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Archives of Environmental Contamination and Toxicology (v.55, #4)
Contrasting the Seasonal Variability of Halogenated Natural Products and Anthropogenic Hexachlorocyclohexanes in the Southern Norwegian Atmosphere by Joachim Melcher; Martin Schlabach; Martin Strand Andersen; Walter Vetter (pp. 547-557).
Halogenated natural products (HNPs) are increasingly recognized as compounds of marine environmental samples. In this study, we explored whether the annual course of the concentrations of HNPs in ambient air samples was different from those of anthropogenic pollutants. For this purpose, air samples taken weekly at Lista, southern Norway, were analyzed by gas chromatography–mass spectrometry for anthropogenic aaeeee- (α-HCH) and aaaeee-hexachlorocyclohexane (γ-HCH, lindane) isomers, as well as the HNPs 2,3,3′,4,4′,5,5′-heptachloro-1′-methyl-1,2′-bipyrrole (Q1), 2,4-di- and 2,4,6-tribromoanisole (24-DBA, 246-TBA), and 2,4,6-tribromophenol (246-TBP). Concentrations of HCH isomers were higher in the warmer summer months than in winter. By contrast, Q1, 24-DBA, 246-TBA, and 246-TBP showed much higher concentrations at the end of the year. Correlations between the concentrations of the compounds and air mass trajectories as well as further meteorological data are discussed. An unknown mixed halogenated substance was detected at high abundance during the summer months. High-resolution mass spectrometry and tandem mass spectrometric techniques were used to unravel the molecular structure, which was found to be C7H8Br3Cl, an elemental composition never reported before in the scientific literature.
Wet and Dry Deposition Fluxes of Inorganic Chemical Species at a Rural Site in Northern Jordan by Idrees F. Al-Momani (pp. 558-565).
Wet and dry deposition samples were collected in a rural region in northern Jordan during the period of December 1998 to April 2000. Concentrations of 20 chemical species (Na, K, Ca, H+, Mg, NH 4 + , Cl−, NO 3 − , SO 4 2− ,Pb, Cd, Zn, Cu, Al, Fe, Mn, Mo, Ni, Sb, and V) were determined in collected samples. Most of the Al, Fe, Mn, Mo, Sb, and V were not soluble, whereas major ions (Na, K, Ca, H+, Mg, NH 4 + , Cl−, NO 3 − , and SO 4 2− ) and some trace elements (Cd, Cu, and Zn) were wet deposited mostly in the soluble form. Concentration of the soil-related elements and/or highly soluble species were washed out at the early stages of a precipitation event, and their concentrations were mostly controlled by dilution, whereas concentrations of anthropogenic species were controlled by other factors. Annual fluxes of the soil-related elements and ions were significantly higher than the primarily anthropogenic elements. This was attributed to the arid nature of the region and to the frequent input of the Saharan dust pulses.
Solid-Phase Control on Lead Bioaccessibility in Smelter-Impacted Soils by F. M. Romero; M. Villalobos; R. Aguirre; M. E. Gutiérrez (pp. 566-575).
The goal of this work was to identify the solid-phase control on lead (Pb) bioaccessibility in soils impacted by smelter activities in the city of San Luis Potosi, in north-central Mexico. Total Pb concentrations in 30 ha of soil terrain from a residential area adjacent to the smelter showed levels above the 400-mg/kg intervention guideline dictated by Mexican Environmental regulations. These concentrations, although raising human health and environmental concerns, showed low water-soluble lead (<0.1 mg/L) and relatively low lead bioaccessibility (2.4–20.5%). X-ray diffraction and electron microscopy techniques showed, in addition to common Pb phases reported in similar contaminated environments [galena (PbS) and anglesite (PbSO4)], the presence of a solid lead arsenate phase. The Pb solubility measured in soils agrees very well with the low solubility reported for the Pb minerals identified and explains the relatively low Pb bioaccessibility values measured, presumably from their low dissolution during passage through the gastrointestinal tract. The results reported are highly relevant for smelter-originated environmental contamination scenarios in general.
Toxicity Assessment of the Herbicides Sulcotrione and Mesotrione Toward Two Reference Environmental Microorganisms: Tetrahymena pyriformis and Vibrio fischeri by J. L. Bonnet; F. Bonnemoy; M. Dusser; J. Bohatier (pp. 576-583).
