Solid cancer risk dependence on the Pasquill-Gifford atmospheric stability classes in a radiological event.

In a radiological event, the lack of preliminary information about the site of explosion and the difficulty in predicting the accurate path and distribution of radioactive plumes makes it difficult to predict expected health effects of exposed individuals. So far, in such a health evaluation, radiation-induced stochastic health effects such as cancer are not included. The Pasquill-Gifford atmospheric classes generally allow connecting atmospheric stability with dispersion of radioactive contaminants to the environment. In this work, an environmental release of radioactive Cs-137 was simulated and the resulting relative risk for solid cancer incidence among the affected population calculated. The HotSpot health physics code was used to simulate the radioactive atmospheric dispersion and calculate the Total Effective Dose Equivalent (TEDE), which was then used to estimate the relative risk of cancer incidence. The main results from this work suggest that the relative cancer risk and atmospheric stability classes are linked by differences in the TEDE. Such a finding may support triage, because it adds additional information on the potentially affected population at the early stages of an emergency response.

Support to triage and public risk perception considering long-term response to a Cs-137 radiological dispersive device scenario.

A radiological dispersive device (RDD) spreads radioactive material, complicates the treatment of physical injuries, raises cancer risk, and induces disproportionate fear. Simulating such an event enables more effective and efficient utilization of the triage and treatment resources of staff, facilities, and space. Fast simulation can give detail on events in progress or future events. The resources for triage and treatment of contaminated trauma victims can differ for pure exposure individuals, while discouraging the "worried well" from presenting in the crisis phase by media announcement would relieve pressure on hospital facilities. The proposed methodology integrates capabilities from different platforms in a convergent way composed of three phases: (a) scenario simulation, (b) data generation, and (c) risk assessment for triage focused on follow-up epidemiological assessment. Simulations typically indicate that most of the affected population does not require immediate medical assistance. Medical triage for the few severely injured and the radiological triage to diminish the contamination with radioactivity will always be the priority. For this study, however, higher priorities should be given to individuals from radiological "warm" and "hot" zones as required by risk criteria. The proposed methodology could thus help to (a) filter and reduce the number of individuals to be attended, (b) optimize the prioritization of medical care,

Radiological Risk Assessment by Convergence Methodology Model in RDD Scenarios.

A radiological dispersal device (RDD) is a simple weapon capable of causing human harm, environmental contamination, disruption, area denial, and economic cost. It can affect small, large, or long areas depending on atmospheric stability. The risk of developing a radio-induced cancer depends on exposure, and an effective response depends upon available timely guidance. This article proposes and demonstrates a convergence of three different capabilities to assess risk and support rapid safe resource efficient response. The three capabilities that are integrated are Hotspot for dispersion, RERF for epidemiological risk, and RESRAD-RDD for response guidance. The combined methodology supports decisions on risk reduction and resource allocation through work schedules, the designation and composition of response teams, and siting for operations. In the illustrative RDD scenario, the contamination area for sheltering, evacuation, and long-term public concern was greatest for calm atmospheric conditions, whilst close-quarter responders faced highest dose rates for neutral atmospheric conditions. Generally, the risks to women responders were found to be significantly greater than for men, and the risks to 20-year-old responders were three times that of their 60-year-old counterparts for similar exposure.

Avaliação da irradiação gama em peitos de frangos refrigerados monitorados pela contagem de bactérias heterotróficas aeróbias mesófilas viáveis e pH / Evaluation of gamma irradiation of refrigerated chicken´s chests monitored by viable heterotrophic aerobic mesophilic bacteria counting and pH

Pesquisas têm demonstrado que a tecnologia de irradiação de alimentos tem sido eficiente na redução de patógenos na carne de aves. O objetivo desta pesquisa foi estudar o efeito da radiação gama em peitos de frangos desossados, sem pele e refrigerados. Utilizou-se um total de 19 amostras, sendo 12 submetidas à irradiação e as restantes, não irradiadas, utilizadas como controle. A irradiação foi efetuada num irradiador de pesquisa com fonte de césio-137, de forma que as amostras, mantidas constantemente sob refrigeração, recebessem uma dose de 3,0 kGy. A temperatura das amostras foi monitorada durante todo o período do experimento. Na avaliação bacteriana, utilizou-se a contagem de heterotróficos aeróbios mesófilosviáveis e, como parâmetro físico-quimico, realizou-se a aferição do pH. A temperatura registrada no momento da colheita foi de : 10,3oC, e, a partir do primeiro dia, foi mantida entre -1 ,5 e 3,5°C, até o 252 dia. A contagem bacteriana inicial das amostras nãoirradiadas foi de 6,5x1 05 UFC/g, apresentando um aumento a partir do primeiro dia e alcançando taxas de ~10 7 UFC/g no 52 dia. A irradiação reduziu a carga bacteriana em ~4 ciclos logarítmicos, observando-se inicialmente uma contagem de 2,4x10 2 UFC/g a qual atingiu ~10 7 UFC/g no 15o dia de armazenamento. O pH das amostras variou entre 5,9 (no dia zero) e 6,8 (11 e 25 dias), para as amostras não irradiadas e irradiadas, respectivamente). De acordo com os resultados, pode-se concluir que a dose de 3,0 kGy, em termos bacteriológicos foi eficaz em prolongar a vida útil do peito de frango em aproximadamente três vezes)