ABSTRACT
Most foodstuffsold in Nigeria outdoor market are often susceptible to pollution due to poor package.This work was aimed to determined five heavy metals content in four different commonly consumed snack foods (Bread, Popcorn, Cake and Meat Pie) in Abeokuta Ogun State. The selected snacks used in this study were purchased from Osielemarket in Abeokuta in a newly polythene bag. All the samples were dried at constant temperature in a laboratory oven and later made into powdery form by crushing and packed with foil paper. Wet acid digestion was carried out on each sample using 0.5g of each samples. The atomic absorption spectrometer (AAS) was used to determine the level of heavy metals on each samples. The metal determined include: Mn, Ni, Pb, Cd and Cr. From the result, it was shown that chromium (Cr) had the highest concentration in the sample while Cd has the lowest concentration. The mean concentration of all the samples determined were within WHO/FAO permissible limit except the mean concentration of lead in bread (0.775mg/kg) which was above the standard limit. The high concentration of lead can be due to environmental pollution which can pose potential health hazard to the consumers.
CHAPTER ONE
1.0 INTRODUTION
1.1 BACKGROUND OF THE STUDY
Snacks food can be found in nearly every corner of the world and have been on sale for thousands of years. Such food are inexpensive, provide a nutritional source based on traditional knowledge, mostly follow the seasonality of farm production and this allows for variation in consumer diets and are widely distributed and available in both urban and rural setting. They provide food distribution activities at the smallest scale, with intensive coverage. Any location with people traffic be it constant to provides an excellent selling ground for snacks food. Many people who are poor and cannot afford food from retail stores depend on food snacks (Brugge et al; 2007).
Generally, snacks food are constant sources of toxic metals and they can accumulate in various organs in human body causing damage. Presence of high content of lead (Pb) and cadmium (Cd) in snack food is associated with cardiovascular diseases (Jarup 2003). Consumption of heavy metals contaminated in snacks food over a long period of time leads to accumulation in snacks food and serious health problem. However, no regulation governing street food in supplies in the market. This has resulted in declining safety and quantity of such snacks food. Lead, mercury and cadmium are considered to be the most dangerous metals and emphasis usually placed on them during food monitoring for heavy metal pollution.
It has been observed that “Heavy metals” has little to do with density but concern with chemical properties. Heavy metals include lead (Pb), silver (Ag), cadmium (Cd),zinc (Zn), mercury (Hg), Arsenic (As), Silver (Ag), chromium(Cr), copper (Cu), Iron (Fe) and the platinium group element. The concept is sometimes extended to include metalloids such as Arsenic and Antimony. Heavy metal broadly speaking is any relatively dense metals. The properties of heavy metals in snacks food are still tropical. The fact can be well documented in enhancing the account of article in recent years. The enhancement is probably attributed to the potential public health risk associated with intake of heavy metals. Heavy metals can be accumulated in human body via direct inhalation, digestion and dermal contact absorption.
Some heavy metals are potentially hazardous due to their intrinsic or selective toxicity particularly in environment contents other commonly encountered toxic heavy metals Chromium, Cobalt, Nickel, Copper, Zinc, Arsenic, Selenium, Silver, Antimony, and Titanium. Heavy metals regarded as essential for human health in small quantities including Vanadium, Manganese, Iron, Cobalt, Copper, Zinc, and Selenium. A deficiency of these essential elements may increase susceptibility of heavy metals poisoning.
Heavy metals, if present even in low concentration in foods have the capability to cause human health problem information about the dietary intake of such metals is important to assess risk to consumers. Dietary intake could account for some fractions of the toxic metals found in the blood and urine of many Nigerians.
1.2 STATEMENT OF PROBLEM
This research work is to determine heavy metals that are present in four different snacks and in some selected markets in Abeokuta. Ogun State Metropolis.
1.3 PURPOSE OF THE STUDY
This research work is set to achieve the following objectives.
i. To determine the concentration of selected heavy metals in four different snacks.
ii. To ascertain some heavy metals that are harmful to human health according to the World Health Organization Standard (WHO).
iii. To know the adverse effects of heavy metals in snacks sold in four selected markets.
1.4 SIGNIFICANCE OF THE STUDY
This study aim at determining the concentration of heavy metals present in four commonly consumed snacks (Bread, Popcorn, Cake and meat pie respectively). The pollution and source of heavy metals are elucidated in this study.