SIX YEARS AGO, on December 3, 1984, a toxic gas leak at a Union Carbide pesticide plant in Bhopal, India, released methyl isocyanate (MIC) and its reaction products. The number of persons "exposed" and "injured" remains uncertain.1 Official estimates from the Indian government place the dead at around 1800.2 Others estimate mortality to have been between 2500 and 5000 and the number of injured to have been up to 200 000.3,4