With reference to the breast cancer cluster which led to the evacuation of the Australian Broadcasting Corporation’s studios in Toowong, Queensland:

(1)   What causal role did extremely low frequency electro-magnetic fields (ELFEMF) have.

(2)   Has ELFEMF been eliminated as a cause or contributory factor; if so, on what grounds.

(3) (a)   What were the ELFEMF levels measured in the studios; and (b) how much higher than background ELFEMF were the levels.

(4) (a)   When were those measurements taken; (b) exactly where were they taken; and (c) by whom.

(5)   What are the ELFEMF levels to be expected in a media studio.

(6)   Do ELFEMF levels affect melatonin production; if so: (a) how; and (b) how might this relate to breast cancer.

(1)   and (2) ELF EMF is not a known causative agent for breast cancer. It cannot be determined whether or not it played a role in this case. The official investigation of the Toowong cluster by an expert panel ruled that ELF EMF was unlikely to be a cause. “It was highly unlikely that this increase was caused by exposure during work on the Toowong site to radiofrequency electromagnetic fields, extremely low frequency electromagnetic fields, ionising radiation or chemicals known or suspected to cause breast cancer.” Ref: “Breast Cancer at the ABC Toowong Queensland - Final Report” (2007), p 40. http://abc.net.au/corp/pubs/documents/breast_cancer_toowong_june2007.pdf

(3)  

(a)   The final report of the expert panel summarises the results of the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) measurements: “During the walk-through, the magnetic fields generally measured under 2 milliGauss (mG), but there were occasional spikes to between 5 and 10mG and rare spikes above 15mG. Average levels in different work areas were all below 2mG with the exception of the kitchen on the first floor of the TV building (2.5mG), the news control room on the ground floor (3.5mG) and the ground floor equipment room (21.1mG). The level in the general office area, in which most newsroom staff members worked, was 1.2mG. The average measurement was 0.87mG. “All staff member measurements on the ground floor of the TV building were less than 2mG and most were less than 1mG. The average was 0.34mG. Most staff member measurements on the first floor of the TV building were less than 2mG but there were several spikes, two in close proximity, reaching just under 9mG. The average was 0.56mG. “In the radio building, the baseline magnetic field was about 2mG with periods of increase to about 4mG and occasional peaks to 6-8mG and to between 15 and 20mG. The average was 2.03mG.”

(b)   These are similar to levels that would be expected in many residences. Natural background levels away from electrical power distribution will be less than 0.1 mG*. *mG: milligauss, unit of magnetic flux density commonly used in Australia and USA in reporting environmental levels of magnetic field. The equivalent metric (SI) unit is the microtesla (µT) which is a unit 10 times larger.

(4)   Measurements were taken on 18 December 2006 between the hours of 11:00 am and 3:00 pm. Spot measurements were carried out on the ground and first floors of the TV building by doing a walk-through survey of the majority of areas accessible to staff. Personal monitoring was carried out to ascertain the magnetic field exposure of three staff members (one each from the ground and first floor of the TV building and one from the radio building). The measurements were carried out by a scientific officer employed by ARPANSA.

(5)   At locations where personnel sit or work, ELF EMF levels in a media studio are not expected to be different from other office environments. Sources of ELF EMFs other than those related to media production are likely to dominate in most circumstances.

(6)   There is little experimental evidence to indicate that ELF EMF at levels commonly encountered affect melatonin production in humans. A recent World Health Organization publication, stated: “The results of volunteer studies as well as residential and occupational studies suggest that the neuroendocrine system is not adversely affected by exposure to power-frequency electric and/or magnetic fields. This applies particularly to the circulating levels of specific hormones of the neuroendocrine system, including melatonin, released by the pineal gland, and a number of hormones involved in the control of body metabolism and physiology, released by the pituitary gland.” and “Most laboratory studies of the effects of ELF exposure on night-time melatonin levels in volunteers found no effect when care was taken to control possible confounding.” Ref: “Extremely Low Frequency Fields Environmental Health Criteria Monograph No.238”, (2007), §6 Neuroendocrine system, conclusions, http://www.who.int/peh-emf/publications/elf_ehc/en/index.html. Other factors, such as night-time exposure to light and undertaking of shift work, are believed to influence melatonin production. There is also inconsistent evidence relating differing melatonin levels to varying risks of breast cancer.