Health Effects of Sewage Aerosols: Additional Serological Surveys and Search for 'Legionella pneumophila' in Sewage

摘要

Antibody levels to Legionella pneumophila, serogroup 1 and Hepatitis A Virus (HAV) were determined for 433 persons living within a 1.6 km radius of an activated sludge plant. Sera of children 6 to 13 years of age were also tested for antibody to Norwalk Virus. The antibody prevalence rates for L. pneumophila, HAV and Norwalk Virus were 23.2%, 31.55 and 7.1%, respectively. The prevalence of L. pneumophila antibody was higher than expected but not the others. Seroconversions were not observed except for a 4-fold rise in HAV antibody in one pair of sera suggesting new infections did not occur in the 8-month study period by any of these agents. Using an index of exposure for the number of viable organisms generated at the plant to which participants were exposed, the average index for persons with antibody to L. pneumophila, or HAV, was not different from the averages of those without antibody. In addition, there was no association between how close people lived to the plant, or how long they lived in the study area, and being seropositive. These findings augment but still did not prove the previous findings that sewage aerosols emitted from this plant had no overt health effects.