The potential toxicity of sulcotrione (2-[2-chloro-4-(methylsulfonyl)benzoyl]-1,3-cyclohexanedione) and mesotrione (2-[4-(methylsulfonyl)-2-nitrobenzoyl]-1,3-cyclohexanedione), two selective triketonic herbicides, was assessed using representative environmental microorganisms frequently used in ecotoxicology: the eukaryote Tetrahymena pyriformis and the prokaryote Vibrio fischeri. The aims were also to evaluate the toxicity of different known degradation products, to compare the toxicity of these herbicides with that of atrazine, and to assess the toxicity of the commercial herbicidal products Mikado® and Callisto®. Toxicity assays involved the Microtox test, the T. pyriformis population growth impairment test, and the T. pyriformis nonspecific esterase activity test. For each compound, we report original data (IC50 values) on nontarget cells frequently used in ecotoxicology. Analytical standards sulcotrione and mesotrione showed no toxic effect on T. pyriformis population growth but a toxic influence was observed on nonspecific esterase activities of this microorganism and on metabolism of V. fischeri. Most of the degradation products studied and the two commercial formulations showed a greater toxicity than the parent molecules. Compared with the effect of atrazine, the toxicity of these triketonic herbicides was less than in T. pyriformis and greater than or the same as in V. fischeri. Additional work is needed to obtain a more accurate picture of the environmental impact of these herbicides. It will be necessary in future experiments to study the ecosystemic levels (aquatic and soil compartments) and to assess the potential toxicity of the newly discovered degradation products and of the additives accompanying the active ingredient in the commercial herbicidal formulations.
Reduced Fitness of Daphnia magna Fed a Bt-Transgenic Maize Variety by Thomas Bøhn; Raul Primicerio; Dag O. Hessen; Terje Traavik (pp. 584-592).
Genetically modified (GM) maize expressing the Bt-toxin Cry1Ab (Bt-maize) was tested for effects on survival, growth, and reproduction of the water flea Daphnia magna, a crustacean arthropod commonly used as a model organism in ecotoxicological studies. In three repeated experiments, D. magna were fed 100% ground maize in suspension, using either GM or isogenic unmodified (UM) maize. D. magna fed GM-maize showed a significantly reduced fitness performance: The mortality was higher, a lower proportion of females reached sexual maturation, and the overall egg production was lower compared to D. magna fed UM isogenic maize. We conclude that the tested variety of Bt-maize and its UM counterpart do not have the same quality as food sources for this widely used model organism. The combination of a reduced fitness performance combined with earlier onset of reproduction of D. magna fed Bt-maize indicates a toxic effect rather than a lower nutritional value of the GM-maize.
Effect of Nutrition on Toxicity of Contaminants to the Epibenthic Amphipod Melita plumulosa by D. A. Spadaro; T. Micevska; S. L. Simpson (pp. 593-602).
The amphipod Melita plumulosa is commonly used to assess the toxicity of contaminated sediments. Seven-day-old M. plumulosa are <1 mm in size, and during 10-day tests in sandy sediments with low nutritional value, starvation can cause >50% mortality. In sediment toxicity tests, therefore, it can be difficult to determine if toxicity is due to contaminants or starvation, particularly in contaminated sandy sediments. This study investigated the influence of amphipod age and food addition on amphipod survival in toxicity tests. The 4-day LC50 increased linearly from 120 to 470 μg/L when M. plumulosa age at the beginning of the test increased from 5 to 30 days. The addition of food as algae or fish food did not significantly affect the sensitivity of 11-day-old M. plumulosa (11-d Mp) to dissolved copper over 4 days in water-only tests. The survival of 11-d Mp in water-only tests over 10 days was poor without feeding, but when fed fish food, the 10-day LC50 was 76 ± 15 μg/L. In sediment tests, feeding 0.063 mg fish food/amphipod on days 3 and 7 of 10-day tests consistently resulted in greater than 80% survival of 11-d Mp for a range of clean, sandy sediments, which had low amphipod survival without added food. Algae were not always suitable as a food source, as their growth can be stimulated by nutrients released from sediment and was inhibited by contaminants. The toxicity of most contaminated sediments was not ameliorated by the addition of food, suggesting that food addition was suitable for inclusion in routine testing protocols for this amphipod.
