Substances that accumulate to hazardous levels in living organisms pose environmental and human-health risks, which governments seek reduce or eliminate. Regulatory authorities identify bioaccumulative substances as hydrophobic, fat-soluble chemicals having high octanol-water partition coefficients (K(OW))(>/=100,000). Here we show poorly metabolizable, moderately hydrophobic with a K(OW) between 100 100,000, do not biomagnify (that is, increase chemical concentration increasing trophic...

The present study examines a new bioaccumulation model for hydrophobic organic chemicals in aquatic food webs. purpose of the is to provide site-specific estimates chemical concentrations and associated bioconcentration factors, biota-sediment accumulation factors organisms webs using limited number chemical, organism, data inputs. modification previous incorporates insights regarding mechanism derived from laboratory experiments field studies as well improvements parameterization. elements...

To better understand the bioaccumulation behavior of perfluoroalkyl contaminants (PFCs), we conducted a comparative analysis PFCs and lipophilic organohalogens in Canadian Arctic marine food web. Concentrations perfluorooctane sulfonic acid (PFOS), perfluorooctansulfoamide (PFOSA), C7−C14 perfluorocarboxylic acids (PFCAs) ranged between 0.01 0.1 ng·g−1 dry wt sediments 40 wet biota, which was equivalent to or higher than levels PCBs, PBDEs, organochlorine pesticides. In beluga whales, PFOS...

Recent reviews by researchers from academia, industry, and government have revealed that the criteria used Stockholm Convention on persistent organic pollutants under United Nations Environment Programme are not always able to identify actual bioaccumulative capacity of some substances, use chemical properties such as octanol-water partitioning coefficient. Trophic magnification factors (TMFs) were suggested a more reliable tool for bioaccumulation assessment chemicals been in commerce long...

Scientists from academia, industry, and government reviewed current international regulations for the screening of commercial chemicals bioaccumulation in context state science. On basis this review, several recommendations were proposed, including a scientific definition "bioaccumulative substances," improved criteria characterization bioaccumulative substances (including trophic magnification factor biomagnification factor), novel methods measuring calculating properties, framework...

Abstract Organophosphate esters (OPEs) have emerged as pervasive environmental contaminants, with concentrations often exceeding those of traditional flame retardants and plasticizers by orders magnitude. Here, we present OPEs in the atmospheric gas phase collected using passive air samplers deployed coastal regions Quebec British Columbia southern Canada. Four OPEs, i.e., tri-n-butyl phosphate (TBP), tris(2-chloroethyl) (TCEP), tris(1-chloro-2-propyl) (TCPP), tris (phenyl) (TPhP) were...

While biomagnification of certain organic contaminants in food chains has been observed field studies, the mechanism process is still unresolved. Knowledge by which are absorbed and biomagnified important environmental risk assessment studies chemical bioavailability. In this study, we hypothesize a fugacity based model gastrointestinal absorption contaminants. We test 73 day laboratory, magnification study 2,2',4,4',6,6'-hexachlorobiphenyl adult rainbow trout (Oncorhynchus mykiss) PCB...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhysical-chemical properties of chlorinated dibenzo-p-dioxinsWan Ying. Shiu, William. Doucette, Frank A. P. C. Gobas, Anders. Andren, and Donald. MackayCite this: Environ. Sci. Technol. 1988, 22, 6, 651–658Publication Date (Print):June 1, 1988Publication History Published online1 May 2002Published inissue 1 June 1988https://pubs.acs.org/doi/10.1021/es00171a006https://doi.org/10.1021/es00171a006research-articleACS PublicationsRequest reuse...

Dialkyl phthalate esters (DPEs) are widely used chemicals, with over 4 million tonnes being produced worldwide each year. On the basis of their octanol−water partition coefficients (Kow), which range from 101.61 for dimethyl to 109.46 di-iso-decyl phthalate, certain have potential bioconcentrate and biomagnify in aquatic food webs. However, there no reported field studies on trophodynamics ester This study reports distribution 8 individual (i.e., dimethyl, diethyl, di-iso-butyl, di-n-butyl,...

Abstract Methods for the regulatory assessment of bioaccumulation potential organic chemicals are founded on empirical measurements and mechanistic models dietary absorption biomagnification. This study includes a review current state knowledge regarding mechanisms intestinal biomagnification in organisms aquatic terrestrial food chains also discussion implications these assessing chemicals. Four models, including biomass conversion, digestion or gastrointestinal magnification,...

Abstract This study presents the development of a quantitative‐structure activity relationship (QSAR) for assessing bioaccumulation potential organic chemicals in aquatic food webs. The QSAR is derived by parameterization and calibration mechanistic web model. Calibration based on derivation large database bioconcentration factors, which evaluated data quality. provides estimates higher trophic level fish species can be adapted to include effect metabolic transformation dilution BAF....

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTGastrointestinal magnification: the mechanism of biomagnification and food chain accumulation organic chemicalsFrank A. P. C. Gobas, Xin Zhang, Ralph WellsCite this: Environ. Sci. Technol. 1993, 27, 13, 2855–2863Publication Date (Print):December 1, 1993Publication History Published online1 May 2002Published inissue 1 December 1993https://pubs.acs.org/doi/10.1021/es00049a028https://doi.org/10.1021/es00049a028research-articleACS PublicationsRequest...

Because early life stages of many species exhibit a greater toxicological sensitivity to contaminants than the adult stages, knowledge exposure during embryonic development is crucial prerequisite for risk assessment. This study presents chemical equilibrium model estimating maternal transfer and resulting developing embryos in eggs several classes oviparous organisms hydrophobic organic chemicals. The tested against (i) results field study, including analysis 44 chemicals tissues 6 fish...

Residues of hydroxylated (OH-) and methoxylated (MeO-) polybrominated diphenyl ethers (PBDEs) have been previously detected in precipitation, surface waters, wildlife, humans. We report measured concentrations OH-PBDEs, MeO-PBDEs, Br3−Br7 PBDEs sediments biota from a Canadian Arctic marine food web. exhibited very low trophic magnification factors (TMFs between 0.1−1.6), compared to recalcitrant PCBs 3 11), indicating biotransformation via debromination and/or cytochrome P450 mediated...

Dialkyl phthalate esters (DPEs) are widely used industrial chemicals with octanol−seawater partition coefficients ranging between 101.80 for dimethyl to 1010.0 di-iso-decyl phthalate, indicating a propensity sorb strongly particulate matter in aquatic environments. Sorption plays key role controlling the long-term fate of DPEs systems and exposure organisms food-webs. However, field observations sorption many commercial do not exist. To characterize sorptive nature real-world ecosystem, we...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTModel of organic chemical uptake and clearance by fish from food waterKathryn E. Clark, Frank A. P. C. Gobas, Donald MackayCite this: Environ. Sci. Technol. 1990, 24, 8, 1203–1213Publication Date (Print):August 1, 1990Publication History Published online1 May 2002Published inissue 1 August 1990https://pubs.acs.org/doi/10.1021/es00078a008https://doi.org/10.1021/es00078a008research-articleACS PublicationsRequest reuse permissionsArticle...

Abstract A model is presented describing the kinetics of uptake and release nonmetabolizing organic chemicals by fish from water. The contains three parameters: a bioconcentration factor which specific to chemical (and can be characterized octanol/water partition coefficient lipid content), water-phase resistance term lipid-phase are fish. These parameters estimated uptake-clearance experiments. Part attributed gill ventilation rate as efficiencies part an “internal” resistance. Procedures...