Project Abstract

Project Overview

<p> 1.1 INTRODUCTION<br>1.2 BACKGROUND OF THE STUDY<br>In line with industrial development; pollution in the environment, and consequently agricultural<br>raw materials, leads to high levels of food contamination across the world from the food safety<br>viewpoint. Cases of environmental pollution confronted very frequently and threatening food<br>safety is due to heavy metals. As a result of soil, atmosphere, underground and surface water<br>pollution, our foods and beverages are getting contaminated by heavy metals [1]. Heavy metals<br>occur in all food as natural or inherent component of plant and animal tissues and fluids and also<br>maybe present as a result of contamination or deliberate addition [2].<br>Heavy metal is a term given to a group of metals and metalloids which in their standard states<br>have atomic density greater than 5g/cm3, usually associated with pollution and toxicological<br>problems [3]. ASTDR states that heavy metals are a group of metals and semi-metals associated<br>with contaminations and are potentially toxic [4]. Based on these definitions and observations,<br>heavy metals are therefore classified as essentials if they play the basic role as components of<br>vital biochemical or enzymatic activities in human body, for example, Fe, Mn, Mo, Cr, V, Zn<br>and as non-essential if they metals are classified as with no biological, chemical and<br>physiological importance to man, for example, Cd, Pb, As and Hg [5].<br>Essentially, heavy metals have only become a focus of public interest since analytical techniques<br>have made it possible to detect them even in very small traces [6]. This has made it possible for<br>toxicologists, in animal experiments to follow up the effects of individual substances down to the<br>smallest concentrations. The warnings they give particularly about the effects of these metals on<br>the health of chronic consumers and the effects of the accumulations leaves the public disturbed<br>and often times creates pandemonium among activists [6].<br>Cereals are the main source of food in many countries. Concerning human diet, the most<br>important cereals are wheat (Titicum), rice (Oryza Sativa), oats (Avena Sativa), barley (Ordeum<br>vulgare), rye (Secale cereale), corn (Zea mays), and millet (Panicum miliaceum)[6]. Among them<br>wheat is one of the most consumed and spread [6]. Nowadays, the derived products of wheat are<br>more relevant than wheat itself, especially wheat flour. Wheat flour is the irreplaceable raw<br>material of a group of basic and essential food in a balanced diet like bread, pastries and cookies<br>as well as pizzas, sponge cakes and other starchy products [7].<br>Increasing demand for flour-based products such as bread, pasta, semolina, meat pies, sausage<br>rolls, and so on etc has continued to expand market for wheat flour. The pastas produced in<br>Nigeria are wheat-based. This commodity is mainly produced by processing wheat, and<br>processing involves sorting and milling of dry grains, and addition of some adjuncts; sugar,<br>honey and dried raisins [8]. Minerals constitute 1 to 3 percent of the weight of a cereal grain and<br>concentrate more in the external areas of the wheat grain [8]. From a nutritional and toxicological<br>point of view, their presence is very important. The metallic content is very variable and will<br>depend on the variety, the type of land where it has been cultivated, the fertilization that has been<br>used and the weather. Concerning wheat flour, the content of heavy metals like lead and<br>cadmium is usually very low [8].<br>Pastas commonly consumed in Nigeria include noodles, macaroni and spaghetti. These<br>commodities serve as quick foods for children and adults in more than one third of homes in<br>Nigeria and beyond [8]. The import ban, changing consumption patterns, increasing demand for<br>more nutritious and easy-to-cook food and the more expensive local substitutes, all have also<br>contributed to the growing demand of domestic pasta products [3]. The high food demand, due<br>principally to the increasing population and urbanization, the severe shortage of time on part of<br>bachelors, spinster and the working mothers and the change in feeding habits and way of life<br>have combined to make the eating of pasta very popular. Regardless of the wide consumption of<br>this group of food (pasta) by Nigerians, little data are available as regards heavy metal levels in<br>them; hence the need for this study. Food safety is an important aspect of a nation’s economic<br>stability and due to previous reports on the degree of pollution of some other food items [9-13] this<br>study was aimed at assessing some heavy metal like Cr, Cd, Cu, Mn, Ni, Pb, and Zn levels in<br>locally produced and imported pasta (noodles, spaghetti and macaroni), and also estimate the<br>associated health risk involved in their consumption by both adults and children.<br>1.3 Statement of the Problem:<br>Heavy metals are persistent in the environment and are subject to bioaccumulation in food<br>chains. Monitoring the concentrations of various metals in food is critical because these<br>contaminants have deleterious effects on humans. Many illnesses and diseases such as<br>hypertension, cancer, depression and metal disorders have been associated with increased<br>concentrations of heavy metals such as cadmium, lead, copper, chromium, nickel, manganese<br>and zinc in human organs [5, 12, 13]. However exposure does not result only from the presence of a<br>harmful agent in the environment. The key word in the definition of exposure is contact [3].<br>Exposure is often defined as “an event that occurs when there is contact at a boundary between a<br>human and the environment with a contaminant of a specific concentration for an interval of time<br>[4]. Since our nation is fast turning into a ‘fast food’ society, it is imperative for a research to be<br>carried out to ascertain if these packaged products are actually good for our health. Considering<br>that food including pasta is a particularly important source of the overall metals exposure,<br>undertaking a risk assessment appears to be justified. This can be done by intake measurement<br>which is a quantitative evaluation of exposure. Several organizations such as FAO, WHO, CDC,<br>USFDA etc provided guidelines on the intakes of metal elements by humans. The acceptable<br>daily intake (ADI) or tolerable daily intake (TDI) or provisional tolerable weekly intakes (PTWI)<br>are used to describe safe levels of intake for several toxicants including toxic metals [14].<br>Exposure exceeding the TDI value for short periods should not have deleterious effect upon<br>health, however acute effects may occur if the TDI is substantially exceeded even for short<br>periods of time [14].<br>1.4 Objective of Study<br>1.4.1 General Objectives<br>· To determine the levels of Cd, Pb, Zn, Mn, Cu, Cr and Ni in locally produced and<br>imported pasta in the Nigerian market.<br>1.4.2 Specific Objectives<br>· To determine the levels of Cd, Pb, Zn, Mn, Cu, Cr and Ni in the locally manufactured and<br>imported pasta available in the Nigerian market.<br>· To compare the levels of these metals in the locally produced and imported pasta.<br>· To determine any correlation in the metal levels in each pasta product.<br>· To compare the extent of compliance to guideline values of these metals to some<br>International Standards.<br>· To estimate the daily intake (DI) of these metals through pasta consumption for adults<br>and children.<br>· To compare the DI values with accepted daily intakes stipulated by International<br>Standard bodies.<br>· To estimate any associated health risk in the consumption of pasta by children and adult.<br>Figure 1: A Cross-section of Some Samples <br></p>