No abstract

The environmental fate/exposure data base (EFEDB) has been under development with U.S. Environmental Protection Agency support since 1979. It was initiated because of the difficulty of identifying environmental release, fate and exposure information using traditional literature searches. Two new components (BIOLOG and BIODEG), which contain microbial toxicity and biodegradation information, and an update of the overall EFEDB file are described. In addition, a chemical fate/exposure file (FATE/EXPOS) is discussed; it contains production and use data as well as physical‐chemical properties, chemical fate data and monitoring information. EFEDB has been greatly expanded since its initial development, and considerable conversions are planned to make most of the files available through the Chemical Information System (CIS). A major goal of EFEDB was to provide a source of data for constructing structure‐activity correlations and BIODEG is one of the first steps in providing evaluated data for such correlations. FATE/EXPOS provides sorting capabilities for setting priorities in testing or regulation based on easily obtainable information about exposure potential.

No abstract

A comparison of the human health risk to consumers using one of two types of toilet rimblock products, either a p-dichlorobenzene-based rimblock or two newer fragrance/surfactant-based alternatives, was conducted. Rimblock products are designed for global use by consumers worldwide and function by releasing volatile compounds into indoor air with subsequent exposure presumed to be mainly by inhalation of indoor air. Using the THERdbASE exposure model and experimentally determined emission data, indoor air concentrations and daily intake values were determined for both types of rimblock products. Modeled exposure concentrations from a representative p-dichlorobenzene rimblock product are an order of magnitude higher than those from the alternative rimblock products due to its nearly pure composition and high sublimation rate. Lifetime exposure to p-dichlorobenzene or the subset of fragrance components with available RfD values is not expected to lead to non-cancer-based adverse health effects based on the exposure concentrations estimated using the THERdbASE model. A similar comparison of cancer-based effects was not possible as insufficient data were available for the fragrance components.

Monitoring studies are expensive to conduct. To promote more cost-effective use of chemical monitoring resources, quantitative structure activity relationships (QSARs) are proposed as methods to identify chemicals that could be found in, and cause adverse effects to, organisms in water, sediment and soil from the Great Lakes basin. QSARs were used to predict the biodegradation, bioconcentration and aquatic toxicity potential of 2697 industrial chemicals and pesticides, 1146 direct food additives, 967 indirect food additives and 282 pharmaceuticals that could be released to the Great Lakes basin. The QSARs identified 47 industrial chemicals and pesticides, 20 direct food additives, 13 indirect food additives and 7 pharmaceuticals with bioconcentration or aquatic toxicity potential or potential to not biodegrade readily. Most of these chemicals were predicted to partition to sediments. Using QSARs to identify chemicals with potential to persist, bioconcentrate or partition to sediments will promote more cost-effective use of chemical monitoring resources by allowing researchers to focus their analytical techniques on measuring chemicals predicted to persist in water or soil, bioconcentrate in fish or partition to sediments so that the effects of these chemicals can be assessed on indigenous organisms.