Acute Pesticide Poisoning in Tobacco Farming, According to Different Criteria

Abstract

Background: Brazil is one of the world’s largest pesticide consumers, but information on pesticide poisoning among workers is scarce. Objective: To evaluate acute pesticide poisoning among tobacco growers, according to different criteria. Methods: This was a two-step cross-sectional study with 492 pesticide applicators. It used a 25 question pesticide-related symptoms (PRS) questionnaire and medical diagnosis for comparison with toxicological assessment. Associations were evaluated using Poisson regression. Results: 10.6% reported two or more PRS, while 8.1% reported three or more. Furthermore, 12.2% received a medical diagnosis of poisoning. According to toxicologists, possible cases accounted for 14.2% and probable cases for 4.3%. PRS increased during the period of greater exposure. Those exposed to dithiocarbamates, sulfentrazone, pyrethroids, fipronil and iprodione exhibited more PRS. The number of exposure types, multi-chemical exposure, clothes wet with pesticides and spillage on the body/clothes were associated with acute poisonings. All criteria showed sensitivity greater than 79% for probable cases but only greater than 70% for medical diagnosis when compared to possible cases, presenting substantial Kappa agreement. Conclusion: The prevalence of acute pesticide poisoning is much higher than officially recorded. Trained physicians can screen for pesticide poisoning. It is necessary to improve workers’ education to reduce pesticide use and exposure to them.

Epidemiological occupational studies in rural areas: methodological challenges

“…To obtain information on pesticide exposure, the first challenge is to identify the main chemical products used. A successful experience was used in the tobacco farming study 6,13 . With the support of key informants (EMATER, Rural Workers Union, agricultural technicians, agricultural stores, and others), a list was created with about 70 trade names of the most used pesticides.…”

“…These cards were used by the interviewers to help the respondents identify the products used on the farm. For analysis, commercial products were unified according to their active ingredients and chemical groups 6,40 .…”

“…For the study on acute pesticide poisoning in tobacco farming 6,13 , the applicators were asked to identify the products used in the last 30 days and the date of the last day of contact. This system may be limited in assessing past exposures but was quite useful in evaluating recent exposure to pesticides 6 . Nevertheless, some doubts persisted regarding differences in the formulation or concentration of some products.…”

“…Exposure forms can be described by the activity performed, such as applying, preparing the solution, assisting in application, cleaning equipment, filling the spraying tank, washing contaminated clothing, transporting, storing, veterinary use, and re-entering the crop/orchard after application 6,13,42 . Moreover, some situations may indicate higher exposure, such as applying in more than one agricultural production unit or spilling the product on clothing while performing these or other activities, which is one of the criteria for characterizing events of high exposure 6,43 .…”

“…While the number and quality of studies in this area have increased, considerable gaps remain, particularly concerning the effects of chronic exposure to pesticides 5 . Furthermore, official health information systems present high underreporting of work-related accidents and diseases, limiting their potential as surveillance tools, especially in agricultural activities 5,6 .…”