efsa-opinion-chromium-food-drinking-water

Chromium in food and drinking water
around 140 µg/m 3 , with Cr(VI) accounting for approximately 50 % of the total Cr. The fraction of
Cr(VI) is much lower during stainless steel welding when applying the MIG/MAG method (Karlsen et
al., 1996).
Air levels of Cr in chromate industry have been reported to achieve concentrations up to 1 mg/m 3 .
Most concentrations reported in the literature are in the range from 0.26 to 0.51 mg/m 3 , but modern
plants show levels < 0.1 mg/m 3 . Most Cr concentrations recorded after personal sampling during
8 hours in a ferrochromium manufacturing plant were in the range of 0.02-0.05 mg/m 3 . In a review, Cr
workplace concentrations up to 5 mg/m 3 in the Cr-plating industry was mentioned, but most exposure
levels reported were in the range of 0.1-0.2 mg/m 3 . In modern plants, values are often < 10 µg/m 3
(IARC, 1990).
ECB (2005) performed an occupational exposure assessment for industrial production and use of
different Cr(VI) salts and reported detected workplace concentrations to Cr(VI) to range between
0.01 and 760 µg/m 3 for various tasks. In the occupational risk assessment, 20 µg/m 3 was taken as
reasonable worst case exposure concentration for chromium salt manufacturing.
Other background exposures
ATSDR estimated that for the general population, oral exposure via food and water is by far the most
important contribution to the exposure to chromium (ATSDR 2012).
Non dietary exposure to chromium in the general population can occur mainly via inhalation, and less
importantly via ingestion and dermal contact (ATSDR, 2012).
Chromium can be present in air mainly as a result of anthropogenic activities. Total Cr concentrations
in air were reported to range from 5 to 525 ng/m 3 in USA urban and non urban areas during the period
1997-1984 (ATSDR, 2012). Cr(VI) was detected in ambient air from residential sites in the
approximate range 0.1 - 2 ng/m 3 (ATSDR, 2012).
In its risk assessment on chromium compounds, ECB (2005) estimated the potential Cr(VI)
concentrations in the proximity of a chromate salt production site and a metal treatment site to be up to
4.3 and 0.71 µg/m 3 , respectively. According to ECB, assuming an absorption rate of 100 % for Cr(VI)
species via inhalation, a daily volume of 20 m 3 of inhaled air, and that Cr(VI) is not reduced following
its emission from the manufacturing plant, the daily uptake could be up to 86 µg per day
(corresponding to a daily dose of 1.2 µg/kg b.w. per day, assuming a 70 kg b.w.) for the adult general
population living in the vicinity of a chromate production site. However, this was considered a worst
case scenario in view of the selected assumptions.
Consumer products including wood preservatives, cement, cleaning materials, textiles, and leather
tanned with chromium may represent an additional source of exposure for the general population
(ATSDR, 2012).
In particular cigarette tobacco has been reported to contain 0.39 mg/kg of Cr (Schroeder et al., 1962),
but there have been no published estimates of the inhaled amount of Cr from smoking. Later values of
0.24-14.6 mg/kg(Al-Badri et al., 1977), or 0.24 to 6.3 mg/kg (IARC, 1980) have been reported, and
more recently total Cr has been determined as a component of cigarette tobacco, ranging from 0.45 to
3.13 mg/kg (Freitas de Sousa Viana et al., 2011). Moreover, the Cr oxidation state upon inhalation is
not known, though the high temperature of the cigarette when it burns could oxidise Cr to Cr(VI).
Increased Cr concentrations have been found in lung tissue from smokers either affected or not from
lung cancer (Pääkkö et al., 1989; Akslen et al., 1990; Adachi et al., 1991; Kuo et al., 2006; De Palma
et al., 2008). Cr has also been determined in smokeless tobacco aerosols (Borgerding et al., 2012).
Based on reports, chromium levels in mainstream cigarette smoke ranges from 0.0002 to
0.5 µg per cigarette (Smith et al., 1997). It is known that Cr accumulates in tissue, especially in the
lung. Concentrations of about 4.3 mg/kg (dry weight) are found in lung tissues of smokers compared
with 1.3 mg/kg in non smokers, increasing with age and smoking time (Pääkkö et al., 1989).
EFSA Journal 2014;12(3):3595 61