 Are there some brands of tuna worse than others? An evaluation of mercury concentrations in three national brands of canned tuna was undertaken recently. In total, they found that 55% of all tuna examined was above the U.S. Environmental Protection Agency's safety limit for human consumption. And mercury is not just a problem for children. As I've noted in videos over the years, the health effects resulting from consumption of methylmercury for adults are considerable. It may include central nervous system damage, ataxia, parasthesia, hearing loss, diminishing vision, loss of sensation and extremities, and loss of consciousness leading to death. Due to the increased susceptibility of the developing nervous system, though, damages are more pronounced in fetuses, infants, and children, may include microcephaly, which is a shrunken brain, delayed development, impaired cognition, and gross neurological disorders. Given the average level of mercury pollution found in canned tuna, they suggest that your average 9-year-old would exceed the EPA limit, eating any more than a can of tuna every 43 days. This is not the first study of canned tuna. Previous studies, going back nearly 20 years, found levels of mercury that were bad, but not as bad as the ones found now. The problem of mercury in tuna appears to be getting worse and worse. But which brand was the worst? National brand number three contains significantly more mercury than the other two, but they failed to disclose which brand was which. They wouldn't say. All they said was that these results indicate that stricter regulation of the canned tuna industry is necessary to ensure the safety of sensitive populations, such as pregnant women, infants, and children.