MERCURY AND METHYL MERCURY IN FISH: CONTAMINATION LEVELS AND HEALTH RISKS

Abstract

This study aims to assess the risks that mercury and methyl mercury would be posing on the health of fish consumers. The fish consumption patterns of Qatar residents aged 18 years and above were obtained using a fish frequency questionnaire. The Mercury contamination levels of the most consumed fish species were determined using a validated ICP-MS method. Total Mercury average concentration were 0.077 mg/kg ww and ranged between 0.001 mg/kg ww in Safi and 0.443 mg/kg ww in Hamour. PCA analysis was done for the contamination and the exposure. Results demonstrated that contamination levels are primarily affected by protein-lipid content in predatory species. Exposure to Mercury and Methyl mercury was determined via the deterministic approach, using both aggregated and disaggregated fish consumption data and simple distribution. Two scenarios were used to determine methyl mercury level from measured mercury level (MeHg100% and MeHg based on values reported in the literature). Hamour, Chanad, and canned tuna contributed significantly to the mercury exposure. The aggregated method revealed that the high fish consumption was the main source of the risk exposure. The median, 75th, and 95th percentile using the Hazard Quotient index (HQ) compared to the TWI and PTWI for all cohorts. Exposure to mercury from fish using aggregated method poses a risk on the health of Qatari women of the child-bearing age, and for all high fish consumers (P95).