Accumulation and Elimination of Chromium by Freshwater Species Exposed to Spiked Sediments by Mercedes Marchese; Ana M. Gagneten; María J. Parma; Paola J. Pavé (pp. 603-609).
The bioaccumulation and elimination capacity of chromium were examined in four freshwater species: the submersed aquatic plant Ceratophyllum demersum (Ceratophyllaceae), the oligochaete Limnodrilus udekemianus (Tubificidae), the crab Zilchiopsis collastinensis (Decapoda), and the fish Cnesterodon decemmaculatus (Poeciliidae). All of the species were exposed simultaneously to sediments spiked with Cr (K2Cr2O7) at different concentrations for 28 days, followed by 7 days without Cr to evaluate the concentration of residual Cr. We found that Cr accumulated in the tissues of all four species. The highest bioconcentration factor obtained for each species is as follows: C. demersum, 718.66 (±272.91); L. udekemianus, 172.55 (±80.8), Z. collastinensis, 67.72 (±35.4); C. decemmaculatus, 23.11 (±12.82), all at 28 days of exposure.
Effects of River Water and Salinity on the Toxicity of Deltamethrin to Freshwater Shrimp, Cladoceran, and Fish by Colette R. Thomas; Grant C. Hose; Michael StJ. Warne; Richard P. Lim (pp. 610-618).
Deltamethrin is a pyrethroid insecticide used extensively to control invertebrate pests on cotton and other crops. It is acutely toxic to nontarget aquatic organisms, but existing toxicity data are mostly from toxicity tests using purified laboratory water that differs greatly from the turbid, high-conductivity rivers in the cotton-growing regions of Australia. The aim of this study was to determine whether the water quality variables conductivity, suspended particles, and dissolved organic matter alter the toxicity of deltamethrin to freshwater crustaceans and a fish. We tested three Australian native species: a cladoceran (Ceriodaphnia cf. dubia), a freshwater shrimp (Paratya australiensis), and larvae of the eastern rainbow fish (Melanotaenia duboulayi). Conductivity of the test solutions ranged from 200 to 750 μS/cm, but such changes did not modify the toxicity of deltamethrin to any of the test species. However, the toxicity of deltamethrin to C. cf. dubia and P. australiensis in river water was significantly decreased (1.8-fold to 6.3-fold reduction) compared to that in laboratory water. Variability in the toxicity data limited our ability to detect differences between laboratory and river water for M. duboulayi. Despite reductions in toxicity in natural waters, deltamethrin remained highly toxic [all L(E)C50 values <0.26 μg/L] to all organisms tested; thus, further investigation of the hazard of deltamethrin is warranted.
Heavy Metals in the Nase, Chondrostoma nasus (L. 1758), and Its Intestinal Parasite Caryophyllaeus laticeps (Pallas 1781) from Austrian Rivers: Bioindicative Aspects by Franz Jirsa; Monika Leodolter-Dvorak; Regina Krachler; Christa Frank (pp. 619-626).
Tissue samples from 121 adult specimens of the predominantly herbivorous fish species nase, Chondrostoma nasus (L. 1758), from five river sites in Austria were analyzed for their metal content. Sediments and water samples of the sites show different levels of metal load, with only one site considered being polluted with metals. The concentrations of cadmium, copper, lead, and zinc in the tissue of the gills, muscle, intestine, and liver of the fish were determined by inductively coupled plasma–optical emission spectrometry (ICP-OES). As in one of the unpolluted and the polluted river site, a well-established population of the tapeworm Caryophyllaeus laticeps (Pallas, 1781) occurred in the intestine of the fish; pooled samples of this worm were analysed as well. Both the nase and C. laticeps show bioindicative ability for metal pollution in rivers. The results allow a more differentiated characterization of the rivers than the sediment analyses. Cadmium is found mainly in the liver, with maximum concentrations of 1.57 μg/g dry weight from unpolluted sites and 5.58 μg/g from the polluted site. The highest concentrations of copper are also found in the liver, with values between 25 and 333 μg/g. A significantly elevated concentration of Cu in the intestine from an “unpolluted” site (mean: 24.06 μg/g) indicates an acute pollution in this area at the time of sampling. Lead was found mainly in the intestine and liver in concentrations between 0.09 and 4.05 μg/g and 0.26 and 1.94 μg/g, respectively. In the samples from the polluted site, it also could be detected in the gills (mean: 1.38 μg/g). The parasite C. laticeps shows different capacities for metal accumulation: Although the concentrations of Cu were significantly lower compared to the values of the fish liver, cadmium was detected in concentrations up to 5.1 times higher. Lead and zinc concentrations were found to be up to 9.7 and 3.0 times higher in the tapeworm compared to the fish liver, respectively.
