Australian
Screen

Teacher’s notes

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This clip shows English scientist Dr Chris Busby describing the health effects of internal radiation as compared to those of external radiation in terms of nuclear energy dose, interspersed with archival footage, graphic animation and voice-over commentary. Footage of the Japanese atomic bombings shows the effects of external radiation on urban areas and Japanese survivors. Busby explains his understanding of internal radiation and an X-ray image of a body details the path of inhaled radiation. The clip concludes with animation showing radiation affecting DNA strands.

Educational value points

• Dr Busby (1945–), an expert on the subject of internal radiation, explains that there is a difference in the health effects between internal and external radiation. The dosage may be the same but the concentrated effect of internal radiation can be more harmful. Ingested or inhaled radioactive particles give very high local energy density within the body, as opposed to the more evenly distributed external radiation absorbed from an atomic bomb.

• Images of the effects of the atom bombing of Japanese cities in 1945 are shown as examples of external exposure to radiation. Scientists could precisely calculate the dosage exposure of the children suffering from radiation sickness. These calculations were used as the basis for estimates of the danger levels of radiation. In contrast, internal radiation dosages received by children living near nuclear power stations are extremely difficult to calculate.

• Busby argues that the effects of internal and external radiation are so different that the results of scientific studies of external radiation cannot be applied to internal radiation. He uses the analogy of the same energy intake being absorbed by someone standing in front of a fire and being warmed all over compared to someone who puts a hot coal in their mouth and receives the dose only in one location in their body. The dose is the same but the effect is very different.

• Animation is used to detail the explanation of how internal radiation enters and affects the body. An X-ray graphic shows a radioactive particle being inhaled into the lungs then into the blood and lymph nodes. Busby’s assertion is that the lymphatic vessels transfer high doses of radiation to various tissues and organs in the body. Another animation shows the effect of a radiation particle on cellular DNA where a link mutates, which can be a precursor to cancer.

• The commentary refers to health ‘nasties’ produced by changes to DNA caused by radiation, such as DNA mutations leading to cancer and other illnesses. According to Busby, research indicates that a cell can repair mutations from a single radiation ‘hit’, but two hits to a single cell inside a 10-hour period may result in failure to repair. Such events are unlikely from external radiation but may occur from internally absorbed radiation.

• The clip uses powerfully persuasive visual language to remind its audience of the dangers of atomic energy. The image of a nuclear wasteland is reinforced through the dramatic use of a newspaper headline ‘The Atomic Plague’ emerging on the screen. Distressing images of very sick children, some in pain and all of whom have been affected by radiation fall-out, prepare the audience for Busby’s warning about dangers of radiation.