Environmental and health impacts of pesticide use practice in vegetable production in Karatu and Arumeru districts, Tanzania

M-IES

anglais. Vegetable production is an important part of local economic growth and export earnings in Tanzania. The government of Tanzania is encouraging vegetable products due to favorable condition and increasing demands. Vegetables serve as a quick income source and important diet components for small-scale farmers. However, pests have become a major constraint to this economically important sector. Consequently, farmers utilized different pesticides to control pests in onion and tomato crops. However, pesticides have negative effects on the health of farmers, workers, consumer and environments. To evaluate the impacts of pesticides on farmers, workers, consumers and environment, the study was conducted in Arumeru and Karatu Districts of Northern Tanzania. Survey was carried out in both districts on 107 onion and 125 tomato-producing farmers belonging to eight tribes and three different religions during the years of 2013. In addition, 30 different crop-producing farmers were also involved in face-face interview during the year 2014. To analyze pesticide residues, onion and tomato samples were collected. The samples were analyzed at department of biotechnology and Plant Health Division in NIBIO, Ås, Norway. The two instrument used for pesticides residue analysis were GC-MS and LC-MS. The impacts of pesticides on consumers, workers and environment were evaluated using EIQ formula. Both onion and tomato farmers applied different pesticides to control pests. Insecticides were applied predominantly due to high prevalence of insect pests. For example, 88% and 100% of the farmers applied insecticides before and after emergence of onion seedlings respectively. The majority of farmers used carbosulfan and profenofos insecticides in onion production. Profenofos and abamectin insecticides had the highest and lowest EIQ values respectively both in onion and tomato production. Farmers used more fungicides in tomato than that of onion. Fungicide, mancozeb had the highest EIQ index on consumers and workers. About 30%, 69% of farmers applied fungicides and insecticides in tomato farms during pre-emergence. Mancozeb had more than six times load of on the health of workers and consumers than metalaxyl applied at similar rate. All farmers agreed that use of pesticides is risky for their health. This is because of entrance of pesticides in their body via inhalation, skin openings, and residues in consumed vegetables. Almost all interviewed farmers experienced headache, burning sensation of skin, eyes, and weakness after spraying. Despite that more than 60% of farmers strongly disagreed on the notion of limiting pesticides use to produce crop. Pesticides residues were detected both in onion and tomato samples. About 84% of residues were above EU MRLs values due to greater amount of carbosulfan (62%) detected in onion samples. However, in tomato out of 24 residues only three residues remain above EU MRLs. Safe application technique and equipment were lacking in the study area. Providing farmers and workers with information and knowledge regarding pesticide choice, safe pesticides storage and disposal facilities, and protective equipment can increase safety level of farmers and workers. Further, investing more on sustainable public health services and environmental friendly pest control methods could be a policy option for Tanzanians.