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European Journal of Applied Sciences – Vol. 10, No. 3

Publication Date: June 25, 2022

DOI:10.14738/aivp.103.12175. Timothy, M. N., Marcus, A. C., & Iyama, W. A. (2022). Assessment of Trace Metal Content in Soils of Automobile Workshops around

Bori Urban Area, Rivers State, Nigeria. European Journal of Applied Sciences, 10(3). 209-221.

Services for Science and Education – United Kingdom

Assessment of Trace Metal Content in Soils of Automobile

Workshops around Bori Urban Area, Rivers State, Nigeria

Timothy, M. N.

Department of General studies, Rivers State

College of Health Science and Management Technology

P.M.B. 5039, Port Harcourt Rivers State, Nigeria.

Marcus, A. C.

Department of Chemistry, Ignatius Ajuru University of Education

Rumuolumeni, PMB 5047, Port Harcourt, Rivers State, Nigeria

Iyama, W. A.

Institute of Geosciences and Environmental Management

Rivers State University, Port Harcourt, Nigeria

ABSTRACT

This study was designed to assess the concentration of trace metals (Cr, Cd, Mn, Ni,

Pb, Zn) in soils of automobile workshops around Bori Urban, Rivers State, Nigeria.

Samples were collected from three auto mechanic workshops within the Bori urban

area, Rivers State, Nigeria. The soil samples were prepared by standard procedures,

and analyzed using the Atomic Absorption Spectrophotometer, AAS (Solaar Thermo

Elemental Atomic Absorption Spectrometer-Model SE 71906). Detectable

concentrations (mg/kg) of the metals, Zn, Mn, Pb, Cd, Ni and Cr were 4.05 ± 1.02,

9.64 ± 0.71, 13.39 ± 2.28, 2.46 ± 0.42, 2.86 ± 0.79 and 2.76 ± 0.99 respectively. The

concentrations and contamination factors (CFs) across the three auto mechanic

garages were of the order, Pb > Mn > Zn > Cd > Ni > Cr and Cd > Cr > Ni > Mn > Pb >

Zn respectively while the pollution load index (PLI) values for the three auto

mechanic garages were all greater than 1, indicating a decline in the soil quality for

the three studied sites following the order station 3 > station1 > station2. The Geo

accumulation index (Igeo) revealed that the soils were extremely contaminated by

Cd and were all contaminated with trace metals when compared with regulatory

standards such as WHO and world average values in shale. Therefore, regular

monitoring of the soil in the studied sites be carried out to mitigate dangers implicit

in the continued presence of the metals determined.

Keywords: Trace metals, Assessment, Auto mechanic workshop, Bori urban area,

Pollution load index, Contamination factor

INTRODUCTION

The most essential part of the earth's crust is soil. It is the material layer that protects the

ground and allows plants to thrive (a flexible mixture of minerals and organic substances

together with water). It is the end product of physical, chemical, and biological weathering

processes on rocks, which mostly creates clay minerals. Inorganic materials which are mostly

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European Journal of Applied Sciences (EJAS) Vol. 10, Issue 3, June-2022

Services for Science and Education – United Kingdom

mineral particles with unique chemical and physical properties that vary depending on the

parent material and soil formation conditions, are the most common component of most soils

[1]. Metals are naturally occurring elements of soils and rocks in a wide range of quantities.

Some metallic species (Cu, Fe, Mn, Zn, Co, Mo, Se, and Ni) are required for significant metabolic

activities in both flora and animals at low concentrations, whereas others (Hg, Pb, Cd, and As)

are toxic even in trace levels.

Heavy metals are prevalent inorganic pollutants in soil, according to Ekpete and Festus [2], in

their study on road soils at Rumuolumeni. Because they are non-biodegradable, they bio- accumulate. As a result of the higher absorption rate relative to excretion rate, their buildup in

the soil is a health concern since they accumulate to dangerous levels over time, are absorbed

by floras, and end up in the food chain, producing numerous toxicological concerns in humans.

Pollution of the environment, whether aquatic or terrestrial, poses a serious health risk to the

flora and wildlife that live there [3,4].

Heavy metals are one of many types of pollutants that can reach critical levels in terms of soil

fertility, food safety, human health, and environmental concerns [1]. Heavy metal retention in

soil is primarily influenced by pH and is linked to clay minerals, humic compounds, iron oxides

and hydroxides, and manganese in the soil, all of which influence the attenuation effect, even

for anionic forms. Humans are exposed to heavy metals through two major absorption

pathways: inhalation and ingestion. Heavy metals travel through the air as gases or as species

adsorbed on or in suspended particulate matter [5] Man's actions, known as human activities,

threw the ecosystem's chemistry out of equilibrium, and man has been working to restore

balance and repair the environment ever since [6]. Heavy metals are released into the

environment as a result of many human activities, and at certain quantities, they become

dangerous to the end users—people, plants, and animals.

