Researchers from the University of Washington School of Public Health and UW Medicine gathered evidence from hundreds of studies characterizing the effect of silver nanoparticle toxicity in the respiratory system. In a new paper published May 24 in Chemical Research in Toxicology, they suggest that existing recommendations on exposure limits may be missing some key factors.
“Current recommendations do not consider genetic or environmental factors,” said Dr. Tyler Nicholas, lead author of the study and a recent doctoral graduate in environmental and occupational health sciences from the UW School of Public Health. “These factors may play a key role in defining sensitive populations and, therefore, have implications for regulatory purposes.”
People with asthma or other chronic respiratory diseases may be more sensitive to silver nanoparticles, according to Dr. Nicholas. Additionally, an individual’s sex could be a relevant genetic factor, given that men and women have different health responses to oxidative stress and allergic inflammation.
The National Institute for Occupational Safety and Health only recently established a draft of recommended exposure limits for silver nanoparticles in occupational settings. “The problem is that regulatory limits are based on in vitro and in vivo studies that used young and healthy animals or cell types that recapitulate the normal phenotype rather than a disease phenotype,” Dr. Nicholas explained. “They’ve also used mice with just a single genetic background.”
Researchers advise regulatory agencies to consider important host genetic and acquired factors that might make a difference in sensitivity to silver nanoparticle toxicity when finalizing the recommendations.Friday Letter Submission, Publish on July 26