Levels of mercury found in hair and fish consumption of riverine communities in the Tapajos region of the Brazilian Amazon

Riverine communities are exposed to mercury due to the high ingestion of fish in their diet. In order to evaluate the levels of exposure in the Tapajos region, also assessing the fish ingestion frequency, a study was conducted in adults living in riverine communities in the municipality of Itaituba in the State of Para. Hair samples were collected for the determination of total mercury and the weekly frequency data of fish ingestion was recorded. The mean concentration of total mercury varied from 7.25 mu g/g (in 2013) to 10.80 mu g/g (in 2014), with no significant difference being observed (p = 0.1436). As for fish ingestion frequency, the majority of the individuals evaluated revealed high consumption both in 2013 and in 2014. High levels of total mercury were observed only in those with high consumption of fish in both years. The importance of ongoing monitoring of exposure levels in humans should be stressed, basing itself on indices of tolerance of 6 mu g/g recommended by the World Health Organization, and investigation about the consumption of fish such that strategies for control and prevention are improved.