Arsenicism in India: Dermal Lesions and Hair Levels

Abstract

Objective: One million people in 8 districts of West Bengal are exposed to high levels of arsenic in drinking water. Two hundred thousand individuals reportedly show arsenic-related symptoms. The clinical manifestations mainly pertain to dermal lesions characterized by diffuse pigmentation superimposed by 2-1 0-mm macules of depigmentation, which are clinically labeled as a rain-drop pattern of pigmentation and/or keratinization of the palms of the hands and the soles of the feet. We confirmed that there is chronic arsenic exposure. We analyzed arsenic levels in hair because objective, biological, etiological evidence is unavailable. Design. We contacted all of the available cases in one of the affected villages, and they were asked to volunteer for the study. We eventually selected only those cases who had (1) skin lesions that evidenced the raindrop pattern of pigmentation and/or keratinization of the palms of the hands and soles of the feet and (2) other family members who had evidence of arsenicrelated problems. Setting. The study was conducted in a small village of Domkal block of Distt Murshidabad in West Bengal. Protocol. Each subject was interviewed about personal, social, and clinical details, and he or she was examined clinically. A sample of hair was obtained from the occiputonuchal region of the head, close to the root, from each subject. The samples, which measured 5-1 5 cm and weighed 0.5-1 .O gm, were stored in labeled paper bags. The hair samples were washed, weighed, cold digested, and analyzed with atomic absorption spectrophotometry. Participants. Of the 19 persons selected, only 7 males and 1 female agreed to participate. Two of the males were excluded because they had recently shaved off their scalp hair. The study, therefore, included 5 males and 1 female. The mean age of the subjects was 31.5 yr (range = 25-47 yr). One of the subjects was an occasional smoker, and none were addicted to any toxicants. All were engaged in agricultural activities, and some were also involved in other supplemental occupations ( e g , carpentry, tea wending, construction work, household work). Results. A rain-drop pattern of pigmentation was present on the trunk and upper arms or thighs of all the subjects. Two of the subjects had keratinization of the palms, and 1 had keratinization of the feet. One of the subjects complained of tingling and numbness in his arms. There was no evidence of occupational exposure to arsenic compounds among any of the study subjects. The levels of arsenic in hair of these subjects ranged between 2.57 pg/gm and 8.85 pg/gm (mean = 5.55 pg/gm, median = 5.68 pg/gm). The subject with the highest level of arsenic in hair had resided continuously in the same area (i.e., without any break), whereas other subjects of the same village gave a history (i.e., during the past 4 yr) of nonresidence in the area that ranged from 5 mo to 1 yr. Conclusion. The cases of dermatoses studied revealed high levels of arsenic in hair, compared with normal values of 0.08-0.2 pg/gm in hair reported among healthy, unexposed subjects. On the basis of existing reports and the present study, we can conclude that the cases of dermatoses reported from West Bengal are initial clinical manifestations of long-term arsenic intake. Investigators are instituting engineering and other measures to provide safe drinking water, but public-health measures for the prevention of additional exposures and for the prevention of a worsening clinical picture require identification of affected individuals. Investigators could use hair arsenic levels to determine risk for debilitating arsenicism.