This is good news.
The Agency for Toxic Substances and Disease Registry ( a branch of CDC) announced today the elimination of the use of 1,000 ppt " action level" for dioxin. In a letter which can be found on their web site ATSDR delineates how this number has been misused and misconstrued. I would suggest that perhaps no one has misused the " action level" more than mid-Michigan legislators in their attempts to do Dow Chemical's bidding. Under the guise of property rights, these legislators attempted on several occasions to legislate the use of 1,000 ppt instead of the state's more stringent standard of 90 ppt.
In addition ATSDR retained their 50 ppt "screening level" and called for evaluation of exposure pathways other than the ingestion of soils. ATSDR comments can be found at the following link:
Citing in part the rationale from ATSDR:
Michelle Hurd Riddick
Lone Tree Council