Use of animal experiments with engineered nanoparticles for health risk assessment and management

摘要

A general methodology of setting safe or reference exposures (RfE)-to nanoparticles (NPs) is still lacking, and in most cases the risk assessment and risk management are implemented with qualification that safe exposure limits for individual NPs are not available. The precautionary approach is that of choice in the NPs-exposed worker's health protection, but search for toxicological substantiation, even if tentative, of RfE- NPs should be intensified. To this end, we carried out short term and sub-chronic animal experiments with microparticles and NPs of Fe3O4, Ag, and Au proving the following: · Although NPs are far more toxic as compared with their micro-counterparts, the organism is able to recruit the usual physiological defences against the former even more efficiently than against the latter, the inference being that safe exposures levels are possible in principle. · There are no reliable foundations for establishing different RfEfor NPs of different size but they should depend on the NP's chemical nature. For NPs toxicologically characterized RfE-NPs can be proposed based on sufficiently conservative approach of decreasing by approximately one.