A woman who weighs less than 135 pounds should eat less than one can of tuna per week. Specific weekly limits for children under six range from one ounce for a twenty pound child, to three ounces for a child weighing about sixty pounds. Review a chart of recommended limits of canned tuna for different bodyweights. These changes can affect their ability to learn. In adults, methylmercury can lead to problems of the central nervous system and possible adverse effects on the cardiovascular system.
Mercury contamination is a worldwide problem.
It can come from many sources. It occurs naturally in the environment in rocks, soils, water and air. Volcanoes may also be a source of mercury in the environment. It can come from industrial pollution, especially the burning of coal and other fossil fuels and from burning household or industrial wastes. Though statewide data for on mercury contamination of fresh water fish is limited, nationally it appears to show that bass, pike and walleye have higher levels of mercury than other species.