Chromium - Toxicology of Metals - page 481

Chromium defi ciency has been described both in
humans and in animals, but a quantitative defi nition
of the daily requirement of Cr in human nutrition has
not been formulated (Mertz, 1969).

dermatitic reaction seems to become less prominent by
renewed contact. It must be differentiated from allergic
eczematous dermatitis.

7.1.2.4 Allergic Dermatitis
7.1.2.4.1 Allergic Eczematous Dermatitis This type
of skin reaction was most likely observed years before
evidence of Cr sensitivity was reported by Engelhart
and Mayer (1931). A large proportion (84%) of chromate
workers with dermatitis reacted positively when tested
with 0.5% ammonium dichromate, but none reacted to
Cr(III) compounds. Samitz et al . (1969) found Cr(VI)
compounds to be strong sensitizers, whereas Cr(III)
compounds were poor sensitizers and elicitors. It is
concluded in different reviews that Cr(VI) compounds
(Pedersen, 1982; Polak et al ., 1973; Proctor et al ., 1998)
are responsible for most cases. These reviews conclude
that the difference in the sensitizing property of the
two valence states results from the fact that Cr(VI) is
capable of penetrating undamaged skin where it is
reduced to Cr(III) that binds covalently to proteins
or other skin components to form allergens. When
sensitization has developed, even the small amounts
of Cr(III) compounds that penetrate the skin may be
capable of eliciting reactions.
Allergic eczematous dermatitis is reported in a
variety of workers (i.e., housewives, cement work-
ers, woodworkers, limestone workers, welders, paint-
ers, printers, leather workers, polishers, and others)
(Pedersen, 1982; Polak et al ., 1973; Proctor et al ., 1998).
Cement eczema has been shown to be induced by traces
of chromate compounds in the cement (Engebrigtsen,
1952; Freget, 1981).
The prevalence of Cr-induced eczema has been
shown to be higher in males than in females. In males
living in industrialized countries, Cr sensitivity seems
to be the most signifi cant skin sensitizer, the skin patch
test being positive in 8-15% of all male patients from
eczematous dermatitis (Proctor et al ., 1998), whereas
the prevalence in female patients is approximately
3-5%. This difference between genders could be
because men are more likely to be exposed to Cr(VI) in
their work than are women (Freget et al ., 1969; Langård
and Hensten-Pettersen, 1981). Estimates of the preva-
lence of Cr sensitivity in the general population varies
from less 1/1000 (Proctor et al ., 1998) to 17/1000 (Pel-
tonen and Fraki. 1983).
For many years, potassium dichromate has been the
most commonly used substance for allergy testing to Cr
(Freget and Bandmann, 1975). Most frequently, a con-
centration of 0.5% of the substance dissolved in water or
petrolatum is used. Test procedures for performing differ-
ent skin patch tests are reviewed by Polak et al . (1973) and
Pedersen (1982) and surveyed by Proctor et al . (1998).

7.1 Local Effects

7.1.1 Animals

Numerous publications reporting on local effects
of Cr compounds in humans are presented, but few
experiments have verifi ed such effects in animals.
Samitz and Epstein (1962) succeeded in inducing ulcers
by applying various Cr(VI) compounds to animal's
skin. They also demonstrated that a local skin defect
might be considered a prerequisite for the develop-
ment of chrome ulcers. Mosinger and Fiorentini (1954)
induced skin ulcers in different animal species through
application of potassium chromate to the skin.

7.1.2 Humans

7.1.2.1 Chrome Ulcers
Generally, chrome ulcers of the skin are induced by
the corrosive action of Cr(VI) compounds. When chromic
acid, dichromate compounds, or other Cr(VI) compounds
are deposited on broken skin surface, a deeply penetrating
round hole may develop (Dewirtz, 1929). Favored sites for
ulcer development are the nail root areas, over the knuck-
les and fi nger webs, on the back of the hands, and on the
forearm (Maloof, 1955). The ulcer may persist for months
and slowly heals. These ulcers are not related to allergic
sensitization to Cr compounds (Edmunson, 1951).

7.1.2.2 Reactions in Upper Airways
7.1.2.2.1 Corrosive Reaction in the Nasal Septum
Ulcerations on and perforations of the nasal septum in
chromate workers were frequently reported on in the
20 th century, but few have been reported recently in
the Western world. The site of the ulceration is usually
approximately 1.5-2 cm from the anterior and lower
margin of the septum (Kleinfeld and Rosso, 1965). Data
by Lindberg and Hedenstierna (1983) indicated that
inhalation of 20

g Cr(VI)/m 3 could result in septum
ulcers. Generally, the ulcerations seem to result from
deposition of relatively large chromate-containing
particles on the mucous membrane. Ulceration on both
sides of the septum may result in necrosis of the cartilage,
leading to septum perforation (Leineberg, 1955).

µ

7.1.2.3 Irritative Dermatitis
7.1.2.3.1 Acute Irritative Dermatitis This disease
may be observed in the Cr industry, particularly among
workers coming in contact with Cr(VI) compounds. This