Environmental Bioaccumulation Potential

Characteristic travel distance Environmental bioaccumulation potential Electron-capture negative ion mass spectrometry Estimation programs interface (EPI) suite European... 

The high Kqa values coupled with relatively high log Kqw values put the SCCPs and MCCPs in the class of chemicals that could bioaccumulate in air-breathers in mammalian terrestrial food webs, i.e., from plants to herbivores to top predators such as humans or wolves [72, 73]. The Environmental Bioaccumulation Potential (EBAP) of selected CPs assuming humans exposed via a marine and agricultural diet is shown in Fig. 9. Most SCCPs can be seen to fall into the category of >60% maximum EBAP. The EBAP values generated by the model vary depending on human dietary habits, the structure of the key food chains, and the properties of the environment in which the chemical is distributed. 

Fig. 9 Assessment of the Environmental Bioaccumulation Potential (EBAP) of selected CPs assuming humans exposed via a marine and agricultural diet based on graphical results presented in Czub and McLachlan [72], The log Kqa values are calculated from log /How and log values in Tables 2 and 3. The hexachlorodecanes discussed in Table 3 are shown separately. The outer (bold) isoline defines EBAP of >10% maximum EBAP and the inner gray area >60% of maximum EBAP...

Harvey J, JJ Dulka, JJ Anderson (1985) Properties of sulfometuroin methyl affecting its environmental fate aqueous hydrolysis and photolysis, mobility and adsorption on soils, and bioaccumulation potential. J Agric Food Chem 33 590-596. 

Fourteen formulations of chemical alternatives were submitted to EPA under confidentiality and they were assessed based on numerous human health and ecotoxicity endpoints in addition to bioaccumulation potential and environmental persistence. They were also screened for potential exposure to workers, users and the aquatic environment. Where data gaps existed, EPA experts used models and chemical analogs to estimate the hazard for a particular endpoint. The literature and test data reviews were published in the final report, Environmentally Preferable Options for Furniture Fire Safety Low Density Furniture Foam . In addition, each hazard endpoint was ranked with a concern level (High, Moderate or Low) based on the criteria used by the EPA s New Chemicals Program to rate the concern level of new chemicals submitted under the Toxic Substance Control Act (TSCA). As seen in Figure 8.2, where the hazard endpoint rankings are bold, the value is based on experimental data. Where the hazard endpoints are presented in italic font, the value is estimated based on models or chemical analogs. In this way, detailed hazard information was summarized and presented in a clear and concise format. 

Ellgehousen, H., J.A. Guth, and H.O. Esser. 1980. Factors determining the bioaccumulation potential of pesticides in the individual compartments of aquatic food chains. Ecotoxicology and Environmental Safety 4 134-157. 

The U.S. Environmental Protection Agency (Lee et al., 1993) designed Bedded Sediment Bioaccumulation tests to estimate the bioaccumulation of sediment-associated contaminants by benthic organisms. The bioaccumulation potential of a chemical in sediment usually is expressed as a Biota-Sediment Accumulation Factor (BSAF). The simplest test determines the BSAF as the ratio of the steady-state chemical concentration in the test organism and the chemical concentration in the sediment. 

Based on high toxicity, persistence, and bioaccumulation potential coupled with high usage and detection in environmental compartments substances whose EQSs appear overly conservative (exceeded at control sites) are targeted for reevaluation... 

Cross-media occurrence inherently toxic persistent bioaccumulation potential presence on the Canadian market likelihood of environmental release detection in the environment at concentrations that may cause harm recent advances in the environmental toxicology of the substance... 

Acetaminophen was found to be inherently biodegradable and has no bioaccumulation potential. No other information about the environmental fate of acetaminophen is currently available. 

The Canadian Environmental Protection Act, 1999 (CEPA 1999) requires the Ministers of the Environment and Health to categorize the substances on the Canadian Domestic Substances List (DSL). The DSL contains 23 000 substances that are subject to categorization (i.e., prioritization). Generally the data selection process involves a search of the scientific literature and databases for quality experimental data for persistence, bioaccumulation potential and inherent toxicity to humans and nonhuman species. If acceptable data are not found, QSARs or other models are used to estimate the persistence, bioaccumulation, and aquatic toxicity of substances based on structure and physical - chemical properties. 

The bioaccumulation potentials of the major components of gasoline range from low to high. Some higher molecular weight components (e.g., naphthalene and substituted naphthalenes) may be taken up by fish and domestic animals and bioconcentrated if they persist in environmental media (Air Force 1989). Alkenes have low log octanol/water partition coefficients (K°w) of about 1 and estimated bioconcentration factors (BCF) of about 10 aromatics have intermediate values (log K° values of 2-3 and BCF values of 20- 200), while O and greater alkanes have fairly high values (log K°w values of about 3-4.5 and BCF values of 100-1,500) (NESCAUM 1989). 

Ecological impact not determined. Similar compounds show low to moderate biodegradability, but rapid hydrolysis under acidic conditions. Similar compounds are also determined to have low bioaccumulation potential and environmental persistence 96 Flour LC50 0.23 mg/L [Rainbow Trout], 0.40 mg/L [Bluegill Sunfish], 0.26 mg/L [Fathead Minnow], 48 Hr EC50 0.44 mg/L [Daphnia Magna],... 

BDE-47 is one of the main PBDE congers found in both environmental samples and human tissue, and is undergoing considerable research. It is biologically persistent, and has a high bioaccumulation potential. It is under investigation as an endocrine disruptor and studies for human health concerns are on going. 

In the search for solutions to chemical risks a hazard-based approach looks upstream for inherently safer chemicals rather than downstream for methods for reducing exposure. The properties of inherently safer chemicals include reduced human and environmental toxicity, reduced physical hazards, such as explodability and corrosivity, and reduced concern for the environmental fate of a chemical (which equals rapid degradation into benign chemicals and low bioaccumulation potential). 

Environmental Fate Persistence and Bioaccumulation. As Table 1 reveals, there is wide variation in setting threshold values for high persistence and high bioaccumulation potential, even within the US EPA. These differences reflect specific organizational goals, interpretations of science, as well as points in time when the values were developed. The threshold values in the Green Screen for persistence and bioaccumulation are set to be highly protective of human health and the environment. 

Compliance environmental monitoring of PCDDs and PCDFs requires the analysis of the 17 2,3,7,8-substituted congeners. Although non-2,3,7,8-substi-tuted congeners are found in the environment, they are not monitored routinely, due to their low bioaccumulation potential and toxicity. However, analysis of non-2,3,7,8-substituted congeners can be useful in tracing the sources and fates of dioxins in the environment. 

Harvey, J., Jr., J.J. Dulka, and J.J. Anderson. Properties of Sulfometuron Methyl Affecting Its Environmental Fate Aqueous Hydrolysis and Photolysis, Mobility and Adsorption on Soils, and Bioaccumulation Potential, J. Agric. Food Chem., 33(4) 590-596 (1985). 

Section 12, Ecological information Environmental effects, ecotoxicity, persistence and degradability, bioaccumulative potential, mobility in soil, and other adverse effects. 

HOCs are chemicals with a wide range of physical and chemical properties. As a result, the various HOCs differ in their toxicity, persistence, or bioaccumulation potential (6). Many of diese compounds are toxic or carcinogenic (3, 7, 8). Many HOCs resist either chemical or biological attack, ixhich contributes to the environmental persistence of diese materials. 

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