Epidemiological study of health hazards among workers handling engineered nanomaterials

The aim of this study was to establish and identify the health effect markers of workers with potential exposure to nanoparticles (20–100 nm) during manufacturing and/or application of nanomaterials. For this cross-sectional study, we recruited 227 workers who handled nanomaterials and 137 workers for comparison who did not from 14 plants in Taiwan. A questionnaire was used to collect data on exposure status, demographics, and potential confounders. The health effect markers were measured in the medical laboratory. Control banding from the Nanotool Risk Level Matrix was used to categorize the exposure risk levels of the workers. The results showed that the antioxidant enzyme, superoxide dismutase (SOD) in risk level 1 (RL1) and risk level 2 (RL2) workers was significantly (p RL1 > RL2). Another antioxidant, glutathione peroxidase (GPX), was significantly lower only in RL1 workers than in the control workers. The cardiovascular markers, fibrinogen and ICAM (intercellular adhesion molecule), were significantly higher in RL2 workers than in controls and a significant dose–response with an increasing trend was found for these two cardiovascular markers. Another cardiovascular marker, interleukin-6, was significantly increased among RL1 workers, but not among RL2 workers. The accuracy rate for remembering 7-digits and reciting them backwards was significantly lower in RL2 workers (OR = 0.48) than in controls and a significantly reversed gradient was also found for the correct rate of backward memory (OR = 0.90 for RL1, OR = 0.48 for RL2, p < 0.05 in test for trend). Depression of antioxidant enzymes and increased expression of cardiovascular markers were found among workers handling nanomaterials. Antioxidant enzymes, such as SOD and GPX, and cardiovascular markers, such as fibrinogen, ICAM, and interluekin-6, are possible biomarkers for medical surveillance of workers handling engineered nanomaterials.