Toxicokinetic interactions and survival of Hyalella azteca exposed to binary mixtures of chlorpyrifos, dieldrin, and methyl mercury

Steevens, Jeffery A.; Benson, William H.

doi:10.1016/s0166-445x(00)00127-2

Cited by 22 publications

(15 citation statements)

References 25 publications

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“…human lymphocytes and chromosomal as well as mitotic aberrations in peripheral blood lymphocytes (Axelred et al, 2002;Bajpayee et al, 2006;Dearfield et al, 1993;Eastman & Barry, 1992;Vijayaraghavan & Nagarajan, 1994). Since most chemicals are assumed to be additive in toxicity (DeLorenzo & Lorimar, 2003;Faust et al, 1993;Marking, 1977;Monosson, 2005;Steevens & Benson, 2001), the detection of synergistic interactions has significant implications for pesticide regulators and environmental managers. Pesticides, endosulfan, and chlorpyrifos were reported to cause genotoxicity and cytotoxicity in human peripheral blood samples at different cell concentrations and final volume of reaction mixture (Eastman & Barry, 1992;Marking, 1977).…”

Section: Discussionmentioning

confidence: 99%

Evaluation of cytotoxicity and genotoxicity of pesticide mixtures on lymphocytes

Shaik

Jamil

et al. 2016

Toxicology Mechanisms and Methods

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The cytotoxicity and genotoxicity of pesticide mixtures viz. endosulfan + chlorpyrifos, chlorpyrifos + profenofos, and endosulfan + profenofos were evaluated on cultured human peripheral blood lymphocytes using assays for cell viability, and genotoxicity using chromosomal aberrations test and comet assay. The LC values for cytotoxicity were 3.50 μM, 4.18 μM, and 10.5 μM for profenofos, endosulfan, and chlorpyrifos respectively. When combined in equimolar concentrations, the LC values for cytotoxicity were 1.4 μM, 1.8 μM, and 2.0 μM for endosulfan + chlorpyrifos, chlorpyrifos + profenofos, and endosulfan + profenofos, respectively. Higher concentrations of individual pesticides (0.5-4.0 μM) but very low concentrations of pesticide mixtures caused significant DNA damage. Additive index values indicated a synergistic effect of toxicity for endosulfan + chlorpyrifos combination (1.12 TTU). The binary mixture of chlorpyrifos + profenofos showed an additive toxicity (0.46 TTU) while an antagonistic effect was observed for endosulfan + profenofos combination. Synergism could be due to these complementary pesticides simultaneously acting in different ways, magnifying their efficacy, whereas an additive interaction would imply that the chemicals are acting by the same mechanism and at the same target. Analysis of toxicity of pesticide mixtures may serve as important biomarker for occupational and household exposure to pesticides, with different modes of action.

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Section: Discussionmentioning

confidence: 99%

Evaluation of cytotoxicity and genotoxicity of pesticide mixtures on lymphocytes

Shaik

Jamil

et al. 2016

Toxicology Mechanisms and Methods

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“…In the treated beakers, the volumes of dosing stock were added directly into the medium (t ¼ 0) and carefully stirred, and then 1 ml of test solution was sampled for analysis of aqueous concentrations. Further samples of the test solution were taken after 12,24,26,48,72, and 168 h, and actual exposure concentrations were quantified by using liquid scintillation counting.…”

Section: Toxicokinetic Experimentsmentioning

confidence: 99%

“…Individual G. pulex were sampled after 2,4,7,12,24,26,28,31,36,48,72,96, and 168 h, and internal concentrations of the test compounds were quantified as total 14 C radioactivity. Organisms were removed from the beaker, blotted dry, placed in preweighed scintillation vials, weighed, and frozen at À208C until analysis.…”

Section: Toxicokinetic Experimentsmentioning

confidence: 99%

“…The rate constants for the toxicokinetic processes of uptake and elimination vary among organisms and compounds [9][10][11][12]. The underlying processes are fairly well understood [13], and some of this variation can be attributed to physical-chemical properties of the compounds, particularly hydrophobicity, described as octanol-water partition coefficient, log K OW [13][14][15][16], as well as biological traits of the organisms, such as lipid content [3] or size [17][18][19][20].…”

Section: Introductionmentioning

confidence: 99%

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Bioaccumulation kinetics of organic xenobiotic pollutants in the freshwater invertebrateGammarus pulexmodeled with prediction intervals

Ashauer

Caravatti

Hintermeister

et al. 2010

Enviro Toxic and Chemistry

119

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Uptake and elimination rate constants, bioaccumulation factors, and elimination times in the freshwater arthropod Gammarus pulex were measured for 14 organic micropollutants covering a wide range of hydrophobicity (imidacloprid, aldicarb, ethylacrylate, 4,6-dinitro-o-cresol, carbofuran, malathion, 4-nitrobenzyl-chloride, 2,4-dichloroaniline, Sea-Nine, 2,4-dichlorophenol, diazinon, 2,4,5-trichlorophenol, 1,2,3-trichlorobenzene, and hexachlorobenzene; all 14C-labeled). The toxicokinetic parameters were determined by least-square fitting of a one-compartment first-order toxicokinetic model, followed by Markov Chain Monte Carlo parameter estimation. The parameter estimation methods used here account for decreasing aqueous concentrations during the exposure phase or increasing aqueous concentrations during the elimination phase of bioaccumulation experiments. It is not necessary to keep exposure concentrations constant or zero during uptake and elimination, respectively. Neither is it required to achieve steady state during the exposure phase; hence, tests can be shorter. Prediction intervals, which take the between-parameter correlation into account, were calculated for bioaccumulation factors and simulations of internal concentrations under variable exposure. The lipid content of Gammarus pulex was 1.3% of wet weight, consisting of 25% phospholipids and 75% triglycerides. Size-dependent bioaccumulation was observed for eight compounds, although the magnitudes of the relationships were too small to be of practical relevance. Elimination times ranged from 0.45 to 20 d, and bioaccumulation factors ranged from 1.7 to 4,449 L/kg. The identified compounds with unexpectedly long elimination times should be given priority in future studies investigating the biotransformation of these compounds.

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“…Steevens and Benson (2001) reported that chlorpyrifos accelerated the uptake of methyl mercury to Hyalella azteca yet reduced its elimination, resulting in synergistic interaction between the two chemicals. Surprisingly, all kinetic parameters (k u , k e , t 1/2 and BCF) for permethrin in C. dilutus showed no significant difference between the two exposure scenarios ( Table 2), suggesting that the presence of cadmium had no obvious effect on the toxicokinetics of permethrin in the midges.…”

Section: Toxicokinetic Parametersmentioning

confidence: 99%

Does cadmium affect the toxicokinetics of permethrin in Chironomus dilutus at sublethal level? Evidence of enzymatic activity and gene expression

Chen

Zhang

et al. 2016

Environmental Pollution

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Toxicokinetic interactions and survival of Hyalella azteca exposed to binary mixtures of chlorpyrifos, dieldrin, and methyl mercury

Cited by 22 publications

References 25 publications

Evaluation of cytotoxicity and genotoxicity of pesticide mixtures on lymphocytes

Evaluation of cytotoxicity and genotoxicity of pesticide mixtures on lymphocytes

Bioaccumulation kinetics of organic xenobiotic pollutants in the freshwater invertebrateGammarus pulexmodeled with prediction intervals

Does cadmium affect the toxicokinetics of permethrin in Chironomus dilutus at sublethal level? Evidence of enzymatic activity and gene expression

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