Results
The estimated annual average heavy metals concentration throughout the study area was 1.08 ng/m3 (standard deviation, SD = 1.03) in 1990 and 0.46 ng/m3 (SD = 0.45) in 2005. The annual average NO2 value in 2005 was 37.46 μg/m3 (SD = 6.56). The concentration maps for heavy metals estimated for 1990 and for 2005 are illustrated in Figure 2a and Figure 2b, respectively. The relative population distributions are rather similar in the two exposure scenarios, although the absolute values are different. Figure 2c illustrates the NO2 concentration map in 2005 indicating no spatial correlation with predicted heavy metals concentrations.