Evaluación de la genotoxicidad en trabajadores expuestos a radiaciones ionizantes en centros de diagnóstico de Barranquilla, un estudio piloto
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Fecha
2019
Autores
García Cuan, Hilda Magaly
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Editor
Ediciones Universidad Simón Bolívar
Facultad Ciencias Básicas y Biomédicas
Facultad Ciencias Básicas y Biomédicas
Resumen
Las radiaciones ionizantes (RI) con fines diagnósticos y terapéuticos tienen la propiedad de penetrar tejidos, transformar las células o incluso llevarla a muerte celular, por tanto, resulta un factor de riesgo importante en los trabajadores ocupacionalmente expuestos (TOE) crónicamente, puesto que a largo plazo esta exposición puede desencadenar enfermedades como cáncer o desordenes hereditarios.
El presente estudio es de tipo descriptivo, transversal, cuyo objetivo principal fue evaluar la exposición ocupacional a radiaciones ionizantes (Rayos X y Rayos Gamma) en centros diagnósticos, mediante el análisis de ensayo cometa, citoma del ensayo de micronúcleo con bloqueo de citocinesis (CBMN Cyt) y citometría de flujo en linfocitos. Para esto, fueron escogidas tres instituciones de la ciudad de Barranquilla e incluidas 15 personas laboralmente expuestas a radiaciones ionizantes, con edades entre 19 a 47 años, y 15 personas no expuestas-control, con edades entre 18 a 45 años. Para el análisis de los biomarcadores, se colectaron 12 ml de sangre para la aplicación del ensayo cometa, el ensayo del citoma de linfocitos y análisis por citometria de flujo.
Dentro de los resultados obtenidos de acuerdo a los hábitos y estilo de vida, el grupo expuesto y no expuesto tienen una dieta similar, alto consumo de frutas, vegetales y suplementos vitamínicos. El grupo expuesto tiene un bajo consumo de alcohol, en contraste con el consumo del grupo no expuesto. En cuanto a los niveles de exposición, el 86,66% de los expuestos tienen contacto sólo con rayos X y el 40% de ellos, tienen un promedio de 2 a 5 años de estar laborando en esta actividad.
En los resultados del ensayo cometa del personal expuesto no se encontró incremento estadísticamente significativo (valor p = 0,140) en relación con el grupo control y no existe correlación con la edad (Coeficiente de correlación (r) = 0,190; valor p = 0,498) y el tiempo de exposición a radiaciones ionizantes (RI), Coeficiente
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de correlación (r) = 0,362; valor p = 0,184. Se encontró diferencia estadísticamente significativa, entre la frecuencia de micronúcleos (MN) del grupo expuesto con relación al grupo no expuesto (valor p = 0,011). Además, se observó asociación entre el tiempo de exposición a RI y la frecuencia de micronúcleos (Coeficiente de correlación de Pearson = - 0,47; valor p = 0,011) pero no con el resto de los biomarcadores analizados.
En los resultados de citometria de flujo, se encontró diferencia estadísticamente significativa entre la media del daño total del grupo expuesto y los no expuestos, evidenciando un daño en el ADN (valor p = 0,024); sin embargo, no se encontró asociación entre el daño del ADN con la edad de los trabajadores expuestos a RI (Coeficiente de correlación de Pearson = 0,375; p = 0,169) ni con el tiempo de exposición (Coeficiente de correlación de Pearson = 0,082; valor p = 0,772).
Los niveles de daño en los ADN observados en este estudio pueden estar relacionados con daño oxidativo, debido a la generación de especies reactivas del oxígeno (ERO), los cuales pueden ser inducidos por las radiaciones ionizantes y su capacidad de interactuar con macromoléculas como el ADN. Estos resultados demuestran la utilidad de estos biomarcadores en estudios de biomonitoreo humano y evaluación del riesgo en poblaciones expuestas.
