**4. Health risk and burden due to mercury**

The exposure diet intake is linked to the Hazard Quotient (HQ ), which signifies the relationship between the exposure obtained in the diet and the oral reference dose for mercury [28]. Choice of the oral reference dose is critical in determining the health risks the vulnerable community is exposed to, that is, use of the general population or vulnerable population oral reference dose [34]. The oral reference doses for mercury in the vulnerable and general population are 1 × 10−4 and 3 × 10−4 mg/kg per day, respectively [35, 36]. Therefore, there is a need to send out a message to this vulnerable group about the health hazard they are encountering daily by consumption of food contaminated with mercury. Use of specific messages for different target groups was demonstrated in the USA during a study by Ref. [34], which involved pregnant women and children and observed that there is a need for a unique message for the vulnerable group.

Hazard Index (HI) for both vulnerable and general populations if computed can spell out the health risk. For the vulnerable populations, if the hazard quotients from the study are added and the hazard index is greater than one spells out probable health risks from the mercury consumed. These results are in agreement with Poulin et al. [29] who documented higher HI levels in carnivorous than herbivorous fish, a pointer toward the hazard index points toward noncarcinogenic risk attributed to mercury uptake in fish parts, especially the Lake Albert Nile perch.
