Work-related symptoms in sewage treatment workers

The aim of this study was to investigate health symptoms in sewage treatment workers. A health questionnaire was distributed among 147 sewage treatment workers. Correlating symptoms were clustered using principal component analysis and the association with self-reported exposure was assessed by calculating prevalence odds ratios (OR). Endotoxin was measured in two treatment plants. Personal endotoxin exposure was low (< 10 Endoroxin Units/m(3)). Factor analysis of 29 symptoms resulted in four clusters of highly correlating symptoms: 'flu-like symptoms'; 'higher airway symptoms'; 'lower airway symptoms'; and 'neurological symptoms'. These clusters were positively associated with working with sewage, but only significant for 'flu-like symptoms' (OR=5.0; 95%CI = 1.4-17.6; p < 0.05) and 'neurological symptoms' (OR = 4.2; 95%CI = 1.5-11.7; p < 0.01). Chemical exposure was associated with 'neurological symptoms' (OR = 8.4; 95CI = 1.1-65.7; p < 0.05). The use of daily washed working clothe!, was negatively associated with 'flu-like symptoms' (OR = 0.3; 95%CI = 0.1-0.6; p < 0.01). In conclusion, sewage treatment workers develop a large variety of work-related symptoms that are not likely caused by endotoxin exposure only. Good hygienic practice at the workplace may prevent some of these symptoms.