RESUMEN
Radiation protection of agrarian ecosystems should be considered as an integral part of a system for radiation protection of environment, with a special concern to agroecosystems' features. A methodology is proposed for an assessment of maximum permissible doses of radiation impact for agrocenoses based on an unified analysis of available data about effects of radiation in cultivated plants. It is considered as a component of radiation protection system for agricultural ecosystems. Critical doses and dose rates are estimated for crops under different exposure situations. It is shown that doses that could result in decreasing indexes of productivity and survival for main crops below 50% are unlikely up to 170-200 Gy and 15-17 Gy at an acute exposure of dormant seeds and vegetative plants, correspondingly. At chronic exposure, above 10% loss of productivity in crops is not expected at dose rates below 3-10 mGy/h.
Asunto(s)
Productos Agrícolas/efectos de la radiación , Monitoreo de Radiación/métodos , Protección Radiológica , Productos Agrícolas/crecimiento & desarrollo , Relación Dosis-Respuesta en la Radiación , Medición de Riesgo , Plantones/efectos de la radiación , Semillas/efectos de la radiaciónRESUMEN
The uptake by barley and the distribution between the vegetative and the generative organs of 137Cs, K and Ca was studied when plants were grown on soddy-podzolic soil with the background content of heavy metals and soil polluted with Cd and Co at concentrations significantly above the maximum permissible concentration (50 i 100 mg/kg accordingly). The reduction was found in 137Cs accumulation and removal with barley in ontogenesis under the action of increased contents of heavy metals in the soil, which was caused by their phytotoxic effect.
Asunto(s)
Radioisótopos de Cesio/análisis , Hordeum/crecimiento & desarrollo , Metales Pesados/análisis , Contaminantes del Suelo/análisis , Biomasa , Radioisótopos de Cesio/farmacocinética , Radioisótopos de Cesio/toxicidad , Hordeum/efectos de los fármacos , Hordeum/efectos de la radiación , Metales Pesados/farmacocinética , Metales Pesados/toxicidad , Semillas/efectos de los fármacos , Semillas/crecimiento & desarrollo , Semillas/efectos de la radiación , Contaminantes del Suelo/farmacocinética , Contaminantes del Suelo/toxicidad , Contaminantes Radiactivos del Suelo/análisis , Contaminantes Radiactivos del Suelo/farmacocinética , Contaminantes Radiactivos del Suelo/toxicidadRESUMEN
The effects of acute gamma-irradiation on the Colorado potato beetle (Leptinotarsa decemlineata Say) and sensitivity of insects, long time exposed on radioactively contaminated territories, to pesticides were studied. LD50 values of insects to ionizing radiation during the ontogenesis process was shown to increase (from 8 to 48 Gy). Differences were noted in the development rates of the natural population of beetles collected on agricultural lands with 137Cs contamination density of 0.05-1.2 MBq/m2, with the sensitivity to various pesticide groups being the same.
Asunto(s)
Escarabajos/efectos de los fármacos , Escarabajos/efectos de la radiación , Resistencia a Medicamentos/efectos de la radiación , Rayos gamma , Insecticidas/toxicidad , Animales , Radioisótopos de Cesio/toxicidad , Accidente Nuclear de Chernóbil , Escarabajos/crecimiento & desarrollo , Relación Dosis-Respuesta en la Radiación , Larva/efectos de los fármacos , Larva/crecimiento & desarrollo , Larva/efectos de la radiación , Dosificación Letal Mediana , Estadios del Ciclo de Vida/efectos de los fármacos , Estadios del Ciclo de Vida/efectos de la radiación , Tolerancia a RadiaciónRESUMEN
The changes studied in 137Cs uptake by plants and its distribution between vegetative and generative organs of barley cultivated with the application of potassium humate. A relationship has been found between 137Cs accumulation size in barley at various ontogenesis stages and way of potassium humate application (treatment of seeds or plants), as well as availability of mineral nutrients in the soil. Changes in K+ and NH4+ concentrations in soil solution are shown to be of prevailing importance in regulating 137Cs uptake by plants compared with potassium humate effects.
Asunto(s)
Radioisótopos de Cesio/metabolismo , Hordeum/metabolismo , Sustancias Húmicas , Compuestos de Potasio , Semillas/metabolismo , Contaminantes Radiactivos del Suelo/metabolismo , Radioisótopos de Cesio/análisis , Fertilizantes , Jardinería/métodos , Hordeum/crecimiento & desarrolloRESUMEN
There is a tendency for a decrease in the yield of cytogenetic disturbances with time elapsed from the Chernobyl accident. But an increased rate of cytogenetical damages significantly dependent on the level of radioactive contamination was observed even in several years after the incident. The rate of decline with time in cytogenetic disturbances induced by chronic exposure considerably lagged behind that of radiation exposure. Analysis of genetic changeability in three sequential generations of winter rye and wheat revealed increased cytogenetic damage in crops grown on contaminated sites during 2 and 3 years.
Asunto(s)
Aberraciones Cromosómicas , Productos Agrícolas/efectos de la radiación , Grano Comestible/efectos de la radiación , Centrales Eléctricas , Liberación de Radiactividad Peligrosa , Aberraciones Cromosómicas/genética , Productos Agrícolas/genética , Relación Dosis-Respuesta en la Radiación , Grano Comestible/genética , Variación Genética/efectos de la radiación , Meristema/genética , Meristema/efectos de la radiación , Contaminantes Radiactivos del Suelo/análisis , Factores de Tiempo , UcraniaRESUMEN
The morphophysiological properties of two generations of seeds from chronically exposed agrocenoses of the Chernobyl NPP accident zone were investigated. The difference in reactions between exposed and control seeds to acute stimulating irradiation and to treatment with biologically active substances was shown. The relationship between the degree of radiation depression of the seed morphological development indexes and biometric characteristics of plants on the plots with different radioactive contamination was revealed.