Assessment of pesticide exposure pathways on humans in Mang'ola ward, Karatu district-Arusha, Tanzania

Masters DissertationA cross-sectional study was carried out in Mang’ola area in Lake Eyasi basin from October 2012 to February 2013 to assess pesticide exposure pathways to vegetable growers and consumers. A total sample size of 263 respondents was selected for the study. Baseline data for exposure pathway scenario, eating habits and quantities of vegetables consumed were collected using structured questionnaires, In-depth interview, Focus group discussion and observations. Health risk characterization was estimated based on FAO/WHO guidelines. Results showed an indiscriminate use of pesticides with limited knowledge on environmental contaminants and public health risks. About 61% of vegetable growers who applied pesticides once pests appeared on their grown vegetables, only 4.9% consulted the Agriculture Extension Officers. Up to 75.6% of vegetable growers mixed more than two types of pesticides and did not abide to basic safety procedures for pesticide application. Also 73.2% of pesticide applicators were not used personal protection devices. Ingestion of contaminated vegetables as the route of pesticide exposure to consumers had 53.7% and most consumed vegetables were onions and tomatoes (97.6%). Among the identified exposure pathways from pesticide contaminated fields were “take-home pathway”, “residential proximity pathway” and “contaminated wind spray drift exposure pathway” associated with direct dermal contact (68%) and inhalation (54%). Secondary retrieved pesticide residue concentrations data ranged from