Pollutant measurements at near road and urban background sites in NewYork, USA

Özet

Due to the potential for heightened exposure to vehicle exhaust pollutants, air monitoring has been required atnear roadway (NR) locations within large urban centers in the United States since 2010. In this paper pollutantmeasurements at two urban NR locations, Rochester and New York City, Queens are discussed. Pollutantsmeasured at these sites include PM2.5mass, nitrogen oxides (NO, NO2,NOx), ultrafine particles (UFP), blackcarbon (BC) and carbon monoxide (CO). Measurements at NR sites are made in conjunction with existing urbanbackground (UB) sites. Although pollutant concentrations at Rochester and Queens are elevated at the NR sitescompared to the UB sites particularly during the daytime hours, all pollutants are below the level of the NationalAmbient Air Quality Standards (NAAQS). At Rochester, BC at the NR site is elevated by a factor of 2–3 between 7a.m. and 3 p.m. and drops to near uniform concentrations at both sites at night. The enhancement or incrementin BC is highest in summer and lowest in winter. Other co-pollutants including NOxand CO are also elevated atthe Rochester NR site by varying degrees during daytime hours. Similarly, enhanced pollutant concentrations areobserved at the Queens NR site. At both locations small increments are observed for PM2.5mass. For example, anannual increment of 0.27μg/m3and a daily increment of 0.80μg/m3was observed at the Rochester NR site. AtQueens NR annual PM2.5mass increments of 0.92 and 1.0μg/m3were observed in 2017 and 2018. In addition, aNR daily increment of 1.4μg/m3was observed at Queens in 2018. The data are analyzed for diurnal, weekday vsweekend and seasonal patterns. Nonparametric wind regression identified the roadways as the major source oftraffic related air pollutants.