SPANISH AGENCY FOR CONSUMER AFFAIRS, FOOD SAFETY AND NUTRITION RECOMMENDATIONS

• Where possible, the consumption of the dark meat in crustaceans, located in the head, should be limited with the aim of reducing exposure to cadmium.

Cadmium

Cadmium (Cd) is a heavy metal naturally found in the environment associated with the minerals of zinc, copper or lead, and it is therefore an inevitable by-product in the mining activities related to these metals. It has many industrial applications and therefore its release to the environment is increased by Man's activities (burning fossil fuels, metallurgy, waste incineration) and the use of phosphate-based fertilizers and waste slurry.

The metal has no biological function in humans or in animals but, although its absorption in the digestive system is low, it tends to accumulate in the body, mainly in the liver and kidney, for an estimated period of 10-30 years. Cadmium is toxic for the kidney, mainly accumulating in the proximal tubules, and may cause renal dysfunction. It may also lead to the demineralisation of the bones, either directly or indirectly as a result of the renal dysfunction. After prolonged and/or high exposure, the progression of the tubular damage leads to a reduction in the glomerular filtration rate and may cause kidney failure and, in the long-term, cancer. (The International Cancer Research Agency (IARC) has classified cadmium as a category 1 agent (carcinogenic for humans) as there is sufficient scientific evidence to support this.

The greatest form of exposure to cadmium in humans is through diet, and therefore it is considered a dietary risk. To maintain cadmium levels in food within acceptable levels for the consumer, given its inevitable presence in the environment, Regulation 1881/2006 establishes maximum permitted contents.

Given its potential to accumulate in the liver and kidneys in animals, the highest levels found in food are in edible offal (kidney>liver>>other offal). It is also found in high levels in shellfish, as often the entire animal, including the guts where the cadmium is concentrated, is eaten. In products of plant origin, the highest levels are found in algae, cocoa, wild mushrooms and oleaginous nuts and seeds. As regards exposure, it should be noted that the food group which provides most cadmium to the total intake is that of cereals, not because it has a high level but because it is a very important part of the diet.

In the case of shellfish, the maximum content established in Regulation 1881/2006, recently amended, is applied to the white meat from the appendages and abdomen, except for crabs and crab-like shellfish (spider crabs, edible crabs, etc.) for which the limit is only applicable to the “white meat of the appendages”. The presence of cadmium in these parts of the shellfish is considered to be “low”.

Nevertheless, in some European countries, including Spain, in addition to the “white” part, other parts of the shellfish are consumed. These include the head of shrimps, prawns, crayfish, etc. and the body of crab-like shellfish, with high levels of cadmium, as the cadmium mainly accumulates in the hepatopancreas, which forms part of the digestive system of the shellfish and is located in the head.

Consequently, the Directorate-General for Health and Consumer Protection (DGSANCO) of the European Commission has published on their web page an Information note on “Cadmium in shellfish”, urging Member States in which there is a high level of consumption of the whole shellfish to draw up recommendations for consumption due to the high content of this heavy metal in certain parts of the animal.

In a control carried out in 2009 and 2010 by the European Commission it was found that cadmium levels in the meat inside the shell of crab-like shellfish were very high and very variable. On average, the cadmium content in this meat was 8 mg/Kg compared to the 0.08 mg/Kg found in the white meat of the appendages. The final cadmium content obtained on combining all the edible parts, both of the appendages and the head, would be 2.3 mg/Kg on average, equivalent to 30 times the content of the appendages. It should be noted that the cadmium content in the shellfish roe, although higher than that found in the appendages, is not high (2.5 times).

The situation of other shellfish, including prawns and similar, is not as extreme as in the case of crabs, as the use of the head with respect to the abdomen is lower. Available data indicate that the intake of cadmium when the head is eaten is 4 times the intake obtained when only the abdomen is eaten.

Consumers of these types of product must be aware that the consumption of these parts of the shellfish may result in unacceptable exposure to cadmium, particularly in the case of regular consumption.

For further information, please see the Scientific Opinion of Cadmium in Foods published by the European Food Safety Authority (EFSA) in March 2009.