When the US Environmental Protection Agency (USEPA) published it's second major risk assessment of dioxin in 2002, the agency did not set a "reference dose," (RfD) for dioxin's developmental, immune, endocrine and reproductive effects. Only cancer was dealt with directly; and that remains controversial. In a sign of further controversy over dioxin, FDA Week , reveals that "The National Academy of Sciences' (NAS) call for EPA to set a non-cancer risk limit for dioxin may rekindle a long-standing dispute between EPA and federal food safety agencies "
We'll let the agencies fight over the numbers. It will take years for the agency disputes to play out, leading to a full employment guarantee for toxicologists and industry lobbyists. Almost nothing they say or write in the interim will make sensible dinner conversation. So, we'd like to mention two important DLC exposure principles.
Vegetarians in general are are exposed to lower levels of dietary DLC's (depending on what sort of vegetarians they are) and typically end up with lower body burdens than meat and diary eaters. Unfortunately, the literature does not support general claims that organically produced meats and dairy products are lower in in DLC content. It helps to understand exposure from these foods if you conssider that dioxin emission sources are ubiquitous. Organic meats and organic animal feeds from various production regions would need to be studied extensively to establish if significantly lower DLC levels exist as a function of geography, husbandry, animal age, etc. Note that we are not asserting here that organic products have uniformly similar levels of DLC's compared to non-organic foods. The differences, if any, could be relatively random. Just needs more study.
For the record, vinyl production and use is not a relatively major source of human dioxin exposure via the food chain. Note that we did not say vinyl should be overlooked: just that it is relatively low in rank among the controllable industrial sources of DLC's. Although incineration of vinyl containing solid waste can be a source of DLC's, coal and wood burning, secondary smelting of aluminum, and other industrial activities are much more important in scale.