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 ΣVMSs (ng/m3) 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 ΣVMSs (ng/m3) 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. - Highlights: → A new passive air sampler is calibrated for volatile methyl siloxanes (VMSs). → The SIP disk sampler is used to map VMS levels around WWTPs and landfills. → The waste sector is shown to be a key emission source of VMSs to air. → This is the first study to quantify this emission pathway. - Wastewater treatment plants and landfills are shown to emit large quantities of chemicals used in personal care products (volatile methyl siloxanes) to the atmosphere.