Biochemical Evaluation of Lipid Peroxidation and Antioxidant Status in Children Exposed to Indoor Biomass Smoke in Edo State

Biochemical Evaluation of Lipid Peroxidation and Antioxidant Status in Children Exposed to Indoor Biomass Smoke in Edo State

Abstract

Indoor biomass smoke exposure remains a critical public health concern in developing countries, particularly among children in rural communities. This study assessed lipid peroxidation and antioxidant status in children exposed to indoor biomass smoke in selected communities of Edo State, Nigeria. Blood samples were analyzed for malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) using standard biochemical methods. Results revealed significantly higher MDA levels and reduced antioxidant enzyme activities in exposed children compared to non-exposed controls. The findings indicate that chronic exposure to biomass smoke may induce oxidative stress, leading to potential long-term health risks. Therefore, interventions such as improved ventilation, cleaner cooking technologies, and public health education are essential to minimize oxidative damage in vulnerable populations.

CHAPTER ONE

1.0 Introduction

Indoor air pollution caused by biomass combustion is one of the leading environmental risk factors for respiratory and systemic oxidative stress in children. In many parts of Nigeria, especially in rural areas of Edo State, households rely on firewood, charcoal, or kerosene for daily cooking activities. These fuel sources release high levels of particulate matter, carbon monoxide, and polycyclic aromatic hydrocarbons (PAHs), which can accumulate indoors and pose serious health hazards.

Children are particularly vulnerable due to their higher respiratory rates and immature antioxidant defense systems. Exposure to these pollutants often leads to oxidative stress, reflected in elevated lipid peroxidation and decreased activities of key antioxidant enzymes. Lipid peroxidation damages cell membranes, while the reduction in antioxidant enzymes such as SOD, CAT, and GPx weakens the body’s defense mechanism against free radicals.

Understanding how biomass smoke affects biochemical parameters in children provides crucial insight into its potential health effects. Such knowledge can inform strategies aimed at reducing exposure and preventing long-term consequences, including respiratory and cardiovascular diseases.

1.1 Statement of the Problem

Despite the widespread use of biomass fuels for cooking, limited biochemical data exist on the oxidative stress impact of this exposure in Nigerian children. In rural areas of Edo State, children are often exposed to smoky environments for several hours daily. This continuous exposure can alter lipid and antioxidant metabolism, yet few studies have explored these biochemical changes. There is a pressing need to evaluate the extent of oxidative damage among these vulnerable populations.

1.2 Aim and Objectives

Aim:
To evaluate lipid peroxidation and antioxidant enzyme status in children exposed to indoor biomass smoke in Edo State.

Objectives:

1. To determine malondialdehyde (MDA) concentrations as an indicator of lipid peroxidation in exposed and control groups.

2. To measure the activities of antioxidant enzymes (SOD, CAT, GPx) in both groups.

3. To compare biochemical indices between children exposed to biomass smoke and those from cleaner fuel households.

4. To assess correlations between exposure duration and oxidative stress biomarkers.

1.3 Significance of the Study

This research provides biochemical evidence of oxidative stress linked to indoor air pollution in Nigerian children. The findings will aid policymakers and health agencies in designing targeted interventions, promoting cleaner cooking practices, and protecting children’s health in rural communities.

1.4 Scope of the Study

The study focuses on children aged 5–12 years residing in selected households in Edo State that utilize biomass fuels for cooking. The investigation includes the determination of lipid peroxidation and antioxidant enzyme levels using validated biochemical methods.

CHAPTER TWO

2.0 Literature Review

2.1 Indoor Biomass Smoke and Air Pollution

Biomass fuels, including firewood, charcoal, crop residues, and animal dung, remain the primary energy source for millions of households in sub-Saharan Africa. When burned indoors, these fuels emit large amounts of particulate matter and toxic gases, such as carbon monoxide and volatile organic compounds. These emissions increase the risk of respiratory illnesses and oxidative damage due to continuous exposure to reactive oxygen species (ROS).

2.2 Oxidative Stress and Lipid Peroxidation

Oxidative stress occurs when the production of ROS exceeds the body’s antioxidant defense capacity. ROS attack cellular components, especially membrane lipids, leading to lipid peroxidation. Malondialdehyde (MDA), a byproduct of this process, serves as a reliable biomarker for oxidative damage. Elevated MDA levels are often linked with chronic exposure to environmental pollutants.

2.3 Antioxidant Enzymes and Defense Mechanisms

The body’s primary defense against ROS includes enzymatic antioxidants such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). SOD catalyzes the conversion of superoxide radicals into hydrogen peroxide, which is subsequently decomposed by CAT and GPx into water and oxygen. Reduced activity of these enzymes in exposed individuals suggests depletion of antioxidant reserves due to excessive oxidative burden.

2.4 Health Implications of Biomass Smoke Exposure in Children

Children exposed to biomass smoke often experience recurrent respiratory infections, impaired lung function, and systemic oxidative stress. Long-term exposure may predispose them to chronic diseases such as asthma, cardiovascular disorders, and weakened immune responses. Studies across African regions have consistently shown elevated oxidative stress markers in children from smoky households compared to those in cleaner environments.

2.5 Biomass Smoke and Public Health Interventions

Mitigating biomass smoke exposure requires a multifaceted approach. Adoption of cleaner cooking technologies, improvement of kitchen ventilation, and community-based health education can significantly reduce pollutant concentrations indoors. Continuous biochemical monitoring of exposed populations provides a scientific basis for evaluating the effectiveness of these interventions.