Biochemical Analysis of Heavy Metal Concentrations in Sachet Water Sold in Lagos Urban Markets

Biochemical Analysis of Heavy Metal Concentrations in Sachet Water Sold in Lagos Urban Markets

Abstract

The increasing consumption of sachet water in Nigeria’s urban centers has raised growing concerns about its biochemical quality and potential health risks. In Lagos, where population density and industrial activity continue to expand, water contamination poses a serious environmental and public health challenge. This study investigates the concentration of selected heavy metals—lead (Pb), cadmium (Cd), zinc (Zn), copper (Cu), and iron (Fe)—in sachet water sold across major urban markets in Lagos.

Fifteen sachet water samples were collected randomly from three metropolitan zones representing high, medium, and low commercial areas. The samples were analyzed using Atomic Absorption Spectrophotometry (AAS) to determine their metal concentrations. Results revealed that while zinc, copper, and iron levels were within acceptable limits set by the World Health Organization (WHO) and the Nigerian Industrial Standards (NIS), some samples recorded slightly higher levels of lead and cadmium. These findings suggest that contamination likely occurs during water processing, packaging, or from environmental exposure to pollutants.

The study recommends that producers implement stricter purification procedures and regular internal quality assessments. In addition, government agencies should intensify regulatory monitoring to ensure compliance with national water quality standards. Continuous public awareness campaigns are also essential to educate consumers about the importance of safe drinking water. Ultimately, the study emphasizes the need for collaboration between manufacturers, environmental health authorities, and consumers to promote safer water consumption and safeguard human health in Lagos.

CHAPTER ONE

1.0 Introduction

Water is one of the most vital natural resources for sustaining life. Every living organism depends on it for survival, yet access to clean and safe drinking water remains a major global concern. In Nigeria, particularly in large cities such as Lagos, the increasing demand for potable water has led to the widespread production and consumption of sachet water, commonly known as “pure water.” While sachet water has become an affordable alternative for millions of residents, its biochemical safety remains questionable due to frequent reports of contamination.

Over the past decade, rapid urbanization, industrial emissions, and poor waste disposal systems have contributed significantly to the degradation of water quality. Heavy metals such as lead, cadmium, zinc, and copper often find their way into water sources through leaching, runoff, and improper industrial waste management. When consumed in excess, these metals can accumulate in human tissues, causing severe health problems such as kidney failure, liver damage, and neurological disorders. Therefore, assessing the biochemical composition of sachet water is essential to ensure consumer safety and public health.

Furthermore, Lagos’ complex environmental setting and dense population increase the risk of contamination during water production, transportation, and packaging. Despite existing regulatory guidelines, many small-scale producers fail to maintain strict adherence to water purification standards. This situation calls for scientific investigation into the presence of toxic elements in sachet water sold across various parts of Lagos metropolis.

1.1 Background of the Study

Safe drinking water is a cornerstone of good health and sustainable development. As the demand for sachet water continues to rise, questions regarding its quality have gained attention among researchers, policymakers, and consumers. Heavy metals, unlike organic contaminants, are non-biodegradable and can persist in water systems for extended periods. The urban environment of Lagos, characterized by traffic congestion, industrial emissions, and waste accumulation, provides multiple sources of potential contamination.

Recent studies have shown that heavy metals can infiltrate water through corroded pipes, contaminated packaging materials, or direct contact with polluted air and soil. Therefore, biochemical assessment of sachet water is a necessary step in identifying the presence and concentration of these metals to evaluate their potential health risks.

1.2 Statement of the Problem

Despite its popularity, the safety of sachet water in Lagos has been a matter of concern. Several informal water producers operate without adequate purification facilities, making their products susceptible to contamination. Moreover, the absence of consistent inspection by regulatory bodies often allows substandard water to reach consumers. Continuous ingestion of heavy metals, even at low concentrations, can lead to chronic toxicity, making this issue a significant public health challenge. Thus, this study focuses on evaluating the biochemical composition of sachet water to determine the levels of heavy metals and their implications for human health.

1.3 Objectives of the Study

The main objective of this study is to determine the biochemical concentrations of selected heavy metals in sachet water sold within Lagos urban markets.
The specific objectives are to:

1. Quantify the levels of lead (Pb), cadmium (Cd), zinc (Zn), copper (Cu), and iron (Fe) in sachet water samples.

2. Compare the observed values with WHO and NIS permissible standards.

3. Identify possible environmental or production-related sources of contamination.

4. Recommend strategies for improving water purification and regulatory monitoring.

1.4 Research Questions

1. What are the concentrations of lead, cadmium, zinc, copper, and iron in sachet water samples sold in Lagos?

2. Do these concentrations meet the safety limits established by WHO and NIS?

3. What factors contribute to the variation in heavy metal levels among different sachet water brands?

4. How can producers and regulators enhance the biochemical quality of sachet water?

1.5 Significance of the Study

This research provides valuable insights into the safety and biochemical quality of sachet water consumed in Lagos. The findings will benefit regulatory bodies such as the National Agency for Food and Drug Administration and Control (NAFDAC) and the Standards Organisation of Nigeria (SON) by offering data-driven guidance for quality monitoring. Additionally, sachet water producers will gain information that can help improve their purification processes. For consumers, the study serves as an awareness tool, encouraging informed choices about drinking water safety.

1.6 Scope of the Study

The study focuses on sachet water samples collected from fifteen markets across Lagos metropolis. It examines only five heavy metals—Pb, Cd, Zn, Cu, and Fe—due to their frequent occurrence and toxicological importance. Other potential contaminants such as microorganisms and organic compounds are outside the scope of this research.

1.7 Limitations of the Study

Challenges such as limited laboratory facilities, financial constraints, and restricted access to certain production sites affected the data collection process. Despite these limitations, all samples were handled with care to ensure the accuracy and reliability of the results.

1.8 Definition of Key Terms

• Biochemical Analysis: A scientific process used to identify and measure the chemical components within biological or environmental samples.

• Heavy Metals: Metallic elements such as lead, cadmium, and zinc that can be toxic at high concentrations.

• Sachet Water: Packaged drinking water sealed in small polythene bags, commonly consumed in Nigeria.

• Atomic Absorption Spectrophotometry (AAS): An analytical technique used to determine the concentration of metals in liquid samples.

• Contamination: The presence of unwanted or harmful substances in water or other materials.