A systematic review of environmentally persistent free radical (EPFR) formation, characteristics, and health effects: are there sufficient data for risk assessment?

, and their ability to generate ROS may pose significant concerns for human health. To determine whether there are sufficient data for risk assessment, recent advances were examined in the following important aspects of EPFR research: (1) atmospheric chemistry, (2) human exposures, (3) animal toxicity, and (4) epidemiology. Our review found insufficient epidemiological and exposure studies; however, toxicological data in animals suggested that EPFR inhalation contributes to cardiovascular, respiratory, and metabolic diseases. Although EPFRs are not currently surveyed by a regulatory monitoring system, data indicate their widespread presence in the environment and their potential to initiate/exacerbate diseases.