Pulmonary toxicity of ultrafine particles

There is considerable evidence that ultrafine particles (UFP) have specific toxic properties. This had already been established in animal studies , but awareness of the issue has been heightened by reports of mortality and morbidity linked to acute episodes of urban pollution. Here, we will only briefly discuss the pulmonary toxicology of low-solubility PUFs. In this context, the parameters most likely to be relevant are particle number and/or surface area, but others have also been mentioned, such as metals, free radicals and adsorbed chemical molecules.