ABSTRACT
This research work aimed at finding the concentration of heavy metal in lettuce sample cultivated around abandoned mining site in Jos Plateau State, using Atomic Absorption Spectroscopy AAS, the study area comprises of 3 Local Government Areas, which are (Jos North, Jos South and Jos East), & compare the result with WHO & FAO Maximum Permissible Limits, the following hevy metals were analysed, Lead (Pb), Cadmium (Cd), Nickel Ni), Copper (Cu) & Zinc (Zn) the result of the analysis showed that the mean concentration of Lead (Pb) from Jos North, Jos South & Jos East are: 75.99+1.79mg/kg, 64.12+2.3 Omg/kg & 113.54+9.3 7mg/kg respectively, which is above the WH0 & FAO Maximum Permissible Limits, the mean concentration of Cadmium are 4.98+0.16mg/kg, 3.75+0.97mg/kg & 5.09+0.44mg kg respectively, and is also above the Maximum Permissible Limit. While ickel with 36.60+2. l l mg/kg, 23.92+3.76mg/kg, & 53.08+0.59mg k8 respectively, Copper (Cu) with 40.20+2.85mg/kg, 36.70+5.69 & 31.94+1.9 7mg kg respectively and Zinc (Zn) with 63.80+4.84mg/kg, 82.80+0.29mg/kg & 58.06 +3.26mg kg respectively are all below the WHO & FAO Maximum Permissible Limits.
TABLE
OF CONTENTS
Title Page
Deceleration
Certification
Approval Page
Dedication
Acknowledgement
Table of Content
List of Tables
Abstract
CHAPTER ONE
1.0 Introduction
1.1 Definition of terms
1.1.1 Lettuce -
1.1.2 Heavy Metals
1.1.2.1 Toxic heavy metals
1.2 Statement of the Problem -
1.3 Aim and Objectives
1.4 Research Questions
1.5 Scope of the Study
CHAPTER TWO
2.0 Literature Review
2.1 Vegetables & Heavy Metals
2.1.1 Lead
2.1.2 Cadmium
2.1.3 Chromium
2.1.4 Copper
2.2 Bioavailability
2.3 Effects of Heavy Metals on Human Health
2.4 Atomic Absorption Spectroscopy -
2.4.1 Analysis by Atomic Absorption Spectrometry
(AAS) -
2.4.2 Principles of Atomic Absorption Spectrometry
(AAS) -
2.5 Drying and digestion
CHAPTER THREE
3.0 Materials and Method
3.1 Study Area
3.2 Materials and Equipment -
3.2.2 Chemicals and Reagents
3.3 Method
3.3.1 Source of Plant Materials
3.3.2 Sample Collection & Storage
3.3.3 Sample Preparation
3.3.3 Methods of Sample Digestion
3.4 Statistical Analysis
CHAPTER FOUR
4.0 Results and Discussion
4.1 Results
4.1.1 Mean Metals Concentrations and Maximum
Permissible Limits in Lettuce (Lactuca sativa) of Jos North LGA
4.1.2 Mean Metals Concentrations and Maximum
Permissible Limits in Lettuce (Lactuca sativa) of Jos South LGA
4.1.3 Mean Metals Concentrations and Maximum
Permissible Limits in Lettuce (Lactuca sativa
4.2 Discussion-
CHAPTER FIVE
5.0 Conclusion & Recommendation-
5.1 Conclusion
5.2 Recommendation -
REFERENCES
CHAPTER ONE
INTRODUCTION
1.1
Background of The Study
Heavy metals are
naturally occurring elements that have a high atomic weight and density
compared to water. While some heavy metals, such as zinc, copper, and
manganese, are essential for plant growth in trace amounts, others, like lead,
cadmium, and mercury, are toxic even at low concentrations. The contamination
of agricultural land with heavy metals has become a major environmental concern
due to the potential risks it poses to human health, soil productivity, and
food security.
Mining
activities, particularly in regions like Jos, Plateau State, Nigeria, are a
significant source of heavy metal contamination. Over the years, the extraction
of tin, columbite, and other minerals in this region has led to the deposition
of heavy metals in the surrounding soil and water bodies. Abandoned mining
sites, in particular, serve as hotspots for environmental contamination because
they lack proper reclamation or remediation efforts, allowing pollutants to
leach into the soil and groundwater.
