. The findings were strongest (p < 0.000) in the zip codes where the PBC was located (14213) and the major highway I-190 passed through (14201). A yearly excess of 230.2 adult asthma hospital discharges was associated with an increase in traffic volume during the period from 1991 to 1996 in the study area. This is in contrast to an overall decrease in the national rate of hospitalizations for asthma by 7.5% in the same period. The results suggest that NAFTA-related commercial traffic has a negative health impact on asthmatics living in close proximity to the trade corridor. Health and social costs due to traffic pollution need to be included in cost estimates of transport decisions related to the NAFTA corridors. Similar health effects due to NAFTA traffic need to be studied at other U.S.-Canada border crossing points.

Spatial relationships among asthma prevalence, health care utilization, and pollution sources in neighborhoods of Buffalo, New York.

In this retrospective study, the authors investigate the spatial distributions of asthma cases in relation to major traffic corridors and the Peace Bridge Complex in Buffalo, New York, and assess possible contributions of other U.S. Environmental Protection Agency (U.S. EPA)--identified pollution release sources. Multiple data sources, including emergency room visits, outpatient visits, and hospital discharge databases are utilized to evaluate whether an association exists between the addresses of diagnosed asthma cases and release sources. Using a two-factor multilevel model, this study finds a statistically significant association between proximity to source and diagnosed asthma (p < .025). The authors further observe that two-thirds of the asthmatic sufferers resided between 204 and 700 meters from pollution sources and that over 40 percent who utilized health care lived within walking distance of the health care facility they patronized. Using Turnbull's method, the authors detect notable geographic asthma clusters in areas within the city of Buffalo, in North Tonawanda, along major roadways, and in the communities adjoining the Peace Bridge Complex. The authors also find local clusters in Buffalo's west side using Turnbull's method, and a significant global cluster using Besag and Newell's method. One-quarter of the case address locations were within 700 meters of identified clusters. The Score Test methods of Lawson and Waller and of Bithell also find statistically significant associations between three previously identified U.S. EPA focus sites and increased risk of asthma. Correlation of these findings with air quality assessments, especially with respect to traffic-related pollution, however, would be required for a definitive link to be made between an increased risk of asthma and identified pollution sources.

Keratinocyte growth factor and autocrine repair in airway epithelium.

BACKGROUND: Delayed or nonreepithelialization of the large conducting airway (ie, trachea and bronchus) is a clinically recognized but poorly understood result of airway trauma. This delay results in granulation tissue formation and scarring, which impairs mucocilliary transport and can critically compromise gas exchange. Keratinocyte growth factor (KGF) is a known epithelial cell mitogen that is derived from mesenchymal cells. We previously observed its expression in injured tracheal explants, and in the present study we investigated its origin. DESIGN: Freshly isolated porcine tracheal epithelial cells were cytospun onto glass slides for immunohistochemical identification and localization of KGF and for in situ hybridization localization of its messenger RNA. Polymerase chain reaction analysis for KGF was also performed. RESULTS: Freshly isolated respiratory epithelial cells were identified as being of epithelial origin and uncontaminated by fibroblasts, as evidenced by stains that were positive for AE3 and negative for vimentin. Immunohistochemical analysis and in situ hybridization revealed a subset of cells that were positive for both the protein and the message for KGF. CONCLUSION: This subset of KGF-expressing respiratory epithelial cells may participate in a hitherto undescribed autocrine loop for stimulating KGF production in response to injury.

Home environmental factors associated with asthma prevalence in two Buffalo inner-city neighborhoods.

To identify factors that may contribute to asthma morbidity, 214 households were surveyed in two Buffalo inner-city neighborhoods. Asthma was reported by 41 percent of households. Race, gender, and age of head of household were significantly associated with prevalence of asthma in a house. Caucasians and Latinos had a significantly higher rate of asthma compared with African Americans. All household triggers were significantly more likely to be present on the west than east side of Buffalo. Overall, smoking, pets, humidifier, and cockroaches were all significantly associated with asthma in the home. There was no significant difference in the treatment for asthma or the age or gender of asthmatics based on residential area. This study suggests that asthma prevalence in the inner city may be affected by multiple factors that must be taken account by policy makers and professionals designing interventions.

A school-based asthma intervention program in the Buffalo, New York, schools.

This project investigated the feasibility and effectiveness of a school asthma program in reducing asthma exacerbations among school children. In 1997-1998, two schools were selected for a case control pilot study. The intervention required that students with asthma, who needed medication daily at school, must present a written plan from the health care provider. Students with asthma were identified through parent/guardian or school reports. The pilot program was expanded into five schools in 1998-1999. All schools kept records of rescue treatments for asthma episodes. The pilot intervention resulted in an 80% decrease in rescue treatments from 1996-1997 to 1997-1998. In the additional five schools, an overall decrease of 17% occurred in rescue treatments during 1998-2000. Overall, 65% of physicians provided requested Asthma Care Plans (ACP). In two schools, the number of asthma care plans that required anti-inflammatory medications tripled. Preliminary results indicate this school asthma program proved feasible and effective in reducing the frequency of asthma exacerbations at school.