What concentration of mercury is safe for humans?
Depends on the form of mercury and route of exposure. OSHA (Occupational Safety and Health Administration) and NIOSH (Nat’l Institute of Occupational Safety and Health) have set exposure limits for workplaces for risk of mercury inhalation. The limit that is applicable to Dr. Clack’s lab is 0.05 milligrams/m3 of air for adult humans working an 8-hour day, 40-hour work week. This represents the limit for chronic (i.e. long-term) exposure. EPA has a recommendation for a safe amount of fish consumption per week. One week’s consumption of fish does not change the level of methylmercury in the body much at all. If you eat a lot of fish one week, you can cut back for the next week or two. Just make sure you average the recommended amount per week.
