Occupational health of drilling waste workers as related to microbial exposure and waste treatment methods.

OBJECTIVES: Exposure to microorganisms is a known contributor to occupational disease. This study assessed drilling waste workers' health status and investigated the potential of inhalable bioaerosols to elicit an immune response in vitro and in vivo. METHODS: Venous blood and self-reported health data were collected from 56 and 73 Norwegian drilling waste workers, respectively. Immunological effects were assessed as Toll-like receptor (TLR) activation potential of personal air samples in vitro and biomarker expression in workers' plasma samples in vivo. Parameters, such as BMI, sex, and smoking habits, were considered along with factors such as purification technology of drilling waste when biomarker expression was interpreted. Symptom prevalence among exposed workers was compared to an unexposed control group. RESULTS: Personal air samples activated TLR signalling in vitro in 90% of all cases. The activation potential correlated significantly with work exposure to microbial agents and total dust. Significant differences in biomarker expression and symptom prevalence were identified between purification technologies and exposure groups. Drilling waste workers had significantly increased OR of skin irritation and respiratory symptoms compared to the control group. CONCLUSIONS: Exposure to microorganisms during the treatment of offshore drilling waste is an occupational health concern.