Abstract
Dust from offices has been known to have a considerable amount of trace metals which may be harmful to human health. The present study investigated levels of trace metals in dust samples collected from air conditioning systems and carpets from offices in one of the university's buildings. Thirty dust samples were collected from offices in one of the newly renovated buildings both from the carpets and air conditions. The samples were analyzed for trace metals contents with the use of ICP-MS and the severity of pollution was calculated using the pollution index method. There was a significant correlation in the values obtained for trace metals from all the offices (p < 0.05). The result further revealed a significant difference in the concentrations of trace metals obtained from the carpet dust and air conditioners dust (p < 0.05). The highest concentration of trace metals was recorded for Zn from all the floors. Concentrations of the elements were as follows: Zn 27.23 +/- 1.03 - 2936 +/- 2.54, Cr 1.53 +/- 0.23 - 218.25 +/- 4.60, Pb 1.23 +/- 0.01 - 178.40 +/- 1.25, Cd 0.04 - 6.73 +/- 0.03, As 0.06 - 9.95 +/- 0.41 and Hg 0.05 - 2.19 +/- 0.02. The pollution index revealed a high level of pollution with Zn while a slight to moderate pollution index was recorded for Cd and Ni. However, it was evident that some of the metals exceeded the allowable limit in the environment and this might pose a serious risk for those working long hours in those offices. The study suggested the impact of vehicular emissions and chemicals from the laboratories as possible sources of these pollutants in the offices.