Industrialization, agricultural endeavors, mining activities, solid waste disposal systems,

incineration, filling stations, and vehicle garages, often known as workshops or mechanic

villages, are the primary anthropogenic sources of heavy metals as pollutants [7]. Elevated

concentrations of these metals result from accumulation through indiscriminate dumping of

used body parts and scrap from automobiles, machinery, and petroleum waste. Osakwe [8],

explains that servicing and repair of automobiles are sources of heavy metals in the

environment. This is done through indiscriminate dumping of the waste generated by their

activities—recharging of automobile batteries, spray painting, panel beating, spilling of

petroleum products, electrolyte, welding, and soldering [9]. The high concentration of metals

in the soils around mechanic sites is a result of these unregulated operations. Due to their non- biodegradable nature, heavy metals accumulate over time and produce toxicants that are

released into ground water and end up in floras via the food chain (soil-florae-humanoid or

soil-florae-animal-humanoid) [10, 7]. According to Harrison and Chirgawi [11], garbage is

dumped indiscriminately with little consideration for environmental repercussions in most

situations, although rubbish may be burned in the open and the ashes left at the site. The

carbon-based elements are removed from the wastes during the burning process, leaving just

the metal contents. After oxidation and corrosion, the metal dissolves in rainwater, leaches into

the soil, and is absorbed by growing plants, making its way into the food chain. In Nigeria,

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Timothy, M. N., Marcus, A. C., & Iyama, W. A. (2022). Assessment of Trace Metal Content in Soils of Automobile Workshops around Bori Urban

Area, Rivers State, Nigeria. European Journal of Applied Sciences, 10(3). 209-221.

URL: http://dx.doi.org/10.14738/aivp.103.12175

Odukoya et al. [12] claim that refuse leachates or trash dumpsites are heavy metal sources in

the soil and aquatic environment.

Bori and its vicinity have a rising number of auto mechanic garages, with heavy vehicular traffic

occasioned by a large market and their operations must be assessed in order to ensure the

environment's safety. Given that the majority of the residents rely heavily on agriculture as

their only occupation, this will raise awareness of the associated health risk, allowing sufficient

planning to be done before erecting a garage around cultivable property.

The study therefore aims at determining some trace metals (Mn, Zn, Pn, Cd, Ni, and Cr) in soil

at auto mechanic garages in Bori urban area by evaluating the status of, and likely effects of

these metals.

MATERIALS AND METHODS

Study Area

Bori, the local government headquarters of Khana Local Government Area in Rivers State,

Nigeria's Niger Delta region, and the traditional headquarters of the Ogoni people, was the

research area. It is located at 40 40’ 22’’ N and 70 22’ 13’’E, with a land area of 20 square miles

(50 km2) east and southeast of PortHarcourt with a population of 294.217 people, and a density

of 10,000 people per square meter (5000 people per square kilometer) according to the 2006

census (retrieved November 12, 2019 from https://www.en.wikipedia.org/wiki/Bori-city).

Bori town, Wiiyaakara, Kpong, Kor, Bua-Kaani, Yeghe, Bo-Ue, Zaakpor, and Betem-3 are all part

of the Bori Urban Area. It is one of the state's agricultural hubs, being the second largest city in

Rivers State after Port Harcourt. As they are blessed with both arable land and water (fresh and

salt), the indigenous people are sole professions in the production of various agricultural items

and fish. Bori serves as a commercial center for the people of the Rivers Southeast Senatorial

District in particular and the entire state in general [13], as well as those from adjacent states

such as the Annang people of Akwa-Ibom State, due to the presence of a daily popular market.

Bori is the home of the foremost Rivers State polytechnic, currently Kenule-Benson Polytechnic,

Bori, in addition to the local government council secretariat. The city's central market and

institution attract a huge number of people, resulting in heavy vehicle traffic and the presence

of various types of automobiles, leading to an increase in the number of existing auto mechanic

shops.

Sampling

Soil samples were collected twice a month for three months (October, November, and

December, 2019) from three (3) different auto mechanic garages using a hand auger. At each

location, surface soil samples were randomly collected from the same depth of 0–20 cm. These

samples were representative of the top soil around each garage (this is because much of the

root uptake of contaminants by flora occurs in this zone, as stated by Wokoma et al.[14], and

affirmed by Abenchi et al. [15] that surface soils are the first locus of input of metals where they

tend to accumulate on a relatively long-term basis), to form composite samples.

Control soil samples were randomly obtained from the same depth and from pristine land that

is a central point and not less than 11 km away from each impacted site, where neither auto

mechanic repairs, industrial nor commercial activities are (or have been) carried out. Thus, a