TITLE:
Exposure and Health Risks of Highway-Associated Heavy Metal Pollution in Orchard Soils and Fruits in Eastern Uganda
AUTHORS:
Charles Oboi, Irene Nalumansi, Denis Byamugisha, Caroline Kiwanuka Nakiguli, Paul Mukasa, Emmanuel Ntambi
KEYWORDS:
Citrus sinensis, Mangifera indica, Orchards, Acceptable Limit, Hazard Index
JOURNAL NAME:
Green and Sustainable Chemistry,
Vol.15 No.4,
November
4,
2025
ABSTRACT: Anthropogenic activities introduce heavy metals (HMs) into soils which can be absorbed by plants. We, in the present study, determined the concentration of four priority HMs (Cu, Pb, Cd and Zn) in orchard soils and edible fruits (sweet oranges and mangoes) grown along the arterial Mbale-Soroti Highway of Uganda. A total of 78 fruit samples were systematically obtained from the fruit trees at distances of 10 m, 100 m, 300 m and 5000 m from the Highway, along with 78 soil samples. They were analyzed for the HMs using inductively coupled plasma-optical emission spectrometry. Health risks were assessed using the hazard index and incremental life cancer risk methods, while ecological risks were evaluated based on geoaccumulation and pollution indices. The mean metal total concentrations followed the order Zn > Cu > Pb > Cd, and were all within permissible limits. In the fruit and soil samples, the concentration ranges (mg/kg) were Cu (0.05 ± 0.01 - 1.81 ± 0.37 and 11.42 ± 3.00 - 30.85 ± 5.97), Zn (2.41 ± 2.18 - 8.11 ± 1.20 and 19.00 ± 1.30 - 40.03 ± 7.28), Pb (0.01 ± 0.00 - 0.06 ± 0.03, and 7.72 ± 1.05 - 21.00 ± 3.13) and Cd (