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Peace Bridge Study - Phase 2 Final Report September 2016

Executive Summary

The NYS Department of Environmental Conservation (NYSDEC) responded to community concerns regarding air quality around the Peace Bridge and undertook a six month air quality study beginning in late August 2012. The study showed that concentrations of fine particulate matter (PM2.5) were below the National Ambient Air Quality Standards (NAAQS) and black carbon (BC), an indicator of diesel exhaust, increased in the afternoon on weekdays. Shortly after the release of the Phase 1 study report, residents in the area and members of the Clean Air Coalition of Western New York voiced concern to NYSDEC that the study should have monitored a full year and included other air contaminants. The NYSDEC held meetings with the community and other stakeholders and designed this Phase 2 study to address those concerns. This follow-up study took place from late summer 2014 until the end of September 2015.

The Phase 2 study included a full year of air monitoring at two locations. A background location within the neighborhood was added and monitoring was expanded to include ultrafine particles (UFP). Close residential proximity to large sources of motor vehicle emissions has been linked to asthma prevalence by researchers including Dr. Lwebuga-Mukasa and others. The community members who were interested in UFP were aware that there are no air quality standards or guidelines for UFP and that these data were being collected to further the scientific understanding of the impact of motor vehicle emissions on public health. The UFP and other study data collected have been provided to the U.S. Environmental Protection Agency's (USEPA) Air Quality System (AQS) database to provide access for scientists working in this field.

Two air monitoring sites were established for this study in urban residential areas. One site was located close to and downwind of the Peace Bridge Complex (PBC) on Busti Avenue and represented higher exposures to vehicle emissions from the PBC. A second monitor was established at Public School 198 (PS198) and far enough away that vehicle emissions from the Peace Bridge and Interstate-190 (I-190) were considered negligible. Meteorological factors including wind speed, wind direction, temperature, relative humidity and barometric pressure were collected at the monitoring site closest to the Peace Bridge. The specific parameters and length of collection time for each monitor are shown in Table 1. Most parameters began in August 2014 and ended September 2015. UFP collection spanned September 2014 to September 2015 at Busti Avenue and June 2015 to September 2015 at PS198. Traffic data were obtained for the Peace Bridge from the Buffalo and Fort Erie Bridge Authority and for I-190 from the New York State Department of Transportation. The Peace Bridge vehicle data included separate data for automobiles and commercial trucks. The vehicle data for I-190 included vehicle count and vehicle length.1

Table 1. Parameters and Monitoring Period by Site
Parameter Busti Ave (days) PS198 (days)
Black Carbon 415 405
Carbonyls 411 not monitored
Meteorological Conditions 415 not monitored
Fine Particulate Matter (PM2.5) 415 400
Ultrafine Particles (UFP) 371 111
Volatile Organic Compounds 411 not monitored

In the analysis portion of this study, the air monitoring results were compared between the two sites and with traffic information to assess impacts of PM2.5 concentrations in the neighborhood from automobiles and trucks on the PB and I-190. Other analysis techniques evaluated community impacts for BC concentrations and UFP counts as indicators of diesel emissions.

The analysis found that PM2.5 concentrations were below the daily and annual NAAQS for both monitoring sites. PM2.5 concentrations were highest for the winter season at both sites and the Busti Avenue monitor seasonal concentrations were nearly 20% higher than PS198. The local contribution of PM2.5 at the Busti Avenue monitor was small and was more pronounced on weekdays. The maximum increase was 2.5 µg/m3 at 10:00 am and remained higher through the late morning and into afternoon which tracks commuting patterns. Although PM2.5 concentrations in this area are primarily from distant upwind sources that impact the area through transport, the local contribution of PM2.5 at the Busti Avenue monitor is probably emissions from motor vehicles.

