Time filter

Source Type

Keswick, VA, United States

Staples C.,Assessment Technologies | Mihaich E.,SABIC | Ortego L.,Bayer CropScience | Caspers N.,Eco toxico consulting | And 3 more authors.
Environmental Toxicology and Chemistry | Year: 2016

The chronic toxicity of BPA to oligochaete Lumbriculus variegates, midge Chironomus riparius, and estuarine amphipod Leptocheirus plumulosus, which are representative of invertebrates occupying the base of the benthic food web, was studied using life cycle tests. No-observed-effect concentrations (NOEC) for the three species ranged from 12 to 54 mg/kg dry weight. The number of oligochaete was reduced at 1.6 mg/L, but not in a dose-dependent manner, since no effect was found for the next three higher concentrations. For the midge, percentage of emergence was reduced at 110 mg/kg, but not 54 mg/kg dry weight. Development rate and survival were unaffected at concentrations ≥ 210 mg/kg dry weight, while for the amphipod, survival and reproduction were reduced in a dose-dependent mode at 78 mg/kg, but not 32 mg/kg dry weight, whereas growth was reduced at 32 mg/kg but not 12 mg/kg dry weight. Lowest-observed-effect concentration and NOEC values were all well above concentrations of BPA measured in sediments collected from North America and Europe.

Arnold S.M.,Dow Chemical Company | Clark K.E.,BEC Technologies | Staples C.A.,Assessment Technologies | Klecka G.M.,Dow Chemical Company | And 2 more authors.
Journal of Exposure Science and Environmental Epidemiology | Year: 2013

A comprehensive search of studies describing bisphenol A (BPA) concentrations in drinking water and source waters (i.e., surface water and groundwater) was conducted to evaluate the relevance of drinking water as a source of human exposure and risk. Data from 65 papers were evaluated from North America (31), Europe (17), and Asia (17). The fraction of drinking water measurements reported as less than the detection limit is high; 95%, 48%, and 41%, for North America, Europe, and Asia, respectively. The maximum quantified (in excess of the detection limit) BPA concentrations from North America, Europe, and Asia are 0.099 μg/l, 0.014 μg/l, and 0.317 μg/l. The highest quantified median and 95th percentile concentrations of BPA in Asian drinking water are 0.026 μg/l and 0.19 μg/l, while high detection limits restricted the determination of representative median and 95th percentile concentrations in North America and Europe. BPA in drinking water represents a minor component of overall human exposure, and compared with the lowest available oral toxicity benchmark of 16 μg/kg-bw/day (includes an uncertainty factor of 300) gives margins of safety >1100. Human biomonitoring data indicate that ingestion of drinking water represents <2.8% of the total intake of BPA.© 2013 Nature America, Inc. All rights reserved.

Mihaich E.,SABIC | Rhodes J.,ABC Laboratories | Wolf J.,Experimental Pathology Laboratories | van der Hoeven N.,EcoStat | And 7 more authors.
Environmental Toxicology and Chemistry | Year: 2012

Bisphenol A (BPA) is an intermediate used to produce epoxy resins and polycarbonate plastics. Although BPA degrades rapidly in the environment with aquatic half-lives from 0.5 to 6 d, it can be found in aquatic systems because of widespread use. To evaluate potential effects from chronic exposure, fathead minnows were exposed for 164 d to nominal concentrations of 1, 16, 64, 160, and 640μg/L BPA. Population-level endpoints of survival, growth, and reproduction were assessed with supplemental endpoints (e.g., vitellogenin, gonad histology), including gonad cell type assessment and quantification. No statistically significant changes in growth, gonad weight, gonadosomatic index, or reproduction variables (e.g., number of eggs and spawns, hatchability) were observed; however, there was a significant impact on male survival at 640μg/L. Vitellogenin increased in both sexes at 64μg/L or higher. Gonad cell type frequencies were significantly different from controls at 160μg/L or higher in males with a slight decrease in spermatocytes compared with less mature cell types, and at 640μg/L in females with a slight decrease in early vitellogenic cells compared with less mature cells. The decrease in spermatocytes did not correspond to a decrease in the most mature sex cell type (spermatozoa) and did not impair male fertility, as hatchability was not impacted. Overall, marginal shifts in gametogenic cell maturation were not associated with any statistically significant effects on population-relevant reproductive endpoints (growth, fecundity, and hatchability) at any concentration tested. © 2012 SETAC.

