Chakraborty, Paromita and Zhang, Gan and Li, Jun and Sampathkumar, P. and Balasubramanian, Thangavel and Kathiresan, Kandasamy and Takahashi, Shin and Subramanian, Annamalai and Tanabe, Shinsuke and Jones, Kevin C. (2019) Seasonal variation of atmospheric organochlorine pesticides and polybrominated diphenyl ethers in Parangipettai, Tamil Nadu, India : Implication for atmospheric transport. Science of the Total Environment, 649. pp. 1653-1660. ISSN 0048-9697
1_s2.0_S0048969718329024_main.pdf - Accepted Version
Available under License Creative Commons Attribution-NonCommercial-NoDerivs.
Download (2MB)
Abstract
During 1990s, residues of several persistent organic pollutants (POPs) in different environmental matrices have been reported from a tropical coastal site, Parangipettai (PI), located along the bank of the Vellar River in Tamil Nadu. Hence to fill the existing data gap after the strict ban on several POPs, high volume air sampling was conducted in PI to study the variability of atmospheric pesticidal POPs and polybrominated diphenyl ethers (PBDEs) during summer, pre-monsoon and monsoon. Emission source regions were tracked by using five days back trajectory analysis. Derived range of air concentrations in pg/m3 were: DDTs; BDL - 1976; HCHs, 260–1135, HCB; 52–135, chlordanes; 36–135, endosulfans; 66–1013. ∑6PBDE ranged between 25 and 155 with highest concentration in summer followed by pre-monsoon and monsoon. Atmospheric DDT and HCH in PI has drastically reduced by several thousand folds from the past report thereby showing the strict ban on agricultural use of these compounds. During monsoon fresh source of o,p′‑DDT, trans‑chlordane and α‑endosulfan was evident. Usually higher level of endosulphan sulfate in PI seems to be likely affected by the air mass originating from a neighbouring state Kerela, where endosulfan has been extensively used for cashew plantations. Similarly in summer, the day showing the highest level of PBDEs, the sample was concurrently impacted by air parcel comprised of two major clusters, 1 (25%) and 2 (49%) that traversed through the metropolitan cities like Bangalore and Chennai. Dominance of BDE-99 over BDE-47 in Parangipettai is in line with the PBDE profile reported from Chennai city during the similar time frame. Average concentration of tetra and penta BDE congeners in summer samples were nearly 2–3 folds higher than pre-monsoon or monsoon. Given the fact that strong localised source for heavier BDE congeners are lacking in PI, regional atmospheric transport from the strong emission source regions in Chennai.