Fate of perchlorate in a man-made reflecting pond following a fireworks display in Albany, New York, USA.

Perchlorate is a widespread contaminant in aquatic environments. Despite this, the aquatic environmental fate of perchlorate released from fireworks displays is not well known. In the present study, we examined the fate of perchlorate in man-made reflecting ponds, from 2008 to 2010, following three fireworks displays in Albany, New York, USA. Immediately after the fireworks display, perchlorate in pond waters increased significantly, with concentrations from 30 to 1,480 times higher than the baseline values. Perchlorate concentrations in pond water increased from 0.11 µg/L to up to 519 µg/L, following the fireworks display in 2008. Perchlorate concentrations in pond water decreased at a first-order kinetic degradation rate, with a mean k(obs) value of 0.026 d⁻¹ and an average half-life of 29 d. The rate of perchlorate deposition into water bodies following fireworks displays was estimated to range from 670 to 2,620 g/ha. We also estimated the perchlorate ingestion rate by the inhalation of aerosols of pond water by people frequently near the ponds. The estimated daily intake of perchlorate through the ingestion of aerosols was 32% (226 ng/kg body wt), 13% (92 ng/kg body wt), and 6% (42 ng/kg body wt) of the U.S. Environmental Protection Agency's reference dose for infants, children, and adults, respectively.

Perchlorate in human blood serum and plasma: Relationship to concentrations in saliva.

The perchlorate anion (ClO(4)(-),MW=99) is present in food, drinking water, groundwater, and surface waters. Exposure to perchlorate is of concern, due to the ability of the anion to disrupt the function of the thyroid gland, and affect the synthesis of thyroid hormones. In this study, liquid chromatography - tandem mass spectrometry (LC-MS/MS) method has been optimized to analyze for perchlorate in blood sera and plasma samples from 84 US donors. In addition, 15 volunteers provided saliva and serum samples concurrently, to enable assessment of the ratio of perchlorate in these two matrices. Recoveries of perchlorate from fortified blanks and from serum/plasma samples were between 92% and 97%. Replicate analysis of blood-matrix spikes had a relative standard deviation (RSD) of <3%, and the relative percent difference (RPD) of repeat analysis of samples was <4%. Perchlorate concentrations in serum and plasma ranged from below the limit of quantitation (0.05ngmL(-1)) to a maximum of 7.7ngmL(-1). Perchlorate concentrations in serum and plasma were log-normally distributed. The mean and median concentrations of perchlorate in 84 serum and plasma samples were 0.32 and 0.17ngmL(-1), respectively. No significant difference existed in perchlorate concentrations between serum and plasma. Analysis of paired saliva and serum samples showed a significant positive correlation for log-normalized perchlorate concentrations (r(2)=0.60) and perchlorate concentrations themselves (r(2)=0.86). The mean saliva:serum concentration ratio of perchlorate was 14:1 (after exclusion of two pairs of outliers). This is the first report to provide measurement data for perchlorate in blood sera and plasma of populations in the US.

Occurrence of perchlorate in drinking water, groundwater, surface water and human saliva from India.

Perchlorate (ClO(4)(-)), which is used as an oxidizer in jet and rocket fuels, pyrotechnic devices and explosives, is a widespread contaminant in surface waters and groundwater of many countries. Perchlorate is known to affect thyroid function. Despite the compound's widespread occurrence and potential health effects, perchlorate levels in drinking water in India are not known. In this study, water samples collected from 13 locations in six states (n=66), and saliva samples collected from four locations in three states (n=74) in India, were analyzed for perchlorate using high performance liquid chromatography interfaced with tandem mass spectrometry (HPLC-MS/MS). Perchlorate was detected in most (76%) of the water samples analyzed at concentrations above the quantitation limit of 0.02 microg L(-1); concentrations ranged from <0.02 to 6.9 microg L(-1) (mean: 0.42+/-1.1 microg L(-1); median: 0.07 microg L(-1)). Mean concentrations of perchlorate in drinking water, groundwater, bottled water, surface water and rain water were 0.1, 1.0, <0.02, 0.05 and <0.02 microg L(-1), respectively. From a total of 66 water samples analyzed, only three samples contained perchlorate levels above 1 microg L(-1); all three were groundwater samples. Perchlorate was found in the saliva samples analyzed at concentrations above 0.2 microg L(-1) and up to 4.7 microg L(-1) (mean: 1.3+/-1.3 microg L(-1); median: 0.91 microug L(-1)). No remarkable differences in perchlorate concentrations were found among the sampling locations of water or saliva or in subgroups stratified by gender or age. Perchlorate concentrations in water samples from India are one to two orders of magnitude lower than the concentrations reported for the United States.

Analysis of perchlorate in human saliva by liquid chromatography-tandem mass spectrometry.

Perchlorate is both a naturally occurring anion and the disassociated anion of manufactured perchlorate salts. Because perchlorate has the abilityto blockthe uptake of iodide bythe thyroid gland, it is considered a potent thyroid hormone disruptor in humans. Methods for the analysis of perchlorate in biological matrices are needed to enable assessment of exposures and to elucidate adverse health outcomes. This study describes a method for the analysis of perchlorate in human saliva samples, using a simple dilution and ultrafiltration technique. Quantification of perchlorate in saliva samples using isotopically labeled standards (Cl18O4) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) offers great selectivity and sensitivity. Matrix effects in perchlorate analysis are compensated by spiking of saliva samples with an isotopically labeled internal standard for perchlorate. The LC-MS/MS calibration was found to be linear over the range from 0.01 to 50 ng/mL for 100 microL injections (i.e., 1-5000 pg injection). Fortified blank and matrix spike recoveries were between 93% and 97%, when spiked at a 2 ng/mL level. Relative standard deviations (RSDs) of daily calibration checks and fortified blanks were < or =10%. The relative percent difference, in laboratory duplicate analysis of original samples, was less than 1%. The method quantitation limit (LOQ) was determined to be 0.4 ng/mL, which includes a sample dilution factor. Salivary concentrations of a convenience sample of 83 persons working and/or living in Albany County of New York State ranged from 0.4 to 37 ng/mL with a mean concentration of 5.3 ng/mL Including sample preparation steps, 25 samples can be analyzed within 8 h. This selective and rapid method for analysis of perchlorate in human saliva will enable investigators and scientists to determine the extent of an individual's perchlorate exposure and, potentially, the compound's effects on human health. Analysis of perchlorate in saliva from a population (n = 86) with no major sources of exposures, using the method developed in this study, suggests the ubiquitous occurrence of this compound in saliva.