Impact of Wet and Dry Seasons on the Distribution of Polycyclic Aromatic Hydrocarbons in Selected Vended Street Foods in Parts of Port Harcourt Metropolis

Abstract

The distribution patterns of PAHs in selected ready-to-eat street foods in parts of Port Harcourt metropolis was investigated during wet and dry seasons in 3 locations (Makoba-station 1, Elekahia-station 2 and Rivers State University-station 3). The study was carried out using a complete randomized design in three factorial experiments (Factors A, B and C). Factor A represented Season, B Location and C Street Vended foods samples. The selected food samples were Roasted plantain (RP1-3), Roasted Fish (RF1-3), Roasted Yam (RY1-3), Meat Pie (MP1-3), Suya (SY1-3) and Doughnut (DN1-3). The foods were sampled twice each season and the mean results recorded. Gas Chromatography-Mass Spectrophotometer (GC-MS) was used for the identification and evaluation of the presence of 16 Polycyclic Aromatic Hydrocarbon (PAHs). Percentage distribution of PAHs in street vended foods during the wet and dry season showed naphthalene value of RY1:57.6% dry and RY1 Not Detected (ND) wet season, MP2: 10.7% dry and MP2: 3.4% wet. Higher naphthalene values distribution during dry season (DN1: 59.6%) was observed, with corresponding lower values recorded during the wet season (DN1: 43.3%). RP1: 10.4% wet and RY1: 19.4% wet while RP1: 9.6% dry and RY1: 2.6% dry showed lower percentage of Flouranthene values during the dry season compared with higher values obtained for the wet season. Chrysene values (RP1: 10.9% wet, RP1: 10.0% dry, SY2: 69.2% wet, SY2: 71.4% dry, MP2: 69.8%, MP2: 22.7% wet) were detected in street vended food as low molecular weight hydrocarbons, with higher degree of distribution during dry season than the wet season. Higher molecular weight Benzo(a)anthracene was detected for all food samples. For RY2: 86.1% dry and 81% wet, RF3:71.3% dry and RF3: 52.0% wet, RF2: 69.0% wet, RF2: 61.4 dry, (DN1-DN3: 28-71.5% wet) and (DN1-3: 21.9-76% dry) seasons for Benzo(a)anthracene. The study showed that Benzo(a)anthracene had the highest percentage distribution during dry season in roasted fish and doughnut (DN2). Benzo(k)fluoranthene (RP1: 2.5% wet, 2.6%dry), Benzo(b)fluoranthene (RY2: 9.9% wet, 1.7% dry, MP2: 8.9% dry and 2.7% wet) and Benzo(a)pyrene (RP1: 5.5% wet, 4.5% dry) were detected in all vended foods during wet and dry seasons, with higher percentage values observed during the dry season. Benzo(a)anthracene, Benzo(k)fluoranthene, Benzo(b)fluoranthene and Benzo(a)pyrene were detected in all vended foods. The study showed that the wet and dry seasons have imparted on the distribution levels of Lower Molecular Weight (LMW) and Higher Molecular Weight (HMW) of PAHs in ready-to-eat vended street foods. The patterns of distribution established the presence of these PAHs in selected ready-to-eat vended street foods. PAHs found in street vended foods is of public health concern to consumers and call for urgent attention for the review of the PAHs sources in food preparations, handling and storage in Port Harcourt metropolis.