Levels of selected heavy metals in paints from selected industries in Dar es Salaam.

The aim of this study was to assess the levels of lead (Pb), cadmium (Cd), cobalt (Co), copper (Cu) and zinc (Zn) in paints manufactured from Dar es Salaam industries. Thirty-nine (n=39) samples of five different colours (yellow, red, white, blue and green) from each of the four different paint brands (Coral, Kiboko, Sadolin and Goldstar) were randomly collected from Dar es Salaam retail shops, among them nineteen (n=19) were oil based and twenty (n=20) were water based paints. The paint samples were digested using analytical grade 70% HNO3 and 30% H2O2 and analysed using Atomic Absorption Spectrophotometer (AAS). T-test and analysis of variance (ANOVA) using GraphPad Instat Demo and MaxStat Lite Version 3.60 Build L 24032015 software were used to analyse data. The results revealed that oil-based paints had high levels of lead and cobalt contents with a range of 4.8 – 73824 and 102-928 mg/kg, respectively. For water-based paints, the brand with the highest mean Pb levels ranged from 29.4 to 30.71 mg/kg while Co was below the detection limit. Cd, Cu and Zn levels in both oil and water based paint samples analysed were below the Canadian set limits of 17, 7700 and 46000 mg/kg, respectively. The accuracy of the method used was evaluated by analysing the spiked samples. The recoveries of the heavy metals were in the range of 94.76 to 99.83% and the precision was 5 to 12.2%. There is a need for TBS to establish its own permissible limits of metals in paints for all manufacturers of paints to abide to, so as to phase out the use of the toxic compounds in paint products. Therefore, the results from this study stimulates further investigations in the field of heavy metals in paints as a way forward for monitoring the toxic heavy metal contents in paints.