Arsenic in the environment: effects on human health and possible prevention.

Arsenic is a major environmental pollutant and exposure occurs through environmental, occupational and medicinal sources. The contaminated drinking water is the main source of exposure and affected countries are India (West Bengal), Bangladesh, China, Taiwan, Thailand, Chile, Argentina and Romania. Concentrations of arsenic in affected areas are several times higher than the maximum contamination level (MCL) (10 microg/l). Arsenic exposure to human results in degenerative, inflammatory and neoplastic changes of skin, respiratory system, blood, lymphatic system, nervous system and reproductive system. There is no particular remedial action for chronic arsenic poisoning. Low socioeconomic status and malnutrition may increase the risk of chronic toxicity. Early intervention and prevention can give the relief to the affected population.

Effect of chronic choline availability on lung and lymph nodes of rat.

Male albino rats were given intraperitoneal injections of choline chloride (0·1,0·33 or 0·5 × lethal dose 50) for a total period of one month and then killed at the end of 30,90 and 240 days for the study of pathotoxicokinetics of choline. Chronic choline administration in rats caused a decrease in growth rate, a dose dependent modulating effect on the somatic tissue indices of lung and lymph nodes, as well as cellularity of lymph nodes. In another experiment, the effect of choline on mica induced pulmonary lesions was studied. The combined effect of choline and mica caused adenocarcinoma of bronchiolar epithelium and marked lymphadenopathy with abnormal cells in the lymph nodes at the termination of experiment (330 days). The results of the present investigation suggest that excess choline availability not only produces pulmonary pathological lesions by itself but it also further enhances the lung lesions in altered pulmonary conditions.