Influences on human internal exposure to environmental platinum.

Different influences on internal exposure to platinum are investigated and for the first time weighted in environmentally exposed subjects as far as individual internal platinum concentrations are concerned. Detailed medical and environmental histories as well as oral cavity status were assessed in 84 dermatological patients, and internal platinum exposure was determined by analyzing platinum in urine using adsorptive voltammetry (AV). Platinum concentrations ranged from <0.9 (detection limit) to 65.5 ng Pt/l urine. Influence of different types and age of alloy restorations and therefore relevance of the exposure pathway due to solubilization of platinum in saliva could be demonstrated. No platinum-related health effects (contact stomatitis, asthma or kidney conditions) were observed. Analysis of covariance showed the number of noble dental alloy restorations (P<0.0001) and to a lesser extent age (P=0.0017) to independently influence internal platinum exposure. Even though spread of environmental platinum has increased, internal platinum exposure is low in subjects without assessable medical or dental devices (usually <4.5 ng/l urine) and not related to adverse health effects. For the first time, detailed individual information on possible exposure pathways to platinum were considered in an analysis of relevant influential factors: Car traffic exposure and dermatological condition showed no association with internal platinum exposure. Uptake from platinum containing noble metal dental alloy restorations (NMDAR) is of greatest relevance, surmounting the influence of each year of lifetime on platinum body load by more than 10-fold.