Chronic arsenic toxicity due to drinking of arsenic-contaminated water has been a major environmental health hazard throughout the world including India. Although a lot of information is available on health effects due to chronic arsenic toxicity in adults, knowledge of such effect on children is scanty. A review of the available literature has been made to highlight the problem in children. Scientific publications on health effects of chronic arsenic toxicity in children with special reference to psychological issues are reviewed. The prevalence of skin abnormalities such as pigmentation change and keratosis, the diagnostic signs of chronic arsenic toxicity, vary in various arsenic-exposed children population in different regions of the world. The occurrence of chronic lung disease including pulmonary interstitial fibrosis has been described in arsenic-exposed children in Chile. Affection of intellectual function has also been reported to occur in arsenic-exposed children studied in Thailand, Bangladesh, and India. Methylation patterns of arsenic in children aggregate in families and are correlated in siblings, providing evidence of a genetic basis for the variation in arsenic methylation. Chronic arsenic toxicity due to drinking of arsenic-contaminated water causes significant morbidity in children resulting in skin lesions, lung disease, and defect in intellectual function.
Key words: Arsenicosis in children, Arsenic skin pigmentation, Intellectual defect, Keratosis ey words:
Many aquifers in various parts of the world have been found to be contaminated with arsenic. Of these, the most noteworthy occurrences are in large areas of India, Bangladesh, Taiwan, and Northern China. Asian countries affected are Lao PDR, Cambodia, Myanmar, Pakistan, Nepal, and Vietnam. Other countries having reports of significant arsenic contamination of groundwater are Hungary, Mexico, USA, Chile, and Argentina. In India over and above West Bengal, other states affected are Bihar, Uttar Pradesh, Jharkhand, and Assam.1 There are suffi cient evidence from human studies that chronic ingestion of inorganic arsenic causes cutaneous and systemic manifestations along with skin, bladder, and lung cancer in adults.2
Skin abnormalities such as pigmentation changes and keratosis have long been known to be hallmark signs of chronic arsenic exposure in adults. These lesions are the most common health effects found in populations exposed to arsenic-contaminated drinking water. Pigmentation and keratosis caused by arsenic are quite distinctive. The hyperpigmentation is marked by raindrop-shaped discolored spots, diffuse dark brown spots, or diffuse darkening of the skin on the limbs and trunk. Spotty depigmentation (leucomelanosis) also occurs in arsenicosis. Simple keratosis usually appears as bilateral thickening of the palms and soles, while in nodular keratosis, multiple raised keratotic lesions appear in palm and soles. Skin lesions pose an important public health problem because advanced forms of keratosis are painful, and the consequent disfigurement can lead to social isolation in the villages. In contrast to cancer which takes decades to develop, these skin lesions are generally observed 5–10 years after exposure commences.
Although limited epidemiological data exist, other reported clinical manifestations resulting from ingestion of arsenic-contaminated drinking water in adults include weakness, conjunctival congestion, hepatomegaly, portal hypertension, lung disease, polyneuropathy, solid edema of limbs, ischemic heart disease, peripheral vascular disease, hypertension, and anemia.2,3
Initial report of the nonmalignant pulmonary effect of chronic ingestion of arsenic by drinking arsenic- contaminated water was available from studies in children in Chile as early as in seventies. Rosenberg conducted autopsies on fi ve children manifesting characteristic features of chronic arsenic toxicity, including pigmentation and/or keratosis. Lung tissue was examined in four of the fi ve children, with abnormalities found in each and two having pulmonary interstitial fibrosis with mild bronchiectasis.4 in 144 school children in Antofagasta, Chile, during a cross-sectional survey in 1976. The investigators further reported that chronic cough was complained of by 38.8% of children with skin lesion compared with 3.1% of children with normal skin.5 Arsenical skin lesions were reported The prevalence of skin manifestations in children due to drinking of arsenic-contaminated water was reported from epidemiological studies carried out in 1995–96 in South 24 Parganas, West Bengal, India.
Pigmentation and keratosis were observed among boys and girls (age