Pesticide use in rice cultivation in Tarapoto, Peru : pesticide residues in blood of farmers, usage behaviour, and health care practices

Abstract: A study of the pesticide use in the rice cultivation in Tarapoto, the largest town in the department of San Martin situated in the northeast part of Peru, was performed. In Tarapoto, an irrigation canal was built in the 1980s, which gave the farmers the prerequisite to cultivate irrigated rice. The pesticides were introduced around the same time and have become a necessity to obtain a good and profitable yield. Large quantities of pesticides are used and many of them are classified as Extremely hazardous (Ia) or Highly hazardous (Ib) according to the WHO. During the study no traces of the use of POPs was found nor observed in the region. The aim of the study was to investigate the pesticide use, and identify the environmental pathways of different pesticides. It was part of a larger interdisciplinary project where this study in particular focused on the concentrations of different pesticides in blood from exposed people. Blood samples from 24 farmers were analysed on GC-ECD after extraction and clean-up. A screening of 21 different pesticides or metabolites was made and the most abundant pesticide residue detected was p,p-DDE. Lower concentrations of α-HCH, γ-HCH, HCB and traces of halogenated biphenyls (PCB) and DDT were detected in many of the samples. An unknown substance detected in all the samples was identified as Pentachloroanisole (PCA) on the MS. The samples show higher concentrations of p,p-DDE than in some European studies but slightly lower than studies from Nicaragua and Mexico. The concentrations of HCB are equivalent or even lower than in the studies from Europe and Latin America whereas the concentrations of γ-HCH seemed to be somewhat higher than in the studies from Nicaragua and Mexico and higher than in a European study. During the blood sampling, short interviews were made with the farmers to obtain some knowledge about how they handle the pesticides. The pesticides were mainly stored at home. The farmers apply the pesticides using back pack sprayers wearing little or no protective clothing at all. Many of the farmers had felt symptoms of poisoning due to pesticides, but they seldom visited the hospitals with them. Instead the most common cure was to drink different blends, like milk with soda. Another 7 deep interviews with farmers were made to obtain a better understanding of the whole cultivation process and thus the reason for the pesticide use. Often the interviews were made out on the field, which gave the possibility of observing the farmers while they were working. A questionnaire was distributed at three different health care centres and filled out by 15 employees. The purpose was to see how farmers and other people with poisoning due to pesticides were treated and also to look at the knowledge and training amongst the staff in how to treat them. Even though many of the personnel had experience in treating patients with poisoning due to pesticides, they were hardly given any professional training in treating them. There did seem to be a standard working procedure for treating these patients in one of the three hospitals, however not all of the personnel working there were aware of this matter.