Literature-derived absorption coefficients for 39 chemicals via oral and inhalation routes of exposure

Owen, B.A.

doi:10.1016/0273-2300(90)90024-6

Cited by 34 publications

(20 citation statements)

References 47 publications

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“…The food digestibility of 99.3%, required to achieve a magnification of 146, appears unlikely. For substances, however, assimilation efficiencies of 98 and 100% have been reported in dietary and oral studies, respectively [42,43]. It suggests that organic microcontaminants can be preferentially as‐similated in birds and mammals at efficiencies higher than those for food and lipids.…”

Section: Resultsmentioning

confidence: 99%

The power of size. 1. Rate constants and equilibrium ratios for accumulation of organic substances related to octanol‐water partition ratio and species weight

Hendriks

Linde

Cornelissen

et al. 2001

Enviro Toxic and Chemistry

216

339

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Most of the thousands of substances and species that risk assessment has to deal with are not investigated empirically because of financial, practical, and ethical constraints. To facilitate extrapolation, we have developed a model for accumulation kinetics of organic substances as a function of the octanol-water partition ratio (Kow) of the chemical and the weight, lipid content, and trophic level of the species. The ecological parameters were obtained from a previous review on allometric regressions. The chemical parameters, that is, resistances that substances encounter in water and lipid layers of organisms, were calibrated on 1,939 rate constants for absorption from water for assimilation from food and for elimination. Their ratio was validated on 37 laboratory bioconcentration and biomagnification regressions and on 2,700 field bioaccumulation data. The rate constant for absorption increased with the hydrophobicity of the substances with a Kow up to about 1,000 and then leveled off, decreasing with the weight of the species. About 39% of the variation was explained by the model, while deviations of more than a factor of 5 were noted for labile, large, and less hydrophobic molecules as well as for algae, mollusks, and arthropods. The efficiency for assimilation of contaminants from food was determined mainly by the food digestibility and thus by the trophic level of the species. A distinction was made between substances that are stable, that is, with a minimum elimination only, and those that are labile, that is, with an excess elimination probably largely due to biotransformation. The rate constant for minimum elimination decreased with the hydrophobicity of the substance and the weight of the species. About 70% of the variation was explained by the model, while deviations of more than a factor of 5 were noted for algae, terrestrial plants, and benthic animals. Labile substances were eliminated faster than isolipophilic stable compounds, but differences in laboratory elimination and accumulation were small compared with those in field accumulation. Excess elimination by vertebrates was faster than by invertebrates. Differences between terrestrial and aquatic species were attributed to water turnover rates, whereas differences between trophic levels were due to the food digestibility. Food web accumulation, expressed as organism-organic solids and organism-food concentrations ratios could be largely explained by ecological variables only. The model is believed to facilitate various types of scientific interpretation as well as environmental risk assessment.

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Section: Resultsmentioning

confidence: 99%

The power of size. 1. Rate constants and equilibrium ratios for accumulation of organic substances related to octanol‐water partition ratio and species weight

Hendriks

Linde

Cornelissen

et al. 2001

Enviro Toxic and Chemistry

216

339

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“…Owen (1990) estimated a mean absorption value of 0.1, while ICRP (1973) reported that approximately 72% of ingested barium is eliminated via fecal excretion following oral exposure. These data suggested an ingestion absorption factor (α ing ) distribution of tri(0.05, 0.1, 0.28).…”

