TAILIEUCHUNG - A Generic QSAR for Assessing the Bioaccumulation Potential of Organic Chemicals in Aquatic Food Webs

This is a frightening development. There are traces within you – or, depending on your circumstances and exposures, more than traces – of several hundred man-made chemicals. Many are harmless (or at least are so far thought to be). Others, however, may cause cancer and damage the nervous systems, reproductive systems, immune systems, or livers of animals. Mounting scientific evidence is confirming long-term suspicions that they do the same to human beings. | A Generic QSAR for Assessing the Bioaccumulation Potential of Organic Chemicals in Aquatic Food Webs A Generic QSAR for Assessing the Bioaccumulation Potential of Organic Chemicals in Aquatic Food Webs Jon A. Arnot and Frank A. p. c. Gobas The School of Resource and Environmental Management Simon Fraser University 8888 University Drive Burnaby British Columbia Canada V5A 1S6 Abstract This study presents the development of a quantitative-structure activity relationship QSAR for assessing the bioaccumulation potential of organic chemicals in aquatic food webs. The QSAR is derived by parameterization and calibration of a mechanistic food web bioaccumulation model. Calibration of the QSAR is based on the derivation of a large database of bioconcentration and bioaccumulation factors which is evaluated for data quality. The QSAR provides estimates of the bioaccumulation potential of organic chemicals in higher trophic level fish species of aquatic food webs. The QSAR can be adapted to include the effect of metabolic transformation and trophic dilution on the BAF. The BAF-QSAR can be applied to categorize organic chemical substances on their bioaccumulation potential. It identifies chemicals with a log KOW between and to exhibit BAFs greater than 5000 in the absence of significant metabolic transformation rates. The BAF-QSAR can also be used in the derivation of water quality guidelines and total maximum daily loadings by relating internal concentrations of organic chemicals in upper trophic fish species to corresponding concentrations in the water. 1 Introduction In recent years several countries and international organizations have worked towards the development of methods and criteria for assessing the impacts of anthropogenic chemicals on both ecosystem and human health 1-5 . A general approach of these methods is to determine the potential of substances to be persistent P bioaccumulative B and toxic T in the environment. The difficulties of these initiatives

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