RESULTS & DISCUSSION
The residents of the studied district were asked
about the most important environmental problems
which might have the highest effect in their lives.
According to the final results, 45 % considered
traffic as their most important problem.
Furthermore, 43 % believed that the main trafficrelated
problem was sound pollution. The mean
level of Leq during the peak and the least hours of
traffic in the streets were 76.6 ± 1.8 dB and 67.6
± 3.1, respectively as shown in Table 2. According
to the changes in the streets and traffic conditions,
the statistical results showed that there was a
significant difference between the heavy and light
traffic (P < 0.05). In order to study the
environmental noise and its level in the main streets
of the mentioned district, which is shown in Table
2, L10 was calculated. The mean and standard
deviations in L10 were calculated as 75.5 ± 1.7
(before Norouz) and 66.8±3 (after Norouz) in the
heavy and light traffic, respectively. The statistical