Atmospheric concentrations of organophosphate esters in Delhi, India.

The rise of organophosphate esters (OPEs) as ubiquitous global air pollutants is in part associated with their high-production volume, physical and chemical properties, and heavy use in consumer products, including many electronics. The current study investigates the composition and seasonal variability of atmospheric OPEs in Delhi, India. Atmospheric PM2.5 (particulate matter with an aerodynamic diameter ≤ 2.5 microns) samples were collected from April to November 2009 in downtown Delhi. PM2.5 samples were extracted using pressurized liquid extraction and the extracts were analyzed for twelve OPEs, including TPhP, using gas chromatography-mass spectrometry. The sum of atmospheric OPE concentrations ranged from 2.71 to 61.4 ng m^-3 abd were up ~600 times that of concentrations reported in the US. Findings from a study were similar to those reported from e-waste recycling areas in Pakistan, where TPhP was the dominant OPE. This may suggest that e-waste recycling is a major source of atmospheric OPEs in Delhi.