Relationships Between Anthropogenic Chemical Contaminant Exposure and Associated Changes in Reproductive Parameters in Male English Sole (Parophrys vetulus) Collected from Hylebos Waterway, Puget Sound, Washington by Sean Y. Sol; Lyndal L. Johnson; Daryle Boyd; O. Paul Olson; Dan P. Lomax; Tracy K. Collier (pp. 627-638).
Effects of chemical contaminant exposure on gonadal development in adult male English sole (Parophrys vetulus) from Hylebos Waterway and Colvos Passage, Puget Sound, Washington were investigated. Hylebos Waterway sediment is contaminated with polycyclic aromatic hydrocarbons (PAHs) and organochlorines (OCs), and Colvos Passage, a nearby nonurban area, is minimally contaminated. Fish from Hylebos Waterway had higher concentrations of both PAHs and OCs in tissues than fish from Colvos Passage. Overall, little correlation was observed between PAH exposure and biological parameters, but strong correlations were observed between OCs and the biological parameters. Migration of fish from less contaminated areas into the Hylebos Waterway during the reproductive season might have influenced these results, based on temporal changes in fish age and contaminant concentrations.
Changes in Population, Growth, and Physiological Indices of Longnose Dace (Rhinichthys cataractae) in the Red Deer River, Alberta, Canada by Ken M. Jeffries; Leland J. Jackson; Lisa E. Peters; Kelly R. Munkittrick (pp. 639-651).
The Red Deer River, Alberta, Canada is a prairie river that is impacted by the point-source input of Red Deer’s municipal wastewater effluent and non-point- source agricultural runoff. We used population, growth, and physiological performance end points in longnose dace (Rhinichthys cataractae), an endemic and abundant minnow, to evaluate changes in fish health over a 220 km section of the Red Deer River. Longnose dace immediately downstream of Red Deer had elevated catch per unit effort with larger body and liver sizes compared to upstream of Red Deer sites, likely due to elevated riverine productivity from Red Deer’s wastewater effluent. Longnose dace immediately downstream of Red Deer showed depressed testosterone production capacity and elevated ethoxyresorufin-O-deethylase (EROD) activity, which is consistent with exposure to endocrine-disrupting compounds and aromatic hydrocarbons, respectively. Longnose dace 150–180 km downstream of Red Deer had reduced liver and gonad sizes, elevated EROD, and increased 11-ketotestosterone production capacity compared to upstream of Red Deer sites, possibly related to a non-point-source agricultural influence on water quality. Longnose dace populations at the most downstream sites were missing the oldest age classes and might reach sexual maturity faster than at upstream sites, which is consistent with a younger age structure. Our results highlight the importance of assessing multiple performance end points to reveal physiological or reproductive effects in natural fish populations. We have demonstrated how longnose dace populations change over a river impacted by municipal wastewater and agricultural runoff; further studies are required to determine if these changes will influence the long-term viability of longnose dace in the Red Deer River.
Ecotoxicological Effects of Buprofezin on Fecundity, Growth, Development, and Predation of the Wolf Spider Pirata piratoides (Schenkel) by Lingling Deng; Muqi Xu; Hong Cao; Jiayin Dai (pp. 652-658).
The toxicological effects of buprofezin, an insect growth regulator, on the fecundity, development, and pest control potential of the wolf spider Pirata piratoides (Schenkel) (Araneae: Lycosidae) were investigated in the laboratory. It was shown that buprofezin had low toxicity to P. piratoides and that the median lethal dosage (LD50) 48 h and 10% lethal dosage (LD10) after topical application for female spiders were 653 and 316 mg buprofezin/mg fresh weight of spider, respectively. Buprofezin significantly reduced the percent hatching of spiders’ eggs but had only a slight effect on egg production. No negative effects on the development and growth were observed. However, spider predation rates were strongly affected: Insecticide-treated females predated on fewer prey than the controls, and their predation rate did not recover even 5 days after insecticide application. This indicated that their pest control potential might be influenced by buprofezin, and the use of buprofezin in biological control of insects is discussed.
