ABSTRACT

This project focuses on the Heavy metal contamination of sliced pineapple and water melon hawked around Owerri Metropolis. Three (3) markets were chosen randomly within Owerri metropolis. These were analyses to determine their heavy metal quality. Five(5) different metals isolates were obtained from the sliced samples namely. Lead(pb) watermelon (0.178mg/kg) pineapple (0.128mg/kg), cadmium(cd) watermelon (0.055mg/kg) pineapple (0.063mg/kg), mercury(Hg) watermelon (0.143mg/kg) pineapple (0.130mg/kg), Arsenic(As) watermelon (0.358mg/kg) pineapple (0.262mg/kg), zinc(Zn) watermelon (3.990mg/kg) pineapple (3.705mg/kg). The findings showed that most “ready-to-eat”foods, hawked in owerri metropolis may constitute source of metallic food poisoning and consequently public health hazards.

CHAPTER ONE

INTRODUCTION

Background of the study

Heavy metals affect the nutritive values of agricultural materials and also have deleterious effect on human beings. National and international regulations on food quality set the maximum permissible levels of toxic metals in human food; hence an increasingly important aspect of food quality should be to control the concentrations of heavy metals in food (Radwan and Salama, 2006) (Sobukola et al., 2008).

Heavy metals are also referred to as substances with a specific gravity of greater or equal to 5.0g/cm3. It is a metallic element that has a relatively high density and is toxic or poisonous at high concentration. They include Mercury, Cadmium, Arsenic, Chromium, Thallium, and Lead.

Heavy metals are non-biodegradable and persistent environmental contaminants which may be deposited on the surface and then absorbed into the tissues of fruits. Plants take up heavy metals by absorbing them from deposits on the parts of plants exposed to the air from the polluted environment as well as from contaminated soils.

Heavy metals contamination may occur due to factors including irrigation with contaminated water, the addition of fertilizers and metal based pesticides, industrial emissions, transportation, harvesting process, storage or sale (Radwan and Salama 2006).

Several cases of human disease, disorders, malfunction and malformation of organs due to metal toxicity have been reported (Jarup, 2003).Excess amount of pb and cd in fruit is associated with etiology of a number of

diseases especially with cardiovascular, kidney, nervous as well as bone diseases (WHO). Heavy metals uptake by plants grown on polluted soils has been studied by many researchers. Heavy metals exposure is not an entirely modern phenomenon.

Zinc obtains its toxicity from essential macro nutrients for fruits and humans. It is also found naturally in water, most frequently in areas where it is mined. It enters the environment from industrial waste, metal plating, and plumbing and is a major component of sludge. Zinc causes no ill health effects except in very high dose. It imparts undesirable taste to water and is toxic to plants at high levels.

Lead is well known for its toxicity and adverse effects on human health. Absorption of ingested lead may constitute a serious risk of public health. Some chronic effects of lead poisoning are colic, constipation, and anemia (Bolger et al 2000).

Iron is an essential element for humans. It is a constituent of hemoglobin, myoglobin and a number of enzymes, and as much as 30%of the body. Iron is found in storage forms such as ferrite and hemosiderin, in the spleen, liver, and bone marrow and a small amount associated with the blood transport protein trasferrin.  Iron is important for formation of red blood cell needed in transportation of oxygen throughout the body.

Fresh water melon may be eaten in a variety of ways and often used in the flavor drinks. It contains about six percent sugar, by weight, the rest being mostly water (92%) as many other fruits.

Water melon plays a very good role in energy production. It is rich in vitamin B necessary for energy production. Our food ranking sampling system also qualified water melon as a very good source of vitamin B6 and a good source of vitamin B1, magnesium and potassium part of this high ranking was due to the higher nutrient richness of water melon. People with low potassium level experience muscle cramps. A whole cup of water melon contains only 48 calories and delivers more nutrients per calorie an outstanding health benefit(Ensminger 1988).

Pineapples are some of the most popular tropical fruits in the world. They are sweet, juicy and delicious, more importantly they are very healthy and nutritious (Edwards 2003). They are packed with vitamins and minerals and prevent cough and cold. It strengthens bones, alleviates arthritis and lowers risk of muscular degeneration; it keeps gum healthy and improves digestion.

It contains four important enzyme systems: indoxylaceticacidoxidase, peroxidase, phosphates and bromelin. The main carbohydrates and amino acids in pineapple are: sucrose, glucose, fructose, and asparagines, alamine, glutamine, and serine in decreasing order of concentration (Ihekoronyeand N. Goddy 1985).

Pineapples are commonly consumed fruits in Nigeria. It is a very nutritious fruit due to its high vitamins and mineral content. It is known to contain a good percentage of iron.

Statement of the Problem

Human activities increase, especially with the application of modern technologies, pollution and contamination of human food chain has become inevitable. In particular, human exposure to heavy metals has risen dramatically in the last 50 years as a result of an exponential increase in the use of heavy metals in industrial processes and products. Heavy metalshave been reported to have positive and negative roles in human life ( Aduano 1984).

Cadmium, lead and mercury are major contaminants of food supply and may be considered the most important problem to our environment. While others like iron, zinc and copper are essential for biochemical reactions in the body.

Purpose of the Study

The main aim of this research work is to find out the heavy metal contamination of sliced watermelon and pineapple.

The purpose of the study is to

1. Find out whether lead contaminates sliced watermelon and pineapple hawked in Owerri metropolis.
2. Find out whether Cadmium contaminates sliced watermelon and pineapple hawked in Owerri metropolis.
3. Find out whether mercury contaminates sliced watermelon and pineapple hawked in Owerri metropolis.
4. Find out whether arsenic ontaminates sliced watermelon and pineapple hawked in Owerri metropolis

Scope of Study

This study is limited to Owerri metropolis with high concentration of people which attract large number of hawkers whose interest is to make quick returns at the detriment of the consumers. Hence, pineapple and watermelon are hurriedly sliced and packaged.

Significance of the Study

This result will be beneficial and important to students, teachers, agricultural experts, public health and hawkers. The research will as well be used to assess the risk of cut (sliced) fruits to public health and sought to quantitatively and qualitatively establish possible heavy metal contamination of sliced pineapple and water melon hawkers.

Research Questions

1. Does Lead contaminate sliced watermelon and pineapple hawked in Owerri metropolis?
2. Does Cadmium contaminate sliced watermelon and pineapple hawked in Owerri metropolis?
3. Does Mercury contaminate sliced watermelon and pineapple hawked in Owerri metropolis?
4. Does Arsenic contaminate sliced watermelon and pineapple hawked in Owerri metropolis?

Pages:  45

Category: Project

Format:  Word & PDF               

Chapters: 1-5                                          

Source: Imsuinfo

Material contains Table of Content, Abstract and References.