Ionizing Radiations (IR) used for diagnostic and therapeutic purposes have the property of penetrating tissues, transforming cells or even causing cellular death. Therefore, it is an important risk factor for the chronically exposed workers (OEW). Since, with long-time exposure they can develop diseases such as cancer or genetic disorders. The current study is transversal and descriptive, whose main objective was to evaluate the occupational exposure to Ionizing radiations (X-Rays and Gamma-Rays) in Diagnostic Centers using the Comet Essay Analysis, the cytokinesis-block micronucleus cytome (CBMN cyt) assay and Lymphocyte Flow cytometry. To carry this out, three institutions were involved in Barranquilla along with 15 people from the age of 19 to 47 years old that were exposed to ionizing radiation at work. Another group of 15 non-exposed people were involved as Control, with an age range from 18 to 45 years old. For the Biomarkers analysis, 12 ml of blood were collected to be tested through Comet assay, CBMN cyt assay and Lymphocyte Flow Cytometry. Within the results obtained according to habits and lifestyle, the exposed and non-exposed groups have a similar diet, high consumption of fruits, vegetables and vitamin supplements. The exposed group has a low consumption of alcohol, in contrast to the consumption of the unexposed group. In the group of workers exposed to the Ionizing radiation, 86.66 % has only been exposed to X-Rays. The same group has been exposed an average of 2 to 5 years. There was no statistically significant increase in the results of the comet assay for the exposed group (p value = 0.140) in relation to the control group and there is no correlation with age (Correlation coefficient (r) = 0.190; p value = 0.498) and the time of exposure to ionizing radiation (IR), Correlation coefficient (r) = 0.362; p value = 0.184. A statistically significant difference was found between the frequency of micronucleus (MN) of the exposed group in relation to the non-exposed group (p value = 0.011). In addition, there was an association between the time of exposure to IR and the frequency of micronucleus (Pearson correlation coefficient = -0.47; p-value = 0.011) but not with the rest of the biomarkers analyzed. The results of the Flow Cytometry showed a statistically significant difference between the presences of damage in the DNA (value= 0,024) in the IR exposed group and the absence of damage in the non-exposed group. Association between the presence of damage of the DNA and the age of the workers in the IR exposed group was not found (Pearson correlation coefficient=0.375; p value=0.169). Association with the presence of Damage of the DNA and the exposing period to the radiation were not found either (Pearson correlation coefficient = 0.082; p value=0.772). The levels of DNA damage observed in this study may be related to oxidative damage due to the generation of reactive oxygen species (ROS), which can be generated by ionizing radiation and their ability to interact with macromolecules such as DNA. These results demonstrate the usefulness of these biomarkers in human biomonitoring studies and risk assessment in exposed populations.
Ionizing Radiations (IR) used for diagnostic and therapeutic purposes have the property of penetrating tissues, transforming cells or even causing cellular death. Therefore, it is an important risk factor for the chronically exposed workers (OEW). Since, with long-time exposure they can develop diseases such as cancer or genetic disorders. The current study is transversal and descriptive, whose main objective was to evaluate the occupational exposure to Ionizing radiations (X-Rays and Gamma-Rays) in Diagnostic Centers using the Comet Essay Analysis, the cytokinesis-block micronucleus cytome (CBMN cyt) assay and Lymphocyte Flow cytometry. To carry this out, three institutions were involved in Barranquilla along with 15 people from the age of 19 to 47 years old that were exposed to ionizing radiation at work. Another group of 15 non-exposed people were involved as Control, with an age range from 18 to 45 years old. For the Biomarkers analysis, 12 ml of blood were collected to be tested through Comet assay, CBMN cyt assay and Lymphocyte Flow Cytometry. Within the results obtained according to habits and lifestyle, the exposed and non-exposed groups have a similar diet, high consumption of fruits, vegetables and vitamin supplements. The exposed group has a low consumption of alcohol, in contrast to the consumption of the unexposed group. In the group of workers exposed to the Ionizing radiation, 86.66 % has only been exposed to X-Rays. The same group has been exposed an average of 2 to 5 years. There was no statistically significant increase in the results of the comet assay for the exposed group (p value = 0.140) in relation to the control group and there is no correlation with age (Correlation coefficient (r) = 0.190; p value = 0.498) and the time of exposure to ionizing radiation (IR), Correlation coefficient (r) = 0.362; p value = 0.184. A statistically significant difference was found between the frequency of micronucleus (MN) of the exposed group in relation to the non-exposed group (p value = 0.011). In addition, there was an association between the time of exposure to IR and the frequency of micronucleus (Pearson correlation coefficient = -0.47; p-value = 0.011) but not with the rest of the biomarkers analyzed. The results of the Flow Cytometry showed a statistically significant difference between the presences of damage in the DNA (value= 0,024) in the IR exposed group and the absence of damage in the non-exposed group. Association between the presence of damage of the DNA and the age of the workers in the IR exposed group was not found (Pearson correlation coefficient=0.375; p value=0.169). Association with the presence of Damage of the DNA and the exposing period to the radiation were not found either (Pearson correlation coefficient = 0.082; p value=0.772). The levels of DNA damage observed in this study may be related to oxidative damage due to the generation of reactive oxygen species (ROS), which can be generated by ionizing radiation and their ability to interact with macromolecules such as DNA. These results demonstrate the usefulness of these biomarkers in human biomonitoring studies and risk assessment in exposed populations.
Descripción
Palabras clave
Genotoxicidad, Rayos X, Rayos Gamma, Ensayo cometa, Citoma, Citometria de flujo, Genotoxicity, X-rays, Gamma rays, Comet assay, Cytome, Flow cytometry