Section: Methodsmentioning

confidence: 99%

Uptake and Trophic Transfer of Barium in a Terrestrial Ecosystem

Hope¹,

Loy²,

Miller³

1996

Bulletin of Environmental Contamination and Toxicology

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At an industrial site in central Virginia, organochlorine solvents and inorganic compounds with the potential to adversely affect wildlife have been released into the environment as a consequence of past industrial activities and practices. In the course of a ecological risk assessment for the site, soil, surface water, vegetation, insect, fish, and small mammal tissues were analyzed to ascertain whether these contaminants were bioavailable and present in the food chain. Although organochlorine solvents were found in the soil, none were found higher in the food chain. Of the inorganic compounds for which chemical analyses were performed, only barium was found at above detection limits at several level trophic levels. Four hypotheses were formed to investigate the behavior of barium in the terrestrial ecosystem at this site, as follows:(1) Barium has high assimilation efficiencies and low depuration rates in mammalian receptors.(2) Barium exhibits high bioaccumulation and / or bioconcentration factors and a potential for biomagnification. (3) Barium has a low toxicity that would allow its accumulation in various terrestrial receptors without adverse effects that could hinder such accumulation, and/or (4) Barium is being released from a persistent source that would provide the chronic exposure required to force its steady accumulation in terrestrial receptors.To assess these hypotheses, measured tissue concentrations in a variety of terrestrial receptors were applied to a food chain model in order to estimate site-specific intake and loss dynamics and bioaccumulation potential of this element in a terrestrial food chain. Extant literature data on the occurrence of barium in soil, plant, and animal tissues, as well as information on barium ecotoxicology, are also provided to assist with this assessment. MATERIALS AND METHODSThe site is located in central Virginia, on the banks of the James River, near Lynchburg, Virginia. Plant communities represented at the site are those typical of the Eastern Piedmont Province mesic uplands and floodplains with varying degrees of disturbance and development. Areas in the floodplain contain different associations than the mesic forest reflecting the higher soil-moisture content. Floodplain forest dominants typically include silver maple (Acer saccharinum) and sycamore (Platanus occidentalis). The floodplain forest contains numerous patches of grassland habitat and forest edge habitat that have been created by construction, development, and landscaping activities at the site.

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“…Data sources, software, and processing A total of 48 values of logarithm of brain-blood distribution coefficients (= log BB) were collected from a number of sources [37][38][39]. Also, for 36 of these compounds, experimental HIA values (ranging between 40 and 100 %, see Table 1) were found in literature [1,[40][41][42][43][44][45][46][47][48][49][50][51][52][53][54]. The experimental values of log BB (Table 1) range between −1.70 and 1.51.…”

Section: Mobile Phase and Sample Preparationmentioning

confidence: 99%

In vitro prediction of human intestinal absorption and blood–brain barrier partitioning: development of a lipid analog for micellar liquid chromatography

et al. 2015

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Over the past decades, several in vitro methods have been tested for their ability to predict either human intestinal absorption (HIA) or penetration across the blood-brain barrier (BBB) of drugs. Micellar liquid chromatography (MLC) has been a successful approach for retention time measurements of drugs to establish models together with other molecular descriptors. Thus far, MLC approaches have only made use of commercial surfactants such as sodium dodecyl sulfate (SDS) and polyoxyethylene (23) lauryl ether (Brij35), which are not representative for the phospholipids present in human membranes. Miltefosine, a phosphocholine-based lipid, is presented here as an alternative surfactant for MLC measurements. By using the obtained retention factors and several computed descriptors for a set of 48 compounds, two models were constructed: one for the prediction of HIA and another for the prediction of penetration across the BBB expressed as log BB. All data were correlated to experimental HIA and log BB values, and the performance of the models was evaluated. Log BB prediction performed better than HIA prediction, although HIA prediction was also improved a lot (from 0.5530 to 0.7175) compared to in silico predicted HIA values.

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Literature-derived absorption coefficients for 39 chemicals via oral and inhalation routes of exposure

Cited by 34 publications

References 47 publications

The power of size. 1. Rate constants and equilibrium ratios for accumulation of organic substances related to octanol‐water partition ratio and species weight

The power of size. 1. Rate constants and equilibrium ratios for accumulation of organic substances related to octanol‐water partition ratio and species weight

Uptake and Trophic Transfer of Barium in a Terrestrial Ecosystem

In vitro prediction of human intestinal absorption and blood–brain barrier partitioning: development of a lipid analog for micellar liquid chromatography

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