SENSITIZATION AND EXACERBATION OF ALLERGIC DISEASES BY DIESEL ENGINE PARTICLES

Most studies of the health effects of diesel exhaust have focused on the controversial issue of its role in cancer. However, recently the role of combustion products such as diesel exhaust particles (DEP) in modulating the immune response has garnered much attention. In particular the effect of DEP on allergic and asthmatic diseases has been the focus of many studies. A link between industrialization and allergic disease has long been presumed. Indeed, only 50 years after the first recorded reported case of allergy in 1819, Charles Blackely wrote that the ''hay-fever epidemic'' was associated with the movement of people from the country into the cities. Ishizaki et al. (1987) found that people in Japan living on busy roads lined with cedar trees have more allergies to cedar than residents living on similar streets with much less traffic. Since that time other epidemiological studies have reported similar findings. Kramer, et al., showed that hay fever is greater in residential areas with heavy truck traffic, while Weiland, et al., reported that allergic symptoms correlate with the distance of residences to roads with heavy traffic