Biochemical Assessment of Lead and Cadmium Exposure and Kidney/Liver Enzyme Alterations Among Battery-Recyclers in Plateau State

Biochemical Assessment of Lead and Cadmium Exposure and Kidney/Liver Enzyme Alterations Among Battery-Recyclers in Plateau State

ABSTRACT

Occupational exposure to heavy metals, particularly lead (Pb) and cadmium (Cd), poses significant health risks to battery-recyclers. This study evaluates the biochemical impact of chronic exposure to Pb and Cd on kidney and liver function among battery-recyclers in Plateau State.

We recruited participants from local battery-recycling sites and collected blood samples for heavy metal quantification using atomic absorption spectrophotometry. Kidney and liver function biomarkers—including serum creatinine, urea, alanine aminotransferase (ALT), and aspartate aminotransferase (AST)—were measured. Our findings revealed elevated Pb and Cd levels in participants compared to controls. Correspondingly, kidney and liver enzyme activities showed significant deviations, suggesting organ stress or early dysfunction.

These results highlight the occupational hazards of battery recycling and underline the need for safety measures, regular monitoring, and health education. The study provides scientific evidence supporting policy interventions to reduce heavy metal exposure among workers in Plateau State.

Keywords: Lead, Cadmium, Kidney function, Liver function, Battery recyclers, Biochemical markers, Plateau State.

CHAPTER ONE

1.0 Introduction

Battery recycling is a common source of livelihood in Plateau State, but it exposes workers to high levels of toxic heavy metals, especially lead and cadmium. Chronic exposure to these metals can result in significant biochemical alterations, particularly in kidney and liver function. Workers often lack protective equipment, and prolonged exposure without safety measures increases the risk of organ damage.

Lead and cadmium accumulate in the body, interfering with enzymatic processes and causing oxidative stress. Studies have shown that heavy metal exposure may elevate liver enzymes (ALT, AST) and kidney biomarkers (urea, creatinine), indicating potential organ dysfunction. Despite the known risks, there is limited research assessing the biochemical status of battery-recyclers in Nigeria, especially in Plateau State.

1.1 Statement of the Problem

Battery-recycling activities release substantial amounts of lead and cadmium into the environment, which workers can absorb through inhalation, ingestion, and dermal contact. Chronic exposure can damage liver and kidney functions, yet many recyclers continue to work without adequate protective measures. The absence of routine monitoring programs leaves workers vulnerable to progressive organ damage and systemic toxicity. This study addresses the knowledge gap regarding the biochemical effects of heavy metal exposure among battery-recyclers in Plateau State.

1.2 Aim and Objectives of the Study

Aim: To evaluate the impact of lead and cadmium exposure on kidney and liver function among battery-recyclers in Plateau State.

Objectives:

1. Measure blood levels of lead and cadmium among battery-recyclers.

2. Assess kidney function biomarkers, including serum creatinine and urea.

3. Evaluate liver enzyme activities, specifically ALT and AST.

4. Compare biochemical markers between exposed workers and non-exposed controls.

5. Provide recommendations to mitigate occupational exposure risks.

1.3 Research Questions

1. What are the blood concentrations of lead and cadmium among battery-recyclers in Plateau State?

2. How does heavy metal exposure affect kidney function biomarkers?

3. How does heavy metal exposure influence liver enzyme activities?

4. Are there significant differences in biochemical markers between exposed and non-exposed populations?

1.4 Research Hypotheses

• H₀₁: Lead and cadmium exposure does not significantly affect kidney function biomarkers among battery-recyclers.

• H₁₁: Lead and cadmium exposure significantly affects kidney function biomarkers among battery-recyclers.

• H₀₂: Lead and cadmium exposure does not significantly alter liver enzyme activities.

• H₁₂: Lead and cadmium exposure significantly alters liver enzyme activities.

1.5 Significance of the Study

This study will provide scientific evidence of the occupational hazards associated with battery recycling in Plateau State. It will inform workers, health authorities, and policymakers about potential biochemical risks, encouraging safety interventions. Additionally, the research contributes to the broader understanding of heavy metal toxicity and occupational health in developing countries.

1.6 Scope of the Study

The study focuses on battery-recyclers in Plateau State and evaluates blood lead and cadmium levels alongside kidney and liver function biomarkers. The investigation is limited to biochemical assessments and does not cover long-term clinical outcomes or environmental measurements beyond worker exposure.

1.7 Definition of Terms

• Lead (Pb): A toxic heavy metal commonly found in batteries that can accumulate in the body and cause organ damage.

• Cadmium (Cd): A hazardous metal used in batteries, known for its nephrotoxic and hepatotoxic effects.

• Kidney Function Biomarkers: Indicators such as serum creatinine and urea that reflect renal health.

• Liver Enzymes: Proteins such as ALT and AST that indicate liver health and possible tissue damage.

• Battery-Recyclers: Individuals involved in the collection, dismantling, and processing of spent batteries.

CHAPTER TWO

2.0 Literature Review

2.1 Heavy Metals and Occupational Exposure

Lead and cadmium are pervasive in battery recycling. Workers often absorb these metals via inhalation of dust or direct contact. Chronic exposure can lead to bioaccumulation, oxidative stress, and organ damage. According to Jarup (2003), lead exposure is associated with neurotoxicity, nephropathy, and hepatotoxicity, while cadmium exposure can disrupt renal tubular function and elevate liver enzymes.

2.2 Biochemical Effects on Kidney Function

Kidney biomarkers, such as serum creatinine and urea, indicate renal performance. Studies in occupationally exposed populations demonstrate that chronic lead and cadmium exposure elevates these markers, signaling early kidney damage (Satarug et al., 2010). Prolonged exposure can progress to chronic kidney disease if left unchecked.

2.3 Biochemical Effects on Liver Function

Lead and cadmium disrupt liver enzyme activities, including ALT and AST. Increased enzyme levels reflect hepatocellular damage. Wani et al. (2015) reported that occupational metal exposure correlates with elevated liver enzymes in workers handling batteries and electronics, highlighting potential hepatotoxicity.

2.4 Gaps in Literature

Few studies in Nigeria have concurrently measured lead/cadmium levels and liver/kidney biochemical markers in battery-recyclers. Most focus solely on environmental or occupational exposure without assessing health impacts. This study addresses these gaps by integrating heavy metal quantification with kidney and liver biomarker evaluation.

2.5 Summary

Battery recycling exposes workers to lead and cadmium, which can disrupt kidney and liver functions. Monitoring these biomarkers provides critical insight into occupational health risks. This research fills a significant gap in Plateau State, offering scientific evidence to guide health interventions and policy formulation.