Risk Assessment of Applicator Exposure to Pesticides on Cotton Farms in Ghana

Abstract

The efforts of Ghana at increasing and sustaining Agriculture production has resulted in the increasing use of plant protection products (PPP) since the 1960s. The major areas of Ghana’s Agriculture sub-sector in which these products are widely used include; the cocoa sector, the vegetables and fruits sector and the cotton sector. The wide spread and indiscriminate use of these products in recent times has drawn public concerns about their human health and environmental impacts. This has resulted in some efforts within the scientific community of Ghana to investigate the levels of these products in the Ghanaian environment, food stuffs and human fluids by way of biological monitoring.  This particular study was commissioned to assess the risk of applicator exposure to pesticides on cotton farms in Ghana. Applicator exposure was evaluated by means of modeling, using two well known and recognized exposure models, namely; the UK-POEM and the German model. The results of the study revealed that in the course of applying pesticides on cotton farms in Ghana, farmers are exposed to unacceptably higher levels of some pesticides. The pesticides classes for which these higher exposure levels were observed are; the dien-organochlrine insecticide (endosulfan) and an organophosphate insecticide (chlorpyrifos). For each of the two insecticides the exposure level was higher than the acceptable operator exposure level (AOEL) of 0.006mg/kgBW/day and 0.01mg/kgBW/day respectively. This exposure levels equally resulted in higher risk to applicators. For the other pesticides considered in this study, including; a neonicotinoid (acetamiprid) and pyrethroids (cypermethrin and ?-cyhalothrin), the exposure levels were below the AOEL of 0.07mg/kgBW/day, 0.05mg/kgBW/day and 0.003mg/kgBW/day respectively. Hence there was less risk in using the latter group of pesticides. It was also observed that there is high risk in applying pesticides on cotton farms during the late season than during the early season.

Key Words: Pesticides, Exposure, Applicator, Cotton Farms, Ghana