Preparing for a “dirty bomb” attack: The optimum mix of medical countermeasure resources

Background: In radiological emergencies with radionuclide incorporation, decorporation treatment is particularly effective if started early. Treating all people potentially contaminated("urgent treatment") may require large antidote stockpiles. An efficacious way to reduce antidote requirements is by using radioactivity screening equipment. We analyzed the suitability of such equipment for triage purposes and determined the most efficient mix of screening units and antidote daily doses.Methods: The committed effective doses corresponding to activities within the detection limits of monitoring portals and mobile whole-body counters were used to assess their usefulness as triage tools. To determine the optimal resource mix, we departed from a large-scale scenario(60,000 victims) and based on purchase prices of antidotes and screening equipment in Germany, we calculated efficiencies of different combinations of medical countermeasure resources by data envelopment analysis. Cost-effectiveness was expressed as the costs per life year saved and compared to risk reduction opportunities in other sectors of society as well as the values of a statistical life.Results: Monitoring portals are adequate instruments for a sensitive triage after cesium-137 exposure with a high screening throughput. For the detection of americium-241 whole-body counters with a lower daily screening capacity per unit are needed. Assuming that 1% of the potentially contaminated patients actually need decorporation treatment, an efficient resource mix includes 6 monitoring portals and 25 mobile whole-body counters. The optimum mix depends on price discounts and in particular the fraction of victims actually needing treatment. The costeffectiveness of preparedness for a "dirty bomb" attack is less than for common health care, but costs for a life year saved are less than for many risk-reduction interventions in the environmental sector.Conclusion: To achieve economic efficiency a high daily screening capacity is of major importance to substantially decrease the required amount of antidote doses. Among the determinants of the number of equipment units needed, the fraction of the potentially contaminated victims that actually needs treatment is the most difficult to assess. Judging cost-effectiveness of the preparedness for "dirty bomb" attacks is an issue of principle that must be dealt with by political leaders.

Pharmacological treatment of inhalation injury after nuclear or radiological incidents: The Chinese and German approach

Inhalation injury is often associated with burns and significantly increases morbidity and mortality. The main toxic components of fire smoke are carbon monoxide, hydrogen cyanide, and irritants. In the case of an incident at a nuclear power plant or recycling facility associated with fire, smoke may also contain radioactive material. Medical treatments may vary in different countries, and in this paper, we discuss the similarities and differences in the treatments between China and Germany. Carbon monoxide poisoning is treated by 100% oxygen administration and,if available, hyperbaric oxygenation in China as well as in Germany. In addition, antidotes binding the cyanide ions and relieving the respiratory chain are important. Methemoglobin-forming agents(e.g., nitrites, dimethylaminophenol)or hydroxocobalamin(Vitamin B12) are options. The metabolic elimination of cyanide may be enhanced by sodium thiosulfate. In China, sodium nitrite with sodium thiosulfate is the most common combination. The use of dimethylaminophenol instead of sodium nitrite is typical for Germany, and hydroxocobalamin is considered the antidote of choice if available in cases of cyanide intoxications by fire smoke inhalation as it does not further reduce oxygen transport capacity. Systematic prophylactic use of corticosteroids to prevent toxic pulmonary edema is not recommended in China or Germany. Stable iodine is indicated in the case of radioiodine exposure and must be administered within several hours to be effective. The decorporation of metal radionuclides is possible with Ca(DTPA)or Prussian blue that should be given as soon as possible. These medications are used in both countries, but it seems that Ca(DTPA) is administered at lower dosages in China. Although the details of the treatment of inhalation injury and radionuclide(s) decorporation may vary, the general therapeutic strategy is very similar in China and Germany.

