The aim of this study was to investigate health symptoms in sewage treatmen
t workers. A health questionnaire was distributed among 147 sewage treatmen
t workers. Correlating symptoms were clustered using principal component an
alysis and the association with self-reported exposure was assessed by calc
ulating prevalence odds ratios (OR). Endotoxin was measured in two treatmen
t plants. Personal endotoxin exposure was low (< 10 Endoroxin Units/m(3)).
Factor analysis of 29 symptoms resulted in four clusters of highly correlat
ing symptoms: 'flu-like symptoms'; 'higher airway symptoms'; 'lower airway
symptoms'; and 'neurological symptoms'. These clusters were positively asso
ciated with working with sewage, but only significant for 'flu-like symptom
s' (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 'neu
rological 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 wor
kers develop a large variety of work-related symptoms that are not likely c
aused by endotoxin exposure only. Good hygienic practice at the workplace m
ay prevent some of these symptoms.