Study of the Health Impact of Glyphosate Misuse in Two Prefectures in Togo and Evaluation of Its Bioaccumulation in Yam

In Togo, as in most sub-Saharan African countries, the use of herbicides in the field has become unavoidable. Because of ignorance, some farmers use them badly. For some health professionals, the misuse of glyphosate would be at the root of the increase of certain diseases observed in recent years. This study aims to verify whether the misuse of glyphosate has an impact on the increase of certain diseases. The study is based on surveys and analysis of soil and yam samples. Surveys are conducted among 73 glyphosate traders, 177 farmers and 34 women volunteers, victims of spontaneous abortions, congenital malformations and stillbirths, as well as on the use of hospital registers gathering data from 147 health centres in two prefectures between the years 2012 and 2018. The analysis of soil and yam samples is performed by thin-layer chromatography. The study reveals that 97.3% of traders have not received any training in pesticide management and 93.63% of farmers use glyphosate inappropriately at a higher than standard rate (6 l/ha). Epidemiological data between 2012 and 2018 revealed an increase in the number of different cases from one year to the next, with similar types of malformations to those found in the 34 women-controls. Thin layer chromatography shows that the soil and yam samples are contaminated with glyphosate. This survey reveals that the glyphosate sold in the survey area is mostly unregistered and its mismanagement would have environmental and health impacts that would justify, on the one hand, the increase in cases of spontaneous abortions, stillbirths and congenital malformations noted in the epidemiological data and, on the other hand, the contamination of soil and yam samples. However, this study requires further work on the determination of glyphosate residues in yam tubers in order to clarify whether the levels found there are detrimental.