Hair mercury concentrations in residents of Sundarban and Calcutta, India

Few studies on hair mercury have been conducted in India despite the fact that India is the world's third largest producer of coal and coal is India's primary energy source. No studies have been conducted in the Indian state of West Bengal which has a coastline with the Bay of Bengal. This study examined the concentration of mercury in hair in two diverse populations in West Bengal, India: Sundarban, a mangrove wetland where fishing is a common occupation, and Calcutta, a megacity and India's oldest functioning port. Individuals from whom scalp hair was collected (N=100) were asked a series of questions on occupation, education, age, smoking and alcohol consumption, and fish consumption. SAS was utilized to generate descriptive statistics including frequency and univariate analyses and to perform regression analyses to determine significant predictors of hair mercury in this population. The mean hair mercury increased across the first three age categories (<21, 21-30, 31-45) and decreased in the fourth category (>45). Hair mercury concentration was significantly higher among residents of Sundarban compared to Calcutta (p=0.0005). In multivariable analysis, location (Sundarban vs. Calcutta) and age were significant predictors of hair mercury concentration (p=0.0120 and p=0.0161, respectively). Average hair mercury concentrations in this study were not particularly elevated. Smoking and alcohol consumption were predictors of hair mercury concentration. The hair mercury in Sundarban residents compared to Calcutta residents may be elevated due to greater consumption of fish and type of fish consumed.