Integrated disinfection by-products research: assessing reproductive and developmental risks posed by complex disinfection by-product mixtures.
This article presents a toxicologically-based risk assessment strategy for identifying the individual components or fractions of a complex mixture that are associated with its toxicity. The strategy relies on conventional component-based mixtures risk approaches such as dose addition, response addition, and analyses of interactions. Developmental toxicity data from two drinking-water concentrates containing disinfection by-products (DBP) mixtures were used to illustrate the strategy. The results of this study showed that future studies of DBP concentrates using the Chernoff-Kavlock bioassay need to consider evaluating DBP that are concentrated more than 130-fold and using a rat strain that is more sensitive to chemically-induced pregnancy loss than Sprague-Dawley rats. The results support the planned experimental design of a multigeneration reproductive and developmental study of DBP concentrates. Finally, this article discusses the need for a systematic evaluation of DBP concentrates obtained from multiple source waters and treatment types. The development of such a database could be useful in evaluating whether a specific DBP concentrate is sufficiently similar to tested combinations of source waters and treatment alternatives so that health risks for the former may be estimated using data on the latter.
Rice
Glenn
G
U.S. Environmental Protection Agency, Cincinnati, Ohio 45268, USA. rice.glenn@epa.gov
Teuschler
Linda K
LK
Speth
Thomas F
TF
Richardson
Susan D
SD
Miltner
Richard J
RJ
Schenck
Kathleen M
KM
Gennings
Chris
C
Hunter
E Sidney
ES
Narotsky
Michael G
MG
Simmons
Jane Ellen
JE
D000818:Animals; D004202:Disinfectants / Q000633:toxicity*; D005260:Female; D047109:Fetal Development / Q000187:drug effects*; D006801:Humans; D019055:No-Observed-Adverse-Effect Level; D011247:Pregnancy; D018570:Risk Assessment / Q000379:methods; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity*; D018508:Water Purification / Q000379:methods*
D004202:Disinfectants; D014874:Water Pollutants, Chemical