Endotoxin exposure and symptoms in wastewater treatment workers

Abstract

Background Wastewater treatment workers can be exposed to biological and chemical agents resulting in work‐related health effects. The aim of this study was to investigate work‐related symptoms in these workers. Methods Questionnaire data of 468 employees from 67 sewage treatment plants is evaluated. Personal endotoxin exposure (8 hr measurements; n = 460) was measured in a sample of workers in three different periods over 1 year. Results Endotoxin exposure ranged from 0.6 to 2093 endotoxin units (EU)/m3, the geometric mean exposure was low (27 EU/m3). Factor analysis yielded three clusters of correlated symptoms: “lower respiratory and skin symptoms,” “flu‐like and systemic symptoms,” and “upper respiratory symptoms.” Symptoms appeared to be more prevalent in workers exposed to endotoxin levels higher than 50 EU/m3. A significant dose‐response relationship was found for “lower respiratory and skin symptoms” and “flu‐like and systemic symptoms” (P < 0.05). Conclusions Wastewater treatment workers reported a wide range of symptoms that may be work‐related. Microbial exposures such as endotoxin seem to play a causal role.