Biolog, Biodeg, and Fate/Expos: New Files on Microbial Degradation and Toxicity as Well as Environmental Fate/Exposure of Chemicals

et al. 1999

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362

155

Abstract-A compound's bioconcentration factor (BCF) is the most commonly used indicator of its tendency to accumulate in aquatic organisms from the surrounding medium. Because it is expensive to measure, the BCF is generally estimated from the octanol/water partition coefficient (K ow ), but currently used regression equations were developed from small data sets that do not adequately represent the wide range of chemical substances now subject to review. To develop an improved method, we collected BCF data in a file that contained information on measured BCFs and other key experimental details for 694 chemicals. Log BCF was then regressed against log K ow and chemicals with significant deviations from the line of best fit were analyzed by chemical structure. The resulting algorithm classifies a substance as either nonionic or ionic, the latter group including carboxylic acids, sulfonic acids and their salts, and quaternary N compounds. Log BCF for nonionics is estimated from log K ow and a series of correction factors if applicable; different equations apply for log K ow 1.0 to 7.0 and Ͼ7.0. For ionics, chemicals are categorized by log K ow and a log BCF in the range 0.5 to 1.75 is assigned. Organometallics, nonionics with long alkyl chains, and aromatic azo compounds receive special treatment. The correlation coefficient (r 2 ϭ 0.73) and mean error (0.48) for log BCF (n ϭ 694) indicate that the new method is a significantly better fit to existing data than other methods.

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Improved method for estimating bioconcentration/bioaccumulation factor from octanol/water partition coefficient

Meylan

Howard

et al. 1999

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362

155

“…This database is available in hard copy [16] and on the Internet at http://www.citi.or.jp/data/searchidx.htm. Another large database of biodegradation information is the BIODEG file of the Environmental Fate Data Base [17], which is available at http://esc.syrres.com/efdb.htm. This database comprehensively covers biodegradation information from screening studies (various protocols), biological treatment simulations, grab sample tests, and field studies on over 800 chemicals.…”

Section: Sources Of Data For Modelingmentioning

confidence: 99%

Recent developments in broadly applicable structure‐biodegradability relationships

Jaworska¹,

Howard

2003

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Abstract-Biodegradation is one of the most important processes influencing concentration of a chemical substance after its release to the environment. It is the main process for removal of many chemicals from the environment and therefore is an important factor in risk assessments. This article reviews available methods and models for predicting biodegradability of organic chemicals from structure. The first section of the article briefly discusses current needs for biodegradability estimation methods related to new and existing chemicals and in the context of multimedia exposure models. Following sections include biodegradation test methods and endpoints used in modeling, with special attention given to the Japanese Ministry of International Trade and Industry test; a primer on modeling, describing the various approaches that have been used in the structure/biodegradability relationship work, and contrasting statistical and mechanistic approaches; and recent developments in structure/biodegradability relationships, divided into group contribution, chemometric, and artificial intelligence approaches.

“…We retrieved anaerobic biodegradation data from the BIODEG file of the Environmental Fate Database (EFDB; http://syrres.com/esc/efdb.htm) [21]. The BIODEG file contains extracted data and experimental details, including test methods [22,23]. In the next step, we searched the linked reference file XREF for papers with the word “anaerobic” or “anaerobic digestion” in the title, and these were screened and relevant papers retrieved (i.e., papers with data derived from the serum bottle test method).…”

Section: Methodsmentioning

confidence: 99%

Chemical structure‐based predictive model for methanogenic anaerobic biodegradation potential

Meylan

Aronson

et al. 2007

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Many screening-level models exist for predicting aerobic biodegradation potential from chemical structure, but anaerobic biodegradation generally has been ignored by modelers. We used a fragment contribution approach to develop a model for predicting biodegradation potential under methanogenic anaerobic conditions. The new model has 37 fragments (substructures) and classifies a substance as either fast or slow, relative to the potential to be biodegraded in the "serum bottle" anaerobic biodegradation screening test (Organization for Economic Cooperation and Development Guideline 311). The model correctly classified 90, 77, and 91% of the chemicals in the training set (n = 169) and two independent validation sets (n = 35 and 23), respectively. Accuracy of predictions of fast and slow degradation was equal for training-set chemicals, but fast-degradation predictions were less accurate than slow-degradation predictions for the validation sets. Analysis of the signs of the fragment coefficients for this and the other (aerobic) Biowin models suggests that in the context of simple group contribution models, the majority of positive and negative structural influences on ultimate degradation are the same for aerobic and methanogenic anaerobic biodegradation.