The VIII Region of Bio-Bio is a major fruit-growing area of Chile that makes intensive use of agricultural pesticides. The cytogenetic damage associated with exposure to mixtures of pesticides was evaluated by comparing peripheral blood lymphocyte micronucleus (MN) frequencies in a group of 64 female agricultural workers and 30 female controls. The exposed subjects worked during the spring and summer in thinning and pruning fruit trees and in harvesting and packing different fruits, such as raspberries, grapes, apples, and kiwis. They did not use any protective measures during their work activities. A significant increase in the frequency of binucleated cells with micronuclei (BNMN) was found in the exposed women as compared with the controls (36.94 +/- 14.47 vs. 9.93 +/- 6.17 BNMN/1000 BN cells; P < 0.001). The frequency of BNMN varied as a function of age in both the exposed and control groups, but no correlation was found between BNMN frequency and the duration of exposure. Also, smoking and other habits had no effect on MN frequency. Our study confirms that occupational exposure to pesticide mixtures results in cytogenetic damage.

*Autor a quien debe ser enviada la correspondenciaRecibido Feb. 2, 2017; Aceptado Mar. 23, 2016; Versión final May. 22, 2017, Publicado Ago. 2017 Resumen El objetivo del estudio que se presenta es analizar las percepciones de estudiantes universitarios frente al uso del póster como estrategia que favorece el avance en las prácticas de lectura y escritura. El estudio considera el uso de un diseño didáctico multimodal para desarrollar la alfabetización científica en estudiantes de primer año de Pedagogía en Ciencias Naturales. La investigación de carácter cualitativo comprende el análisis de datos de 68 sujetos a partir de la teoría de variación fenomenográfica que permitió la identificación de la forma en que los estudiantes logran aprendizajes de calidad y la validación del póster como herramienta didáctica en la producción de textos científicos. Entre los resultados se destaca la conciencia adquirida por los alumnos sobre la integración de códigos semióticos con apoyo de tecnología. En conclusión, se evidencia un progreso significativo tanto a nivel de contenido como lingüístico, y una apropiación de estructuras de composición multimodal de la información científica. Palabras claves: alfabetización científica; diseño didáctico multimodal; póster; escritura; tecnología Perceptions Concerning the Application of a Multimodal Design for Scientific Literacy in the Health Area AbstractThe objective of this study is to analyze the perceptions of university students in relation to poster presentation as a strategy that benefits the progress in reading and writing practices. The study considers the application of a multimodal didactic design to develop scientific literacy in freshmen students of the bachelor of Pedagogy in Natural Sciences. This is a qualitative research which includes the analysis of 68 subjects from the phenomenographic variation theory. This allowed the identification of the way students achieve quality learning and the validation of the poster as a didactic tool in the production of scientific texts. Some of the results highlight the awareness acquired by the students about the integration of semiotic codes with technological support. In conclusion, there is evidence of significant progress in the students concerning not only the content and but also the linguistics level, besides there is an appropriation of multimodal composition structures of the scientific information.