摘要：Summary. - PM10 is a complex mixture of particles and we have focused here on the ultrafine
component, i.e. particles with a diameter of less than 100 nm. In PM10 this fraction is mostly composed of
combustion-derived, carbon-centred particles with associated hydrocarbons and metals. Progress in understanding
the effects of ultrafine particles in the lungs has been achieved largely through the use of surrogate
particles such as ultrafine carbon black and titanium dioxide. Using these types of particles, ultrafines have
been shown to cause oxidative stress and pro-inflammatory effects in a number of in vivo and in vitro
models. The mechanisms of the generation of the oxidative stress is not understood, but appears to be
related to the large particle surface area in some way. Modulation of calcium signalling also appears to be
involved in the stimulation of cytokine release by macrophages in response to ultrafines. Effects of PM10 are
seen on cardiovascular mortality and morbidity, as well as on the lung. Although the role of ultrafine
particles in these effects are not well understood there are plausible pathways that remain to be explored.
