Study of Serum Liver Enzyme Activities and Heavy Metal Exposure Among Residents Near Oil-Spillage Impacted Sites in Edo State

Study of Serum Liver Enzyme Activities and Heavy Metal Exposure Among Residents Near Oil-Spillage Impacted Sites in Edo State

Abstract

Oil spillage remains one of the major causes of environmental pollution and public health risks in Nigeria’s oil-producing regions. This study investigated the relationship between heavy metal exposure and serum liver enzyme activities among residents living close to oil-spillage impacted areas in Edo State. Blood samples were collected from residents of affected communities and compared with those from non-impacted control areas. The concentrations of lead (Pb), cadmium (Cd), and chromium (Cr) were analyzed using Atomic Absorption Spectrophotometry (AAS). Serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) were determined using standard biochemical methods.

Results showed significantly elevated levels of heavy metals in residents from oil-polluted areas. Correspondingly, the mean activities of liver enzymes were higher in the exposed group, suggesting potential hepatic stress and early toxicity. The study concludes that prolonged exposure to oil-related heavy metals may impair liver function and contribute to chronic health complications. These findings emphasize the need for environmental monitoring, medical screening, and pollution control policies in oil-impacted regions.

CHAPTER ONE

1.0 Introduction

Oil spillage is a major environmental challenge that affects both the ecosystem and human health. In Nigeria, repeated spills from petroleum exploration and transportation have contaminated soil, air, and water resources, particularly in oil-producing states such as Edo, Delta, and Bayelsa. Residents in these areas are often exposed to heavy metals and hydrocarbon residues that can accumulate in their bodies through food, water, and air.

The liver, being the body’s primary detoxification organ, plays a key role in metabolizing toxic substances. Continuous exposure to heavy metals such as lead, cadmium, and chromium can cause oxidative stress, enzyme leakage, and cellular damage in the liver. Elevated levels of serum enzymes like ALT, AST, and ALP are early indicators of liver dysfunction, making them useful biomarkers for assessing environmental toxicity.

Thus, studying the biochemical effects of heavy metal exposure on liver function provides valuable insight into the health risks associated with living near oil-spillage zones.

1.1 Background of the Study

Nigeria’s dependence on crude oil has brought significant economic gains but also widespread environmental degradation. Oil spills occur frequently due to equipment failure, pipeline vandalism, and inadequate maintenance. When crude oil enters the environment, it releases toxic compounds, including heavy metals that persist for long periods.

These metals—especially lead, cadmium, and chromium—can contaminate drinking water, farmlands, and local food sources. Over time, people who live in these polluted areas absorb the metals through ingestion and inhalation. Once in the body, heavy metals bind to proteins and enzymes, disrupting cellular metabolism and liver integrity.

Previous studies in the Niger Delta region have linked chronic exposure to increased liver enzyme activity, oxidative damage, and impaired detoxification. However, there is limited research focusing specifically on Edo State, despite its increasing reports of oil pollution incidents. This study, therefore, aims to bridge that knowledge gap.

1.2 Statement of the Problem

Many residents of oil-impacted communities rely on contaminated water and locally grown food for survival. Continuous exposure to heavy metals through these sources may lead to gradual liver impairment and other health disorders. Unfortunately, most of these communities lack routine medical monitoring and environmental health surveillance.

Without reliable data on metal concentration and corresponding biochemical changes, public health interventions remain inadequate. There is, therefore, a pressing need to assess both the extent of heavy metal exposure and its impact on liver enzyme activities among residents in these high-risk areas of Edo State.

1.3 Aim and Objectives of the Study

The main aim of this research is to investigate serum liver enzyme activities and heavy metal exposure among residents near oil-spillage impacted sites in Edo State.

Specific objectives include:

1. To determine the concentrations of lead, cadmium, and chromium in blood samples of residents.

2. To evaluate serum ALT, AST, and ALP activities in the study population.

3. To compare biochemical results between exposed and non-exposed groups.

4. To assess the relationship between heavy metal levels and liver enzyme alterations.

5. To recommend preventive and remedial strategies for minimizing exposure risks.

1.4 Significance of the Study

This research contributes to a clearer understanding of how environmental contamination affects human health in oil-producing regions. The findings will help public health authorities, environmental agencies, and policy makers design better interventions for pollution control and health protection.

Moreover, the study provides scientific evidence that can guide routine screening programs for residents in oil-affected areas. Increasing public awareness about heavy metal toxicity can also promote safer community practices and strengthen the call for environmental justice in Edo State.

1.5 Scope of the Study

The study focuses on selected oil-spillage affected communities in Edo State. It compares biochemical data from exposed residents to that of control populations in unaffected areas. Heavy metals (Pb, Cd, Cr) and liver enzymes (ALT, AST, ALP) are the primary parameters analyzed. Other risk factors such as age, occupation, diet, and duration of residence are also considered.

1.6 Definition of Key Terms

• Heavy Metals: Metallic elements such as lead, cadmium, and chromium that are toxic even at low levels.

• Liver Enzymes: Biological catalysts like ALT, AST, and ALP used to assess liver health.

• Oil Spillage: The accidental release of crude oil into the environment, leading to pollution.

• Environmental Toxicity: Harmful effects caused by exposure to pollutants in air, water, or soil.

• Bioaccumulation: The buildup of toxic substances in living organisms over time.