Project Abstract

<p> </p><p>Concentrations of 16 priority polycyclic Aromatic Hydrocarbons (PAHs) were determined in<br>30 brands of Nigerian and imported pastas in Nigerian market. The pasta samples were<br>categorised into (1) noodles (2) spaghetti and (3) macaroni. Analysis were performed by GC<br>– MS after soxhlet extraction of the sample and clean up of the extract. The concentration of<br>Σ16 PAHs in both the Nigerian and imported brands are in the range of 0.009 to 0.8 mgkg-1<br>and 0.002 to 0.007 mgkg-1 respectively. The Bap concentrations in 75% of the Nigerian<br>samples were less than 0.001mgkg-1 permissible limit specified for processed cereal based<br>food while all the brands of imported samples were below the maximum limit. The<br>concentrations of Σ8 carcinogenic PAHs in both the Nigerian and imported brands ranged<br>from 0.001 to 0.01 mgkg-1 and 0.001 to 0.004 mgkg-1 respectively. The Margin of Exposure<br>based on PAH8 as an indicator for the occurrence and effects of PAHs in food for generally<br>exposed individuals were less than 10,000 in 25% and 0% for child and Adult scenarios<br>respectively for Nigerian brands. For typically exposed individuals, it were 38% and 0% for<br>child and Adult scenarios respectively. For imported brands of pastas, the MOE values were<br>far higher than 10,000 for generally and typically exposed individuals in both child and Adult<br>cases. The MOE values indicate serious concern particularly for children who are consumers<br>of Nigerian brands.</p><p>&nbsp;</p><p><strong>&nbsp;</strong></p> <br><p></p>

