ABC Toowong
Hazards assessment and further monitoring requirements
Geza Benke, PhD
Centre for Occupational and Environmental Health Department of Epidemiology and Preventive Medicine
Monash University Victoria
Brief
This report aims to document the history of the ABC Toowong site with respect to hazards possibly causative of breast cancer. The hazards investigated were in part identified through information from the work histories collected by Professor Malcolm Sim and also in part from a walk through survey undertaken by Dr Benke on Monday 13th November 2006. The information in this report should be used to direct further environmental monitoring where considered necessary and to comparatively assess risk from all possible environmental hazards on the site.
1. Site history: Overview
Prior to the construction of the first ABC buildings on the site in 1959, the site spanned two residential premises, Middenbury House and Sydney House. The plans of 1/5/1959 clearly show that the TV building was constructed over a former driveway/car-park to the original residences. This history eliminates the possibility that the TV building was constructed on a former orchard (possible pesticide residues) or an industrial site (unknown radiation source or contaminated site).
The TV building was constructed in five stages, with the initial stage in 1959, stage two in 1961, stage three about 1967, stage four in about 1985 and the latest refurbishment over the former car-park in 2000. The current TV building is constructed on a concrete slab and does not have any basement levels.
Prior to 1985 the TV News group was broken across a number of locations i.e. under the lower ground and off site. Management of Radio was at Sherwood Road prior to 1985. In 1985 TV News was located in the First Floor of the TV Building. In 2000, following an extension of the ground floor, that involved the inclusion of the former river side car-park, the TV News group was relocated to the ground floor. The current occupiers of the first floor are the Digital group that went “On-line” about 2003, but were formed in 1997. The Digital group formed as a small subunit in 1997 and were part of the Radio News group for the first 5 to 6 years of operation. Radio News has been located on the ground floor since 1985, and was joined by TV News after the 2000 refurbishment.
2. Physical Hazards
2.1 Ionizing radiations
There is no documented history of the use of ionizing radiation on the site. Given the nature of the operation of the ABC at Toowong it is also unlikely any irradiating apparatus i.e. X-ray or industrial radiography machines, or radioisotopes, have been ever used/operated on the site. Radiation contamination could only be possible on-site if the original (or subsequent) construction material had been inadvertently contaminated (an extremely unlikely occurrence) prior to it arriving on-site. Radon gas exposure is unlikely, but possible. Radon gas and it’s progeny usually builds-up in cellars and well sealed buildings and a survey undertaken by ARPANSA about 20 years ago found that exposure inside Australian buildings and dwellings to radon is negligible.
2.2 Non-Ionizing radiations 2.2.1 Radiofrequency (RF)
Since this has been a TV and radio broadcasting and receiving site for over 40 years it has numerous RF communications devices located within its perimeter. The current RF sources are described in both the THL Australia report of 16th February 2004 and the EMC Technologies report B050401, 2nd May 2005. A history of the equipment on site prior to 1980 was not forthcoming. However, it appears that most of the equipment on site was added in the past twenty years due to advances in technology, with little replacement of older receivers and transmitters. It can be assumed that the current RF exposure levels are probably higher than at any time during the operation of the site, due to the incremental addition of RF sources.
The THL RF Hazard control document of 16th February 2004 indicates that the most prominent RF source on site is the 7 meter satellite dish on the TV Building rooftop, operating at 14 Ghz. The three VHF Comms, 3 metre antennae have high maximum power and operate between 168 and 172 MHz. Overall the RF sources on site cover a wide range of frequencies and power outputs. In these circumstances it is advisable to check the broadband exposures in the offices below.
The EMC RF survey clearly indicated that broadband exposure levels were well below the ARPANSA reference levels, as outlined in the 2002 ARPANSA standard for exposure to RF radiation between frequencies of 3kHz and 300GHz. In all the office work areas in the TV building the levels were below the detection limit of the survey meter (<2 V/m). This is not surprising in view of the RF sources currently in place and the known high directionality of these sources. Additionally, since the broadband measurements do not indicate any excess exposure to RF it is most unlikely any future narrow band measurements will result in excessive exposure results in the office areas.
