is being treated for cancer by means of a radiopharmaceutical where a radioisotope is used as a drug (usually a liquid or pill). a review of this topic was published in 1999. because the radioactive material becomes intimately mixed with the affected object it is often difficult to decontaminate the object or person in a case where internal exposure is occurring. while some very insoluble materials such as fission products within a uranium dioxide matrix might never be able to truly become part of an organism, it is normal to consider such particles in the lungs and digestive tract as a form of internal contamination which results in internal exposure. boron neutron capture therapy (bnct) involves injecting a boron-10 tagged chemical that preferentially binds to tumor cells. neutrons from a nuclear reactor are shaped by a neutron moderator to the neutron energy spectrum suitable for bnct treatment. the tumor is selectively bombarded with these neutrons. the neutrons quickly slow down in the body to become low energy thermal neutrons. these thermal neutrons are captured by the injected boron-10, forming excited (boron-11) which breaks down into lithium-7 and a helium-4 alpha particle both of these produce closely spaced ionizing radiation. this concept is described as a binary system using two separate components for the therapy of cancer. each component in itself is relatively harmless to the cells, but when combined for treatment they produce a highly cytocidal (cytotoxic) effect which is lethal (within a limited range of 5-9 micrometers or approximately one cell diameter). clinical trials, with promising results, are currently carried out in finland and japan. when radioactive compounds enter the human body, the effects are different from those resulting from exposure to an external radiation source. especially in the case of alpha radiation, which normally does not penetrate the skin, the exposure can be much more damaging after ingestion or inhalation. the radiation exposure is normally expressed as a committed dose. history although radiation was discovered in late 19th century, the dangers of radioactivity and of radiation were not immediately recognized. acute effects of radiation were first observed in the use of x-rays when german physicist wilhelm röntgen intentionally subjected his fingers to x-rays in 1895. he published his observations concerning the burns that developed, though he misattributed them to ozone, a free radical produced in air by x-rays. other free radicals produced within the body are now understood to be more important. his injuries healed later. as a field of medical sciences, radiobiology originated from leopold freund's 1896 demonstration of the therapeutic treatment of a hairy mole using the newly discovered form of electromagnetic radiation called x-rays. after irradiating frogs and insects with x-rays in early 1896, ivan romanovich tarkhanov concluded that these newly discovered rays not only photograph, but also "affect the living function". at the same time, pierre and marie curie discovered the radioactive polonium and radium later used to treat cancer. the genetic effects of radiation, including the effects on cancer risk, were recognized much later. in 1927 hermann joseph muller published research showing genetic effects, and in 1946 was awarded the nobel prize for his findings. more generally, the 1930s saw attempts to develop a general model for radiobiology. notable here was douglas lea, whose presentation also included an exhaustive review of some 400 supporting publications. before the biological effects of radiation were known, many physicians and corporations had begun marketing radioactive substances as patent medicine and radioactive quackery. examples were radium enema treatments, and radium-containing waters to be drunk as tonics. marie curie spoke out against this sort of treatment, warning that the effects of radiation on the human body were not well understood. curie later died of aplastic anemia caused by radiation poisoning. eben byers, a famous american socialite, died of multiple cancers (but not acute radiation syndrome) in 1932 after consuming large quantities of radium over several years; his death drew public attention to dangers of radiation. by the 1930s, after a number of cases of bone necrosis and death in enthusiasts, radium-containing medical products had nearly vanished from the market. in the united states, the experience of the so-called radium girls, where thousands of radium-dial painters contracted oral cancers— but no cases of acute radiation syndrome— popularized the warnings of occupational health associated with radiation hazards. robley d. evans, at mit, developed the first standard for permissible body burden of radium, a key step in the establishment of nuclear medicine as a field of study. with the development of nuclear reactors and nuclear weapons in the 1940s, heightened scientific attention was given to the study of all manner of radiation effects. the atomic bombings of hiroshima and nagasaki resulted in a large number of incidents of radiation poisoning, allowing for greater insight into its symptoms and dangers. red cross hospital surgeon dr. terufumi sasaki led intensive research into the syndrome in the weeks and months following the hiroshima bombings. sasaki and his team were able to monitor the effects of radiation in patients of varying proximities to the blast itself, leading to the establishment of three recorded stages of the syndrome. within 25–30 days of the explosion, the red cross surgeon noticed a sharp drop in white blood cell count and established this drop, along with symptoms of fever, as prognostic standards for acute radiation syndrome. actress midori naka, who was present during the atomic bombing of hiroshima, was the first incident of radiation poisoning to be extensively studied. her death on august 24, 1945, was the first death ever to be officially certified as a result of radiation poisoning (or "atomic bomb disease"). the atomic bomb casualty commission and the radiation effects research foundation have been monitoring the health status of the survivors and their descendants since 1946. they have found that radiation exposure increases cancer risk, but also that the average lifespan of survivors was reduced by only a few months compared to those not exposed to radiation. no health effects of any sort have thus far been detected in children of the survivors. areas of interest the interactions between organisms and electromagnetic fields (emf) and ionizing radiation can be studied in a number of ways: radiation physics radiation chemistry molecular and cell biology molecular genetics cell death and apoptosis high and low-level electromagnetic radiation and health specific absorption rates of organisms radiation poisoning radiation oncology (radiation therapy in cancer) bioelectromagnetics electric field and magnetic field - their general nature. electrophysiology - the scientific study of the electrical properties of biological cells and tissues. biomagnetism - the magnetic properties of living systems (see, for example, the research of david cohen using squid imaging) and magnetobiology - the study of effect of magnets upon living systems.