POLYCYCLIC AROMATIC HYDROCARBONS (PAHS) IN THE LEAVES OF PIPER GUINEENSE FROM TWO MARKETS WITHIN UMUAHIA METROPOLIS

Abstract

Polycyclic aromatic hydrocarbons (PAHs) were probed in the leaves of Piper guineense obtained from Orieugba and Isigate markets within Umuahia metropolis in Umuahia North Local Government Area of Abia State. Prior to drying, milling and extraction procedures, P. guineense obtained from each of these markets was divided into three portions. The first portion was not washed (UW), the second portion was washed with ordinary tap water (WTW) while the third portion was washed with about 0.17 mol dm-3 of NaCl solution (WSS). Quantitation of the PAHs was done using Gas Chromatography/Mass Spectrometry (GC/MS) technique. Eighteen PAHs were analyzed and P. guineense samples from Orieugba market gave a total PAHs content of 30.71, 22.18 and 8.31 mg kg-1 for UW, WTW and WSS, respectively. The samples from Isigate market gave 18.27, 15.59 and 1.20 mg kg-1 for UW, WTW and WSS, respectively. This investigation showed that the level of PAHs in the leaf samples of P. guineense from the two markets decreased when washed with ordinary tap water but decreased more significantly when washed with the salt solution. In addition, the risk assessment of ΣPAH4 (the sum of benzo[a]pyrene, benz[a]anthracene, benzo[b]fluoranthene and chrysene) in the vegetable sample indicated that there was no risk associated with the consumption of the vegetable samples. However, it is pertinent to wash vegetables with a salt solution before proper rinsing as this would help to reduce the quantity of PAHs in them. Keywords: PAHs; P. guineense; GC/MS; Vegetables; Leaf sample