BC analysis found that the concentration was less than 10% of the concentration of PM2.5. BC concentration at Busti Avenue was 40% higher than corresponding BC at PS198, suggesting diesel emissions are higher near Busti Avenue than PS198. Early morning BC concentrations are low and peak shortly after the morning commute with a similar profile for both the winter and summer commutes. BC concentrations are higher in the summer than the winter and correspond better with Peace Bridge truck traffic volume on the weekdays and to a lesser degree on Sunday. The relationship with automobiles was not readily apparent.

For the period of time (June to September 2015) when both Busti Avenue and PS198 monitors were measuring UFP, the particle counts at Busti Avenue were 40% higher than at PS198. In comparison, for the summer period, Busti Avenue and PS198 measured lower particle counts than other monitors in NYSDEC's network including the Buffalo near-road monitor along I-90 and the Queens, New York City (NYC) monitor near I-495. UFP data exhibit a strong seasonal dependence and at Busti Avenue, the summertime particle counts were about one half of the wintertime particle counts. Both automobiles and trucks contribute to UFP but the data from the Busti Avenue monitor indicated that truck emissions are responsible for a higher proportion of the UFP than automobiles.

Motor vehicles are large contributors of Volatile Organic Compounds (VOCs) in the ambient air. The USEPA has identified specific VOCs as mobile source air toxics (MSATs) and has developed regulations to reduce ambient concentrations.2 The analysis of the 1-year monitoring data included four MSATs: acetaldehyde, 1,3 butadiene, benzene and formaldehyde. All of these air toxics were found to be greater than their respective health-based annual air guideline concentrations (AGCs), however, these four air toxics are consistently found above the AGCs in all locations of the State - even rural State park locations. The findings in this study are not unusual, nor higher than other similarly sized metropolitan areas. Additionally, the results for these four air toxics are within NYSDEC's risk management guidelines.

Four 1-hour air samples were collected by community members and analyzed for VOCs. The results were compared to their respective health-based short-term air guideline concentrations (SGCs) and all were found to be below the guideline concentrations. The results were also compared to the data collected at Busti Avenue and were found to be similar. Staff concluded that the measured results for the air toxics from this short-term assessment would not be considered an immediate public health concern.

Analysis of traffic on both the Peace Bridge and I-190 found that the number of trucks on the Peace Bridge was consistent from season-to-season but there were considerably more automobiles in the summer months. Automobile bridge crossings were higher on the weekend whereas truck crossings on the weekend were much lower than weekdays. Traffic volume on I-190 was five times higher than the traffic volume on the Peace Bridge. The percent of trucks on I-190 was about 10% of the total volume of traffic while trucks on the Peace Bridge were about 23% of the total traffic. Summertime traffic volume on I-190 was higher than other seasons. Traffic volume for automobiles and trucks on I-190 tended to be higher on weekdays than weekends.

The USEPA in recent years has begun studying near-road community exposures with greater intensity. USEPA requires near-road monitoring for nitrogen dioxide, carbon monoxide and PM2.5 in cities with populations over one million. The USEPA also recommends that states collect UFP data at near-road monitoring sites and encourages states to submit these data to the USEPA so it can be used by health researchers. This is important because the USEPA uses data such as these to set air quality standards, approve the locations for air monitors and set motor vehicle emission limits. Data from the NYSDEC and the other monitoring networks across the country are used by the USEPA to further their understanding of the impact of mobile source emissions and the adequacy of national ambient air quality standards. The Phase 2 study results have already increased the USEPA's understanding of the wintertime behavior of UFP in cold climates. The NYSDEC will continue to collect data focused on mobile source emissions at the near-road monitors established in Buffalo, Rochester and in Queens. These results along with the findings from the Phase 2 study will provide health researchers with the information needed to investigate linkages between near-road vehicle emissions and human health outcomes.

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1 The New York State Department of Transportation and other highway agencies use 12 classes to describe vehicle type. For this Study, on I-190, any vehicle longer than 20 feet was considered a truck.
2 United States Environmental Protection Agency (2007). Control of Hazardous Air Pollutants from Mobile Sources: Final Rule. Federal Register 72:37 February 26, 2007.