Cadmium is a heavy metal that occurs in the environment, generated by volcanic emissions and the degradation of rocks, as well as from industry and agriculture. It collects in the soil, water, and air, from where it is taken up by plants and animals eaten by humans. High amounts of cadmium, a carcinogen, can cause kidney damage and bone demineralisation.
Until now the EU has used the TWI of 7 micrograms per kilogram of body weight (ug/kg bw), which was set by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) in 1988 and reaffirmed in 1995. But the EFSA's panel on contaminants in the food chain has decided to lower it considerably to 2.5 ug/kg bw.
The new level will be of interest to risk assessors, and could affect sourcing decisions for ingredients grown in areas of high contamination.
Frequently consumed foods that are particularly likely to come with a high content are grains, vegetables, pulses and nuts, as well as meat. Other foods that can have a high content but that are eaten less often include fish, chocolate, mushroom and dietary supplements.
Although such ill effects are rather rare, according to EFSA, some people such as vegetarians, children, and smokers are more likely to consume more than the TWI - in some cases up to twice as much. Smoking is understood to be as big a source of cadmium as food sources.
Risk assessment
The European Commission asked EFSA to assess the health risk posed by cadmium in foodstuffs, the aim being to provide support to risk managers.
The panel took into consideration a raft of studies that investigated levels of cadmium in the urine and levels of beta-2-microglobulin, a protein that indicates kidney function. The new TWI of 2.5 ug/kg bw when the results of this analysis translated cadmium in the urine to actual dietary exposure.
Even though the panel concluded that exposure should be reduced, they said that the risk of actual kidney damage from exceeding the TWI was very low since the TWI is based on early indicators of a change in kidney function, not damage itself.
In addition the panel looked at data on cadmium in food in 20 countries and consumption data.
While high exposure was seen to be 3.0 µg/kg per week and average 2.3 µg/kg bw, vegetarians could eat as much as 5.4 µg/kg bw.
Children could exceed the TWI as they tend to eat more food per kilogram of bodyweight.