Evaluation of a Questionnaire-Based Method for the Estimation of Methylmercury Exposure of Recreational Anglers in the James Bay Territory (Québec, Canada)

Abstract

The impoundment of reservoirs temporarily increases the methylation of mercury bound to flooded soils and vegetation and the transfer of methylmercury (MeHg) to fish. MeHg levels in various fish species of hydroelectric reservoirs located in the James Bay territory increased by factors of 3 to 7, then gradually declined toward initial concentrations 10 to 20 years after flooding, depending on reservoir characteristics. The potential risk of increased MeHg exposure for recreational anglers who consume fish from these reservoirs had not been assessed previously. A less invasive method than systematic measurement of Hg levels in hair was developed to determine MeHg exposure of recreational anglers. A fish consumption questionnaire-based approach was combined with a toxicokinetic model to estimate the corresponding hair MeHg concentrations. The results were compared with actual analytical determinations of hair Hg levels for the 94 recreational anglers recruited for the study. The values predicted by the model based on selfreporting consumption overestimated actual hair Hg levels by an average factor greater than 6. The mean hair level predicted for the most recent period (September-October) was 23.3 µg·g -1 compared to 3.6 µg·g -1 for the measured value. Al-* Loranger et al.though the questionnaire protocol may certainly be improved to increase the precision of estimations, direct hair Hg measurement remains the more effective means to assess Hg exposure.

Assessment of hair and bone accumulation of beryllium by mice exposed to contaminated dusts

“…In fact, hair is commonly used for several toxic metals such as mercury, arsenic, lead or cadmium (e.g. Samanta et al, 2004;Morton et al, 2002;Puchyr et al, 1998;Loranger et al, 2002;Rodushkin and Axelsson, 2000). There are several advantages of using hair to monitor exposure history, since hair is a minor excretory organ (Ho et al, 2001).…”