Mercury Exposure Assessment from the First Harmonised Total Diet Study in Portugal

The aim of this study was to estimate the Portuguese population’s baseline exposure to methyl and inorganic mercury by a harmonised total diet study (TDS) methodology and the risk of exceeding the Tolerable Weekly Intake (TWI). TDS food samples representative of the whole diet of the population were prepared as consumed, and analysed for total mercury. European Food Safety Authority’s (EFSA) conservative approach was used to estimate methylmercury and inorganic mercury and exposure was estimated using Monte Carlo Risk Assessment (MCRA) software. Mean, median and P95 exposure of the overall population (18 to 74 years old) to methylmercury and to inorganic mercury were 1.25, 0.01 and 5.45 µg/kg bw/week, and 0.37, 0.15 and 1.27 µg/kg bw/week, respectively. The percentage of individuals exceeding TWI was 27.6 for methylmercury and 3.5 for inorganic mercury. Regarding childbearing age women (18 to 45 years old), methylmercury mean exposure was 1.13 µg/kg bw/week with 25% of women exceeding the TWI. Cod and hake were the main contributors to mercury intake.