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Risk assessment of cumulative environmental exposure to perchlorate, nitrate and thiocyanate based on NHANES biomonitoring data

We are pleased to announce a recently published study by scientists from ToxStrategies that evaluated the National Health and Nutrition Examination Survey (NHANES) data from multiple survey cycles to assess potential effects to thyroid hormones from cumulative exposures to perchlorate, nitrate, and thiocyanate. This study, titled “The effect of perchlorate, nitrate, and thiocyanate on free thyroxine for potentially sensitive subpopulations of the 2001-2002 and 2007-2008 National Health and Nutrition Examination Survey,” was published in the Journal of Exposure Science and Environmental Epidemiology. Using the NHANES data, we conducted multiple regression models of free thyroxine (T4) in serum and urinary chemical concentrations, which also included covariates known to impact thyroid hormone status. In addition, meta–analyses of the NHANES females in the two survey cycles were conducted. We observed that perchlorate, nitrate, and thiocyanate can affect free T4 levels in non-pregnant females. The effects were not observed in males and pregnant females. Our study indicates that the potential for cumulative risk of co-exposures exist, and risk assessment of perchlorate exposures should be conducted in consideration of effects from nitrate and thiocyanate exposures.