Assessment of onions contamination by pesticides residues and characterization of market gardeners’ cultural practices in the region of Boucle du Mouhoun (Burkina Faso)

Abstract

This study was initiated in order to study cultural practices and assess levels of contamination in pesticide residues of onion samples produced in the region of Boucle du Mouhoun, Burkina Faso. A collection of samples was carried out at three gardening sites. A survey was also carried out to list the various pesticides used on market gardening sites and the practices for using pesticides. The QuEChERS method allowed the quantification of pesticides. The results show that 93% of the market gardeners were men, and more than 67% were between 25 and 35 years old. Nearly 55% of market gardeners are illiterate and do not have adequate means of protection when applying pesticides. A total of 16 pesticides have been accounted and most of them are Category II which are dangerous for human health and environment. 12 pesticide residues were quantified. Most of the active substances detected above the MRL (set by Codex Alimentarius and EU) were from the organochlorine family. These results reveal a fairly high level of contamination for pesticide residues. The study revealed that cultivation practices in market gardening sites as well as the consumption of onion pose numerous health risks for humans and the environment.