Human health risks of PAHs in soil and vegetables from Tiga, Kano State, Nigeria

This study evaluates the concentrations of seventeen polycyclic aromatic hydrocarbons (PAHs) in soil and selected vegetable samples (onions, tomatoes, hot peppers, sweet peppers, and garden eggs) from Tiga agricultural locations in Kano State, Nigeria. Soil samples were collected from ten plots (dep...

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Main Authors: Enyojo S. Okwute, Zakari Mohammed, David E. Arthur, Haruna B. Wayar, Joseph C. Akan
Format: Article
Language:English
Published: Elsevier 2025-06-01
Series:Toxicology Reports
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Online Access:http://www.sciencedirect.com/science/article/pii/S221475002500023X
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author Enyojo S. Okwute
Zakari Mohammed
David E. Arthur
Haruna B. Wayar
Joseph C. Akan
author_facet Enyojo S. Okwute
Zakari Mohammed
David E. Arthur
Haruna B. Wayar
Joseph C. Akan
author_sort Enyojo S. Okwute
collection DOAJ
description This study evaluates the concentrations of seventeen polycyclic aromatic hydrocarbons (PAHs) in soil and selected vegetable samples (onions, tomatoes, hot peppers, sweet peppers, and garden eggs) from Tiga agricultural locations in Kano State, Nigeria. Soil samples were collected from ten plots (depth profiles of 0–10 cm, 10–20 cm, and 20–30 cm) and combined at each depth to create composite samples. Additionally, 20 g of each vegetable were collected and divided into fruit, stem, and root components. Standard procedures were used for the extraction and clean-up of PAHs from both soil and vegetable samples, and instrumental analysis was conducted using SHIMADZU GC-MS (GC-17A). PAH levels in soil ranged from 1.20E-02 mg/kg to 3.80E-02 mg/kg, while vegetables showed concentrations from 1.00E-03 mg/kg to 8.90E-02 mg/kg. The 0–10 cm soil samples displayed higher PAH concentrations among all the depths studied, while the vegetables with the highest PAH concentration followed the trend: Onions > Sweet Pepper > Tomatoes > Hot Pepper > Garden Egg. Overall, total PAH concentrations in vegetables exceeded those in soil. Estimated daily PAH doses were below the Tolerable Daily Dose Limit set by FAO, indicating low health risks. Incremental lifetime cancer risk values also fell below US EPA acceptable levels (10E-06), suggesting negligible cancer risk while the hazard index was less than 1, implying no appreciable non-cancer health risks. PAH pollution was attributed to both petrogenic and pyrogenic sources. The findings of this study indicate that under the assessed conditions, the five vegetables evaluated from Tiga pose no significant risk and are considered safe for consumption.
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spelling doaj-art-2b54a91f436d461d923e3f5dfaacc5132025-01-19T06:25:04ZengElsevierToxicology Reports2214-75002025-06-0114101905Human health risks of PAHs in soil and vegetables from Tiga, Kano State, NigeriaEnyojo S. Okwute0Zakari Mohammed1David E. Arthur2Haruna B. Wayar3Joseph C. Akan4Corresponding author.; Department of Pure and Applied Chemistry, University of Maiduguri, NigeriaDepartment of Pure and Applied Chemistry, University of Maiduguri, NigeriaDepartment of Pure and Applied Chemistry, University of Maiduguri, NigeriaDepartment of Pure and Applied Chemistry, University of Maiduguri, NigeriaDepartment of Pure and Applied Chemistry, University of Maiduguri, NigeriaThis study evaluates the concentrations of seventeen polycyclic aromatic hydrocarbons (PAHs) in soil and selected vegetable samples (onions, tomatoes, hot peppers, sweet peppers, and garden eggs) from Tiga agricultural locations in Kano State, Nigeria. Soil samples were collected from ten plots (depth profiles of 0–10 cm, 10–20 cm, and 20–30 cm) and combined at each depth to create composite samples. Additionally, 20 g of each vegetable were collected and divided into fruit, stem, and root components. Standard procedures were used for the extraction and clean-up of PAHs from both soil and vegetable samples, and instrumental analysis was conducted using SHIMADZU GC-MS (GC-17A). PAH levels in soil ranged from 1.20E-02 mg/kg to 3.80E-02 mg/kg, while vegetables showed concentrations from 1.00E-03 mg/kg to 8.90E-02 mg/kg. The 0–10 cm soil samples displayed higher PAH concentrations among all the depths studied, while the vegetables with the highest PAH concentration followed the trend: Onions > Sweet Pepper > Tomatoes > Hot Pepper > Garden Egg. Overall, total PAH concentrations in vegetables exceeded those in soil. Estimated daily PAH doses were below the Tolerable Daily Dose Limit set by FAO, indicating low health risks. Incremental lifetime cancer risk values also fell below US EPA acceptable levels (10E-06), suggesting negligible cancer risk while the hazard index was less than 1, implying no appreciable non-cancer health risks. PAH pollution was attributed to both petrogenic and pyrogenic sources. The findings of this study indicate that under the assessed conditions, the five vegetables evaluated from Tiga pose no significant risk and are considered safe for consumption.http://www.sciencedirect.com/science/article/pii/S221475002500023XPolycyclic Aromatic Hydrocarbons (PAHs)Tiga DamGas Chromatography-Mass Spectrometry (GC-MS)Health Risk AssessmentKano State
spellingShingle Enyojo S. Okwute
Zakari Mohammed
David E. Arthur
Haruna B. Wayar
Joseph C. Akan
Human health risks of PAHs in soil and vegetables from Tiga, Kano State, Nigeria
Toxicology Reports
Polycyclic Aromatic Hydrocarbons (PAHs)
Tiga Dam
Gas Chromatography-Mass Spectrometry (GC-MS)
Health Risk Assessment
Kano State
title Human health risks of PAHs in soil and vegetables from Tiga, Kano State, Nigeria
title_full Human health risks of PAHs in soil and vegetables from Tiga, Kano State, Nigeria
title_fullStr Human health risks of PAHs in soil and vegetables from Tiga, Kano State, Nigeria
title_full_unstemmed Human health risks of PAHs in soil and vegetables from Tiga, Kano State, Nigeria
title_short Human health risks of PAHs in soil and vegetables from Tiga, Kano State, Nigeria
title_sort human health risks of pahs in soil and vegetables from tiga kano state nigeria
topic Polycyclic Aromatic Hydrocarbons (PAHs)
Tiga Dam
Gas Chromatography-Mass Spectrometry (GC-MS)
Health Risk Assessment
Kano State
url http://www.sciencedirect.com/science/article/pii/S221475002500023X
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