Abstract
To determine the elemental composition and health risk of particles in the roadside microenvironment, particulate matter samples (PM10 and PM2.5) were collected at the side of four roads in winter, spring, and summer of 2015. The total concentrations of crustal elements, trace elements, and the average concentration of most single elements followed the sequence of spring, winter, and summer. Crustal elements accounted for 18.9%, 13.2%, and 9.3% of PM10 and 15.1%, 11.2%, and 18.8% of PM2.5 in the three seasons, respectively. The average concentration of Zn was highest in PM10 and PM2.5 samples, and accounted for 34.0%, 32.2%, and 34.2% of total trace elements in PM10 and accounted for 35.2%, 28.3%, and 35.6% in PM2.5 for winter, spring, and summer, respectively. The enrichment factor results showed that Mn, K, Na, Co, and Si originated from crustal sources; V, Ca, Mg, Mo, Cr, Fe, Ti, and Ba were derived from both anthropogenic and crustal sources; and Cd, Sb, Zn, Cu, Pb, As, and Ni were largely derived from anthropogenic origins. The results of principal component analysis explained 72.64% of the total variance for PM10 and 78.76% of the variance for PM2.5. Possible sources included road dust resuspended, vehicular exhaust, fugitive dust (road dust and soil dust), and tire/brake wear. The respective ratios of Fe/Al, Mn/V, Cu/Sb, Cu/Zn, Zn/Pb, V/Ni, and Cu/Pb in this study were 0.58, 2.87, 11.07, 0.28, 1.23, 1.34, and 4.45 for PM10 and 1.07, 0.83, 23.07, 0.44, 1.83, 1.60, and 4.18 for PM2.5. Accumulative non-cancerous toxic elements in winter and spring may pose risks to roadside workers via inhalation. The integrated cancer risks (CR) of As, Co, Cd, Cr, Ni, and Pb in PM2.5 and PM10 ranged from 1.58E-05 to 4.95E-05 CR.
