Effects of Traditional Smoking Methods on the Concentrations of Polynuclear Aromatic Hydrocarbons (PAHs) in Some Species of Smoked Fish Traded in Benue State, Nigeria

S T Ubwa,L Tarzaa,U J Ahile,J Abah,R L Tyohemba

doi:10.5539/jfr.v4n2p119

Abstract

The effects of three traditional smoking methods on the concentrations of polynuclear aromatic hydrocarbons (PAHs) in smoked fishes were studied. Samples of five different species of fish highly traded for immediate consumption were purchased from fishermen and processed using saw dust smoke, firewood smoke and charcoal smoke respectively. Some of the fresh fishes were also sun-dried and analyzed as control. The PAHs content were extracted with standard dichloromethane using solid-liquid extraction, and analyzed using Gas chromatography – Mass spectrophotometer (GC-MS) method. The results showed that fish samples processed with saw dust smoke recorded the highest concentrations of total PAHs, ranging from 815.75 µg/kg to 1550.28 µg/kg, followed by firewood smoked samples with total PAHs content varying between 738.14 µg/kg to 994.09 µg/kg while charcoal smoked samples recorded the least total PAHs levels of 135.02 µg/kg to 614.42 µg/kg. Benzo(a)pyrene concentrations of 5.68 µg/kg and 5.44 µg/kg respectively were detected in the samples of Arius heude loti and Mud minnow processed using saw dust smoke. The Benzo(a)pyrene levels exceeded the EC regulatory limit of 5 µg/kg. Because benzo(a)pyrene has been associated with intense carcinogenicity in humans, its levels recorded in the smoked Arius heude loti and Mud minnow may have implication for the quality and safety of these fish products. Therefore, it is imperative that regulatory bodies conduct awareness campaigns to educate both the smoked fish processors, traders and consumers on the need to discourage the use of saw dust in smoking fish and adopt safer and improved methods of smoking fishes.

Highlights

Polynuclear aromatic hydrocarbons (PAHs) constitute the largest class of chemical compounds containing two or more fused aromatic rings made up of carbon and hydrogen atoms, known to be genotoxic agents (EC, 2002)
The results showed that fish samples processed with saw dust smoke recorded the highest concentrations of total polynuclear aromatic hydrocarbons (PAHs), ranging from 815.75 μg/kg to 1550.28 μg/kg, followed by firewood smoked samples with total PAHs content varying between 738.14 μg/kg to 994.09 μg/kg while charcoal smoked samples recorded the least total PAHs levels of 135.02 μg/kg to 614.42 μg/kg
Benzo(a)pyrene concentrations of 5.68 μg/kg and 5.44 μg/kg respectively were detected in the samples of Arius heude loti and Mud minnow processed using saw dust smoke

Summary

Introduction

Polynuclear aromatic hydrocarbons (PAHs) constitute the largest class of chemical compounds containing two or more fused aromatic rings made up of carbon and hydrogen atoms, known to be genotoxic agents (EC, 2002). They are generally classified as relatively persistent organic environmental contaminants (Deshpande, 2002; Harvey, 1997; Martson et al, 2001), formed during incomplete combustion processes which occur whenever wood, coal or oil are burnt (Ciecierska & Obiedzinski, 2007); with combustion sources being the most predominant (Simko, 2002). Human exposure to PAHs occurs in three ways: inhalation, dermal contact and consumption of contaminated foods (Silva et al, 2011), with diet being the major source as it accounts for 88 to 98% of such contamination (Farhadian et al, 2011)

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Conclusion