To meet public health standards and ensure the safety of infants and developing fetuses, the U.S. Food and Drug Administration's (FDA) Action Level for mercury in commercial fish should be reduced from 1,000 parts per billion, according to a Purdue University study.

The authors of the study on canned fish, which appeared in the December 2004 issue of Journal of Food Science, consider this reduction a way for women of child-bearing age who regularly eat substantially high amounts of canned tuna to benefit from its important omega-3 fatty acids and remain safe from exposing their babies to unhealthy levels of mercury.

The study measured mercury and omega-3 fatty acids in canned tuna, salmon and mackerel.

All mercury levels in the fish studied were found well below the FDA's Action Level and should be considered safe for the general populace.

The study also recommends introduction of a "kid-safe" label for the variety of canned tuna shown to have very low mercury levels comparable to canned salmon and mackerel. "By recommending a 'kid-safe' label, we are not implying canned tuna is unsafe," said Charles Santerre, coauthor of the study, a fish toxicologist, and professor at Purdue University. "For the average consumer, canned tuna is a safe and nutritious food when eaten in moderation."

"An alternative to 'kid-safe' would be a 'kid nutritious' label, used on light tuna that could be fortified with DHA, the healthy omega-3 fatty acid. It's the light tuna that is lower in mercury but also lower in the DHA that kids need," Santerre explained.

Meantime, another recommendation of the authors is for pregnant or nursing women and children to reduce their intake of canned white albacore tuna and eat more canned salmon and mackerel. Each is higher in the omega-3 fatty acids.

"A few months ago, we replaced canned tuna with salmon-in-a-pouch to make salmon-salad sandwiches. Kids loved it," Santerre said.