The use of nanomaterials in industrial and consumer applications has resulted in a rapid increase in the numbers of workers exposed to engineered nanoparticles. Although no human illness to date is confirmed to be attributed to engineered nanoparticles, occupational epidemiological studies are needed to verify the health effects of nanoparticles. Dr. Wei-Te Wu and Dr. Saou-Hsing Liou from the National Institute of Environmental Health Sciences conducted a repeated measures design to explore the potential adverse health effects of workers handling nanomaterials.
Dr. Wu and team recruited 206 nanomaterial-handling workers and 108 unexposed controls from 14 nanotechnology plants, and followed the study population no less than two times in 4 years. The subjects were given questionnaires to collect potential confounders and detailed work conditions. Control banding was adopted to categorize risk level for each participant as a surrogate marker of exposure. Health hazard markers include cardiopulmonary dysfunction markers, inflammation and oxidative damage markers, antioxidant enzymes activity, and genotoxicity markers. The Generalized Estimating Equation model was applied to analyze repeated measurements.
The team found a significant dose-dependent increase on risk levels for the change of superoxide dismutase (p<0.01) and a significant increase of glutathione peroxidase change in risk level 1 was found for nanomaterial-handling workers. However, the change of cardiovascular dysfunction, lung damages, inflammation, oxidative damages, neurobehavioral and genotoxic markers were not found to be significantly associated with nanomaterials handling.. Industrial hygiene surveys and environmental emission surveys indicated that exposure concentrations of nanoparticles was dramatically reduced due to wet processes and liquid suspensions used in the workplace. Although nanomaterial handling in current low emission scenarios may not have 4-year health impact on the workers, long-term health effects of more than 5 years for nanomaterial used still need research.
Citation:
Wu, WT; Li, LA; Tsou, TC; Wang, SL; Lee, HL; Shih, TS; Liou, SH. Longitudinal follow-up of health effects among workers handling engineered nanomaterials: A panel study. Environmental Health. 2019 Dec 9;18:Article number 107.