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Use of loading rates to establish dioxin criteria for land application of sludge
Author(s) -
Thiel David A.,
Martin Stephen G.,
Goodman Beth B.,
Sullivan John R.
Publication year - 1995
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.5620140822
Subject(s) - wildlife , hectare , bioaccumulation , environmental science , environmental chemistry , toxicology , chemistry , biology , ecology , agriculture
A methodology derived from empirical field and laboratory data on wildlife toxicology, chemical concentrations, and loading rates is developed for defining criteria for protecting wildlife exposed to landspread materials containing 2,3,7,8‐tetrachlorodibenzo‐ p ‐dioxin (TCDD) and TCDD‐like compounds. The method controls mass loading, giving it clear advantages over soil‐concentration‐based criteria in situations where material is spread in a relatively thin layer on the surface and not incorporated into the soil. It also controls dioxin toxic equivalents in the target organism rather than in the landspread material. It achieves a high level of protection for bird embryos by applying a safety factor to a no‐observed‐adverse‐effect level (NOAEL) derived from egg toxicity data and combining this adjusted NOAEL with bioaccumulation data from the most efficient avian accumulator of TCDD on a landspread site. Assuming that bird embryos are among the most sensitive organisms to TCDD in the terrestrial environment, dioxin restrictions adequate to safeguard eggs will protect other wildlife inhabiting landspread sites. Using this methodology, the Wisconsin Department of Natural Resources has derived the following wildlife dioxin criterion for surface spreading (i.e., no incorporation) a paper industry sludge: The sum of the mass of TCDD plus 0.0013 times the mass of 2,3,7,8‐tetrachlorodibenzofuran (TCDF) shall not exceed 1.3 mg per hectare.