Vegetables, such
as lettuce (Lactuca sativa), commonly cultivated around mining areas,
are prone to bioaccumulation of heavy metals. These crops absorb metals from
contaminated soil and water, which can then enter the human food chain. Chronic
exposure to heavy metals through the consumption of contaminated vegetables has
been linked to severe health issues, including kidney damage, neurological
disorders, and cancer. The risks are further exacerbated in regions where
farming near mining sites is a primary livelihood, and vegetables are a staple
part of the diet.
Jos Plateau
State, known for its long history of mining activities, provides a critical
case for examining the extent of heavy metal contamination and its implications
for public health and agriculture. Despite the recognized threats, limited
research has been conducted to assess the impact of heavy metals on vegetables
grown in this area.
Understanding
the extent of contamination and its potential health risks is essential for
informing policy, guiding agricultural practices, and developing effective
mitigation strategies. The findings from this research will contribute to
raising awareness about environmental and public health risks while providing a
basis for sustainable agricultural practices in areas affected by mining
activities.
1.2
Statement of the Problem
The
contamination of vegetables with heavy metals poses a serious health threat to
consumers, particularly in regions like Jos with a history of mining
activities. Despite the known risks of heavy metal toxicity, limited research
has been conducted to assess the extent of contamination in vegetables grown
around abandoned mining sites in Plateau State.
Farmers and
local communities may be unaware of the potential health risks, while
regulatory frameworks for monitoring and controlling heavy metal pollution in
agricultural produce are often weak or non-existent. This situation raises
concerns about the safety of vegetables consumed by the public and the
long-term implications for human health and environmental sustainability.
This study
addresses the gap in knowledge by analyzing the levels of heavy metals in
selected vegetables cultivated around abandoned mining sites in Jos. It also
explores the potential health risks associated with their consumption and
proposes measures for mitigation.
1.3
Objectives of the Study
The objectives
of this study are as follows:
- To determine the concentration
levels of heavy metals (e.g., lead, cadmium, arsenic, mercury) in
vegetables grown around abandoned mining sites in Jos, Plateau State.
- To assess the extent of soil
contamination in these areas and its correlation with heavy metal
accumulation in vegetables.
- To evaluate the potential health
risks associated with the consumption of contaminated vegetables.
- To provide recommendations for
mitigating heavy metal contamination in agricultural practices around
abandoned mining sites.
1.4
Research Questions
The study seeks
to answer the following research questions:
- What are the concentration levels
of heavy metals in vegetables grown around abandoned mining sites in Jos?
- How does soil contamination
contribute to heavy metal uptake by vegetables in these areas?
- What are the potential health risks
associated with the consumption of these vegetables?
- What strategies can be implemented
to reduce heavy metal contamination in agricultural produce?
1.5
Significance of the Study
The findings of
this study will provide valuable insights into the environmental and public
health implications of heavy metal contamination in vegetables cultivated
around abandoned mining sites. The study will benefit:
- Policy Makers: By offering
evidence-based recommendations for formulating and enforcing regulations
on agricultural practices in contaminated areas.
- Farmers: By increasing awareness of
the risks associated with cultivating crops near mining sites and
encouraging the adoption of safer practices.
- Public Health Authorities: By
highlighting potential health risks and the need for regular monitoring of
heavy metals in food products.
- Researchers: By providing baseline
data for further studies on heavy metal contamination in agricultural
ecosystems.
1.6
Scope of the Study
The study
focuses on vegetables grown around abandoned mining sites in Jos, Plateau
State. It examines heavy metal contamination in selected vegetables such as
lettuce, spinach, and tomatoes, which are commonly cultivated in the area. The
research involves soil and vegetable sampling, laboratory analysis of heavy
metal concentrations, and health risk assessment based on international safety
standards.
1.7
Definition of Terms
- Heavy Metals:
Metallic elements with high atomic weights and densities that can be toxic
even at low concentrations, such as lead, cadmium, and mercury.
- Bioaccumulation:
The gradual accumulation of substances, such as heavy metals, in an
organism over time.
- Abandoned Mining Sites:
Areas previously used for mining activities that are no longer operational
and often left without proper rehabilitation.
- Contamination:
The presence of harmful substances in the environment, such as heavy
metals in soil and water.
- Health Risk Assessment:
The process of estimating the potential adverse health effects resulting
from exposure to hazardous substances.
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