CHRONIC ARSENIC TOXICITY IN WEST BENGAL : THE WORST CALAMITY IN THE WORLD

Since 1984 arsenic toxicity due to groundwater contamination has been detected in 6 districts of West Bengal India. This paper presents findings of clinical and laboratory investigations of 156 patients admitted to a West Bengal hospital with signs of chronic arsenic toxicity. All these patients had typical raindrop-like skin pigmentation; 65.5% had thickening of the palm and sole. Other clinical features included weakness (70%) gastrointestinal symptoms (58.6%) respiratory system involvement (57.1%) nervous system involvement (50.6%) and restrictive lung disease (53%). Liver enlargement was found in 76.9% of patients and splenomegaly in 31.4%. Liver function tests revealed elevated levels of globulin in 15.8% alkaline phosphatase in 51.3% alanine amino transferase in 11.8% and aspartate amino transferase in 27.6%. Liver biopsy in 45 patients showed noncirrhotic portal fibrosis in 41 and cirrhosis in 2 patients. 34.8% had abnormal electromyography and 34.8% had altered nerve conduction velocity. 33.3% of patients had evidence of portal hypertension. There were no correlations between the quantity of arsenic ingested and the level of arsenic in hair nail and liver tissue or the degree of fibrosis. There were 5 deaths in this series: 3 from hepatic encephalopathy 1 from variceal hemorrhage secondary to portal hypertension and 1 from skin cancer. The noncancerous manifestations of arsenic toxicity observed in these patients especially those affecting the hepatic and respiratory systems were far more severe than those reported from other parts of the world. Correction of this problem will require collaboration on the part of environmental scientists chemists geologists and geohydrologists engineers social scientists and medical practitioners.