Journal of Materials Science and Emerging Technologies
Research Article Volume: 1 & Issue: 2
Abstract
In Nigeria, where traditional processing methods like roadside drying are common, heavy metal contamination of staple foods poses a serious concern to public health.
The degree of heavy metal contamination in cassava flour (Manihot esculenta Crantz) processed and marketed in Ijebu Igbo, Ogun State
was evaluated in this study. Samples were collected from three sources; a commercial outlet at Ijebu Igbo Central market, a roadside drying
site along the Ibadan-Ijebu Ode road, and a controlled self-dried batch from the researcher resident in Ijebu Igbo. Inductively Coupled
Plasma-Mass Spectrometry (ICP-MS) was used to measure the amounts of manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), lead
(Pb), cadmium (Cd), chromium (Cr), and selenium (Se) concentration in all the three samples and compared with WHO/FAO standards.
Results revealed that the market-bought sample from Ijebu Igbo Central market contained Pb (2.2 mg/kg) and Cr (3.3 mg/kg) exceeding
WHO/FAO permissible limits. The roadside-dried sample from Ibadan-Ijebu Ode road had the highest levels of Fe (21.7 mg/kg) and Cr
(0 mg/kg), also exceeding WHO/FAO permissible limits. In contrast, the self-dried sample showed no detectable Cd, or Cr, indicating it
was the safest. However, all samples had Selenium levels (1.3–3.2 mg/kg) above the WHO/FAO permissible limit. The findings highlight
the elevated health risks associated with cassava flour from market and roadside sources due to environmental contamination during
processing and drying. The study recommends the adoption of controlled drying practices, enhanced market processing standards, and
stricter regulatory enforcement to ensure the safety of this widely consumed staple food.
Keywords: Manihot esculenta, heavy metals concentration, WHO/FAO permissible levels.