Platinové kovy z mobilních zdrojů jako potenciální zdroj rizik

Abstract

Autocatalysts presented a major breakthrough in reducing emissions of gaseous pollutants from transport and thus solved one of the biggest problems of automobile industry. However, introduction of new technologies bring new potential risks. The technology for emissions control is not the exception. Nowadays, autocatalysts are considered the main source of platinum group metals (Pt, Pd, and Rh – PGM) emissions into the environment. Since their introduction, the significant increase of naturally very low PGM concentrations has been observed in different environmental compartments. Concerns, which present the accumulation of these contaminants in the environment, are raised by toxicity of certain PGM compounds well known from the working environment. Soluble Pt compounds are among the most efficient sensitizers. The aim of the doctoral thesis was to evaluate the current state of knowledge about risks to human health from environmental contamination by PGM from transport and to apply the findings in the Czech Republic (CR). The evaluation of the current state was carried out by confrontation between the results of the analysis of available data on the issue and the requirements for appropriate health risk assessment. The requirements come out from the US National Academy of Sciences risk assessment paradigm. The evaluation has shown that, to date, the scientific information is not sufficient for appropriate risk assessment. However, there are reasonable grounds for concern that potential hazards may affect the human health in the future. Thus, conditions for application of precautionary principle (PP) are set up. In compliance with the Communication from the Commission on the PP, a decision was made to fill in some missing data in the CR. With respect to identified research needs, possibilities and experiences of analytical laboratories in the CR as well, the attention was focused on soil contamination. The target was to obtain preliminary data for environmental monitoring and exposure assessment of PGM. The sampling plan was worked out and a PGM screening at locations with different traffic loads, including sites with potential exposure of children as a highly sensitive group, was carried out. The results indicate a significant increase of PGM concentrations against the background at sites with traffic load. Increased concentrations of Pt, Pd, and Rh were found not only in the immediate vicinity of roads with high traffic load, but also in soils of kindergarten playgrounds situated further from the source. And so, the question of potential health risks from environmental contamination by PGM from transport become relevant in the CR as well. With respect to the obtained results, it is necessary to continue applying the PP. Further strategy of management of PGM health risks should be aimed on the following areas: i) Becoming part of the European community in research of environmental and biological fate of PGM, and their hazards for human health; ii) Improvement of analytical methods and procedures for determination of PGM, including speciation; iii) Long-term environmental monitoring of PGM and biological monitoring of exposure; iv) Support for development of autocatalysts with reduced PGM emissions; v) Communication of potential health risks with stakeholders.