Assessing mercury contamiantion in the Amazon

3. Discussion

3.7.4. Predicted mercury concentrations in humans

In order to use the single-compartment model human populations must be in a steady state with regards to methylmercury. I assume that this is the case. The interconversion between mercury in fish and mercury in human hair was done as summarized by WHO (1990).

Hg daily intake (µg) = daily fish consumption (g) x Hg conc. in fish    (equation 1)

[Hg] in human blood (µg/l) = 0.95 x daily fish consumption (g)             (equation 2)

[Hg] in human hair (µg/g) = (250/1060) x [Hg] in human blood               (equation 3)

Interestingly, predicted mercury concentrations in humans from both rivers are similar to observed vales (Table 4). This is further indication that methylmercury exposure in ribeirinhos is through the ingestion of methylmercury-contaminated fish. The results also suggest that methylmercury concentrations in fish could be used to assess human exposure and thus human health risks to methylmercury.

Tabel 4: Observed and predicted hair mercury concentrations in humans from the Madeira and Tapajos River, Brazil.
Mercury concentrations in hair ( µg/g )
Predicted Observed

Madeira River 16.1 14.8
Tapajos River 13.4 13.8

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