Health effects among employees in sewage treatment plants: A literature survey

Background Over the years, there have been regular reports in the media of work-related symptoms among employees at sewage treatment plants. Concern h as spread among employees over the lack of knowledge of risk agents' sympto ms, and diseases in that environment. This paper reviews the investigations of health risks in employees working in the sewage treatment plants. Methods A literature search was performed with the search terms; sewage, wa ste water, health effects, infection, and health hazards. Articles on healt h effects in relation to sewage were selected. Results Work in sewage water plants can involve exposure to different types of microorganisms and chemicals. The bacterial exposure is dominated by ba cteria that naturally occur in nature. However; different bacteria and viru ses that give rise to infections can be present in this environment and thu s there exists a risk of infection, especially of hepatitis A. Investigatio ns suggest that gastrointestinal tract symptoms are more common among emplo yees at sewage treatment plants than among controls. Respiratory symptoms, fatigue, and headache have also been reported in several Investigations. Th e cause of the symptoms is unknown, although certain data suggest that they are caused by inflammation. The results suggest that endotoxin in Gram-neg ative bacteria may be one of the causative agents. As regards cancer, some studies report an increased risk of stomach cancer and a few studies report an increased risk of cancer in the larynx, liver or, prostate or of leukem ia. The spread of the cancers over a multitude of organs does not support a hypothesis of causality with agents commonly found in sewage treatment pla nts. Conclusions Further Investigations are needed to determine the work-related effects and ascertain the causal agents. (C) 2001 Wiley-Liss, Inc.