Pilot Study: Pesticide exposure in agriculture workers in Colombia and Bolivia
Pesticides are chemical or biological agents used to kill or incapacitate unwanted organisms. Currently large quantities of pesticides are used all around the world. Earlier pesticides, such as organochlorines (e.g. dichlorodiphenyltrichloroethane (DDT)) and organophosphates (e.g. paraquat), while extremely effective in controlling the target organisms, had marked adverse effects. Additionally most pesticides tend to bio-concentrate and bio-magnify in the food chains, causing a variety of reproductive, carcinogenic, immunological, neurological and other adverse effects for both animals and humans. For that reason some pesticides have been banned in a large number of countries, however their use continues remains unregulated and uncontrolled in some developing countries. In addition, these products are sold without proper training of farmers on safe application and without warning of the harmful effect on the environment and health.
Agricultural workers are exposed to a variety of chemical, physical, and biological hazards in the process of cultivating and harvesting crops. As many pesticides are applied by spraying, exposure through inhalation and dermal contact to the operator is of particular concern. Several studies have reported that pesticides can cause acute irritant responses in the lung, adverse respiratory effects in those with pre-existing respiratory diseases or increase the risk for healthy individuals developing respiratory conditions when they are exposed repeatedly.
Even though some publications of Latin America have reported high concentration of pesticides components in farmers, there are few studies assessing health effects. In this sense Maria Teresa Solis Soto (Alumna) and Leonardo Briceño (Universidad del Rosario, Colombia), developed a cross-sectional study to explore pesticide exposure in agriculture workers in Bolivia. It was not possible to develop the study in Colombia due to logistical reasons.
In Bolivia, a cross-sectional study was carried out in rural districts 6 and 7 of the municipality of Sucre in the department of Chuquisaca. Both districts, being rural, develop agricultural activities, but these develop with greater intensity in the 7th district (Zone of Rio Chico), due to their geographical and climatic characteristics, producing more than 63 species mainly tomatoes, potatoes, guava, avocado , lemon and papaya, being the main source of these products for the city of Sucre.
Approximately 400 people (16 or older) were invited to participate in the study. Visits were previously coordinated in each family, and instruments were applied to explore home characteristics, age, sex, education, family situation, health status, smoking habits, knowledge, attitudes and practices to buy, handle and store pesticides, impact in perceived health, perceived damage associated with pesticides, experiences of acute poisoning with pesticides and toxic symptoms in connection with spraying. As health outcomes, asthma and chronic cough symptoms and neurotoxicity symptoms were explored. Additionally, spirometries (EasyOne ™) were performed to evaluate lung function and urine samples were collected to analyze the presence of organophosphorus pesticide metabolites.
International ethical research guidelines were considered at all research steps. A written informed consent form as well as a letter explaining the importance of the study were included to the questionnaire. Voluntary participation was respected. The study protocol has the Ethical approval for the Bioethics Committee of the medical faculty of the Universidad San Simón in Cochabamba–Bolivia. Additionally we asked for authorization of the Regional and local health services and the local authorities in the study communities.
The preliminary results were socialized with the regional health office and with the Health Centers, that took part in the study, in order to coordinate educational programs and other actions to reduce pesticide exposure and take care of farmers' health.