Atmospheric pollution with heavy metals at Tabouk City-KSA

Air pollution with heavy metals at Tabouk City in the Kingdom of Saudi Arabia was evaluated using street dust and tree bark as indicators. Air pollution with six heavy metals (Copper, Zinc, Nickel, Manganese, iron and Cadmium) from the city of Tabouk City were evaluated by collecting street dust and tree bark samples from residential areas, the city center, and a remote site for results comparison. The results showed that higher air pollution was found at the city center in comparison to the residential areas using tree bark and street dust samples. The abundance of analyzed heavy metals concentration in the descending order for street dust were iron higher than manganese higher than zinc higher than copper higher than nickel higher than cadmium. The city center and residential areas showed similar trends due to the same pollution source which is traffic emission in this case. The concentration of heavy metals in descending order from tree bark samples were iron higher than zinc higher than copper higher than manganese higher than nickel and higher than cadmium reflecting the existence of air pollution for years and at the earlier stages of the tree growth. It can be concluded from this research that the major source of air pollution in the city of Tabouk is majorly due to traffic activities as no major industries are located within the investigated area. Street dust is commonly attributed to the transportation of heavy metals with prevailing wind direction in the study area. The results of heavy metal air pollution found in this study were compared with some other cities around the world. The levels of the metal ion concentrations were generally below the mean concentration values in comparison to the commonly known air polluted cities of the world.