Tetra-Ethyl Lead Poisoning

Tetra-ethyl lead is the active ingredient of ethyl fluid, an antiknock compound which for many years past has been widely used by the oil industry for addition to petrol. The toxic properties of tetra-ethyl lead are well known and have been very completely investigated and described-notably by Kehoefollowing the occurrence of cases of poisoning when the manufacture of this substance was begun on a commercial scale in the United States in 1924. The absence hitherto of any cases of tetra-ethyl lead poisoning in this country has probably distracted attention from the possibility of its occurrence, and it may be timely to show how it can occur and to recall the symptoms, diagnosis, and treatment of the condition. Properties of Tetra-ethyl Lead.-Owing to its ready miscibility with fats and oil, tetra-ethyl lead can be absorbed through the intact skin. The vapour given off is readily absorbed through the pulmonary epithelium, and though the substance is of low volatility its vapour pressure is of great significance toxicologically, since it is chiefly from inhalation of the vapour that poisoning is liable to occur. Air saturated with its vapour at ordinary temperatures contains approximately 5 mg. of lead per litre. Its toxicity is a function of the lead content and not of any peculiar qualities characteristic of the compound, but its fat-soluble character allows selective localization in the nervous tissues of the body, and for this reason tetra-ethyl lead poisoning is essentially a central nervous system intoxication (Kehoe, 1925, 1927). Aetiology