Search

Abstract PM 2.5 particles were collected to study the distribution, accumulation and health risk assessment of metal pollutants. The concentrations of 11 kinds of metal elements in PM 2.5 during heating period and non-heating period were analyzed. Based on the American health risk assessment model as well as the human exposure parameters in China, the human health risk was assessed. The concentrations of metal components in PM 2.5 during the heating period were, in descending order, Pb, Mn, Cr, As, Sb, Se, Ni, Cd, Tl, Hg, and Be, while during the non-heating period, they were basically in the same order, except Cd and Ni, as the concentration of the former was a little higher than that of the latter. The concentrations of As, Cd, Hg, Ni, Se, and Tl were quite different in the heating period and non-heating period. The non-carcinogenic risks caused by metal elements were lower than the minimum acceptance 10−6 per year during both the heating period and non-heating period. The non-carcinogenic results of a descending order were Pb, Mn, Sb, Tl, Se, and Hg. The carcinogenic risks of a descending order were Cr, As, Cd, Ni, and Be. The risks of As and Cr to children were over 10−6. Hence, As and Cr should be considered as priorities. Highlights • The pollution characteristics of 11 kinds of metal pollutants were analyzed. • The concentrations were significant differences between heating period and non-heating period. • Higher non-carcinogenic and carcinogenic risks were shown for children during heating period. • Cr and As had higher carcinogenic risks for people. [ABSTRACT FROM AUTHOR]

PM 2.5 and PM 10 samples were collected from the outdoor environment of five types of cities (provincial central cities, regional central cities, resource-based cities, agricultural cities, and forested cities) situated in Northeast China. Based on bioaccessibility and respiratory deposition fluxes, health risks of PM 2.5 - and PM 10 -bound six heavy metals [HM 6 : Arsenic (As), Chromium (Cr), Cadmium (Cd), Nickel (Ni), Cobalt (Co), and Lead (Pb)] were studied. Cobalt (Co) and Cr were found to be the most abundantly bioaccessible fraction among HM 6 after extraction of simulated lung fluids. After inhalation exposure, among HM 6, Co mainly contributed 88.39–93.19% to the non-carcinogenic risk, while Cr account for 82.92–93.72% of cancer risk. The estimated daily intake of bioaccessible HM 6 in outdoor environment during the heating period was calculated to be 293.11 ± 121.03, 117.08 ± 32.46, 105.57 ± 32.49, 100.35 ± 25.58 and 83.11 ± 17.64 ng/h for provincial central cities, regional central cities, agricultural city, resource-based cities and forested cities, respectively, for local residents. During the heating period of 180 days, non-carcinogenic risks (As, Cr, Cd, Ni, Co) in outdoor environment of 0.5 residence time were below the safety threshold (HQ < 1). Cancer risks for Cr and Co were above 10−5 in the five types of cities, but in the assumable range (< 10−4). Our study highlighted the wide range of measures needed to cut airborne particles pollution to safer levels. [Display omitted] • Bioaccessibility of airborne particles-bound heavy metals in five types of cities were measured. • Cr and Co were found in the most bioaccessible fractions in airborne particles. • Strong relationships between inhalation exposure and characteristics of city. • Higher levels of carcinogenic and non-carcinogenic risk were estimated in provincial central city. [ABSTRACT FROM AUTHOR]