RADIOACTIVE clouds from two atomic tests at Maralinga were swept across the Nullarbor Plain to Adelaide, classified documents have revealed.
Despite repeated official denials the fallout was dangerous, levels recorded at secret sampling stations exceeded those now permitted under federal health standards.
The Advertiser has obtained classified documents which reveal radioactivity was detected in Adelaide, Woomera, Oodnadatta, Ceduna, Giles, Cook, Cleve, Leigh Creek, Tarcoola, Marree, Port Augusta and Mt Gambier after atomic bombs were exploded at Maralinga in 1956 and 1957.
Fallout from the first SA tests at Emu Field, 480km northwest of Woomera, as part of Operation Totem was not officially monitored, but The Advertiser understands air sampling devices in the Adelaide central business district also detected radioactivity.
Fallout from the first Totem explosion on October 15, 1953, heavily contaminated nearby cattle stations, particularly Welbourn Hill and Wallatinna, with station owners, their families, workers and desert Aborigines exposed to a mushroom cloud dubbed "The Black Mist".
Adelaide was hit by radioactive fallout from the final and biggest explosion of the four-bomb Operation Buffalo series on October 22, 1956, with further fallout detected 12 months later after three bombs exploded during Operation Antler. The contamination occurred when inversion layers either trapped the mushroom clouds and pushed them towards Adelaide or forecast winds changed direction and dispersed the clouds to the east, rather than north as planned.
The clouds were tracked across SA, Victoria, New South Wales and Queensland by RAAF aircraft, which became so contaminated they had to be cleaned at a special facility.
A national monitoring program established by the Menzies government in 1956 detected three nuclear byproducts strontium 90, caesium 137 and radioactive iodine in human and sheep bones, air samples, rainwater, soil, cabbages and flour in SA.
Similar results were obtained in Queensland, New South Wales, Western Australia, Victoria, the Australian Capital Territory, the Northern Territory and Tasmania.
Strontium 90 is one of the most dangerous nuclear fission byproducts. It has a half-life of 28 years and lodges in bone tissue, causing leukemia and cancer. It was still being detected when the national program of testing the bones of dead children and adults was officially stopped in 1971.
The compound continued to be detected in milk samples randomly collected from Adelaide and other capital cities until 1984. No official monitoring for strontium 90 has occurred since then.
Caesium 137, which causes cancers and birth defects, was detected in SA children and adults during a Royal Adelaide Hospital study in 1962.
The results of the study were secretly presented to the Atomic Weapons Tests Safety Committee, established to monitor radioactive fallout two years after the first atomic tests were held at Emu Field.
The AWTSC assembled official data to deny radioactive fallout was dangerous, leading to a confrontation with Adelaide University biochemist Hedley Marston, who secretly gathered contaminated air samples at Urrbrae and Roseworthy.
The committee then tried to stop Dr Marston from publishing a paper detailing how his air samples and contaminated thyroid glands from sheep and cattle proved the SA public had been exposed to strontium 90.
Four Adelaide hospitals the Institute of Medical and Veterinary Science, Adelaide Children's Hospital, the RAH and the Queen Elizabeth Hospital provided bones from dead children, including stillborn babies, for strontium 90 testing for 14 years. AWTSC chairman Sir Ernest Titterton told successive federal governments the levels were so low the radioactive fallout could not have endangered Australians.