Determination of biomarkers of chlorine exposure from biological samples: a review of analysis techniques.

Chlorine gas can be toxic when inhaled or absorbed at high concentrations through the skin. It can cause pulmonary edema, pulmonary inflammation, respiratory failure, and potentially death. Monitoring chlorine exposure helps in determining treatment regimens and may inform safeguards, such as personal protective equipment and ventilation systems. Therefore, verification of chlorine exposure is crucial to protecting human health. This has led to identification of multiple biomarkers of Cl2 exposure with associated innovations in methods of analysis to monitor these markers. In this review of the last 30 years of literature, biomarkers and associated methods of detection for the determination of chlorine exposure from biological samples are detailed and critically evaluated. From the 36 included studies, the most useful biomarkers for Cl2 exposure include tyrosine adducts, chlorohydrin, chloro-fatty-acids, chloro-fatty-aldehydes, and chloro-fatty-alcohols. The most common sample preparation methods for these markers are hydrolysis and extraction and the most common analysis techniques are chromatographic separation with mass spectrometric detection. The findings of this review emphasize the need for continued research into biomarkers and stronger evaluation of proposed analytical methods, including validation, to allow more appropriate comparison, which will ultimately improve patient outcomes.