Organochlorines (OCs) such as polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were analysed in plastic pellets collected from four beaches of Mumbai coast bimonthly from May 2011 to March 2012. A total of 72 pools of pellets were extracted and analysed by gas chromatograph equipped with a Ni63 electron capture detector (ECD). The median concentrations of seven ΣPCBs and 16 ΣOCPs were 37.08 and 104.90 ng g−1 (n = 72), respectively. PCB-28 was recorded at the highest concentration with a mean of 17.58 ± 2.77 ng g−1 among the seven PCBs studied, followed by PCB-52 and PCB-101. Bimonthly variation was significant for ΣPCBs. The ΣPCB concentration in November was at par with that of September and was significantly higher than those of the other months (p < 0.05) with an increasing trend during the monsoon period. Among the OCPs, γ-HCH recorded the highest concentration with a mean of 33.88 ± 5.97 ng g−1 followed by heptachlor and α-HCH. The ΣOCPs and ΣHCHs are not significantly varied among the months and sites. However, significant variation was observed for ΣDDTs among the months and sites (p < 0.05). The significantly higher concentration of ΣDDT (46.55 ± 12.23 ng g−1) was found in January than in the other months while it was intermediate in November. The study confirmed that plastic pellets are a trap for various cyclodine compounds in addition to PCB, HCH and DDT. Further, pellets can be used to study the temporal variability for a range of organic micropollutants.
H. B. Jayasiri, C. S. Purushothaman, A. Vennila, Environmental Monitoring and Assessment June 2015, 187:469