Environ Sci Pollut Res Int 2020 Mar 9. Epub 2020 Mar 9.
College of Natural and Computational Sciences, Department of Chemistry, Ambo University, P. O. Box 19, Ambo, Ethiopia.
Environmental pollution by paint-based heavy metals have been continued to be a great concern. Thus, this study was aimed at investigating the levels of selected heavy metals (Ni, Cd, Cr, Zn, and Pb) in oil-based paint samples being manufactured and sold in Ethiopia. An optimized acid digestion procedure using conc. HNO, conc. HClO, and 30% HO mixture by volume ratio of 3:4:1 mL, respectively, for 2 h at 200 °C were used for paint samples digestion, and the contents of heavy metals were assayed by flame atomic absorption spectroscopy. The 13 out of 14 (92.9%) analyzed paint samples had contained Pb > 90 mg/kg with the highest content of 51,200 mg/kg (dry weight) in the orange colored paint. Likewise, the levels of Cr, Ni, and Zn obtained were ranged from 43.75 to 50.00, 60.02 to 128.81, and 323.69 to 1102.16 mg/kg (dry weight), respectively, while Cd was not detected in all the paint samples. Generally, the mean contents of heavy metals in the investigated paint samples have followed the order: Pb > > Cr > Zn > Ni, demonstrating the occurrence of higher lead metal content. The elevated levels of heavy metals detected in the oil-based paint samples could be attributed to the continued usage of these metals in different form during paint manufacture. On the bases of the findings, a strict monitoring and evaluation of paints being produced in Ethiopia has been recommended so that the manufacturers comply with the national (policy issue) and/or international regulations on the levels of toxic metals in paints to ensure consumers safety.