A number of factors have been suggested for recently observed amphibian decreases, and one potential factor is pesticide exposure. We studied the uptake and effects of environmentally relevant concentrations of the pyrethroid insecticide cypermethrin on two different amphibian species, Bombina variegata and Rana arvalis. The uptake from water of 14C-labeled cypermethrin (0.4 microg/L) by eggs and tadpoles of B. variegata was investigated. After 24 hours of exposure, 153.9 ng cypermethrin/g fresh weight were found in embryos, thus indicating that the jelly mass of the eggs does not act as a sufficient physical barrier to protect embryos from exposure to this compound. Uptake of cypermethrin into tadpoles of both species and in all exposed individuals caused dose-dependent deformities; behavioral abnormalities such as twisting, writhing, and coordinated swimming; and mortality. In tadpoles of B. variegata and R. arvalis, the activity of microsomal and cytosolic glutathione S-transferase (mGST and sGST, respectively) were measured after treatment with cypermethrin. Activities of both GST systems increased significantly with increasing duration and concentration of cypermethrin exposure, with the reaction seeming stronger in B. variegata than in R. arvalis tadpoles. Alpha-cypermethrin--a racemic mixture of two cis isomers of cypermethrin--induced a stronger enzymatic response in the cytosolic fraction of R. arvalis tadpoles than cypermethrin at the same concentration. The observed physical and behavioral abnormities caused by environmentally relevant concentrations of cypermethrin indicate that despite detoxication of the chemical via GST-system contamination of ponds by cypermethrin could result in adverse effects on the development of amphibian embryos and tadpoles.
"18 ) are a multigene family of cytosolic enzymes involved in the conjugation of electrophilic metabolites with the tripeptide glutathione to yield a water - soluble conjugated metabolite . GST activity is also used as a biomarker in ecological risk assessment of a pesticide - contaminated environment ( Greulich and Pflugmacher 2004 ; Attademo et al . 2007 ) . "
[Show abstract][Hide abstract] ABSTRACT: Different biological variables of tadpoles, including survival, development and growth rates, and biomarkers [cholinesterases, glutathione-S-transferases (GST), and blood cell morphology] were evaluated in two anuran species, Scinax squalirostris (Hylidae) and Leptodactylus mystacinus (Leptodactylidae), using in situ experimental chambers in a rice field (RF) sprayed with insecticide Lambda-cyhalothrin (LTC) by aircraft in Santa Fe Province, Argentina. We found a significant decrease in body weight (0.62 ± 0.04 g) of L. mystacinus and an increased development rate of S. squalirostris in individuals from RF (41 ± 1; Gosner) with respect to individuals from the reference site (RS: 0.93 ± 0.04 g and 37 ± 0; respectively). In S. squalirostris, individuals from RF mean values of butyrylcholinesterase activities decreased at 48 (4.09 ± 0.32 nmol min(-1) mg(-1) of TP) and 96 h (3.74 ± 0.20 nmol min(-1) mg(-1) of TP), whereas inhibition of acetylcholinesterase was observed at 96 h (47.44 ± 2.78 nmol min(-1) mg(-1) of TP). In L. mystacinus from RF, an induction of acetylcholinesterase activity was observed at 96 h (36.01 ± 1.09 nmol min(-1) mg(-1) of TP). Glutathione-S-transferase levels varied between species, being higher in L. mystacinus individuals but lower in S. squalirostris from RF at 48 (272.29 ±11.78 and 71.87 ± 1.70 nmol min(-1) mg(-1) of TP; respectively) and 96 h (279.25 ± 13.06 and 57.62 ± 4.58 nmol min(-1) mg(-1) of TP, respectively). Blood cell parameters revealed a lower number of mitotic cells (MC: 0.36 ± 0.31%o for S. squalirostris and 0.08 ± 0.05 %o for L. mystacinus) and higher number of eosinophils (E: 3.45 ± 1.75 %o for S. squalirostris and 7.64 ± 0.98 %o for L. mystacinus) in individuals from the RF than in individuals from the RS (MC: 2.55 ± 0.74 %o for S. squalirostris and 1.87 ± 0.72%o for L. mystacinus; and E: 0.13 ± 0.09 for S. squalirostris and 3.20 ± 0.80 for L. mystacinus). Overall, our results demonstrate the existence of apparent differences in sensitivity between species in a series of sublethal responses to short-term exposure in RF after the application of Lambda-cyhalothrin. We suggest that the integral use of biological endpoints (development and growth) together with biomarkers (cholinesterase, GST, and blood cell parameters) may be a promising integral procedure for investigating pesticide exposure in wild frog populations.
"We found some evidence suggesting that the pyrethroid insecticide, tefluthrin, may increase deformity rates of exposed turtle embryos, at least at exposures greater than typical applications. Another pyrethroid, cypermethrin caused physical and behavioral abnormalities in yellowbellied toads (Bombina variegate) and moor frogs (Rana arvalis) exposed at concentrations as low as 0.1 μg/L (Greulich and Pflugmacher, 2004). Similarly, Kim et al. (2008) found that deformities in larval Japanese medaka (Oryzias latipes) were elevated at concentrations of 40 μg/L of cypermethrin following 96 h of exposure. "
[Show abstract][Hide abstract] ABSTRACT: Many reptiles oviposit in soils associated with agricultural landscapes. We evaluated the toxicity of a pesticide and fertilizer regime similar to those used in corn production in Ontario on the survivorship of exposed snapping turtle (Chelydra serpentina) eggs. The herbicides atrazine, dimethenamid, and glyphosate, the pyrethroid insecticide tefluthrin, and the fertilizer ammonia, were applied to clean soil, both as partial mixtures within chemical classes, as well as complete mixtures. Eggs were incubated in the soil in a garden plot in which these mixtures were applied at a typical field application rate, and higher rates. Otherwise, the eggs were unmanipulated and were subject to ambient temperature and weather conditions. Eggs were also exposed at male producing temperatures in the laboratory in covered bins in the same soil, where there was less opportunity for loss through volatilization or leaching. Egg mortality was 100% at 10× the typical field application rate of the complete mixture, both with and without tefluthrin. At typical field application rates, hatching success ranged between 91.7 and 95.8%. Eggs exposed only to herbicides were not negatively affected at any application rates. Although fertilizer treatments at typical field application rates did not affect eggs, mortality was remarkably higher at three times this rate, and 100% at higher rates. The frequency of deformities of hatchlings was elevated at the highest application rate of the insecticide tefluthrin. The majority of the toxicity of the mixture was not due to the herbicides or insecticide, but was due to the ammonia fertilizer. At typical field application rates, the chemical regime associated with corn production does not appear to have any detrimental impacts upon turtle egg development; however toxicity dramatically increases if this threshold is passed.
Science of The Total Environment 08/2011; 409(20):4306-11. DOI:10.1016/j.scitotenv.2011.06.046 · 4.10 Impact Factor
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