Skip to main content

Assessment of Environmental Levels of Pollution in Soil Contaminated with Crude Oil Using Soil Contamination Indexes Models Cover

Assessment of Environmental Levels of Pollution in Soil Contaminated with Crude Oil Using Soil Contamination Indexes Models

Civil and Environmental Engineering

By: Khalid Ahmed Salih and Amjad Kallel

Open Access

|Mar 2026

Figures & tables

Figures & Tables

Table 1:

Division of study area

Ajeel oil field
Zone 1	Zone 2
Sample 1	Sample 5
Sample 2	Sample 6
Sample 3	Sample 7
Sample 4	Sample 8

Map of study sampling

Container model uses to save the collected samples

Collection samples from Ajeel oil field

Measurement of heavy metal concentrations in soil samples in Zone 1 of the Ajeel oil field

Measurement of heavy elements concentrations for soil models in Zone 2 of the Ajeel oil field

Table 2:

A statistical analysis of the results of heavy metal concentrations samples, Zone 1

Heavy elements (mg/l)	Mean	Median	Std. deviation	Min.	Max.
Lead Pb⁺²	20.46	22.09	8.52	9.11	28.54
Cadmium Cd⁺²	1.19	0.41	1.58	0.33	3.44
Chromium Cr⁺³	105.86	136.83	33.72	70.63	140.97
Zinc Zn⁺²	58.07	68.89	22.02	30.13	72.48
Nickel Ni⁺²	43.14	43.08	24.16	20.32	67.41
Copper Cu⁺²	18.06	19.34	4.67	11.25	22.41
Iron Fe⁺³	3.84	4.09	1.05	2.31	4.77
Manganese Mn⁺²	693.50	725.50	102.50	537.0	733.0
Cobalt Co⁺²	9.87	9.79	3.23	6.80	13.10
Molybdenum Mo⁺⁶	1.13	1.12	0.49	0.61	1.65
Arsenic As	3.75	4.10	2.87	1.20	6.70

Table 3:

The statistical analysis of the results of soil contamination, Zone 2

Heavy elements (mg/l)	Mean	Median	Std. deviation	Min.	Max.
Lead Pb⁺²	37.58	38.08	1.83	35.11	38.93
Cadmium Cd⁺²	3.79	4.69	2.52	0.06	5.72
Chromium Cr⁺³	101.33	97.68	9.94	94.22	115.75
Zinc Zn⁺²	91.90	89.92	5.25	87.52	99.52
Nickel Ni⁺²	61.55	65.73	11.23	45.38	69.36
Copper Cu⁺²	33.83	37.46	9.17	20.17	40.25
Iron Fe⁺³	433.29	441.28	425.92	48.37	897.40
Manganese Mn⁺²	30.92	30.30	10.95	7.32	33.76
Cobalt Co⁺²	1.86	1.89	0.10	1.71	1.95
Molybdenum Mo⁺⁶	7.73	7.70	0.81	6.90	8.60
Arsenic As⁺³	7.23	7.10	0.82	6.50	8.10

Table 4:

Pollution levels of Nemerow Pollution Index PN

Pollution level	PN
Low pollution	PN < 1
Moderate pollution	1 ≤ PN < 2
High pollution	2 ≤ PN < 3
Very high pollution	PN ≥ 3

Results of PN for the Ajeel oil field – Zone 1

Outcomes of pollution index PN – Ajeel oil field – Zone 2

Pollution level distribution map for Nemerow Pollution Index model in the Ajeel oil field

Table 5:

Limitation of potential environmental index PRI

Degree of risk	PRI value
Low risk	PRI≥50
Moderate risk	50 > PRI ≤ 100
Considerable risk	100> PRI ≥ 150
Very high Risk	150> PRI ≥ 200
Extreme Risk	PRI>200

PRI results of Ajeel oil field - Zone 1

Outcomes of PRI-Ajeel oil field - Zone 2

Map of the distribution of PRI levels, model of environmental risk PRI of Ajeel oil field

Articles in this issue

DOI: https://doi.org/10.2478/cee-2026-0086 | Journal eISSN: 2199-6512 (formerly 1336-5835) | Journal ISSN: 1336-5835

Journal RSS Feed

Language: English

Submitted on: Oct 18, 2025

|

Accepted on: Dec 1, 2025

|

Published on: Mar 19, 2026

Published by: University of Žilina

In partnership with: Paradigm Publishing Services

Publication frequency: 4 issues per year

Keywords:

crude oil contamination,

contaminated soil,

environmental hazard,

contamination levels

Related subjects:

Business and economics,

Business management,

Environmental management

© 2026 Khalid Ahmed Salih, Amjad Kallel, published by University of Žilina
This work is licensed under the Creative Commons Attribution 4.0 License.

Previous article