To rise to the challenge of access to safe drinking water, hygiene and sanitation, Catholic Relief Services through his project named Koom yilma provided fifty-seven (57) elementary schools with boreholes in the centre-north region in Burkina Faso. This study aims to assess the organoleptic, physicochemical and heavy metal contents of water consumed in these schools. Thus, twenty-three (23) parameters were analyzed according to international standards. The results showed that the turbidity of 25% of water samples from boreholes were between 5.4-66.33 NTU, so non-compliant with WHO standard. The pH of 17.30% of water samples was between 8.52-8.9. 0.325-2.62 mg/L of iron were observed in 28.85% of water samples. The content of potassium was above WHO standard in 13.46% of water. Concerning nitrate and arsenic, 3.8% of samples were non-compliant with WHO standards. Water from Saada borehole was contaminated with 101.725 mg/L and those from Yaoghin with 125 µg/L of arsenic. Globally, waters from boreholes located in schools were of good quality except those of Saada and Yaoghin. Despite these good results, it is necessary to monitor the physicochemical and toxicological quality of these groundwater because of the geological context of site (gold region). That will prevent the consumption of water contaminated with heavy metal and therefore chronic diseases among children.

Soil management, such as organic amendments application, may play an important role in the effects of pesticide residues on soil microbial activity. In order to evaluate these effects, a field experiment was set up. Deltamethrin and profenofos were used for treatment and applied at the recommended dose. Manure, urban waste compost and green waste compost were provided at a rate of 20 t / ha. Respiratory activity was measured every hour. After 7 days of incubation, glucose, nitrogen and phosphorus were added. The interaction between organic amendments and pesticides have showed that only treatment with deltamethrin-manure have significantly decreased the basal respiration (RB) with 0.038 mg C-CO2 g-1 soil compared to the pesticide control (0.058 mg C-CO2 g-1 soil). Profenofos- cattle manure and profenofos-compost treatments have significantly inhibited SIR (Substrate Induction Respiration) compared to profenofos-control (0.097). Both deltamethrin and profenofos have significantly increased the lag time and maximal respiration compared to the control (P˂0.05). The organic amendments and pesticides interaction have significantly reduced the lag time (11h), compared to the pesticide control (26h). Cattle manure has reduced microbial catabolism in the presence of deltamethrin, but urban waste compost and green waste compost have stimulated microbial catabolism (BR) and anabolism (SIR).