Environmental assessment of the influence of pesticides on non-target arthropods using PRIMET, a pesticide hazard model, in the Tiko municipality, Southwest Cameroon.

Pesticide use in farming is unescapable to enhance the harvest and prevent deleterious organisms. Unfortunately, certain pesticide users most often unveil poor practices, remarkably in developing countries. This study aimed at estimating pesticide risk to non-target arthropods (NTAs) using PRIMET (Pesticide Risks in the Tropics to Man, Environment and Trade), a pesticide risk model, in the Tiko municipality, Southwest Cameroon. To achieve this, data was assembled on the pesticide treatment plan (active ingredient, crops, dosage, number of applications, application interval) and ecotoxicological properties (LR), and typeset one at the time in PRIMET 2.0 for risk appraisal. The model estimated the Acceptable Effect Concentration (AEC), the In-Field and Off-Field Exposure (PEC) and Exposure Toxicity Ratio (ETR = PEC/AEC). If ETR < 1, there is "No Risk", if 1 ≤ ETR≤ 100, there is a "Possible Risk", and if ETR > 100, there is a "Definite Risk". Amongst the thirty-nine (39) pesticides evaluated, the most dangerous compound was imidacloprid (ETR = 255 000 000), followed by cypermethrin (ETR = 299 800) and oxamyl (ETR = 57 917). Epoxiconazole was the only fungicide, out of fourteen predicted to pose a definite in-field risk to NTAs with ETR = 1491. Half of the fungicides (50%) posed a possible in-field risk. One third of herbicides evaluated posed a possible in-field risk to NTAs. In this classification, paraquat (ETR = 51) exhibited the highest risk. All the herbicides were predicted for no off-field risk to NTAs. NTAs seemed to be more tolerant to most fungicides and herbicides than insecticides. The strengthening of the directive on pesticide purchasing and operation is inevitability in order to protect anthropoid and environmental health.