Environmental Sources, Speciation, and Partitioning of Selenium

Maher, William A.; Roach, Anthony C.; Doblin, Martina A.; Fan, Teresa W.‐M.; Foster, Simon; Garrett, Reid; M√∂ller, Gregory; Oram, Libbie L.; Wallschl√§ger, Dirk

doi:10.1201/ebk1439826775-c4

Cited by 36 publications

(46 citation statements)

References 193 publications

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“…Inorganic Se such as selenite can be biotransformed by algae and bacteria into organic forms including selenomethionine (SeMet), a selenoamino acid, which is considered to be one of the more toxic forms of Se generally (Maher et al 2010). Extrapolated concentrations of various Se compounds sufficient to cause 5% mortality after a 10-day aqueous exposure revealed that SeMet was more toxic to newly hatched zebrafish compared to selenite and selenate (Niimi et al 1976).…”

Section: Introductionmentioning

confidence: 99%

Antioxidant Rescue of Selenomethionine-Induced Teratogenesis in Zebrafish Embryos

Arnold

Forte

Osterberg

et al. 2015

Arch Environ Contam Toxicol

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Selenium (Se) is an essential micronutrient that can be found at toxic concentrations in surface waters contaminated by runoff from agriculture and coal mining. Zebrafish (Danio rerio) embryos were exposed to aqueous Se in the form of selenate, selenite, and L-selenomethionine (SeMet) in an attempt to determine if oxidative stress plays a role in selenium embryo toxicity. Selenate and selenite exposure did not induce embryo deformities (lordosis and craniofacial malformation). L-selenomethionine, however, induced significantly higher deformity rates at 100 μg/L compared to controls. SeMet exposure induced a dose-dependent increase in the catalytic subunit of glutamate-cysteine ligase (gclc) and reached an 11.7-fold increase at 100 μg/L. SeMet exposure also reduced concentrations of TGSH, RGSH, and the TGSH:GSSG ratio. Pretreatment with 100 μM N-acetylcysteine (NAC) significantly reduced deformities in the zebrafish embryos secondarily treated with 400 μg/L SeMet from approximately 50% to 10% as well as rescued all three of the significant glutathione level differences seen with SeMet alone. Selenite exposure induced a 6.6-fold increase in expression of the glutathione-S-transferase pi class 2 (gstp2) gene, which is involved in xenobiotic transformation and possibly oxidative stress. These results suggest that aqueous exposure to SeMet can induce significant embryonic teratogenesis in zebrafish that are at least partially attributed to oxidative stress.

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Section: Introductionmentioning

confidence: 99%

Antioxidant Rescue of Selenomethionine-Induced Teratogenesis in Zebrafish Embryos

Arnold

Forte

Osterberg

et al. 2015

Arch Environ Contam Toxicol

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“…However, it is unclear to what extent inorganic material contributes to the total mass of field derived periphyton samples (thus diluting reported Se concentrations and reducing EFs). Further, contaminated field sites (both marine and freshwater) most likely contain a mixture of dissolved selenate and selenite Maher et al 2010). It is generally agreed that most primary producers absorb selenite more readily than selenate (Riedel et al 1991;Besser et al 1993), but see also Simmons and Wallschläger (2011).…”

Section: Periphyton Bioconcentrationmentioning

confidence: 99%

Food rationing affects dietary selenium bioaccumulation and life cycle performance in the mayfly Centroptilum triangulifer

