efsa-opinion-chromium-food-drinking-water

Chromium in food and drinking water
The current dietary exposure to Cr(III) does not raise concerns from a public health point of
view.
Hexavalent chromium
As recommended for substances which are both genotoxic and carcinogenic, the CONTAM
Panel adopted the MOE approach for the risk characterisation of neoplastic effects of Cr(VI),
by using the BMDL 10 of 1.0 mg Cr(VI)/kg b.w. per day for the combined incidence of
adenomas and carcinomas in the mouse small intestine as RP.
The EFSA Scientific Committee has concluded that for substances that are both genotoxic and
carcinogenic, an MOE of 10 000 or higher, based on a BMDL 10 from an animal study, is of
low concern from a public health point of view.
The MOEs calculated for all age groups on the basis of the mean chronic exposure to Cr(VI)
via consumption of drinking water indicate low concern (MOE values > 10 000) for all age
groups with the exception of infants at UB exposure estimates (maximum UB - minimum LB,
6 300 - 71 000).
When considering the 95 th percentile exposure, MOE values below 10 000 were found at UB
exposure estimates, particularly for ‘Infants’ (maximum UB - minimum LB, 3 100 - 21 000),
‘Toddlers’ (maximum UB - minimum LB, 4200 - 62 000), and ‘Other children’ (maximum
UB - minimum LB, 6 600 - 360 000).
Similarly to the risk characterisation carried out for all drinking water, in the case of exposure
to Cr(VI) through the consumption of bottled water MOEs values below 10 000 were mainly
found at UB estimates when considering the 95 th percentile exposure in the youngest
populations (‘Infants’, ‘Toddlers’ and ‘Other children’).
The CONTAM Panel noted that the MOE values calculated for exposure to Cr(VI) via
consumption of all types of drinking water, as well as only bottled water were highly
influenced by the high proportion of left-censored data.
In addition, when interpreting the numerical values of the MOEs, it should be considered that
they were calculated by using as RP the BMDL 10 for the combined incidence of adenomas
and carcinomas in the mouse small intestine. Because of lack of in vivo data on the capacity
and rate of reduction of Cr(VI) in the rodent and human gastrointestinal tract, there is a
significant uncertainty associated with the use of tumour data in mice to estimate risk at doses
of Cr(VI) relevant for human exposure.
Based on the MOE values for neoplastic effects, the CONTAM Panel concluded that the
current levels of exposure to Cr(VI) via the consumption of all types of water or of bottled
water only are of low concern from a public health point of view for the average consumers
but there might be a potential concern for high consumers particularly in ‘Infants’, ‘Toddlers’
and ‘Other children’.
The inclusion of the water used in the preparation of specific foods (coffee, tea infusions, and
infant dry and follow-on food mainly, but also some others such as instant soup, evaporated
and dried milk, and dehydrated fruit juice) led to an increase up to two-fold of the exposure to
Cr(VI). However, the CONTAM Panel was not able to consider this additional contribution to
the exposure to Cr(VI) when deriving MOEs since no reliable data to quantify Cr(VI) in food
exist
The MOEs calculated for non-neoplastic lesions, based on the BMDL 10 of 0.11 mg Cr(VI)/kg
b.w. per day selected as RP, were 690 and 340 when considering the maximum UB for mean
and 95 th percentile chronic exposure, respectively. The MOEs calculated for haematotoxic
effects, based on the BMDL 05 of 0.2 mg/kg b.w. per day selected as RP, were 1 300 and
630 when considering the maximum UB for mean and 95 th percentile chronic exposure,
respectively.
EFSA Journal 2014;12(3):3595 127