Seasonal occurrence, concentrations, and occupational exposure to VMSs in different environments of a WWTP

• Type: Article in International Scientific Journal
• Date: 2022

Authors

Nuno Ratola (Author) FEUP; Francisco Sánchez-Soberón (Author) Other

Journal

Title: Environmental Pollution

Vol. 315

Pages: 1-9

ISSN: 0269-7491

Publisher: Elsevier

Indexing

ISI Web of Science

Other information

DOI: 10.1016/j.envpol.2022.120423

Abstract (EN): In the present study, indoor and outdoor environments of a wastewater treatment plant (WWTP) were monitored by passive air samplers to assess the presence and seasonal trends of three linear (L3-L5) and four cyclic (D3-D6) volatile methylsiloxanes (VMSs). Furthermore, passive sampling rates (PSRs) were estimated from literature values to calculate VMSs air concentrations and occupational exposure to potentially toxic (D4-D6) congeners. Results showed a seasonal pattern of VMSs in outdoor locations (especially in the aeration tank and preliminary treatment), being the highest levels of total VMSs reached in Summer and the lowest in Spring, caused by the confluence of changing weather conditions and VMSs consumption patterns. This seasonality was not found in indoor sites. The congener profiles of VMSs were consistent throughout the year, showing a prevalence of D5 outdoors, and of D3 and D4 in strictly indoor environments. Different sources of VMSs, together with an air filtering system installed in the sampled buildings explain these differences. Estimated PSRs yielded lower values indoors (0.16–0.21 m3/day) than outdoors (0.32–0.49 m3/day), due to different wind speeds. Overall, outdoor locations showed higher VMSs concentrations in air than indoors. However, the values detected in both environments (∑VMSs between 8.00 and 2000 ng/m3) were within the ranges described in the literature for these locations. The occupational exposure to D4-D6 estimated for three different activities in the WWTP showed the highest values for Maintenance Technicians (8010 ± 722 ng/(kg·year)) and the lowest for Laboratory Technicians (5410 ± 874 ng/(kg·year)), in direct correlation with the higher amount of time spent outdoors by the former. In any case, the exposure was below the inhalation threshold of 150 μg/(kg·day) proposed as safe by other authors. © 2022 Elsevier Ltd

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 9