| Summary: | In epidemiological research on pesticides, the major limitation has been inadequate exposure assessment. This is of relevance in studies of populations occupationally exposed to these toxic compounds, given the growing epidemiological evidence of their association with cancer, neurological and neurocognitive deficits, and immunological, metabolic and reproductive dysfunctions. The province of Cordoba has substantially increased the use of pesticides in recent decades, in parallel with the increase in areas planted with extensive crops, mainly with glyphosate-resistant transgenic soybeans. The first studies of the population of pesticide applicators in this province date only from the middle of the last decade and were initiated by the Environmental Epidemiology Group of Cancer and other Chronic Diseases in Córdoba (GEACC). These studies report a significant occupational exposure and viability of workers and a high prevalence of symptoms, medical consultations and hospitalization associated with the work. In order to perform epidemiological studies of chronic diseases and risk assessment for preventive purposes, tools were generated to evaluate the apposition. The present thesis proposes to optimize this methodological construction process by constructing pesticide exposure scales to classify extensive crop applicators in the province, according to exposure levels, in order to obtain the relative risk of apposition in this population; A cross-sectional observational study (CIECS N° 134/12) was conducted on the population of workers who attended the courses to obtain the applicator's license during the period 2007-312. Through the application of a self-administered survey, specifically adapted for this work, a random sample of 2115 workers was characterized and studied. .. Two indices, exposure intensity level (ILEec) and cumulative exposure CEIec), obtained from algorithms with previously unused exposure determinants, were defined and the empirical distributions of ILEec (n=645) and CEIec (n=523) were studied with Bootstrap resampling and Monte Carlo simulation methods. Once the theoretical distributions were obtained (n=30,000 random samples) and the best-fitting ones were identified, their percentiles were tabulated and, with P25 and P75 as cut-off points, scales of both indexes were generated in categories of low, medium and high exposure. The associations between categories and the characteristics of the subjects were studied by means of contingency tables. The sample of applicators had an average age of 36 years, 6.2% older than 55 years, mainly with completed secondary school or higher and married or cohabiting. Smoking was lower and alcohol consumption higher than those reported for Argentina; 65.6% showed alterity. The predominant age was in the range of up to 10 years, areas applied up to 10,000 l/year average, 33% used unsafe machinery, low use of protective equipment (PPE) and 50% lived less than 500 m from the nearest crop. The main crops were soybeans, corn and wheat, and the use of glyphosate, 2,4-D, atrazine, cypermethrin, dorpyrifos, endosulfan, among others, predominated. Only 50% received indications for the use of pesticides with a prescription from a licensed professional. The percentages of symptoms, medical consultation and hospitalization due to the use of pesticides were high, including subjects diagnosed with non-Hodgkin's lymphoma, leukemia and melanoma. The prevalence of congenital anomalies in the children of applicators was high and higher than those of the Argentine Registry of Congenital Anomalies. High exposure intensity (HEIec) was significantly associated with less seniority, application up to 10000 ha/year, use of machines without cabs and with cabs without filters, less use of PPE during work, not immediate change of clothes after spillage, distance of residence to the nearest crop and storage of pesticides less than 500 m away. High cumulative exposure (HAEec) was also associated with low use of PPE, not immediate post-spill change of clothes, distance of pesticides close to the dwelling, and drinking while working. HAEec was associated with less schooling than for HEIec, seniority from 6 to more than 20 years, not respecting re-entry time, greater use of all pesticides except glyphosate, used by almost 100% in the three categories, and to all symptoms and medical consultation due to pesticide use. In conclusion, this thesis provides valuable evidence on the differential levels of exposure to pesticides among extensive crop applicators in the province of Córdoba, through another contribution of this work, which is the optimization of a methodology previously developed by the GEACC, specifically for the estimation of occupational exposure levels. The exposure analysis made it possible to identify highly exposed and very vulnerable groups of applicators, given their significant association with the main determinants of exposure and with the effects on workers' health. Another contribution of this thesis is an exhaustive description of a sample with probabilistic rigor, representative of the population of applicators in Córdoba studied since 2007. A work activity with weak safety standards, exposure to potentially carcinogenic compounds, obesogens, diabetogens and endocrine disruptors, among other effects, the low compliance with existing sanitary regulations, the proximity of the houses to the treated crops, complete a complex risk scenario for workers, the environment and their families, manifested by the high presence of congenital anomalies in the children of applicators. Key words: agricultural pesticides, occupational exposure, extensive crops, cross-sectional observational study, exposure scales, Córdoba, Argentina.
|
|---|
