Use of QSARs to Promote More Cost-Effective Use of Chemical Monitoring Resources. 1. Screening Industrial Chemicals and Pesticides, Direct Food Additives, Indirect Food Additives and Pharmaceuticals for Biodegradation, Bioconcentration and Aquatic Toxicity Potential

Abstract

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.

Bioaccumulation Factors for PCBs Revisited

“…In absence of environmental measurements of a chemical in biota and water to calculate BAFs, BCFs predicted from KOWs are useful tools for exposure and risk assessments of new chemicals; however, for animals with dietary exposure and uptake of POPs they may be underpredicted. Programs such as Registration, Evaluation and Authorization of CHemicals (REACH) in the European Union (5), the Canadian Environmental Protection Act (CEPA)'s Domestic Substances List (DSL) (6), and the USEPA high production chemicals assessments (7) are screening large numbers of chemicals for bioaccumulation potential using predicted BCFs. Future candidate POPs will likely be chemicals with BCF or BAFs greater than 5000, and field evidence for this will probably be essential to develop a strong case for inclusion on the POPs list.…”

Use of QSARs to Promote More Cost-Effective Use of Chemical Monitoring Resources. 2. Screening Chemicals for Hydrolysis Half-Lives, Henry's Law Constants, Ultimate Biodegradation Potential, Modes of Toxic Action and Bioavailability

“…Hydrolysis half-lives, Henry's Law constants, ultimate biodegradation probabilities in water, bioavailability and modes of toxic action were predicted for 87 chemicals (47 industrial chemicals and pesticides, 20 direct food additives, 13 indirect food additives and 7 pharmaceuticals) that were previously discussed (Walker et al 2004). The names and Chemical Abstract Service (CAS) registry numbers of the chemicals that are not protected by confidential business information and the Simplified Molecular Input Line Entry System (SMILES) notations of all 87 chemicals for which hydrolysis half-lives, Henry's Law constants, ultimate biodegradation probabilities in water, bioavailability and modes of toxic action were predicted are listed in Table 1.…”

“…Previous studies identified 87 chemicals (47 industrial chemicals and pesticides, 20 direct food additives, 13 indirect food additives and 7 pharmaceuticals) that had bioconcentration or aquatic toxicity potential or potential to not biodegrade readily (Walker et al 2004). While these predictions probably account for most persistence, it is possible that some of these chemicals are susceptible to hydrolysis, volatilization or biodegradation to carbon dioxide in the water prior to sediment partitioning.…”

“…QSARs for predicting hydrolysis half-lives, Henry's Law constants, ultimate biodegradation potential, modes of toxic action and bioavailability were used to screen four lists of previously described chemicals (Walker et al 2004). Hydrolysis half-lives, Henry's Law constants and ultimate biodegradation probabilities in water were predicted using the BIOWIN program from the Syracuse Research Corporation EPI Suite of estimation programs (http://www.…”

“…Previous studies identified 47 industrial chemicals and pesticides, 20 direct food additives, 13 indirect food additives and 7 pharmaceuticals that had bioconcentration or aquatic toxicity potential or potential to not biodegrade readily (Walker et al 2004). While 96% of these chemicals were predicted to partition to sediment, it is highly unlikely that they would be discharged directly to sediment, but would be discharged to air and enter the aquatic environment as a result of deposition or would be discharged to water prior to partitioning to sediment.…”