Canned tuna at school lunches should be reduced. (Photo: www.mercurypolicy.org/FIS)
Children must curtail their intake of canned tuna: report
Friday, September 21, 2012, 04:00 (GMT + 9)
"Children should not eat albacore tuna at all and should never eat tuna daily," warns the Mercury Policy Project, which has released the first research that documents mercury levels in tuna served to children in schools. The coalition of consumers groups had 59 samples of canned tuna from this market sector in 11 states tested for mercury in a contract lab.
“Canned tuna is the largest source of methylmercury in the US diet, contributing 32 per cent of the total, and is a major source of mercury exposure for children,” the report reads.
Teh report Tuna Surprise: Risk Management Advice for Schools and Parents by Edward Groth, PhD notes that even though the average American eats 100 g of tuna per month, some children eat much more, which when combined with children’s small body weights can result in very high mercury doses.
The samples tested included 35 large (66.5 oz) cans and 24 large (43 oz) foil pouches, representing six brands of “light” tuna and two brands of albacore tuna.
The findings include:
- The average mercury level in the 48 samples of light tuna was 0.118 µg/g, slightly lower than the Food and Drug Administration's (FDA) reported average of 0.128 µg/g. The 11 samples of albacore averaged 0.56 µg/g, much higher than the FDA’s 0.35 µg/g.
- Mercury levels were highly variable between samples, varying within types of tuna and even within some packages. The average mercury content in light tuna ranged from 0.02 to 0.64 µg/g and in albacore from 0.19 to 1.27 µg/g.
- 50 out of 59 samples contained imported tuna. The nine samples of US-caught light tuna had the lowest country-of-origin average mercury level at 0.086 µg/g, while tuna from Ecuador had the highest at 0.25 µg/g, and light tuna from Thailand and the Philippines averaged 0.104 and 0.108 µg/g, respectively.
- US brands StarKist and Chicken of the Sea made up 60 per cent of the light tuna samples. The overall average mercury levels in the two brands were 0.13 and 0.126 µg/g, respectively.
The US Government’s established Reference Dose (RfD) for methylmercury, a definition of acceptable exposure, was set in 2000. The Mercury Policy Project defined the “safest” exposure to mercury from canned tuna as less than 25 per cent of the current RfD.
Further, more recent research, presented in the report itself, associates adverse effects with prenatal mercury doses around or even lower than the RfD.
The report includes the following recommendations:
- Children should not eat albacore tuna, as it contains about triple the mercury content of light tuna;
- Smaller children should eat light tuna no more than once monthly;
- Schools and parents should limit most children’s light tuna consumption to twice a month;
- Children should “never” be allowed to eat tuna daily, as this can cause methylmercury poisoning;
- Parents of children who eat tuna weekly or more often should have the child’s blood tested for mercury;
- The US Department of Agriculture (USDA) should phase out subsidies for tuna in the school lunch programme;
- Schools should avoid buying tuna from Latin American countries.
- Groups push for protection from mercury in seafood
By Natalia Real