Differences in methylmercury exposure among residents of sundarban and calcutta, India

Objectives: This study examined the concentration of mercury in hair in two populations in India: Sundarban, a mega delta and fishing area, and Calcutta, a large city and India's oldest functioning port. Methods: Individuals from whom hair was collected (N=100) were asked a series of questions on occupation, education, age, smoking, alcohol consumption, and fish consumption. SAS was utilized to generate descriptive statistics including frequency analysis and univariate analysis and to perform linear stepwise regression to determine significant predictors of hair mercury. The Kruskal-Wallis test was executed to determine if there was a difference in median hair mercury concentration between fishermen and non-fishermen. Results: The mean hair mercury concentration was 0.725 mg/kg (range: 0.119-2.556 mg/kg). Hair mercury concentration increased with the first three age groups (<21, 21-30, 31-45) and decreased in the fourth age group (>45). Location and age were significant predictors of hair mercury concentration (p=0.0030 and p=0.0456, respectively). Hair mercury concentration was significantly higher in the residents of Sundarban compared to Calcutta (p=0.0004). There was no significant difference in hair mercury between fishermen and non-fishermen (p=0.9232). Conclusion: Average hair mercury concentration in this study was consistent with the results from studies of hair mercury in other fishing communities. Location of residence and age are important predictors of mercury concentration in hair in these two populations. Hair mercury may be elevated in Sundarban residents due to greater consumption of fish and type of fish consumed.