O-Chlorobenzylidene Malononitrile (CS Riot Control Agent) Exposures and Associated Acute Respiratory Illnesses in a United States Army Basic Combat Training Cohort

Abstract

Abstract : Acute Respiratory Illnesses (ARIs) are among the leading causes for hospital visits and lost work time in United States (US) military training populations. The occurrence of ARIs in military recruit populations has been well studied, but understanding of casual factors is limited. Studies consistently demonstrate an increased ARI rate during week four through six of US Army Basic Combat Training (BCT), immediately following mandatory exposure to the riot control agent o-chlorobenzylidene malononitrile (CS tear gas) during Mask Confidence Training (MCT). MCT is conducted during the first three weeks of BCT by thermally dispersing CS in a relatively air-tight structure where recruits wearing military issued M40 series protective masks enter, perform a series of exercises, remove their protective masks, and exit the structure. Recruits feel an intense burning sensation on exposed skin and, after removing the mask, almost immediate lacrimation, violent coughing spasms, and sometimes vomiting. Partly as a result of initial studies conducted for this dissertation, the US Army implemented All Army Activities Message (ALARACT) 051/2013 to decrease CS exposure concentrations and health effects associated with this training. Currently, no studies exist that quantify CS exposure concentrations in a US Army BCT population; furthermore, there are no studies that consider CS exposure as a potential risk factor for ARI diagnoses in this population.