Evaluation of lead, cadmium, and chromium levels in automotive paints in Kenyan market.

Abstract

Heavy metals such as chromium, lead and cadmium are added to paint because of their beneficial properties. Some of the compounds of chromium and cadmium are added to paints to provide protection against corrosion and for reflective properties while lead provides decorative colours, enhanced drying time and prevents corrosion of metallic surfaces. These heavy metals are however toxic even at low concentrations and are responsible for quite a number of health effects due their accumulation in the body more so to the automobile paint sprayers and are persistent in the environment.This study was conducted to assess the levels of lead, chromium and cadmium in automotive paints frequently used by automotive paint sprayers in Nairobi City. A total of thirty-two (n = 32) cans of automotive paints consisting of 4 sets of red, blue, green and white colours were obtained from each of the four formal and informal retail shops. The levels of lead, chromium and cadmium in the paint samples were analysed using Atomic Absorption Spectrophotometer after the digestion of the samples according to the standard procedures. The study revealed that all the automotive paint samples from informal retail shops had total lead levels above 90 ppm set limit according to the Kenya Bureau of Standards (KEBS). The mean levels of lead ranged from 221.0±1.4 ppm to 2688.4±19.5 ppm. Lead levels were comparatively lower in the formal than informal retail shops, although only one out of sixteen samples from formal retail had lead levels of 83.3±2.2 ppm that fell within the stipulated limit. The other samples from the formal retail shops had concentrations ranging from 115.6±16.1 to 555.2±36.1 ppm with white colour having the lowest concentrations and green colour having the highest. In the case of chromium, the levels ranged from 120.5±10.6 to 2771.9±35.6 ppm with only two paint samples out of sixteen from formal retail shops having chromium levels of 39.3±7.0 and 94.8±8.1 ppm that was within the recommended limit of 100 ppm according to European Union while the rest of the paint samples from the informal and formal retail shops exceeded this limit.. Cadmium levels in paint samples from informal retail shops ranged from 2.4±1.5 to 12.5±0.6 ppm while those from formal retail shops ranged from 7.5±0.3 to 24.8±0.1 ppm. In both formal and informal retail shops blue colour had the lowest cadmium concentrations while green colour had the highest concentrations. It was observed that some automotive paint samples from formal retail shops had higher concentrations of cadmium than those from informal retail shops. However, concentrations of cadmium in all the automotive paint samples were below the set limit of 100 ppm. The results showed that automotive paints sold on the Kenyan market from both the informal and formal retail shops contained lead and chromium levels that were of health and environmental concern however the levels of cadmium were within the set limit. Therefore, there is urgent need to enforce the set standards to ensure the lead and chromium paints sold on the Kenyan market are within the required standards and that automotive spray painters are made aware of the adverse health effects associated with these paints.