AWWA PATH56552

Exposure of sewage treatment workers to Legionella pneumophila and enteric pathogens through aerosols at different sewage treatment installations was quantified in this research.The presence of Legionella sp. and L. pneumophila in water and air samples at different sewage installations was determined by cultivation, Direct Fluorescence Assay and PCR. Simultaneously, coliforms, F-RNA phages and spores of sulphite reducing clostridia (SSRC) were enumerated in water and air. For enteric pathogens, the aerosolization efficiency of coliforms, F-RNA phages and SSRC were combined with published data on the concentration of Campylobacter, enteroviruses and Cryptosporidium parvum, respectively, in wastewater to calculate the concentration of these pathogens in the air. The frequency and duration of the presence of sewage workers at or in the different installations was determined by a questionnaire. The concentration of micro-organisms in the air and the data on the presence of workers at these locations were combined into an estimate of the exposure to Legionella and the enteric pathogens. The calculated concentrations in air ranged from very low (<0.001/m up to 0.3-17/m3 at sites with high aerosolization). During cleaning activities, the concentrations rose up to 100/m3. These concentrations were translated into the probability of infection using published dose-response models. The annual probability of infection for sewage workers was high (worker with average exposure 19%, high exposure worker (95-percentile) 100%). Includes 26 references, table, figures.

Product Details

Edition:

Vol. - No.

Published:

09/22/2002

Number of Pages:

10

File Size:

1 file , 160 KB