Source: San Francisco Chronicle

California State regulators on Tuesday continued their 5-year legal battle to compel food companies to paste labels on tuna cans warning of potentially unhealthy mercury levels.

The Food and Drug Administration and the Environmental Protection Agency already advise women who are pregnant or may become pregnant, nursing mothers and young children to avoid eating the fish because of its high levels of mercury that can cause brain damage in babies.

But the federal government doesn't require tuna companies to place consumer warning labels on their products.

An effort by California to require labels was back in state court Tuesday.

The California Attorney General's Office argued that state law requiring warning labels on products containing chemicals shown to cause cancer and birth defects means tuna should be labeled. The companies said the federal advisory is good enough.

In 2006, a trial judge threw out a lawsuit California filed two years earlier pushing for labels. The judge sided with the tuna companies and scientists who argued that 95 percent of the mercury found in tuna comes from natural sources. Products that contain natural-occurring chemicals are excluded from the California labeling law.

"The key finding is that wherever it's coming from, it's naturally occurring and not man-made," Justice Ignacio Ruvolo told the government's lawyer at the outset of Tuesday's hour-long hearing at a state appellate court here.

The two other judges on the panel didn't indicate which way they were leaning. A decision is due within 90 days and is expected to be appealed to the California Supreme Court.

Deputy Attorney General Susan Fiering argued that the trial judge incorrectly discounted the state's scientific conclusions that more man-made mercury is found in tuna than the companies' claim. She also argued that even if company scientists were to be believed, the 5 percent of man-made mercury found in tuna was still enough to trigger warning labels in California.

The companies insisted that regulators need to consider how much tuna a pregnant woman consumes over time, rather than at one sitting, when measuring the health effects of the remaining five percent of the mercury caused by pollution. If a pregnant woman, for instance, eats one can of albacore tuna every week, then the health effects of man-made mercury in the cans falls below California's labeling standard, industry attorney Forrest Hainline argued.

Hainline represents the three companies sued by California: Bumble Bee Seafoods LLC, the San Diego-based maker of Bumble Bee tuna; San Diego-based Tri-Union Seafoods LLC, which makes Chicken of the Sea brand tuna; and., Starkist – which is now owned by the Korean company Dong Won.

While the federal agencies advise pregnant women to avoid eating tuna, they encourage Americans to consume it and other seafood as part of a healthy diet.