Levels of heavy metals in drinking water, cosmetics and fruit juices from selected areas in Dar es Salaam, Tanzania

Abstract

Heavy metals were determined in samples of drinking water, cosmetics (nail polish, lip glosses and hair dye) and fresh fruit juices in Dar es Salaam. The samples were analyzed using Atomic Absorption Spectrometry (AAS) after digestion with concentrated acids, filtration and dilution. Lead, zinc and iron were detected in the water samples and the concentration ranges were below detection limit (BDL) to 0.114, 0.01 to 1.47 and 0.027 to 0.39 mg/L, respectively, whereas cadmium was not detected. The concentrations of lead in 70.83% of the samples exceeded the WHO permissible limit, implying that the water in most of the areas was not suitable for human consumption. Lead, zinc, and cadmium were detected in all the cosmetics at concentrations ranging from 6.6 to 37400, 21.5 to 2600, and up to 0.25 mg/kg, respectively. Most of the concentrations of lead in cosmetics exceeded the EU/US permissible limits. The continued use of products containing such heavy metals may increase the body intake of the metals and cause harmful effects. Only copper was detected in the fruit juices and the water used for their preparations at concentrations ranging from 0.008 ± 0.003 to 0.215 ± 0.014 mg/L, which were below the WHO permissible limit.

Keywords: Heavy metals, drinking water, tap water, cosmetics, fruit juice, Tanzania