Journal of Exposure Science and Environmental Epidemiology (2011) 21, 328–335; doi:10.1038/jes.2010.33; published online 26 May 2010
Comparison of a toxicokinetic and a questionnaire-based approach to assess methylmercury intake in exposed individuals
- aDepartment of Environmental and Occupational Health, Faculty of Medicine, Université de Montréal, P.O. Box 6128, Main Station, Montreal, Quebec H3C 3J7, Canada
- bHydro-Québec, Health and Safety Division, 75 boulevard René-Lévesque West, Montreal, Quebec H2Z 1A4, Canada
Correspondence: Professor Michèle Bouchard, Department of Environmental and Occupational Health, Faculty of Medicine, Université de Montréal, P.O. Box 6128, Main Station, Montreal, Quebec H3C 3J7, Canada. Tel: +514 343 6111 ext 1640; Fax: +514 343 2200; E-mail: email@example.com
Received 7 January 2010; Accepted 16 April 2010; Published online 26 May 2010.
Methylmercury (MeHg) is a neurotoxic contaminant and one of the main sources of exposure in humans is seafood consumption.
It is thus of interest to assess precisely MeHg exposure.
The objective of this study was to estimate MeHg daily intake in exposed individuals using two different approaches, a food questionnaire and toxicokinetic modeling, and compare the complementary and use of each method.
For this purpose, a group of 23 fishermen from northern Quebec provided blood and hair samples and answered a standard food questionnaire focusing on seafood consumption.
A published and validated toxicokinetic model was then used to reconstruct MeHg daily intakes from mercury (Hg) measurements in biological samples.
These intakes were compared to those estimated using a standard food questionnaire on seafood consumption.
Daily intakes of MeHg from seafood (mean/median (range)) estimated from hair concentrations with the toxicokinetic-based approach were 6.1/5.2 (0.0–19) μg/day.
These intake values were on average six times lower than those estimated using a food questionnaire, that is, 49/32 (7.2–163)μg/day.
No correlation was found between the toxicokinetic-based and the questionnaire estimates of MeHg daily intakes.
Most of the MeHg intakes estimated with the food questionnaire (21/23) exceeded the US EPA RfD of 0.1 μg/kg bw/day, whereas only a small proportion (6/23) of modeled estimates exceeded the RfD.
This study shows that human health risk estimates strongly depend on the chosen approach.
methylmercury; toxicokinetic modeling; food questionnaire; daily intake; seafood consumption; biomarker