Lab Matters Summer 2019 - Page 18

FROM THE BENCH Measuring Human Exposures to Triclosan and Parabens by Jed Waldman, PhD, laboratory manager, California Department of Public Health Environmental Health Laboratory; Qi Gavin, MS, research scientist, California Department of Public Health Environmental Health Laboratory and Jianwen She, PhD, section chief, California Department of Public Health Environmental Health Laboratory The California Environmental Contaminant Biomonitoring Program (Biomonitoring California) conducts studies to measure chemical levels in the state’s population and track those exposures over time. Antimicrobial agents have been included in many of these studies. Triclosan (TCS) was previously widely used in “antibacterial” or “antimicrobial” liquid soaps and body washes until this use was banned by the Food & Drug Administration (FDA) in 2016. But TCS is still used in healthcare antiseptics, in some toothpaste and cosmetics. It can also be added to household products like cutting boards, toys and garden hoses. Parabens are antimicrobial compounds also widely used as preservatives in cosmetics and pharmaceutical products, and to prolong the shelf life of various foods. There is evidence that TCS and parabens can affect the endocrine system even at low levels. These compounds are primarily excreted in urine as conjugates formed with glucuronic acids or sulfates. To monitor exposures in urine, our laboratory uses a method that deconjugates then measures the parent compounds for six phenolic compounds (including TCS) and four parabens by high-pressure liquid chromatography (HPLC) tandem mass spectrometry (MS/MS). Urinary measurements provide a sensitive assessment of chemical exposures in human subjects, with limits of detection of 0.2 to 0.5 ng/ml (or part per billion, ppb). TCS and parabens—particularly methyl paraben (MPB)—have been detected frequently by Biomonitoring California in studies of various groups, including pregnant women, firefighters and adults in the Central Valley. In the Health and 16 LAB MATTERS Summer 2019 Environmental Research in Make-up of Salinas Adolescents (HERMOSA) Study led by the University of California at Berkeley, a cohort of 100 Latina teens restricted their use of products containing certain endocrine-disrupting compounds for three days. Our laboratory analyzed urine samples collected before and after this intervention. Urinary concentrations were reduced by 36% for TCS and 44% for MPB following the intervention. These results showed how consumer choices could significantly affect the levels in human subjects for some compounds of concern. In a repeat of the HERMOSA design, a Good Morning America reporter used only low-paraben cosmetics for four days; the laboratory found that her urinary MPB level had dropped by more than twenty- fold after this intervention. It is difficult to compare results across Biomonitoring California studies because of differences in demographics and the relatively small numbers of study participants. However, it is notable that the levels of TCS measured in urine samples collected from adult women in the California Regional Exposure Study in Los Angeles County in 2018 after the FDA ban were much lower than the levels found in adult participants of earlier Biomonitoring California studies, as well as levels measured in the 2013-14 cycle of the National Health and Nutrition Examination Survey (NHANES). Our most recent study of adults in northern California (urine samples collected in 2018) also measured comparably lower TCS levels. This is one example of the power of biomonitoring surveillance to demonstrate the effectiveness of regulatory efforts and consumer choices to reduce chemical exposures. n References ABC, 2016. Chemical Regulations: What Is Really in Your Makeup? Good Morning America (December 8, 2016) reported by Serena Marshal. Lifestyle/chemical-regulations-makeup/ story?id=44033705 Biomonitoring California, 2018. Triclosan Fact Sheet. Available https://biomonitoring. TriclosanFactSheet.pdf Biomonitoring California, 2019. Biomonitoring California Projects. projects US Centers for Disease Control and Prevention, 2019. Fourth Report on Human Exposure to Environmental Chemicals, Updated Tables, (January 2019). Atlanta, GA: US Department of Health and Human Services. https://www.cdc. gov/exposurereport/ Federal Register, 2016. Safety and Effectiveness of Consumer Antiseptics; Topical Antimicrobial Drug Products for Over-the-Counter Human Use. A rule by the Food and Drug Administration, 9/6/2016. documents/2016/09/06/2016-21337/safety- and-effectiveness-of-consumer-antiseptics- topical-antimicrobial-drug-products-for Food and Drug Administration, 2019. Antibacterial Soap? You Can Skip It, Use Plain Soap and Water. consumers/consumer-updates/antibacterial- soap-you-can-skip-it-use-plain-soap-and-water Gavin QM, Ramage RT, Waldman JM, She J, 2013. Development of HPLC-MS/MS method for the simultaneous determination of environmental phenols in human urine. Intern. J. Environ. Anal. Chem. 94: 168-182. https://doi. org/10.1080/03067319.2013.814123 Harley KG et al. 2016. Reducing Phthalate, Paraben, and Phenol Exposure from Personal Care Products in Adolescent Girls: Findings from the HERMOSA Intervention Study. Environ Health Perspect. 124:1600–1607. http://dx.doi. org/10.1289/ehp.1510514 PublicHealthLabs @APHL