An Estimation of Daily Intake of Potentially Toxic Elements from Urban Dust of Abakaliki, Nigeria

Abstract

This study examined the total concentration of eight potentially toxic elements (PTEs) in urban dust of Abakaliki and also calculated the daily intake (DI) of these PTEs. Fifteen samples were investigated and the result revealed that the range of mean total PTE concentrations was found in this order: 3.59 – 15.3 mg/kg (As); 66.8 -172 mg/kg (Cd); 0.288 – 1.36 mg/kg (Cr); 25.4 – 86.6 mg/kg (Cu); 55.5 – 1815 mg/kg (Pb); 397 – 1389 mg/kg (Mn); 22.3 – 52.7 mg/kg (Ni) and 73.3 – 434 mg/kg (Zn). For each element the highest concentration (representing the worst-case scenario was used to calculate the daily intake and it was observed that only Pb with a DI of 4.88 μg kgbw ^-1 day^-1 exceeded Pb recommended tolerable daily intake (TDI) of 3.6 μg kgbw^-1 day^-1. Based on a soil and dust ingestion rate of 50 mg /day for children between the age of 1 and <6 year, the amount of dust that a child would ingest in order to exceed the recommended tolerable daily intake TDI was also calculated.

Keywords: urban dust, potentially toxic elements (PTEs), oral ingestion, Abakaliki, tolerable daily intake (TDI)