SCIENCE: Atmospheric levels and cytotoxicity of PAHs and heavy metals in TSP and PM2.5 at an electronic waste recycling site in southeast China

Article in Atmospheric Environment 40 (2006) 6945–6955 by W.J. Deng, P.K.K. Louie, W.K. Liu, X.H. Bi, J.M. Fu, M.H. Wong (Croucher Institute for Environmental Sciences and Department of Biology, Hong Kong Baptist University, Kowloon, Hong Kong, China & other institutes).

Abstract

Twenty-nine air samples of total suspended particles (TSP, particles less than 30–60 μm) and thirty samples of particles with aerodynamic diameter smaller than 2.5 μm (PM2.5) were collected at Guiyu, an electronic waste (e-waste) recycling site in southeast China from 16 August 2004 to 17 September 2004. The results showed that mass concentrations contained in TSP and PM2.5 were 124±44.1 and 62.12±20.5 μgm-3, respectively. The total sum of 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs) associated with TSP and PM2.5 ranged from 40.0 to 347 and 22.7 to 263 ngm-3, respectively. Five-ring and six-ring PAHs accounted for 73% of total PAHs. The average concentration of benzo(a) pyrene was 2–6 times higher than in other Asian cities. Concentrations of Cr, Cu and Zn in PM2.5 of Guiyu were 4–33 times higher than in other Asian countries. In general, there were significant correlations between concentrations of individual contaminants in TSP with PM2.5 (i.e. PAHs, Cd, Cr, Cu, Pb, Zn, Mn except Ni and As). The high concentrations of both PAHs and heavy metals in air of Guiyu may impose a serious environmental and health concern. Cytotoxicity of the extract of TSP and PM2.5 of ten 24 h samples collected against human promonocytic leukemia cell line U937 (ATCC 1593.2) was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cytotoxicity assay. The results showed that under the same concentrations of extract, PM2.5 cytotoxicity was 2–4 times higher than TSP.

Extracts

... The uncontrolled combustion of electronic scraps has the potential to produce highly toxic heavy metals and metalloids, such as lead (Pb), cadmium (Cd), chromium (Cr), arsenic (As), as well as polyhalogenated pollutants, including Polycyclic aromatic hydrocarbons (PAHs) (Qiu et al., 2004). Our previous studies have shown the contamination of the terrestrial environment of Guiyu by persistent organic pollutants and heavy metals (Leung et al., 2006; Wang et al., 2005). PAHs are known to be persistent, bio-accumulative, carcinogenic and mutagenic. High levels of PAHs and heavy metals in air will impose serious environmental and biological problems (Park et al., 2002). Increased risks of mortality and morbidity have been associated with elevated levels of total suspended particles (TSP) in ambient air, especially for fine particles with aerodynamic diameter less than 2.5 mm (PM2.5) (Schwartz et al., 1996). ...

... The World Health Organization (WHO World Health Organization, 2000) regards BaP [Benzo(a)pyrene] as an indicator of carcinogenic risk. ...

... Size distribution of PAHs determines the degree of human respiratory system penetration. Small sizes (<>. ...