The security card readers operate at only 125kHz , significantly lower than the other RF sources on site. The card readers can be categorized as low frequency (LF) sources compared to the other sources on site. The concern from staff was that if the hands were engaged in carrying books, bags or equipment, the employee would simply bring their chest in close proximity to the card reader and perhaps be exposed to intermittent high levels of RF radiation. The EMC report indicated that at 5 centimetre distance
from the card reader the levels were only about a quarter the reference levels. In addition, given the brief exposure periods over the course of a work-shift i.e. perhaps 1 to 2 minutes at most per day, the time-weighted average exposure should be extremely low.
2.2.2 ELF-EMF
The ELF-EMF (50/60 Hz) exposure has not been measured in the TV building. Given the high concentration of communications equipment in many of the workstations in this building, exposure is expected to be higher than in a normal office environment e.g. computers and Decart audio systems are located at many workstations, there are also large number of editing rooms with electronic equipment etc. The power requirement to the ABC Toowong site is clearly significant, given the site has its own substation. This indicates that there exists many potential power intensive sources and that power frequency currents, required for high ELF-EMF exposures are present.
3. Chemical Hazards
3.1 Asbestos
The construction of the TV building involved the use of materials containing asbestos.
These were primarily the use of AC sheeting, asbestos vinyl tiles and millboard.
Significant removal was undertaken in the late 1980s with a few small batches removed about 2000 (at the time of refurbishment of the ground floor and renovation of the air-conditioning system). Asbestos in the heater banks and asbestos containing millboard were also involved in the latter removals. All removal was undertaken by an approved asbestos removalist and all documentation required under Queensland OHS regulations are kept on site.
Generally, the removal of AC sheeting does not present a high risk for asbestos exposure, if the removal is undertaken by a competent removalist. It is also unlikely exposure to friable asbestos would be present in the office areas of the TV building at the times during removal given the requirement for containment in the Queensland regulations dating back to the mid-1980s.
3.2 Environmental Tobacco Smoke (ETS)
Smoking was banned inside buildings at the Toowong ABC site in March 1989. It is now impossible to assess the extent of passive smoke exposure in the work areas of the TV building in the 1980s. Recall of persons that may have worked in this environment would be unreliable and could not be compared with other office environments. Population smoking rates were higher in the 1980s and so an estimate of exposure based on the current number of smokers in the employ of the ABC today would probably be an underestimate.
3.3 Pesticides
Since the site was a residential premise prior to construction of the ABC buildings it is unlikely any pesticide contamination was present at the site pre-1960. Arrest-a-Pest has been the pest control contractor since at least the early 1980s. The pesticides of most concern are the organochlorines (OCs) comprising chemicals such as DDT, Lindane and Chlordane. This group of insecticides has a relatively long residual time in the environment (5 years) and they are weak estrogens which may increase breast cancer risk by mimicking endogenous estradiol. The pesticides of less concern are the
organophosphates, carbamates and synthetic pyrethrins, which have relatively short environmental residual times (days to a month at most) and do not accumulate in body tissue over prolonged time periods.
The use of OCs was discontinued in Queensland about 1995. Between 1985 and 1995 OCs were used in very limited quantity for termite control around the exterior of buildings and under slabs prior to construction. The use of OCs inside buildings and homes was discontinued in Queensland in the early 1980s. Synthetic pyrethrins have been predominantly used for termite control in the past 10 years. Following contact with Mr Chris Hill of Arrest-a-Pest it was confirmed that no significant quantities of OCs were used at the ABC Toowong site (Mr Hill has been in the employ of Arrest-a- Pest since 1989). Mr Hill could not comment on the use of OCs at the site pre-1980s.
