The sources of Cu emission are mainly related to traffic, such as brake abrasion and corrosion of metallic parts of cars [29,31]. In an air pollution study by Rajšić et al.[29], based on data collected for two years, significant negative correlation between Cu in airborne particulate matter in Belgrade central area and wind speed was reported, indicating that Cu was mainly emitted from
some local sources. Bearing this in mind, and noting that bus and trolleybus terminus is located in vicinity of this sampling location (Table 1), a possible explanation for high Cu concentration is that vehicle-related emission sources, such as brake and trolley pole abrasion,could be responsible for high Cu concentration in SP