Characterization, Pollution Sources, and Health Risk of Ionic and Elemental Constituents in PM2.5 of Wuhan, Central China

Abstract

Atmospheric PM2.5 samples from Wuhan, China were collected during a winter period of February and a summer period of August in 2018. The average PM2.5 mass concentration in winter reached 112 μg/m3—about two-fold higher than that found in summer. Eight ionic species constituted 1/3 of PM2.5, whereas more than 85% represented secondary ionic aerosols (NO3−, SO42− and NH4+). Higher ratios of NO3−/SO42− (0.95–2.62) occurred in winter and lower ratios (0.11–0.42) occurred in summer showing the different contribution for mobile and stationary sources. Seventeen elemental species constituted about 10% of PM2.5, with over 95% Na, Mg, Al, Ca, Fe, K and Zn. Higher K-concentration occurred in winter indicating greater contribution from biomass and firework-burning. Carcinogenic risks by Cr, As, Cd, Ni and Pb in PM2.5 indicated that about 6.94 children and 46.5 adults among per million may risk getting cancer via inhalation during surrounding winter atmospheric sampling, while about 5.41 children and 36.6 adults have the same risk during summer. Enrichment factors (EFs) and elemental ratios showed that these hazardous elements were mainly from anthropogenic sources like coal and oil combustion, gasoline and diesel vehicles.

Impact of Municipal, Road Traffic, and Natural Sources on PM10: The Hourly Variability at a Rural Site in Poland

“…EF values for these elements changed during the day, with the highest values (higher than the average over the whole measurement period) recorded between 12.00 a.m and 11.00 a.m. This may indicate a strong impact of several anthropogenic sources during this time period, e.g., combustion of fuels by vehicles, abrasion of vehicle elements (wheels, brakes) and road surfaces, the influx of contaminated air masses from urbanized areas, and low-stack emissions [47][48][49][50]. An interesting case is that of V and As.…”

Source Apportionment and Health Risk Assessment of Heavy Metals in PM2.5 in Handan: A Typical Heavily Polluted City in North China

“…In order to determine the risk levels of Cr, Ni, As, Cd, and Pb in PM 2.5 in Handan, the carcinogenic risks of heavy metals were compared to those for other Chinese cities in the case of adults (Table 4). It can be seen that the carcinogenic risks of the five heavy metals were higher than those for Beijing, Tianjin, Nanjing, and Changzhi, but lower than those for Wuhan and Baoding [25,31,55,[60][61][62].…”

“…The normal average daily dose (ADD; µg/m 3 ) is used to represent non-carcinogenic metals such as V, Cr, Mn, Ni, As, and Cd, while the lifetime average daily dose (LADD; µg/m 3 ) is used to represent carcinogenic metals such as Cr, Ni, As, Cd, and Pb [30][31][32].…”

“…Heavy metals in PM 2.5 enter the human body mainly through the respiratory route. Amid the estimated elements in this study, V, Cr, Mn, Ni, As, and Cd are non-carcinogenic, while Cr, Ni, As, Cd, and Pb are carcinogenic [30][31][32].…”

“…In order to determine the risk levels of Cr, Ni, As, Cd, and Pb in PM2.5 in Handan, the carcinogenic risks of heavy metals were compared to those for other Chinese cities in the case of adults (Table 4). It can be seen that the carcinogenic risks of the five heavy metals were higher than those for Beijing, Tianjin, Nanjing, and Changzhi, but lower than those for Wuhan and Baoding [25,31,55,[60][61][62]. In order to determine the risk levels of Cr, Ni, As, Cd, and Pb in PM 2.5 in Handan, the carcinogenic risks of heavy metals were compared to those for other Chinese cities in the case of adults (Table 4).…”