Real-Time Size Distributions of Air Pollutants From a Wastewater Treatment Plant in the New York State Capital District

While airborne particle emissions from wastewater treatment plants (WWTP) have been identified in studies as a public health concern, few studies have quantitatively assessed particulate matter (PM) emissions. Our study objective was to investigate PM levels as well as bacterial and fungal exposure at a WWTP to understand the time of day and location with the highest potential exposure. We performed real-time monitoring of size-segregated PM using an AEROCET 531 at the aeration tanks (site A), upwind (site B), and downwind (site C) as determined by prevailing winds. Using an Optical Particle Sizer (OPS), we measured PM from 0.3 to 10 µm near site A. Passive surveillance of microbial activity was conducted at all locations. The highest microbial counts were observed near site A, which was consistent with high levels of total suspended particles (TSP) at site A. The mean TSP level at site A was 11.4 µg/m 3 and results suggest large particle distributions were consistent at all locations. The highest concentration of 0.3 µm particles (the smallest particle fraction measured) was 72,180 #/cm 3 , with a mean of 37,605 # /cm 3 . PM data exhibited diurnal patterns across all sampling locations. Elevated PM concentrations were observed on warm days while levels fell on cooler days. High quantities of organic matter within particulates may be concerning given the potential release of bioaerosols within and possibly beyond the WWTP facility. Other studies have identified risks from similar exposures; however, population-based health outcomes were not considered in this study. Highlights. Particulate matter levels and bioaerosols have increased activity at WWTPs Higher temperatures appear to increase both large and small PM Consistent time periods show increased levels High fine particle levels were observed at the source of aeration at the WWTP