Urinary thiocyanate concentrations are associated with adult cancer and lung problems: US NHANES, 2009-2012

Links between environmental chemicals and human health have emerged but the effects from perchlorate, nitrate and thiocyanate were unclear. Therefore, it was aimed to study the relationships of urinary perchlorate, nitrate and thiocyanate concentrations and adult health conditions in a national and population-based study. Data was retrieved from US National Health and Nutrition Examination Surveys, 2009-2012, including demographics, blood pressure readings, self-reported health conditions and urinary perchlorate, nitrate and thiocyanate concentrations. Analyses included chi-square test, t test survey-weighted logistic regression models and population attributable risk estimation. There were no clear associations between urinary perchlorate concentrations and adult health conditions, although people with hearing loss and diabetes could be at the borderline risk. Urinary thiocyanate concentrations were significantly associated with emphysema (odds ratio (OR) 2.70 95% confidence intervals (CI) 1.91-3.82, P < 0.001), cancer (OR 1.21 95%CI 1.06-1.39, P = 0.008), chronic bronchitis (OR 1.23 95%CI 1.10-1.52, P = 0.003), wheezing (OR 1.24 95%CI 1.05-1.46, P = 0.011), coughing (OR 1.19 95%CI 1.03-1.37, P = 0.018) and sleep complaints (OR 1.14 95%CI 1.02-1.26, P = 0.019). The population attributable risks accounted for 3.3% (1.8-5.3%), 1.9% (0.6-3.5%), 1.2% (0.5-2.6%), 2.2% (0.5-4.1%), 1.8% (0.3-6.2%) and 1.3% (0.2-2.4%) for emphysema, cancer, chronic bronchitis, wheezing, coughing and sleep complaints, respectively. In addition, there was an inverse association observed between urinary nitrate level and heart failure. This is for the first time observing significant risk effects of urinary thiocyanate concentrations on adult cancer and lung problems, although the causality cannot be established. Elimination of such environmental chemical in humans should be included in future health policy and intervention programs.