Examination of xylene exposure in the U.S. Population through biomonitoring: NHANES 2005–2006, 2011–2016

Abstract

Aim: Xylenes are aromatic hydrocarbons used for industrial applications such as the production of petrochemicals and plastics. Acute xylene exposures can negatively impact health through neurotoxicity and irritation of respiratory and dermal tissues. We quantified urinary biomarkers of xylene exposure [2-methylhippuric acid (2MHA) and a mixture of 3- and 4-methylhippuric acids (34MH)] in a representative sample of the U.S. population.

Methods: Spot urine obtained during the National Health and Nutrition Examination Survey 2005–2006 and 2011–2016 was analysed using ultra-high-performance liquid chromatography/tandem mass spectrometry. Exclusive smokers were distinguished from non-users using a combination of self-report and serum cotinine data.

Results: The median 2MHA and 34MH levels were higher for exclusive smokers (100 µg/g and 748 µg/g creatinine, respectively) than for non-users (27.4 µg/g and 168 µg/g creatinine, respectively). Participants who smoked cigarettes had significantly higher 2MHA and 34MH levels (p < 0.0001) than unexposed participants. Smoking 1–10, 11–20, and >20 cigarettes per day (CPD) was significantly associated with 181%, 339% and 393% higher 2MHA levels, respectively. For 34MH, smoking 1–10, 11–20, and >20 CPD was significantly associated with 201%, 398%, and 471% higher 34MH levels, respectively.

Conclusion: We confirm that tobacco smoke is a significant source of xylene exposure as measured by urinary 2MHA and 34MH levels.

Keywords:

• Xylene
• VOC metabolites
• tobacco smoke exposure
• biomonitoring
• NHANES

Acknowledgements

The authors would like to thank Ms. Brittany Pine for discussions of the data for this study. The views and opinions expressed in this report are those of the authors and do not necessarily represent the views, official policy or position of the US Department of Health and Human Services or any of its affiliated institutions or agencies. Use of trade names is for identification purposes and does not imply endorsement by the Centers for Disease Control and Prevention, the Public Health Service, or the US Department of Health and Human Services.

Disclosure statement

No potential conflict of interest was reported by the author(s).