3.4 Water
The water supply to the site is from the Brisbane community water supply and most unlikely to be contaminated. There has been no water testing undertaken from water taps at the site. Heavy metal contamination, such as arsenic, cadmium, chromium, lead, mercury or nickel is possible if the water piping has been contaminated by some outside source or there has been significant corrosion of old piping. Testing of the drinking water in accordance with the NHMRC Australian Drinking Water Guidelines 2004, could reveal if heavy metal contamination is present. Although we believe these measurements are unlikely to identify any heavy metal concentrations above the guideline standards, they should eliminate this as a potential source of toxic intake. It must also be emphasised that measurements undertaken in 2006 are unlikely to have much bearing upon the water quality of earlier years e.g. 1995 or 1985, since concentrations to some metals could change due to corrosion in the metal pipes etc.
3.5 Other chemicals, hydrocarbons and solvents
Concerns were raised that there may have been exposure to other chemicals, hydrocarbons and solvents via:
(i) Tanks removed from the car-park area in 2000
Two former petrol tanks were removed from the car-park in 2000. These tanks were disused since 1996 and remained in-situ for four years. This time period would have enabled any volatile hydrocarbons trapped in the tanks or soil to have successfully evaporated. There would only have been high-carbon hydrocarbons remaining at the time of removal, with little if any volatile hydrocarbons present. Soil measurements were taken at the time of the removal with the results showing no contamination found.
(ii) Cleaning of the air-conditioning system
Concerns had been raised about chemicals used for the cleaning of the air- conditioning system for the TV building. Contact was made with Mr Bruce Clayton of Haden, the air-conditioning contractors for the site. Mr Clayton confirmed that the condensate trays were cleaned with a common detergent to remove slime on an infrequent basis. This is a soap-based detergent and therefore not considered toxic. There is also routine maintenance undertaken on the ductwork that involves vacuuming also on an infrequent basis. The filters are not cleaned but replaced once the pressure drop exceeds 150 pascals, and this is normally required about once a year. The heat exchangers are
cleaned of grime on an infrequent basis by a chemical named “Coil and Filter cleaner AK’ manufactured by Sterile-Care Pty Ltd. The Material Safety Data Sheet (MSDS) was obtained for this product and indicated that the active ingredient was a Quaternary ammonium compound and that it also contained alkaline salts at a concentration of 90 grams per litre. Neither of these compounds are considered carcinogens or suspected carcinogens in the literature. Ammonium compounds have been linked with respiratory disease such as occupational asthma, and alkaline salts are considered skin irritants.
(iii) Ceiling tiles
The ceiling tiles in the ground floor of the TV building were installed during the refurbishment undertaken in 2000. These are Armstrong RH90 tiles manufactured in the USA in December 1997 with batch no. S3570B, recorded on them. Access to the MSDS of this product can be obtained via the Armstrong website: www.armstrong.com/home/us/en/. Prior to the refurbishment in 2000, Gyprock with vinyl coating ceiling tiles were fitted throughout the building since the 1970s. These products are unlikely to have any off-gassing of volatile organic compounds (VOCs) such as n-hexane, n- pentane, xylenes, toluene or 2-mthyl butane. Formaldehyde off-gassing has been a hazard in commercial office buildings using older style ceiling tiles, but this is almost certainly not the case in the TV building.
4. Recommendations for further monitoring
Recommendation 1:
Given that ionizing radiation is the only known environmental exposure that increases breast cancer risk, it would be prudent to undertake radiation dose rates, contamination monitoring and radon gas concentration measurements in the TV building. This should confirm whether radiation levels are at normal background or whether there has possibly been some contamination present from an as yet unknown source.
Recommendation 2:
An ELF-EMF measurement survey should be undertaken on the ground and first floor of the TV building. This should involve dosimetry to workers in various workstations on both floors.
Recommendation 3:
Water testing be undertaken in accordance with the NHMRC Australian Drinking Water guidelines 2004.