Project Overview

<p> BACKGROUND<br>1.1 INTRODUCTION<br>The introduction and distribution of man-made compounds or excessive amount of natural<br>compounds have created avenue to understanding the effects of polycyclic aromatic<br>hydrocarbons on humans and the environment. It is therefore, necessary to study the effects<br>on individuals to population, communities and environments. The contamination of food by<br>chemical hazards is a worldwide public health concern. Among organic contaminants,<br>polycyclic aromatic hydrocarbons (PAHs) represent an important class of food<br>contaminants.1<br>Food can be contaminated from environmental source, industrial food processing and certain<br>home food preparation.2 – 4 Humans are exposed to PAHs by various pathways. For nonsmokers,<br>the major route of exposure is consumption of food and it contributes to more than<br>90% of total PAHs exposures of the general pollution in various countries.5 – 7 Food<br>contamination may also occur during periods of atmospheric pollution in which PAHs are<br>deposited on seeds, fruits or vegetables, which are then consumed.7 – 9 Many studies have<br>shown that cereals, vegetables10, oil and fat11 – 12 are the main contributors to the ingestion of<br>PAHs. However, grilled or smoked fishes and meats show a relatively low contribution,<br>except in specific cases or due to socio- cultural reasons that cause these foods to occupy a<br>prominent place in the diet.7, 13- 14<br>Over the years, different sources of PAH contamination of food have been found. Food items<br>and products could be contaminated by soils, polluted air and water.15 Some aquatic food<br>2<br>products, such as fish, can be exposed to PAHs present in water and sediments and the PAH<br>content greatly depend on the ability of the aquatic organisms to metabolize them.16<br>Furthermore, in the food processing industry, food additives such as smoke flavouring<br>products (SFP), lubricants, solvents, propellants, glazing agents and protective coating<br>contribute to contamination of food items by PAHs.17<br>The occurrence of PAHs in human foods reflects the conditions of the environment and<br>consequences of some thermal treatments that are used during the preparation and<br>manufacture of foods.66 The amounts and types of polycyclic aromatic hydrocarbon<br>compounds generated during thermal processing of foods depend on the temperature, oxygen<br>availability, fuel type used, treatment duration, fat content and distance from the energy<br>source.57 In areas remote from urban or industrial activities, the levels of PAHs found in<br>unprocessed foods reflect the background contamination, which originates from long<br>distance airborne transportation of contaminated particles and natural emission from<br>volcanoes and forest fires. In the neighborhood of industrial areas or along highways, the<br>contamination of vegetation can be ten-fold higher than in rural areas.18<br>In general, PAHs are not present individually but in mixtures. Sixteen PAHs that have be<br>extensively monitored are the compounds included in the United States Environmental<br>Protection Agency (USEPA) list of priority organic pollutants.19 The 16 compounds are<br>given in Table 1 along with their abbreviation, molecular weight, Chemical abstract service<br>(CAS) number and structure. Of these 16 PAHs, Benzo [a] Pyrene (BaP) is probably the<br>most studied and has been widely used in environmental analysis as marker for the entire<br>PAH content.5<br>3<br>Different approaches have been proposed for the assessment of the risk of PAH mixtures in<br>human foods which include the use of Benzo [a] Pyrene as a maker, the toxic equivalency<br>factor (TEF), margin of exposure (MOE).2, 20 These approaches have been evaluated and the<br>TEF was adjudged not scientifically valid because of lack of data on the oral carcinogenicity<br>studies on the individual PAHs, their mode of actions and evidence of poor productivity of<br>the carcinogenic potency of PAH mixture based on the current proposed TEF values.2, 5, 15 In<br>2008, the CONTAM Panel of EFSA concluded that the use of BaP as indicator of<br>occurrence and effects of PAHs in food is not suitable and suggested that the eight higher<br>molecular weight PAHs (PAH 8): Benz[a] anthracene, Chrysene, Benzo[a] Pyrene, Benzo [b]<br>fluoranthene, Benzo [k] fluoranthene, Dibenz [a,h] anthracene, Benzo [g,h,i] perylene and<br>indeno [1,2,3-c,d] pyrene and a sub groups of four PAHs (PAH 4: Benz[a] anthracene,<br>Benzo[a] Pyrene, Benzo[b] fluoranthene, and Chrysene) are the most suitable indicators of<br>occurrence and effects of PAHs in food. It was also suggested that the margin of exposure<br>(MOE) approach should be used for assessment of risk exposure.2<br>Table 1: Polycyclic aromatic hydrocarbons considered in the present study.<br>Compound Abbr. Mw CAS Structure<br>Acenaphthene Ace 154.2 83-32-9<br>Acenaphthylene Acy 152.2 208-96-8<br>Anthracene Ant 178.2 120-12-7<br>4<br>Benz [a] anthracene BaA 228.3 56-55-3<br>Benzo[a] Pyrene BaP 252.3 50-32-8<br>Benzo[b] fluoranthene Bbf 252.3 205-99-2<br>Benzo[g,h,i] Perylene Bghip 276.3 191-24-2<br>Benzo[k]<br>Fluoranthene<br>Bkf 252.3 207-08-9<br>Chrysene Chy 228.8 218-10-9<br>Dibenz [a,h]<br>anthracene<br>DahA 278.3 53-70-3<br>Flouranthene Flt 202.3 206-44-0<br>Fluorene Flu 166.2 86-73-7<br>5<br>Indeno[1,2,3-<br>c,d]Pyrene<br>Indp 276.3 193-39-5<br>Naphthalene Nap 128.2 91-20-3<br>Phenanthrene Phe 178.2 85-01-8<br>Pyrene Pyr 202.3 129-00-0<br>Abbr: Abbreviation, Mw: Molecular weight, CAS: Chemical Abstract society service number<br>1.2 GENERAL OBJECTIVE<br>This study aims at determining the levels of PAHs in some brands of locally produced and<br>imported pastas in Nigerian market and also estimate the possible potential health risk<br>involved in their consumption by both adults and children.<br>1.3 SPECIFIC OBJECTIVES<br>1. Determine the level of some polycyclic aromatic hydrocarbons in different brands<br>of locally produced and imported pasta<br>2. To assess the level of compliance to guideline values of this PAHs from<br>international organization.<br>3. To correlate the levels of PAHs in the different brands<br>4. Compare the concentration of polycyclic aromatic hydrocarbons in both Nigerian<br>and imported brands of pastas<br>6<br>5. Estimate any possible potential health risk involved in the consumption of these<br>pasta<br>1.4 STATEMENT OF THE PROBLEM<br>In Nigeria and many other countries, pastas are relatively cheap, affordable by all income<br>classes and contribute a significant proportion to the daily food intake of children and even<br>adults as well. The main source of exposure to PAHs for non-smokers and nonoccupationally-<br>exposed adults is food. The quantity coming from the diet depends largely in<br>the way of cooking and the potential food contamination, which originates from packaging<br>materials and manufacturing.8, 21<br>A number of PAHs have been found to have carcinogenic and mutagenic effects while some<br>of them may act as synergists.22 These compounds can reach the food chain by different<br>ways as PAHs have been found in different food products, such as dairy products,<br>vegetables, fruits, oils, coffee, tea, cereals and smoked meat, therefore the analysis of PAHS<br>in food is a matter of concern.16<br>Monitoring the concentrations of PAHs in food is critical because these contaminants have<br>adverse effects on human<br>Considering that diet is a primary source of human to PAH and given the high rate of cancers<br>and other related diseases in the society, it is therefore necessary to determine the levels of<br>PAHs in human foods, estimate the dietary intakes and possible potential health risk<br>associated with its consumption.<br>7<br>1.5 SIGNIFICANCE OF THE STUDY<br>A survey of the literature indicates that there is a dearth of information on PAHs in pastas<br>hence, this finding will:<br>a. provide baseline data on PAHs for future work<br>b. Provide information on the risk associated with the consumption of pastas.<br>c. Provide data for framing guidelines and standards for PAHs in foods in Nigeria<br>1.6 SCOPE OF THE STUDY<br>The study is designed to determine the levels of 16 PAHs designated as priority pollutants by<br>United State Environmental Protection Agency (USEPA) in some brands of locally<br>manufactured and imported pastas using Gas chromatography- mass spectrometry. The<br>possible potential health risk will also be assessed. This work will be limited to pastas sold in<br>Nigeria markets. <br></p>