I went to the company supervisors and told them people shouldn't work in these situations, with these chemical exposures. I tried to look out for their safety, but those people needed their jobs. Now I think they'll be better off knowing what's going on with their health. Marsha Pierce, an occupational nurse specialist with the local health department, and Rick Letz, a behavioral scientist, survey the site. Study participants were given extensive tests, which analyzed everything from mercury levels to neuropsychological data.
Nobody really knows how to measure a person's mercury level.
On a group level, these measures reflect exposure. But on an individual level, both measures are highly variable and have limited value as biomarkers of exposure. While early findings have suggested that porphyrin profiles are a signature of mercury exposure, this hypothesis has not been confirmed. That's important, because we know that a lot of metals are toxic to porphyrin metabolism. But that's not fully understood in the case of mercury.