Effect of traffic density on heavy metal content of forest trees in chessmaster park in Astana, Kazakhstan
摘要
The study investigates the changes in heavy metal concentrations in the leaves of urban trees in Chessmaster Park in Astana, Kazakhstan. Samples were collected from areas located 10–15 m from the main road (high pollution), 15–30 m from the secondary road (moderate pollution), and 30–80 m from the non-road (low pollution). Air pollution data for 2020 and 2021 was sourced from Kazhydromet, and graphs were created. The findings indicate that traffic-related pollution has led to significant variations in the accumulation of most heavy metals, except for manganese, nickel, and zinc. In areas of light and moderate pollution where Betula pendula was present, higher concentrations of zinc (197.488 and 481.275 mg kg−1), and manganese (163.07 and 157.741 mg kg−1) were observed, while lead (3.123 mg kg−1) was found in higher concentrations in the moderate pollution zones. Silver concentrations were notably higher in all tree species across all traffic pollution levels. Aluminum and iron deficiencies were observed in all pollution zones, particularly in Betula pendula and Picea pungens. The results also revealed extremely high levels of PM2.5 and PM10 in 2021, with mean concentrations of 50.7 µg m−3 and 130 µg m−3, respectively, exceeding the limit values. Additionally, heavy metal accumulation in urban trees was found to be influenced by air quality, traffic density, and silver toxicity, especially when tree roots were exposed to sewage. Overall, these results highlight the accumulation of heavy metals from groundwater, air pollution, traffic emissions, and other human activities.