Atmospheric polychlorinated biphenyls from an urban site near informal electronic waste recycling area and a suburban site of Chennai city, India.

Recent studies evidenced informal electronic waste (e-waste) recycling as a potential source of polychlorinated biphenyls (PCBs) in the metropolitan environment of India. Given the recent evidences on the release of hazardous organic compounds from the informal e-waste recycling workshops in the Chennai city, we have conducted high volume air sampling in an urban site close to the informal e-waste recycling corridor and in a suburban site located about 35 km away from the urban center. Weekly diurnal gaseous and particulate phase samples were collected from both urban and suburban sites during summer and winter samples were collected only from suburban site. Mean atmospheric PCB levels in the urban site (Avg ± Stdev, 46 ± 16 ng/m3) is several orders of magnitude higher than suburban summer (10 ± 12 ng/m3) and winter (4 ± 3 ng/m3). Back trajectories originating from the land seems to have impacted the samples recorded with maximum PCB concentration. No significant difference was seen between summer and winter atmospheric PCBs in the suburban site. In urban site, PCB-52 and dioxin like PCBs (dl-PCBs) have increased from the past observations with maximum PCB-52 concentration in night time samples. Positive matrix factorization source-receptor model outputs suggest that in the urban centers, open burning in municipal dumpsites is a major source for PCB-52, while dl-PCBs were related to e-waste recycling by the informal sector. Exponential increment in most toxic non-ortho dl-PCBs proclaims the severity of on-going sources which contributed to the high toxic equivalency (TEQs) upto 105 pg TEQ/m3.