Things to Know About Heavy Metals in Popular Food

A recent study by the Korea Food and Drug Administration of 113 popular food items found that they contain acceptable levels of heavy metals such as lead and mercury. But while the heavy metal content was below the maximum limits set by the Joint FAO/WHO Expert Committee on Food Additives (JECFA), experts still advise consumers to be aware of what they are eating. While the levels are considered permissible, the study reveals just how pervasive these substances are in the average diet.

"Even if there are heavy metals in one's daily food intake, they are not harmful to healthy adults as long as they do not surpass the limits recommended by JECFA," said Won Jong-wook, a specialist in preventive medicine at Severance Hospital. "But pregnant women, breastfeeding mothers or children under the age of two whose brains are still developing should cut back on foods that are known to contain higher levels of heavy metals, since they are relatively more vulnerable to heavy metal poisoning."

◆ Mercury

Many types of seafood were found to contain large amounts of mercury. Yellow corvina ranked first with 0.2484 ㎍, followed by mackerel (0.2460 ㎍), halibut (0.1828 ㎍), hairtails (0.1818 ㎍) and squid (0.1664 ㎍). Tuna was excluded from the study, since it is not as widely consumed among Koreans as yellow corvina and mackerel. But tuna has been known to contain high levels of mercury, which has become a serious issue in countries where it is popular such as the U.S. The WHO recommends that no more than 0.3 mg of mercury be consumed per week. That is equivalent to consuming 140 yellow corvinas a day, far more than the average adult could possibly eat.

◆ Lead

Dried anchovies and radish stems were found to contain the highest levels of lead (0.0007 mg), followed by littleneck clams (0.0006 mg), seaweed (0.0006 mg) and spinach (0.000 4 mg). The maximum weekly intake of lead recommended by the WHO is 25 ㎍/kg, the equivalent of eating 290 anchovies a day for a week. These items should be avoided for infants because they absorb more lead than adults do.

"Dried anchovies are a great source of calcium, so children and pregnant women tend to eat more of them. It's recommended to fully remove the innards before eating the fish," said Cho Young-jae, a professor of food science at Pukyong National University.

englishnews@chosun.com / Nov. 20, 2009 07:44 KST