Biological monitoring of workers exposed to engineered nanomaterials

•A growing number of workers are exposed to engineered nanomaterials.•Exposure to some engineered nanomaterials may cause health effects in workers.•There is a rich literature on biomarkers of exposure and effect from exposure to engineered nanomaterials.•Biomonitoring of workers may ultimately be of utility as tool for exposure assessment and risk management.•Further research is needed to validate biomarkers for biomonitoring nanomaterial workers. As the number of nanomaterial workers increase there is need to consider whether biomonitoring of exposure should be used as a routine risk management tool. Currently, no biomonitoring of nanomaterials is mandated by authoritative or regulatory agencies. However, there is a growing knowledge base to support such biomonitoring, but further research is needed as are investigations of priorities for biomonitoring. That research should be focused on validation of biomarkers of exposure and effect. Some biomarkers of effect are generally nonspecific. These biomarkers need further interpretation before they should be used. Overall biomonitoring of nanomaterial workers may be important to supplement risk assessment and risk management efforts.