Perchlorate (ClO4 ) has been detected in numerous ground and surface waters, and has recently been added to the drinking water Candidate Contaminant List in the United States. Perchlorate can be removed from drinking water using ion exchange, but this results in the production of highly saline (7–12%) perchlorate-contaminated brines. Perchlorate-degrading microbial enrichments capable of growth...

Introduction: Perchlorate (ClO4), a highly oxidizing compound, was identified on the martian surface by the Phoenix Lander at concentration levels up to 1.0% [1,2]. There is some debate as to whether an environment with perchlorate salts is too harsh for any organism to survive. Methanogens are able to survive in a numerous unwelcoming environments. Due to their ability to survive in extreme co...

The Colorado River is contaminated with low levels of perchlorate. Perchlorate has the potential to disrupt thyroid function by inhibiting the uptake of iodide. Brassica are rich sources of thiocyanate and nitrate, also inhibitors of iodide uptake. This study was conducted to estimate potential human exposure to perchlorate, thiocyanate, and nitrate from Brassica sp. irrigated with Colorado Riv...

Perchlorate is a persistent and mobile contaminant in the environment with both natural and anthropogenic sources. Stable isotope ratios of oxygen (δ(18)O, Δ(17)O) and chlorine (δ(37)Cl) along with the abundance of the radioactive isotope (36)Cl were used to trace perchlorate sources and behavior in the Laurentian Great Lakes. These lakes were selected for study as a likely repository of recent...

BACKGROUND Perchlorate is an emerging water contaminant that disrupts normal functioning of human thyroid gland and poses serious threat to health, especially for pregnant women, fetus and children. RESULTS High level of perchlorate contamination in fresh water sources at places nearby ammonium perchlorate (rocket fuel) handled in bulk is reported in this study. Of 160 ground water samples an...

CONTEXT Breastfed infants rely on adequate maternal dietary iodine intake. OBJECTIVE Our objective was to measure breast milk iodine and perchlorate, an inhibitor of iodide transport into the thyroid and potentially into breast milk, in Boston-area women. PARTICIPANTS The study included 57 lactating healthy volunteers in the Boston area. MEASUREMENTS Breast milk iodine and perchlorate con...

Perchlorate ion interferes with thyroid function by competitively inhibiting the sodium-iodide symporter, thus blocking iodide uptake into the thyroid gland. In this study, the effect of perchlorate exposure on thyroid function and thyroid-responsive gene expression were examined in (1) embryos from eggs laid by perchlorate-treated Japanese quail hens and (2) perchlorate-treated young Japanese ...

UNLABELLED Although much work on the biochemistry of the key enzymes of bacterial perchlorate reduction, chlorite dismutase, and perchlorate reductase has been published, understanding of the molecular mechanisms of this metabolism has been somewhat hampered by the lack of a clear model system amenable to genetic manipulation. Using transposon mutagenesis and clean deletions, genes important fo...

A practical analytical method was developed for the routine analysis of perchlorate in environmental and drinking-water samples by liquid chromatography-electrospray ionization mass spectrometry (LC/ESI-MS) using an anion exchange column. By using (18)O-enriched perchlorate as an internal standard, the limits of quantification of perchlorate determined by tenfold of the signal-to-noise ratio an...

[1] Isotopic studies indicate that natural perchlorate is produced on Earth in arid environments by the oxidation of chlorine species through pathways involving ozone or its photochemical products. With this analogy, we propose that the arid environment on Mars may have given rise to perchlorate through the action of atmospheric oxidants. A variety of hypothetical pathways can be proposed inclu...