Chromium and Lead Concentrations in Tomatoes (Solanum Lycopersicum) and Red Peppers (Capsicum Frutescens) Cultivated in Roadside Farmland around High Traffic Density Area of Ibadan, Nigeria

Abstract

The total concentrations of Pb and Cr were determined in tomatoes and peppers cultivated in roadside farmland around a high traffic density area of Ibadan. The measurements were determined by atomic absorption spectrophotometer after wet digestion with nitric acid. The ranges of accumulation factors (AF) for Cr in tomatoes and pepper were 6.25–6.63 and 2.86–4.86. The degree of accumulation of Pb in tomatoes ranged from 30.5 to 40.6. Tomatoes and peppers planted in farms located near high traffic roads presented higher concentrations of Cr and Pb compared with the corresponding levels in tomatoes and peppers from the control farm. Pb concentrations as high as 7.75 ± 1.08 mg/kg, 7.74 ± 0.56 mg/kg, and 7.80 ± 0.10 mg/kg were obtained in tomatoes. The average concentrations of Cr in tomatoes and peppers were in the ranges of 1.50–1.59 mg/kg and 1.0–1.70 mg/kg, respectively. These differences in concentrations of Cr and Pb can be attributed to exhaust from automobiles as the primary source of metal contamination of roadside-grown tomatoes and peppers in addition to the concentration derived from the soil.

Keywords:

• contamination
• heavy metal
• roadside farming
• accumulation factor
• crop

Notes

*Accumulation factor: Ratio of average metal concentration in a given plot to average concentration in control site.

*Source = Onianwa (2001).