Assessment of the contamination of vegetable crop by polycyclic aromatic hydrocarbons (PAHS) on gardening sites in south Benin

Vegetables produced in Benin's coastal towns play a major role in the supply of fruit and vegetables to households. These production areas are close to interstate highways that are busy with vehicles or trucks and sometimes with passing aeroplanes. However, these vehicles, trucks or aeroplanes can contaminate market garden produce with aromatic and polycyclic hydrocarbons (PAHs).  This study aims to assess PAH levels in amaranths and carrots in the market garden areas of Houéyiho, Sèmè-Kpodji and Grand-Popo in southern Benin. A total of 10 vegetable samples (4 samples at the Houéyiho site, 4 samples at the Sème-Kpodji site and 2 samples at Grand-Popo) were collected. The analyses were carried out by gas chromatography-mass spectrometry. The data collected were subjected to an analysis of variance followed by a 5% Newman Keuls student test. The results of the PAH analyses showed the presence of twelve PAHs in the vegetables (Amaranth and Carrot) at all three sites. The levels of Benzo (a) Anthracene, Benzo (a) Pyrene and Dibenzo (a, h) Anthracene varied very significantly (P<0.001) both between the different vegetables and between the sites and were more concentrated in the amaranths than in the carrots.  This study shows that there are potential health risks associated with the high consumption of the vegetables studied at the different sites.