Dimethyl sulfate poisoning in China: a fatal case and a 45-year retrospective study

Dimethyl sulfate (DMS) is a highly toxic chemical that appears innocuous and is commonly used as a methylating agent in industry. It can be readily absorbed leading to poisoning or death through the skin or mucous membranes of the respiratory tract in the process of production or transportation. Although there are some articles on treatment for DMS poisoning, reports of death resulting from acute fatal DMS poisoning are very rare. Here, we present a case of a 50-year-old Chinese man who died accidentally from DMS poisoning after he broke a plastic storage tank full of DMS during transportation. The patient complained of eye irritation. In addition, the corrosive damage could be seen in his corneas and skin. The autopsy revealed erosions and ulcers in the respiratory tract, as well as massive congestion, necrosis, edema, and pseudomembrane formation on the mucous layer of the trachea and main bronchi. Histopathological examination confirmed extensive pulmonary edema, multifocal hemorrhages, whole-cell swelling in the brain, as well as disintegration of the neuronal cell. We inferred that DMS poisoning caused the symptoms resulting from the production of methanol and sulfate through hydrolysis, including respiratory toxicity and neurotoxicity, and these symptoms had temporal continuity. Toxicological analysis revealed no DMS or methanol, but formic acid was detected in the brain, both qualitatively and quantitatively. In this report, we also present a retrospective study of 8 similar cases of DMS poisoning in literature in China, including some clinical data and autopsy information.