20 years of medical surveillance on exposure to allergenic and non-allergenic platinum compounds: the importance of chemical speciation.
OBJECTIVE
Chloroplatinates are potent allergens but other soluble platinum compounds such as tetraammine platinum dichloride (TPC) do not provoke reactions in subjects who are sensitive to chloroplatinates. TPC has been used in the manufacture of autocatalysts for 20 years. This study analyses 20 year data on exposure to soluble platinum compounds and medical surveillance to confirm that TPC is not allergenic.


METHODS
Workers in three distinct operations were exposed to soluble platinum compounds as chloroplatinates, chloroplatinates with TPC, or to TPC alone. Results of personal air sampling for soluble platinum compounds were compared together with the results of medical surveillance.


RESULTS
The levels of exposure to soluble platinum compounds in each operation were comparable but the incidence of allergy was significantly different. In a subgroup of workers consistently exposed to chemical processes in each operation, the cumulative chance of being sensitised after 5 years of exposure was estimated as 51% for chloroplatinate exposure, 33% for mixed exposure, and 0% for TPC alone. The differences in sensitisation rates could not be explained by age, sex, and atopy. Nor could they be explained by the increased frequency of smoking in the workers with chloroplatinate exposure, despite the markedly higher risk of sensitisation in smokers. The differences could only be explained by the chemical stability of TPC.


CONCLUSIONS
This study shows that the soluble platinum compound TPC is not allergenic under normal industrial conditions. Characterisation of the chemical compound (speciation) is essential to prevent stringent exposure limits being imposed for all soluble compounds on a generic basis.
Linnett
P J
PJ
Johnson Matthey, Hertfordshire, UK. linnep@matthey.com
Hughes
E G
EG
D000293:Adolescent; D000328:Adult; D000485:Allergens / Q000009:adverse effects*; D004342:Drug Hypersensitivity / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D008669:Metallurgy; D008875:Middle Aged; D009784:Occupational Diseases / Q000209:etiology*; D016273:Occupational Exposure / Q000009:adverse effects; D017671:Platinum Compounds / Q000009:adverse effects* / Q000276:immunology; D011159:Population Surveillance; D012189:Retrospective Studies
D000485:Allergens; D017671:Platinum Compounds