Platinum Group Elements in the Environment: Emissions and Exposure - Reviews of Environmental Contamination and Toxicology - page 121

Table 2 Toxicity of specific platinum compounds in laboratory rats [after peroral (po) or
intraperitoneal (ip) administration]

Platinum compound Route of exposure Toxicity LD 50 (mg Pt kg −1 )
Cis-platinum Ip 7.4 a
Sodium heksachloroplatinate (IV) Po 15-50 b
Hexachloroplatinic acid (IV) Ip 15-19 b
Platinum (IV) chloride Ip 22 c
Platinum (IV) chloride Po 136 c
Potassium tetrachloroplatinate (II) Po 23-94 b
Ammonium heksachloroplatinate (IV) Po 88 b
Platinum (II) chloride Ip 490 c
Platinum (II) chloride po >1400 c >975 d
Platinum (IV) oxide po >6900 c >2926 d
LD 50 amount of a substance in mg kg −1 body weight, which causes the death of 50% (one
half) of a group of test animals LD lethal dose
a WHO (1991)
b Lindell (1997)
c Holbrook (1976)
d Holbrook et al. (1975)

5.3 Evaluation of Human Health Risks

Health problems from occupational exposure to Pt were first reported in 1911
(Karasek and Karasek 1911; Farago et al. 1998). It is now well known that Pt com-
pounds can cause a range of toxic effects in humans (Leœniewska et al. 2001). Miners
and personnel employed in purifying and processing PGE-bearing ores are exposed
to potentially high concentrations of these metals, which poses a serious health threat,
including allergies to Pt salts. It is also known that certain Pt species have a skin-
sensitizing potential, and that metallic Pd can cause contact dermatitis.
The first inhalation toxicity study from inhaling Pt-containing particles was
published in the 1970s (Moore et al. 1975b; Ravindra et al. 2004). The level of soluble
Pt compounds in air that can cause an allergic reaction is 0.1 µg m −3 (Rosner and
Merget 2000). The following Pt compounds are considered to be the strongest
allergens: hexachloro platinic acid (IV), ammonium and potassium hexachloropla-
tinate (IV), and sodium and potassium tetrachloroplatinate (II).
It has been established that Pt, and its derivatives, mainly accumulate at sites in the
respiratory tract; however, significant Pt concentrations were also found in kidneys.
Breathing problems were reported for about one half of refinery employees exposed
to the Pt salts used in industrial catalysts (Hughes 1980). The period between initial
exposure to Pt salts and the first appearance of toxicity syndromes ranged from a couple
of mon to 6 yr. In general, employees removed from the hazardous environment did not
display the long-term effects of exposure (Ravindra et al. 2004).
Studies were also performed among employees of a catalyst manufacturing and
recycling factory to evaluate exposure to metal compounds from the Pt group. The
examination consisted of completing a work exposure and medical questionnaire,