Background Low-dose mercury exposure has been shown to be associated with adverse childhood health outcomes. Fish is the major source of mercury exposure in children. Our aim was to investigate the associations between estimated fish intake with total mercury (tHg), inorganic mercury (iHg), and methylmercury (MeHg).

Methods Based on fish food frequency questionnaire (FFQ) data, subjects above the top and below the bottom quartiles of monthly fish intake frequency were contacted for recruitment. Subject hair tHg, iHg, MeHg levels were determined, and fish intake assessed by fish FFQ and 14-day food diary (FD). Associations between fish intake and hair mercury were analysed.

Results 96 children were recruited and 38 of them completed the FD. Among these 96 children and those who have FD data, 55% and 50% were high fish consumers, respectively. The mean ratio of iHg: MeHg was 1:1.4. Comparisons between hair mercury levels and fish intake levels of high and low fish consumers are shown in Figure 1. Fish intakes calculated from both FFQs and FD were positively correlated with tHg, iHg and MeHg (all p < 0.05). However, in general, better correlations were found between FD data and hair mercury (Spearman’s rho for tHg = 0.416; iHg = 0.352; MeHg = 0.448) than between FFQ and hair mercury (Spearman’s rho for tHg = 0.308; iHg = 0.360; MeHg = 0.262).

Conclusions Fish intake data obtained from both FFQs and FDs were positively associated with hair mercury levels. FDs performed better than FFQs. The high proportion of iHg: MeHg is unexpected and warrants further study.

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Abstract PS-001 Figure 1

Box plot graphs for low and high fish consumers of their hair iHg, MeHg and tHg MeHg, tHg levels