Lung Diseases
Subsequent information provided by the local environment control authorities on nitrogen dioxide indicated a difference of 41 ^g/m3 (mean annual levels: 59 ^g/m3 in Pisa and 18 ^g/m3 in Po Delta).
The Study on Air Pollution and Lung Diseases in Adults also found that the annual average concentration of air pollutants was higher in urban areas than in rural/alpine areas. Moreover, it showed a relationship between annual average air pollution concentration and decrement in lung function parameters: for example, a 1.59% reduction in FEV1 was estimated in healthy never-smokers for a 10 ^g/m3 increase of particulate matter with aerodynamic diameter < 10 ^m.
The prevalence rates of respiratory symptoms and the chromosome aberrations baseline frequency were significantly higher in Pisa than in Po Delta. These findings might be due to the larger exposure to air pollution in Pisa. An indication of this hypothesis comes from the data regarding the self-perception of air pollution exposure: 55% of the Pisa subjects reported exposure to air pollution sources (industrial fumes/gases and traffic), while only 15% of Po Delta subjects did so. A study in Scotland highlighted that urban residence is associated with worse respiratory health status or quality of life among subjects reporting respiratory symptoms/ diseases than rural residence. Moreover, people living in the urban area of Pisa had a higher value of serum antibodies to benzo(a)pyrene diol epoxide-DNA adducts than people living in the suburban area of Pisa.
Few recent studies analyzed the relation between BHR and air pollution indicators, confirming our findings. Jang and colleagues found a significant increase in BHR and atopy in children living near a chemical factory with respect to those in rural/coastal areas. A similar result has been shown in a study about BHR in urban, periurban, and rural South African children. Furthermore, Longhini and col-leagues showed that normal children living in an air-polluted area had a higher prevalence of BHR, compared with those living in mountain valleys.