et al. 2011

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Selenium effects in nature are mediated by the relatively large bioconcentration of aqueous Se by primary producers and smaller, yet critical, dietary transfers to primary consumers. These basal processes are then propagated through food webs to higher trophic levels. Here we quantified the movement of dissolved Se (as selenite) to periphyton, and used the resultant periphyton as a food source for conducting full life-cycle dietary Se exposures to the mayfly Centroptilum triangulifer. Periphyton bioconcentrated Se ~2,200-fold from solution in a log-linear fashion over dissolved Se concentrations ranging from 1.1 to 23.1 μg L(-1). We examined the influence of two feeding ration levels (1x and 2x) on trophic transfer, tissue Se concentrations, maternal transfer, and functional endpoints of mayfly performance. Mayflies fed a lesser ration (1x) displayed greater trophic transfer factors (mean TTF, 2.8 ± 0.4) than mayflies fed 2x rations (mean TTF, 1.1 ± 0.3). In 1x exposures, mayflies exhibited significant (p < 0.05) reductions in survivorship and total body mass at dietary [Se] ≥ 11.9 μg g(-1), reduced total fecundity at ≥ 4.2 μg g(-1), and delayed development at ≥ 27.2 μg g(-1). Mayflies fed a greater ration (2x) displayed reduced tissue Se concentrations (apparently via growth dilution) relative to 1x mayflies, with no significant effects on performance. These results suggest that the influence of Se on mayfly performance in nature may be tied to food resource availability and quality. Furthermore, nutritional status is an important consideration when applying laboratory derived estimates of toxicity to risk assessments for wild populations.

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“…Although total aqueous selenium in the watershed is initially almost exclusively in the selenate form, a separate investigation of two lentic areas, for which data are included in the food chain models in the present study, showed a transition toward reduced forms selenite and organoselenium in the water column approaching the sediment-water interface [20]. By comparison, selenate is presumed to dominate the water column in well-oxygenated lotic environments [21][22][23]. Selenium uptake by aquatic algae, plants, and bacteria is most rapid for organoselenium followed by selenite and then selenate [24][25][26].…”

Section: Comparison Of Lentic Versus Lotic Modelsmentioning

confidence: 93%

Food chain model based on field data to predict westslope cutthroat trout (Oncorhynchus clarkii lewisi) ovary selenium concentrations from water selenium concentrations in the Elk Valley, British Columbia

Orr

Wiramanaden

Paine

et al. 2012

Enviro Toxic and Chemistry

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Previous studies conducted in the Elk River watershed showed that selenium concentrations are higher in aquatic biota in lentic compared to lotic habitats of the system having similar water selenium concentrations. Studies have also shown that water selenium concentrations have increased over time (~10% per year) and recent annual average concentrations have ranged up to 0.044 mg/L in areas downstream from mine discharges. For the present study, trophic transfer of selenium was characterized in lotic versus lentic habitats using concentrations measured in field-collected samples and assuming a three-step food chain of water to the base of the food web (biofilm), to benthic invertebrates, and then to westslope cutthroat trout (WCT) ovaries. Food chain models were developed for each habitat type (lotic and lentic) by combining linear regression equations for the three transfer relationships, allowing for prediction of fish ovary concentrations from water concentrations. Greater accumulation of selenium in lentic areas was mostly attributable to greater uptake at the base of the food chain compared to lotic areas. Enrichment/trophic transfer factors for selenium at all levels of the lotic and lentic food chains decreased and then became near constant as exposure concentrations increased. The lotic model predicted little increase in WCT ovary selenium concentrations over an eightfold increase in water concentrations (~0.005-0.040 mg/L), accounting for the lack of observed increase in within-area fish tissue concentrations over time despite increasing trends in water concentrations.

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Environmental Sources, Speciation, and Partitioning of Selenium

Cited by 36 publications

References 193 publications

Antioxidant Rescue of Selenomethionine-Induced Teratogenesis in Zebrafish Embryos

Antioxidant Rescue of Selenomethionine-Induced Teratogenesis in Zebrafish Embryos

Food rationing affects dietary selenium bioaccumulation and life cycle performance in the mayfly Centroptilum triangulifer

Food chain model based on field data to predict westslope cutthroat trout (Oncorhynchus clarkii lewisi) ovary selenium concentrations from water selenium concentrations in the Elk Valley, British Columbia

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