Variation in the biological half-life of methylmercury in humans: Methods, measurements and meaning

•Biological half-life directly determines internal exposure and toxicity of methylmercury resulting from fish consumption.•Metabolism and elimination of methylmercury shows wide variation between individuals and within individuals over time.•Improved methodologies now make individualized determination of methylmercury metabolism and kinetics readily obtainable.•Advances in understanding methylmercury kinetics will lead to strategies to reduce toxicity risk.