IOSR Journal of Applied Chemistry (IOSR-JAC) e-ISSN: 2278-5736.Volume 13, Issue 3 Ser. II (March. 2020), PP 01-17 www.iosrjournals.org DOI: 10.9790/5736-1303020117 www.iosrjournals.org 1 |Page Evaluation of Levels of Persistent Organic Pollutants in Crude Oil Contaminated Soils at Omuigwe-Aluu Rivers State Nigeria 1 Ideriah T. J. K., 2 Ndukwe G. I.and 2 Ighomuaye, M. N., 1 Institute of Pollution Studies, Rivers State University Nkpolu Oroworukwo, Port Harcourt 2 Department of Chemistry, Rivers State University Nkpolu Oroworukwo, Port Harcourt Abstract: Following recent crude oil spill at Omuigwe-Aluu in Rivers State, Nigeria, the levels of polycyclic aromatic hydrocarbons, organochlorine compounds and total petroleum hydrocarbons in the crude oil contaminated soils were determined using gas chromatography-flame ionization detector and gas chromatography–mass spectrometer. The concentrations of toxic and carcinogenic polycyclic aromatic hydrocarbons which exceeded permissible limits in the soils were benz(a)anthracene 0.08±0.01 ppm, chrysene 0.04±0.01 ppm, benzo(b)fluoranthene 0.04±0.007 ppm, benzo(k)fluoranthene 0.02±0.00 ppm, benzo(a)pyrene 0.02±0.01 ppm and dibenzo(a,h)anthracene, 0.04±0.01 ppm. The concentrations of all the organochlorine compounds analysed were below detectable limits implying that the area is not polluted with organochlorine compounds. The highest concentration of total petroleum hydrocarbon (1016 ppm) was found at the spill site and is below intervention value of 5000 ppm. The exceedance of the toxic and carcinogenic polycyclic aromatic hydrocarbons could be due to oil exploitation activities. The area is contaminated with Total petroleum crude oil, soils. hydrocarbons. Regular monitoring of these pollutants in the study area is recommended. Keywords: Polycyclic Aromatic Hydrocarbons, Organochlorine compounds, Total Petroleum Hydrocarbons, Crude oil, Soils --------------------------------------------------------------------------------------------------------------------------------------- Date of Submission: 09-03-2020 Date of Acceptance: 23-03-2020 --------------------------------------------------------------------------------------------------------------------------------------- I. Introduction Crude oil is a primary raw material on earth and the greatest energy resource to human. Crude oil originates from the leftover of plants and animals over a long period [1]. Soil is an essential raw material supporting various parts of the ecosystem for human use [1]. Hence soil is a sink which absorbs or filters and could retain materials from infiltrating natural waters. Environmental (mainly land and water) contamination with crude oil is called oil pollution and it has been estimated that 80% oil pollution comes from spillage [2]. Many communities in the Niger Delta region of Nigeria, including Omuigwe-Aluu have been contaminated with petroleum as a result of its production and exploration activities. The presence of artificial and natural contaminants in soils, sediments and ground water above the standard limits has impacted negatively on the ecosystems and raw materials, as well as the health of man [3]. Generally, Soils be may contaminated by the pilling up of heavy metals and polycyclic aromatic hydrocarbons from industrial emissions, mine tailings, wastes from metals, gasoline and paints containing lead, spraying of fertilizers, sewage sludge, pesticides, irrigation of wastewater, leftover of coal combustion, spilling of chemicals and rainfall [4] [5]. Globally, agricultural and industrial activities have increased the contamination of the ecosystem with organochlorines, products of petroleum and toxic metals [6]. These contaminants last very long and some remains in the area [7]. They are also harmful to plants and animals [8]. Organochlorines have been defined as highly toxic man made organic chemicals containing carbon used in industry and agriculture, as well as unintentional combustion processes of chlorine [9]. Organochlorine compounds (pesticides) are organic chemicals containing chlorine. Most of them are synthetic and they get into our surroundings through anthropogenic activities. Polycyclic aromatic hydrocarbons (PAHs) which are generally everywhere (soil, water and air) are group of different chemicals formed due to incomplete combustion of coal, oil and gas, garbage, tobacco. PAHs structures contain two or more benzene rings [10], [11], [12], [13], [14], [15], [16], [17] and have heteroatoms or substituents. PAHs with two to four rings are light PAHs while those with four rings and above are heavy PAHs. Heavy ones are usually harmful and stabilize better than the light PAHs [18], [19]. Exposure to PAHs has negative effects on humans, causing lungs cancer, DNA mutation and reproductive problems [20].Some examples of PAHs are naphthalene, anthracene, phenanthrene, fluorine and pyrene. PAHs are either natural and synthetic and are usually colourless, white or pale yellow- green solids. PAHs are used in the production of coal tar, crude oil, creosote, roofing tar and with little used in medicines or for the production of dyes, plastics and pesticides [21].