Spatial and seasonal variations of organochlorine compounds in air on an urban–rural transect across Tianjin, China

Abstract

a b s t r a c tThe spatial and seasonal variations of atmospheric organochlorine compounds (OCs) concentrations was investigated at six sites on an urban-rural transect in Tianjin, China from July 2006 to June 2008 using XAD-based passive air samplers. The samplers were deployed for six time periods. Hexachlorocyclohexanes (HCHs) air concentrations were highest at Tanggu and Tuanbowa and decreased dramatically further away from these two sites. The maximum proportion of b-HCH compared to RHCHs (12.1-32.2%) was found in Hangu, suggesting its persistence. The a/c-HCH ratio was between 1.26 and 5.79 which signified the combined influence of technical HCHs and lindane. Dichlorodiphenyltrichloroethane related compounds (DDTs) were higher at Hangu compared with other sites which was attributed to its continuing production there. Low p,p 0 -DDE/p,p 0 -DDT in Hangu and Tanggu were found, reflecting the fresh input of DDTs while the relatively high o,p 0 -DDT/p,p 0 -DDT ratios indicated the agricultural application of dicofol. Polychlorinated biphenyls distribution elucidated that the urban area could be their emission source. Hexachlorobenzene, with the highest concentrations in Tanggu, showed the smallest industrial/urbanrural gradient ($4-9 times) than those of other chemicals ($17-49 for RHCHs, $10-77 for RDDTs), but comparable with PCBs (PCB28 and PCB52) ($3-10). Seasonal variations of OCPs were featured by higher concentration in spring and summer and lower in winter. This was likely associated with (i) their temperature-driven re-volatilization and (ii) application of dicofol in late spring and summer and DDTcontaining antifouling paints for fishing ships in summer. However seasonality of PCBs concentrations was site-specific on the Tianjin scale.

Occurrence, phase distribution and depositional intensity of dichlorodiphenyltrichloroethane (DDT) and its metabolites in air and precipitation of the Pearl River Delta, China

“…1) reported by Li et al (2007) and from the major cities (1470 ± 1010 pg m À3 ) of India including New Deli, Kolkata, Mumbai, Chennai, Bangalore, Goa, and Agra (Chakraborty et al, 2010), comparable to those from Guangzhou (300 pg m À3 ) by Yang et al (2008), Tianjin (mean: 330 pg m À3 ) (Zheng et al, 2010), and New Brunswick (mean: 247 pg m À3 ) (Gioia et al, 2005), but higher than those in Camden, Delaware Bay, Jersey City, Pinelands and Sandy Hook in the MidAtlantic region of the United States (140, 41, 33, 33 and 22 pg m À3 , respectively) (Gioia et al, 2005).…”

Does an analysis of polychlorinated biphenyl (PCB) distribution in mountain soils across China reveal a latitudinal fractionation paradox?

“…PCBs were used in China mainly in electric equipment and painting (SEPA, 2003). Similarly to other parts of the world (Motelay-Massei et al, 2005;Yeo et al, 2004;Zhang et al, 2008a), previous assessment of PCBs distribution in soils and other environmental compartments in China evidenced the existence of an urban-rural gradient with highly populated urban and industrial districts representing the areas with highest density of potential primary atmospheric sources (Cui et al, 2013;Ren et al, 2007;Xing et al, 2005;Zheng et al, 2010). In China industrial and major urban clusters closely overlap (Xing et al, 2005).…”

Distribution of organochlorine pesticides in atmospheric air of Tamilnadu, southern India

“…Wind circulation plays a major role in transport and deposition of OCPs around the world. Despite the ban of most OCPs, higher atmospheric levels are still reported in many parts of the world (He and Balasubramanian 2009;Zheng et al 2010). Further, their trace quantification in distant polar environment signifies its long-range transport and bioaccumulation scenario.…”