Chronic industrial exposure to lead in 63 subjects. II. Evaluation of chelation therapy.

Efficacy of chelation therapy with intravenous calcium disodium edetate, oral Ca EDTA, and oral penicillamine was tested in 63 subjects with chronic minimal industrial exposure to lead. All three agents increased the urinary lead excretion. The effect was greatest with intravenous Ca EDTA, next with oral penicillamine and least with oral Ca EDTA. Symptoms, particularly colicky abdominal pain, improved during the period of chelation therapy. Anaemic subjects showed improvements in haematological parameters. It is recommended that subjects with chronic minimal industrial exposure to lead receive chelation therapy. The relative merits of the three agents are discussed.