The waste is used to fertilise fields. Their pre-treatment can impact on human health and the environment. A study was carried in Bobo-Dioulasso, precisely in Kuinima and Dogona, with the main objective of assessing the impact of waste treatment methods on the environment and health. The data was obtained from individual interviews with farm managers. The results show that 56.67% of the producers practise sorting followed by incineration and 20% practised sorting only, 23.33% of the producers did not perform any treatment. Sorting caused injuries to 33.33% of the producers, 10% were harassed by insects. As for the impact of the treatment methods on the environment, 83.33% of the producers who sorted their waste had their fields invaded by new weed species, compared to 76.47% of those who sorted and incinerated. For 88.23% and 66.67% of the producers who were sorting followed by incineration and sorting only respectively, the crop yield was good. From these results, we can conclude that the waste treatment methods used by producers have negative effects on the environment and human health.

The ability of certain vegetable crops has been proven in the accumulation of heavy metals. Among these species is lettuce (Lactuca sativa L.). In Burkina Faso, the ability of some local species to accumulate heavy metals has also been demonstrated. Among these species we have lemongrass (Cymbopogon citratus). To promote their introduction into cropping systems, a study was initiated to evaluate the effects of lettuce-citronella associations on the transfer of heavy metals in lettuce organs and soil chemical parameters. The experimental setup was in completely randomized factorial blocks comprising three treatments and three replicates. Treatments compared pure lettuce (T0) culture with alternating lettuce-lemongrass combinations on the same line (T1) and citronella lettuce where lemongrass plants are placed in interline lettuce (T2). The effects of these associations on the transfer of heavy metals in lettuce were evaluated. Their effects on soil chemical parameters were also evaluated. The results obtained show a significant reduction (p> 0.05) of the amount of lead accumulated in the leaves of lettuce compared to that of lemongrass for treatments T1 and T2. As for the chemical parameters of the soil; cation exchange capacity, organic matter, assimilable phosphorus and total potassium were significantly affected by the associated culture compared to the pure culture of lettuce. The promotion of lettuce-citronella associations can be considered for the reduction of lead accumulation by lettuce.