Bioaerosols and Water Respiratory and Gastrointestinal Viruses in Wastewater Treatment Plants

ÉMIE LACHANCE, Arthur Ouradou, Salim Khaddouma, Marc Veillette, Émilie Bédard, Caroline Duchaine, Université Laval

     Abstract Number: 549
     Working Group: Bioaerosols

Abstract
Several processes within wastewater treatment are sources of bioaerosols, potentially containing various pathogens such as viruses responsible for respiratory and gastrointestinal illnesses. Although the occupational exposure of workers to bioaerosols has been demonstrated repeatedly, the existing link between viruses contained in bioaerosols and in wastewater is not well understood. To better understand the contribution of water, aerosolization process and nature of the potential exposure by these workers, ambient concentrations of specific viruses in the bioaerosols and the treated wastewater were assessed. Fifteen different wastewater treatment plants were visited during summer period. Respiratory and gastrointestinal viruses (rotavirus, adenovirus and rhinovirus) were quantified using qPCR. For each air sample collected, a wastewater sample was also taken to determine source concentrations, verify the existence of a correlation and calculate a spray factor. At present, rhinovirus and rotavirus have either not been detected or have been detected in low levels. These preliminary results can be explained by the generally lower frequency of infections with these viruses during the summer season. However, adenovirus was detected in air samples with a frequency of 32% at an average concentration of 6.99x103 copies/m3, and in wastewater samples with a frequency of 69% at an average concentration of 1.5x107 copies/m3. No correlation could be established between the different concentrations detected in the air and in wastewater, suggesting complex aerosolization processes. These results will later be combined with the ambient concentrations of other pathogens as well as the detection of serum IgG antibodies specific to immunogenic agents to evaluate occupational exposure in wastewater treatment plants. All these findings will be instrumental in establishing new measures aimed at reducing the exposure of wastewater treatment plant workers to bioaerosols.