BPA exposure tests in questionby Melissa Stamm Feb. 8, 2011, 8:37 AM
The safety of industrial chemicals bisphenol A (BPA) and alkylphenols, which are used in commercial products like plastics, has recently been called into question. Exposure to these chemicals is typically measured by their excretion in urine, but impaired kidney function may make such measurements inaccurate.
To assess how kidney function influences urinary excretion of these compounds, Qi Dai, Chuan-Ming Hao and colleagues calculated renal function in 2,573 adults without known kidney impairment. In Environmental Health Perspectives, they report that between 42.6 percent and 58.2 percent of subjects had mildly to significantly reduced renal function. Urinary excretion of triclosan (an alkylphenol), and possibly BPA, decreased with decreasing renal function. These associations differed by age and sex of the subject.
Whether the reduced urinary excretion indicates that the chemicals accumulate in the body or are metabolized through another pathway, the findings suggest that more study is needed to determine the value of these measures as biomarkers of exposure.