Embryo Toxicity of 2,3,7,8-Tetrachlorodibenzo-p-Dioxin to the Wood Duck (Aix sponsa) by T. P. Augspurger; D. E. Tillitt; S. J. Bursian; S. D. Fitzgerald; D. E. Hinton; R. T. Di Giulio (pp. 659-669).
We examined the sensitivity of the wood duck (Aix sponsa) embryo to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) by injecting the toxicant into their eggs. Six groups of wood duck eggs (n = 35 to 211 per trial) were injected with 0 to 4600 pg TCDD/g egg between 2003 and 2005. Injections were made into yolk prior to incubation, and eggs were subsequently incubated and assessed weekly for mortality. Significant TCDD-induced mortality was not observed through day 25 (90% of incubation). Liver, heart, eye, and brain histology were generally unremarkable. Hepatic ethoxyresorufin-O-deethylase activity, a biomarker of dioxin-like compound exposure, was induced by 12-fold in the 4600 pg/g treatment relative to controls. The median lethal dose for chicken (Gallus domesticus) eggs we dosed identically to wood duck eggs was about 100 pg/g, similar to other assessments of chickens. Among dioxin-like compound embryo lethality data for 15 avian genera, the wood duck 4600 pg/g no-observed-effect level ranks near the middle. Because no higher doses were tested, wood ducks may be like other waterfowl (order Anseriformes), which are comparatively tolerant to embryo mortality from polychlorinated dibenzo-p-dioxins and dibenzofurans when exposed by egg injection.
Accumulation of Environmental Contaminants in Wood Duck (Aix sponsa) Eggs, with Emphasis on Polychlorinated Dibenzo-p-Dioxins and Polychlorinated Dibenzofurans by T. P. Augspurger; K. R. Echols; P. H. Peterman; T. W. May; C. E. Orazio; D. E. Tillitt; R. T. Di Giulio (pp. 670-682).
We measured polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs), organochlorine pesticides, and mercury in wood duck (Aix sponsa) eggs collected near a North Carolina (USA) bleached kraft paper mill. Samples were taken a decade after the mill stopped using molecular chlorine. Using avian toxic equivalency factors, 2,3,7,8-tetrachlorodibenzo-p-dioxin toxicity equivalent (TEQ) concentrations were 1–30 pg/g fresh wet weight in eggs (n = 48) collected near the mill in 2002–2005 and were significantly higher than those from a reference site (<1 pg/g) 25 km away. Geometric mean wood duck egg TEQs (6 pg/g) were one-fifth those measured at this site prior to the cessation of molecular chlorine bleaching. Concentrations of mercury in wood duck eggs from nests of the Roanoke River sites ranged from 0.01 to 0.14 μg/g (geometric mean, 0.04 μg/g) and were significantly higher than those from the reference site, where concentrations did not exceed 0.04 μg/g (geometric mean, 0.02 μg/g). All concentrations were lower than those associated with adverse effects in birds. The congener profiles, lack of contamination in reference site eggs, and decline in contaminant concentrations after process changes at the mill provide strong evidence that mill discharges influenced contamination of local wood duck eggs. Collectively, the results indicate that the wood duck is an effective sentinel of the spatial and temporal extent of PCDD, PCDF, and mercury contamination.
Trace Element Concentrations in Blood of Nesting King Eiders in the Canadian Arctic by Mark Wayland; Ray T. Alisauskas; Dana K. Kellett; Katherine R. Mehl (pp. 683-690).
The king eider (Somateria spectabilis) is a migratory species of sea duck whose North American population is thought to be declining. We determined levels of cadmium, lead, selenium, and mercury in blood from female king eiders nesting in the central Canadian Arctic from 2001 to 2003. Year-to-year repeatability estimates were calculated from birds sampled in 2 or 3 years. Repeatability coefficients were 0.45, 0.35, 0.58, and 0.25 for cadmium, lead, selenium, and mercury, respectively. The first three were significantly different from zero (p < 0.05), whereas the last approached significance (0.05 < p < 0.1). In 2001 and 2002, we also identified probable wintering locations of a subset of the birds. In both years, cadmium levels were higher and selenium levels were lower in birds inferred to have wintered in the eastern part of their range compared to those that had wintered in the west. There was little evidence that timing of breeding, timing of sampling, or body condition were related to levels of these trace elements, although in 1 of 2 years, lead levels were influenced by body condition and nest initiation date (R 2 = 0.24) and cadmium levels were related to incubation day (partial R 2 = 0.04). Year-to-year repeatability of cadmium and selenium levels among individuals in this population of king eiders was likely influenced by where they wintered.
