Fish are a good, low-cost, low-fat source of nutrition, rich in healthy, omega-3 fatty acids. However, some fish may be contaminated with mercury, a natural and abundant environmental element, and particularly methylmercury, a toxic product biotransformed from mercury by selected bacteria. These and other toxicants from the water from which fish are harvested present health risks to vulnerable populations such as pregnant and lactating women, unborn children, and young children. Exposure to high…