Wastewater treatment plants and landfills emit volatile methyl siloxanes (VMSs) to the atmosphere: Investigations using a new passive air sampler

Volatile methyl siloxanes (VMSs) are a class of chemicals with an increasing range of applications and widespread distribution in the environment. Passive air samplers (PAS) comprising sorbent-impregnated polyurethane-foam (SIP) disks were first calibrated and then deployed around two wastewater treatment plants (WWTPs) and at two landfill sites to investigate inputs of VMSs to air. SIP-derived air concentrations for Sigma VMSs (ng/m(3)) at background sites on the perimeter of the WWTP were 479 +/- 82.3 and comparable to results for the upwind samples at the landfills (333 +/- 194). Order of magnitude higher concentrations of Sigma VMSs (ng/m(3)) were found for on-site samples at the WWTPs (3980 +/- 2620) and landfills (4670 +/- 3360). Yearly emissions (kg/yr) to air were estimated and ranged from 60-2100 and 80-250, respectively, for the cyclic VMSs. These findings demonstrate and quantify for the first time, waste sector emissions of VMSs to the atmosphere. Crown Copyright (C) 2011 Published by Elsevier Ltd. All rights reserved.