Klecka G.M.,Dow Chemical Company | Staples C.A.,Assessment Technologies | Losey B.,RegNet Environmental Services
Water Environment Research | Year: 2010

Nonylphenol ethoxylates (NPEs) are surfactants often used in applications that result in their disposal and treatment in wastewater treatment plants (WWTPs). In this study, three municipal activated sludge WWTPs, receiving primarily residential wastewater, were monitored, with their receiving waters, to determine the occurrence of NPEs and their biodegradation metabolites, including nonylphenol (NP), low-mole and higher-mole nonylphenol ethoxylates (NPE1, NPE2-8, and NPE≥9), and nonylphenol ether carboxylates (NPECs). The facilities were moderately sized and operating normally when influent and effluent samples were taken. Treatment efficiencies, taking into account concentrations of the parent ethoxylate and metabolites, ranged from 97.2 to 99.8%. Samples of receiving stream water, sediment, and pore water were collected upstream, downstream at the end of the mixing zones, and farther downstream from the WWTP discharges, to determine the occurrence of NPE and their metabolites and to assess the potential effect on the receiving stream ecosystems. Concentrations of nonylphenol or total nonylphenol equivalents measured upstream (<0.02 to 1.29 μg/L), at the end of the mixing zone (0.2 to 3.15 μg/L), and farther downstream (<0.02 to 1.84 μg/L) were compared with the recently established national ambient water quality chronic criteria of 6.6 μg/L. On the basis of this analysis, the likelihood of adverse effects on aquatic species within the three receiving streams is low.

Staples C.,Assessment Technologies | Friederich U.R.S.,Dow Chemical Company | Hall T.,Bayer CropScience | Klecka G.,Dow Chemical Company | And 4 more authors.
Environmental Toxicology and Chemistry | Year: 2010

Bisphenol A (BPA) is a high production volume substance primarily used to produce polycarbonate plastic and epoxy resins. During manufacture and use, BPA may enter wastewater treatment plants. During treatment, BPA may become adsorbed to activated sludge biosolids, which may expose soil organisms to BPA if added to soil as an amendment. To evaluate potential risks to organisms that make up the base of the terrestrial food web (i.e., invertebrates and plants) in accordance with international regulatory practice, toxicity tests were conducted with potworms (Enchytraeids) and springtails (Collembolans) in artificial soil, and six plant types using natural soil. No-observed-effect concentrations (NOEC) for potworms and springtails were equal to or greater than 100 and equal to or greater than 500 mg/kg (dry wt), respectively. The lowest organic matter-normalized NOEC among all tests (dry shoot weight of tomatoes) was 37 mg/kg-dry weight. Dividing by an assessment factor of 10, a predicted-no-effect concentration in soil (PNECsoil) of 3.7 mg/kg-dry weight was calculated. Following international regulatory guidance, BPA concentrations in soil hypothetically amended with biosolids were calculated using published BPA concentrations in biosolids. The upper 95th percentile BPA biosolids concentration in North America is 14.2 mg/kg-dry weight, and in Europe is 95 mg/kg-dry weight. Based on recommended biosolids application rates, predicted BPA concentrations in soil (PECsoil) would be 0.021 mg/kg-dry weight for North America and 0.14 mg/kg-dry weight for Europe. Hazard quotients (ratio of PECsoil and PNECsoil) for BPA were all equal to or less than 0.04. This indicates that risks to representative invertebrates and plants at the base of the terrestrial food web are low if exposed to BPA in soil amended with activated sludge biosolids. © 2009 SETAC.

Discover hidden collaborations