High iron accumulation in hair and nail of people living in iron affected areas of Assam, India

• Iron plays a significant role in the oxygen transport, electron transport and storage.
• The iron deficiency may cause anemia and its excess accumulates in the vital organs.
• In Northeast Indian states, ground water is highly ferruginous.
• A possible relationship was established between iron toxicity and its deposition among the residents.
• We observed a high iron content in hair and nail of people living in Northeast India.

Human populace of Assam, India repeatedly exposed to high concentration of iron in groundwater results in adverse health effects like hemochromatosis, liver cirrhosis and siderosis. In the present study, human hair and nail analysis were carried out to establish a possible relationship between iron toxicity and its deposition among the residents. Nail and hair iron concentrations ranged from 28.2 to 1046 μg g−1 (n=114) and 26.5–838 (n=108) μg g−1 levels, respectively, among all the study participants. The iron content of the groundwater (421–5340 μg L−1) (n=64) used for drinking purposes was positively correlated with both nail (r=0.788, p<0.0001) and hair (r=0.709, p<0.0001) iron concentrations. Age- and sex-matched controls corresponding to each group were selected from population residing in other parts of the country where groundwater does not have excess iron. All the study groups included population drinking iron-contaminated water above the WHO/BIS limit (>300 µg L−1) for 5 years (Group 1), for more than 5–10 years (Group 2) and for more than 10 years (Group 3). Results suggested that the participants consuming groundwater exceeding the WHO limit of iron had significantly more iron accumulation than those using groundwater containing ≤300 μg L−1 iron (p<0.01). There was statistically higher concentration of iron in the nail samples than the hair samples in all the study groups (p<0.01). There was a positive correlation in iron concentration and the residence time of the participants (p<0.01). Iron levels in the male participants were significantly higher than the female participants in the present study (p<0.01). The current findings are sufficiently compelling to warrant more extensive study of iron exposure through drinking water and adverse effects to the human in the areas where iron concentration is high.