Heavy Metal Transfers Between Trophic Compartments in Different Ecosystems in Galicia (Northwest Spain): Essential Elements by X. I. González; J. R. Aboal; J. A. Fernández; A. Carballeira (pp. 691-700).
In the present study, we determined the concentrations of Cu, Fe, Mn, and Zn in soil and several trophic compartments at a total of 16 sampling stations. The trophic compartments studied were primary producers, represented by two species of terrestrial mosses (Pseudoescleropodium purum and Hypnum cupressiforme) and oak trees (Quercus robur or Q. pyrenaica); primary consumers, represented by the wood mouse (Apodemus sylvaticus) and the yellow necked mouse (A. flavicollis); secondary consumers, represented by the shrew (Sorex granarius); and finally, detritivores, represented by slugs (Arion ater). Thirteen of the sampling stations were located in mature oak woodlands (Quercus sp.); two of the sampling stations were located in the area surrounding a restored lignite mine dump, and the other in an ultrabasic area. The analytical determinations revealed a lack of significant correlations among trophic compartments, possibly caused by effective regulation of metals by organisms and/or spatial variation in availability of metals from soil or food. Furthermore, the only element that showed a clear pattern of biomagnification was Cu; as for the other elements, there was always some divergence from such a pattern. Finally, the patterns of bioaccumulation in contaminated and woodland sampling stations were very similar, although there was enrichment of the concentrations of Cu, Mn, and Zn in the mice viscera, which, except for Mn, were related to higher edaphic concentrations.
Survey of Organosilicone Compounds, Including Cyclic and Linear Siloxanes, in Personal-Care and Household Products by Yuichi Horii; Kurunthachalam Kannan (pp. 701-710).
The determination of organosiloxanes in consumer products is important for the evaluation and characterization of sources of human and environmental exposures. In this study, we determined concentrations of cyclic siloxanes [octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), dodecamethylcyclohexasiloxane (D6)], tetradecamethylcycloheptasiloxane (D7)] and linear siloxanes (L4 to L14) in a variety of consumer products (n = 76), including hair-care products, skin lotions, body washes, cosmetics, nursing nipples (i.e., pacifiers), cookware, and household sanitation products such as cleansers and furniture polishes, using gas chromatography–mass spectrometry with selected ion monitoring. Prior to the analysis of samples, a method was developed to reduce the contamination arising from organosiloxanes present in certain gas chromatograph (GC) parts, such as the inlet septum; use of a Restek BTO septum at an inlet temperature of 200°C gave the lowest background level (D4: 0.8 pg; D5: 0.3 pg; D6: 0.2 pg). Concentrations of cyclic siloxanes in consumer products analyzed ranged from <0.35 to 9380 μg/g, from <0.39 to 81,800 μg/g, from <0.33 to 43,100 μg/g, and from <0.42 to 846 μg/g for D4, D5, D6, and D7, respectively. Concentrations of linear siloxanes varied from <0.059 to 73,000 μg/g. More than 50% of the samples analyzed contained D4, D5, or D6. Cyclic siloxanes were predominant in most of the sample categories; D5 was predominant in hair-care products, skin lotions, and cosmetics; D6 or D7 was predominant in rubber products, including nipples, cookware, and sealants. Potential daily exposure to total organosiloxanes (sum of cyclic and linear siloxanes) from the use of personal-care products by adult women in the United States has been estimated to be 307 mg. Significant positive correlations (p < 0.01) existed in our study between D4 and D7, D4 and linear siloxanes, D5 and D6, and D5 and linear siloxanes. The correlations can be related to the composition of organosiloxanes used in consumer products. The results of our study suggest that a wide variety of consumer products that are used on a daily basis contain cyclic and linear siloxanes and these products can contribute considerably to human exposures.
Effect of Nutrition on Toxicity of Contaminants to the Epibenthic Amphipod Melita plumulosa
by D. A. Spadaro; T. Micevska; S. L. Simpson (pp. 711-711).