ing water (Giblin et al., 2000a,b; Herman and Frankenberger, 1999; Miller and Logan, 2000; Wallace et al., Perchlorate (ClO 4 ) contamination of ground water and surface 1998; Kim and Logan, 2000, 2001). Factors that affect the water is a widespread problem, particularly in the western United States. This study examined the effect of biodegradation on perchlofate and transport of perchlorate in...

BACKGROUND Findings from a recent large study suggest that perchlorate at commonly occurring exposure concentrations may decrease thyroid hormone levels in some women. Decreases in thyroid hormone seen with perchlorate exposure could be even greater in people with concomitant exposure to agents such as thiocyanate that may affect the thyroid by mechanisms similar to those of perchlorate. OBJE...

The effect of nitrate on perchlorate and chlorate reduction by perchlorate-respiring bacteria (PRB), and on chlorate reduction by chlorate-respiring bacteria (CRB), is not well understood, particularly with respect to the induction of pathways used to degrade these different chemicals. Based on kinetic data obtained in a series of batch tests, we determined that perchlorate respiratory enzymes ...

Ammonium and potassium perchlorate are strong oxidants widely employed in the pyrotechnic compositions in fireworks. Although its reduction is thermodynamically highly favorable, the perchlorate anion’s reactivity is kinetically inhibited, primarily attributable to steric hindrance of access to the central chlorine atom within the tetrahedral ClO4 structure. This relative inactivity has histori...

CONTEXT Thyroid hormone, requiring adequate maternal iodine intake, is critical for fetal neurodevelopment. Perchlorate decreases thyroidal iodine uptake by competitively inhibiting the sodium/iodide symporter. It is unclear whether environmental perchlorate exposure adversely affects thyroid function in pregnant women. Thiocyanate, derived from foods and cigarette smoke, is a less potent compe...

The development of perchlorate-free hand-held signal illuminants for the US Army's M195 green star parachute is described. Compared with the perchlorate-containing control, the optimized perchlorate-free illuminants were less sensitive toward various ignition stimuli while offering comparable burn times and visible-light outputs. The results were also important from the perspective of civilian ...

Perchlorate (ClO4−) is globally enriched in Martian regolith at levels commonly toxic to plants. Consequently, perchlorate presents an obstacle developing agriculture on Mars. Here, we assess the effect of different concentrations plant growth and germination, as well metal release a simulated Gusev Crater generic potting soil. The presence was uniformly detrimental regardless growing medium. P...

in this work we introduce a practical use of synthesized schiff base metal complex in sensing application. a new perchlorate-selective electrode based on the complex n, n'-4-nitro-phenylmethanebis-(salicylaldiminato) copper (ii) [cul] as the membrane carrier was developed. the electrode exhibits a good  nernstian slope of -55.0 ± 1.0 mv/decade and a linear range of  for perchlorate. the limit o...

A series of microcosm experiments were performed to determine the effectiveness of various gaseous electron donors (including hydrogen, 1-hexene, ethyl acetate, and liquefied petroleum gas [LPG]) for supporting biological perchlorate reduction under different electron donor concentrations and soil moistures. Under high soil moisture (16% w/w) conditions, complete or partial perchlorate degradat...

This study was undertaken to determine the kinetics of uptake and elimination of perchlorate in channel catfish, Ictalurus punctatus. Perchlorate--an oxidizer used in solid fuel rockets, fireworks, and illuminating munitions--has been shown to effect thyroid function, causing hormone disruption and potential perturbations of metabolic activities. For the uptake study, catfish were exposed to 10...