When ATSDR started the investigation it found arsenic, cadmium, chromium and manganese at levels higher than ATSDR’s health-based comparison values (CVs). These chemicals were therefore identified as the site chemicals of concern.
Important Notes: Exposure to a chemical in the environment at a concentration below its CV is not likely to result in a health threat to residents. On the other hand, concentrations above a CV for a chemical do not necessarily represent a heath threat to residents, but they do indicate the need for further investigation and evaluation of levels of that chemical in the environment. At the Marietta site, ATSDR continues its investigation and evaluation of chemicals of concern.
Because CVs are designed to be conservative and are often hundreds or thousands of times lower than levels known to cause health problems, ATSDR reviewed the available scientific exposure studies to evaluate these metals further. We found that arsenic, cadmium, and chromium air concentrations were not detected at levels much different from normal (or background). Because manganese was the only metal that exceeded normal air concentration ranges and exceeded our CVs, manganese became the main chemical of concern and the focus of our investigation.
For more information about the manganese, click on the following linked documents:
- Manganese Fact Sheet [PDF - 99 KB]
- Manganese Toxfaq [PDF - 94 KB]
- Manganese Toxicological Profile [PDF - 6.43 MB]
- Public Health Statement on Manganese [PDF - 90 KB]