Unintentional drinking-water contamination events of unknown origin: surrogate for terrorism preparedness.

Drinking-water is a direct conduit to many human receptors. An intentional attack (e.g.

Gestational exposure to high perchlorate concentrations in drinking water and neonatal thyroxine levels.

Objective: To assess the effect of gestational perchlorate exposure through drinking water on neonatal thyroxine (T(4)).

Design: T(4) values were compared among newborns in Ramat Hasharon, Israel, whose mothers resided in suburbs where drinking water contained perchlorate < or = 340 microg/L (very high exposure, n = 97), 42-94 microg/L (high exposure, n = 216), and < 3 microg/L (low exposure, n = 843). In the very high and high exposure areas, T(4) values in newborns whose mothers drank tap water exclusively (as determined by a telephone interview) were analyzed as a subset.

Antioxidants and total oxyradical scavenging capacity during grass shrimp, Palaemonetes pugio, embryogenesis.

During embryogenesis in grass shrimp the capacity to scavenge oxyradicals increased as measured by the Total Oxyradical Scavenging Capacity (TOSC) assay. The increase in TOSC during embryogenesis was associated with increasing concentrations of a number of antioxidants, including coenzyme Q (ubiquinone), alpha-tocopherol and reduced glutathione. Glutathione concentrations ranged from 0.

Antioxidant defenses in killifish (Fundulus heteroclitus) exposed to contaminated sediments and model prooxidants: short-term and heritable responses.

A population of killifish (Fundulus heteroclitus) inhabiting a Superfund site on the Elizabeth River (VA, USA) is tolerant of the acute toxicity of the sediments from the site; previous work suggests that this tolerance is based both on genetic adaptation and physiological acclimation. In this study, larval first- and second-generation (F1 and F2) offspring of Elizabeth River killifish were more resistant to the toxicity of t-butyl hydroperoxide (a model prooxidant) than were King's Creek (reference site) offspring, indicating a heritable tolerance of exposure to oxidative stress. In laboratory experiments designed to elucidate the mechanistic basis for this increased tolerance, we exposed laboratory-raised F1 and F2 offspring from Elizabeth River and King's Creek killifish to Elizabeth River sediments, menadione, or t-butyl hydroperoxide, and measured the following antioxidant parameters: total oxyradical scavenging capacity (TOSC); glutathione content (total and disulfide); activities of glutathione reductase (GR); glutathione peroxidase (GPx); and glutamate cysteine ligase (GCL) activities and protein levels of copper-zinc superoxide dismutase (CuZnSOD); and protein levels of manganese superoxide dismutase (MnSOD).

Integrating enzymatic responses to organic chemical exposure with total oxyradical absorbing capacity and DNA damage in the European eel Anguilla anguilla.

In this work, susceptibility to oxidative stress was analyzed under laboratory conditions in the European eel Anguilla anguilla. Eels were treated with increasing concentrations of benchmark environmental pollutants, namely, benzo[a]pyrene ([BaP], at 0, 0.1, 1, 10, and 50 mg/kg), beta-naphthoflavone ([BNF], at 0, 0.

A tap water turbidity crisis in Tel Aviv, Israel, due to technical failure: toxicological and risk management issues.

Herein, we report on the actual events linked to an ammonia spillage into the main waterline of the Tel-Aviv metropolitan area and its surrounding municipalities. Based upon a large magnitude increase of unknown origin in the turbidity and ammonia levels of the main drinking water supply, area residents were warned of possible serious contamination and advised to refrain from drinking tap water until further notice. Turbidity was later linked only to CaCO3, which was precipitated from the water due to the rise in pH caused by the excessive ammonia levels.

Application of biomarkers for assessing the biological impact of dredged materials in the Mediterranean: the relationship between antioxidant responses and susceptibility to oxidative stress in the red mullet (Mullus barbatus).

In the period 1997-2000, approximately 1,800,000 m3 of material dredged from the Port of Leghorn was discharged into a sea dumping site located 14 miles from the coast. The red mullet (Mullus barbatus) was used as a bioindicator species for monitoring the biological impact of these discharges on a geographical and temporal scale. Organisms were sampled over three years (1998-2000) at different stations and several biomarkers, both of exposure and effect, were analyzed.

Bioorganic mechanisms of the formation of free radicals catalyzed by glucose oxidase.

In this communication, we have described the activation of several xenobiotics by glucose oxidase from Aspergillus niger. The following compounds are readily reduced by d-glucose, in the presence of glucose oxidase: p-nitroso-N,N-dimethylaniline, methyl-1,4-benzoquinone, and 7,7,8,8-tetracyano-quinodimethane. In each case, the products of enzymatic reduction undergo a dismutation reaction with the parent compound and thus afford the formation of free radicals.