efsa-opinion-chromium-food-drinking-water

Chromium in food and drinking water
7.3.2.4. Allergenic response
Oral doses of potassium dichromate exacerbated the dermatitis of sensitized individuals.
Worsening of dermatitis was observed in a randomized double-blind cross-over study in 11 of
31 Cr-sensitive individuals after ingestion of 0.036 mg Cr(VI)/kg b.w. as potassium dichromate
(Kaaber and Veien, 1977).
Goitre et al. (1982) carried out an oral tolerance test using 7 mg K 2 Cr 2 O 7 equivalent to 2.5 mg Cr in an
52 year old worker with a 20 year history of chromuium contact dermatitis with mild potassium
dichromate sensitivity. At 2.5 mg Cr an increased local itching after 2 days was observed. Applying
5 mg Cr led to appearance of dysdrotic lesions on the hands 12 h after intake, microbial invasion with
slight lymphangitis, axillary lymphadenitis and fever.
Insufficient data are available to assess the allergenic potential of Cr(VI) by oral exposure.
7.3.2.5. Developmental and reproductive toxicity
The Reproductive and Cancer Assessment Branch of the Office of Environmental Health Hazard
Assessment of the CA EPA evaluated in 2009 Cr(VI) for developmental and reproductive toxicity
including human data.
Two studies on developmental toxicity were identified by CA EPA: The matched case-control study
of Aschengrau et al. (1993) that associated late adverse pregnancy outcomes (congenital abnormlity,
stillbirth, neonatal death) in the period 1977-1980) with drinking water quality in Boston (MA) in
USA and the study of Eizaguirre-Garcia et al. (2000) on birth defects (congenital anomalies) in a
population near Glasgow (UK) which has been reported in Section 7.3.2.3, in particular, for the
investigation of leukemia risks. Both studies geo-linked exposure to Cr including Cr in drinking water
to effects and were unable to identify statistically significant associations between estimated exposure
and developmental effects although the odds ratio for all stillbirth in the first study was elevated
(adjusted OR = 1.2). CA EPA noted several limitations of both studies regarding the definition of the
exposure, time-delay between conception and exposure determination, co-exposure, selection of the
endpoint.
For female reproductive toxicity with direct exposure to Cr(VI) (i.e. not mediated via male exposure)
only studies from Russia (Shmitova, 1978, 1980) were available which had been assessed by ATSDR
(2012). The cited rates of birth complications were larger than 70 % in exposed women reflecting
possibly both exposure and working conditions when that of controls were larger than 40 %. Because
the publication were in Russian and the ATSDR judgement of poor study quality and reporting no
conclusions were made.
Male reproductive toxicity studies on Cr(VI) has been studied extensively for welding occupations in
stainless steel production regarding semen quality, infertility, fecundability and male-mediated
spontaneous abortion, in particular, in Danish populations but also in India. Since the studies were
based on exposure measurements on ambient air of the occupational site or on urine or blood (whole
blood, erythrocytes) concentrations of workers the CONTAM Panel could not use their results to
assess developmental and reproductive toxicity of Cr(VI) in food and water.
7.3.3. Other observations in humans
The Chinese Public Health Epidemiological Study investigated the association between oral cancer
and Cr concentrations in blood and in farm soil in 79 patients from Changhua County in Taiwan
recruited from 2008 to 2009 in one single hospital in Changhua (Chiang et al., 2010). Using
n = 641 controls identified as non-cancer residents log(Cr) blood levels were regressed, using
piecewise linear and rank regression on log(Cr) farm soil concentrations adjusted for covariates (using
a propensity type balancing score) and a statistically significant association (p < 0.02) was found. A
case-control study on the association of oral cancer with Cr and Ni exposure concentrations in blood
in patients from the same hospital in Changhua County was reported later by Yuan et al. (2011).
Blood levels of nickel and Cr in oral cancer cases were 1.6 and 1.4 times higher, respectively, than
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