5. References
Hansen J. Breast cancer risk among relatively young women employed in solvent–
using Industries. Am J Ind Med 1999;36:43-47
McElroy J, Shafer M, Trentham-Dietz A et al. Cadmium exposure and breast cancer risk. J Natl Cancer Inst 2006;98:869-73
Tokunaga M, Land C, Tokuoka S et al. Incidence of female breast cancer among atomic bomb survivors 1950-1985. Radiat Res 1994;138:209-223
Weiderpass E, Pukkala E, Kauppinen T et al. Breast cancer and occupational exposures in women in Finland. Am J Ind Med 1999;36:48-53
Wells A. Breast cancer, cigarette smoking, and passive smoking. Am J Epidemiol 1991;133:208-210
APPENDIX 1. Specifications for measurements according to recommendations:
Ionizing Radiation
Surface contamination should be checked in the office areas of the ground floor and first floor of the TV Building with a Portable Contamination Meter fitted with an alpha/beta radiation probe. Dose rates are to be measured in the office areas with a calibrated dose-rate meter. Radon concentrations should be measured by use of a real- time radon monitor. In addition, dose-rate measurements should be measured at the air-conditioner filters to the building, as these are most likely to trap natural radioactivity from the air. Results are to be compared with the backgrounds in the Brisbane area.
Power Frequency EMF
For a survey of ELF-EMF exposure we suggest the use of EMDEX-II dosimeters to assess the time-weighted daily exposure of about four or five workers on the ground floor and a similar number on the first floor of the TV Building. It is important that personal measurements are ascertained as spot measurements alone will not be sufficient. A handful of measurements should also be undertaken with workers in the Woodhouse building and the Riverside Block (to act as controls). The results may then be compared with industry norms published in the Australian and international literature.
Spot magnetic field measurements should also be undertaken in the TV Building, particularly in the vicinity of the workstations where the personal dosimetry is undertaken. These measurements should indicate the main sources of ELF exposure.
Water Testing
The water testing should be undertaken according to the National Health and Medical Research Council- Australian Drinking Water Guidelines 2004. We suggest that samples be taken on the ground floor and first floor of the TV Building. The samples should be analysed for concentrations of arsenic, cadmium, chromium, lead, mercury, barium and nickel and compared with the health standards in Table 10.10 in section 10.8 of the Guidelines. We do not see any need to analyse the samples for organochlorine pesticides listed in Table 10.11 of the guidelines.
APPENDIX 2: Summary of Known and Suspected Occupational &
Environmental Breast Cancer Risk Factors and Exposures Assessed
Breast Cancer Risk Factor (known=K, suspected=S)
Source Exposure levels at
ABC_Toowong plausible?
Exposure Assessed?
Assessment of Current Exposure adequate?
Current Exposure at Level of
concern?
Ionizing Radiation (K)
Tokunaga et al, 1994
No. There have never been any known sources on site.
No. No. Unknown.
ELF (S) Laden and Hunter, 1998
Yes. Many sources present.
No. No. Unknown.
RF Broadband (S) Nil Yes. Many
sources present.
Yes. Yes. Not of
concern.
Pesticides for Termites (S)
Laden and Hunter, 1998
Possible exposure to OCs in the 1970s and 1980s.
No Not necessary.
Not of concern.
Asbestos (S) Weiderpass et al, 1999
Yes. Yes, by
clearance monitoring
Not necessary.
Not of concern.
ETS (S) Wells,
1991
Yes. No. Not
possible.
Not of concern.
Water (Metals?) (S)
McElroy et al, 2006
Possible. No. No. Unknown.
Solvents/Cleaning agents for AC system (S)
Hansen, 1999
Possible. No. Not necessary.
Not of concern.
Soil,
hydrocarbons (around underground tank) (S)
Weiderpass et al, 1999
No.
Hydrocarbons and
contaminated soil not likely to be airborne.
Yes, soil testing in 2000
Not necessary.
Not of concern.