Medical management of victims contaminated with radionuclides after a “dirty bomb” attack

A wide spectrum of scenarios may lead to radiation incidents and the liberation of radioactive material. In the case of a terrorist attack by a "dirty bomb", there is a risk of mechanical and thermal trauma, external irradiation, superficial contamination and incorporation of radioactive material. The first treatment priority must be given to the care of trauma patients with life-threatening injuries, as the health effects of radiation occur with latency. Radionuclide incorporation will lead to a longer-lasting irradiation from inside the body, associated with a higher risk of stochastic radiation effects(e.g., occurrence of tumors) in the long run. It must be expected that victims with potentially incorporated radionuclides will far outnumber trauma patients. The elimination of radionuclides can be enhanced by the administration of decorporation agents such as(Ca) Diethylenetriaminepentaacetic acid(DTPA) or Prussian blue,reducing the radiological burden of the body. There is still no consensus whether decorporation treatment should be started immediately based only on a suspicion of radionuclide incorporation("urgent approach") or if the results of internal dosimetry confirming the necessity of a treatment should be awaited, accepting the delay caused by the measurements and computations("precautionary approach"). As the therapeutic effectiveness may be substantially decreased if treatment initiation is delayed only by several days, depending on the radionuclide, the physicochemical properties of the compounds involved and the route of absorption, we favor an "urgent approach" from a medical point of view. In doubt, it seems justified to treat victims by precaution, as the adverse effects of the medication seem minimal. However, in the case of a high number of victims, an "urgent treatment approach" may require a large number of daily doses of antidotes, and therefore, adequate investments in preparedness and antidote stockpiling are necessary.

Estimation of radiation-induced health hazards from a“dirty bomb”attack with radiocesium under different assault and rescue conditions

In the case of a terrorist attack by a“dirty bomb”,blast injuries,external irradiation and the incorporation of radioactivity are to be expected.Departing from information about the radiological attack scenario with cesium-137 in the U.S.National Scenario Planning Guide,we estimated the radiological doses absorbed.Similar calculations were performed for a smaller plume size and a detonation in a subway.For conditions as described in the U.S.scenario,the committed effective dose amounted to a maximum of 848 mSv,even for very unfavorable conditions.Red bone marrow equivalent doses are insufcient to induce acute radiation sickness(ARS).In the case of a smaller plume size,the ARS threshold may be exceeded in some cases.In a subway bombing,doses are much higher and the occurrence of ARS should be expected.The health hazards from a dirty bomb attack will depend on the location and the explosive device.The derived Haddon matrix indicates that preparing for such an event includes education of all the medical staff about radiation effects,the time lines of radiation damages and the treatment priorities.Further determinants of the outcome include rapid evacuation even from difficult locations,the availability of a specific triage tool to rapidly identify victims at risk for ARS,the availability of an antidote stockpile and dedicated hospital beds to treat seriously irradiated victims.

细胞间黏附分子-1:一种在活体内外表现一致的放射性皮肤反应的炎性标记

Background: Radiation damage to skin is a key diagnostic and prognostic parameter for patients accidentally exposed to radiation. Moreover, skin is a target organ for crucial side-effects of routine radiotherapy. The pathophysiology of the cutaneous radiation reaction is in many respects still unknown. The acute inflammatory radiation reaction of skin has been shown to involve alterations in cell-cell and cellmatrix interactions, which are mediated by cellular adhesion molecules. Objectives: To evaluate the effect of ionizing radiation on intercellular adhesion molecule-1 (ICAM-1) expression in human skin cells. Methods: Dermal monolayer cells, a three-dimensional skin model and skin biopsies were investigated for ICAM-1 expression after ionizing radiation using flow cytometry, quantitative reverse transcription-polymerase chain reaction and immunohistochemistry. ICAM-1 expression in monolayer cells pretreated with protein kinase inhibitors and dexamethasone prior to irradiation was analysed by flow cytometry. Results: Using different sources of skin cells, we demonstrated a consistent upregulation of both ICAM-1mRNA and protein expression by ionizing radiation. Blocking experiments revealed that tumour necrosis factor-α, another ICAM-1 inducer, does not account for the effect of radiation. Radiationinduced upregulation of ICAM-1 expression was significantly attenuated by inhibitors to protein kinase C, mitogen-activated protein (MAP) ERK kinase, p38MAP kinase and phosphatidylinositol 3-kinase. The anti-inflammatory agent dexamethasone suppressed the effect of radiation on ICAM-1 expression, suggesting its usefulness to treat the cutaneous radiation reaction. Conclusions: Our data suggest that ICAM-1 is a consistent inflammatory parameter of the cutaneous radiation reaction both in vitro and in vivo that might provide new therapeutic options for diagnosis and treatment of effects of radiation.