7 no 2, 1999
By Elizabeth O'Brien,
Coordinator, The LEAD Group Inc.,
Q: What is in ceiling void dust?
3. Q: What are the usual amounts of these contaminants in ceiling dust?
4. Q: Why is
lead a good "marker" contaminant?
5. Q: How does ceiling void dust get into the living spaces of homes? A: See the factsheet Lead Safe: Lead in Ceiling Dust.PDF by the Lead Reference Centre (LRC - within the NSW EPA) which mentions, among other things, water damage to ceilings which may cause ceilings to crack or collapse.
6. Q: What is a "safe" or "acceptable" level of lead in ceiling dust? A: Jason Bawden-Smith, lead assessor of JBS Environmental, answers this question with the following statement on his analysis reports:
"Ceiling Dust Biohazard
Levels (parts per million)
"Ceiling dust only poses a health risk to occupants, especially pre-school children, if the lead dust is accessible, that is:
"Health risk is also related to the amount of dust present."
To give some idea of how much lead needs to enter the living areas of a house for there to be a contamination problem, another lead assessor (Graeme Waller of Graeme Waller and Associates) informed a ceiling dust removalist that just 2 tablespoons of ceiling dust with a concentration of 2,800 ppm (2,800 mg/kg) would contaminate a room and just 2 cups of the same dust would contaminate a whole house. Graeme uses an "acceptance criteria" of 1 mg of lead per square metre of floor - anything above this is "contaminated". A third lead assessor, Fred Salome of CTI Consultants, also prefers the United States standards that have been set for floor wipes inside a home. If the ceiling void is going to become a floor (for instance in an attic room) then the dust should be vacuumed to give any chance of complying with the clearance level of 1mg of lead per square metre. According to Fred, if the ceiling dust is going to be disturbed (eg when a ceiling is demolished) then the dust should be vacuumed because ceiling dust is always contaminated, and testing it is an unnecessary expense. The NSW EPA's publication Significant Risk of Harm from Contaminated Land (released April 1999) advises that an appropriate expert be consulted in relation to dust on contaminated land.
7. Q: Does it make a difference that the lead in ceiling dust is always found in combination with other contaminants? A: "Yes" it is significant that lead is always found with other contaminants in ceiling dust because some contaminants are synergistic ie the effect of the two together is greater than the sum of the effects of each on its own. Mercury and lead are synergistic for example. In a study by Schubert, Riley and Tyler ("Combined Effects in Toxicology a Rapid Systematic Testing Procedure: Cadmium, Mercury, and Lead", Journal of Toxicology and Environmental Health, 4: 763-774, 1978) male rats were injected with an LD1 (lethal dose for one) of lead ie, the amount of lead that, when injected into 100 male rats would, on its own, normally kill only one of the rats. When an LD1 of lead was injected in combination with an LD1 of mercury, all of the rats died. This is called the LD100 (lethal dose for 100). Thus LD1 lead + LD1 mercury = LD100 lead with mercury.
8. Q: How
much lead is in ceiling void dust in Sydney?
Levels of Heavy Metals in Sydney Ceiling Dusts, that have been reported to The LEAD Group's advisory service between June 1995 and June 1999
Published Results for Heavy Metals in Sydney Ceiling Dusts
References to the table of ceiling dust results:
Bawden-Smith, Jason (1992) Environmental Lead Contamination - The Mort Bay [section of Balmain] Pilot Study, Masters Thesis, Applied Science in Environmental Studies, University of NSW, Sydney, Australia. Whicker, C.L.; Hayes, W., Khoo, C.S. and Bhathal, R.S. (1997) Heavy Metals in Ceiling Dust of Some Sydney Houses, New South Wales, Australia, in "Journal and Proceedings of the Royal Society of NSW", Sydney, Australia, Vol.130 Parts 3-4, 65-78. Woodward-Clyde (1999) Remediation Action Plan, Dulux Cabarita, Sydney, Australia] Notes: The Woodward-Clyde report noted that homes assessed in the area had a ceiling dust lead loading of around 35 mg/m2. The Whicker study also published ceiling dust levels of copper (range 57 - 517 mg/kg, mean 150 mg/kg) and zinc (range 97 - 3664 mg/kg, mean 1027 mg/kg).
9. Q: Is ceiling void dust a health risk and who could determine this? A: Looking at the above list of what can be in ceiling dust and at the table showing what has been measured to be in ceiling dusts in Sydney, the precautionary principle would indicate that we must assume ceiling void dust is a health risk until proven otherwise, especially considering the following points:-
In particular, lead assessors and the Senior Environmental Health Officer at South Eastern Sydney Public Health Unit concur that ceiling dust, if disturbed or falling into living spaces, is a health risk, due to the lead alone. The risk is that current or future resident young children will pick up the lead dust off the floor and other surfaces and their hand-to-mouth activity will provide the pathway for lead poisoning. For adults, the more usual pathway for lead poisoning is inhalation, so it is safe to assume that there is a lead health risk for any adult breathing in large amounts of ceiling dust, such as roofers or ceiling repairers who do not use respiratory protection. The lead health risk to these workers would easily be determined by blood lead testing, which could be carried out by individual workers, organised by employers, done through GP's or at the Workers Health Centre, or carried out as a research project by WorkCover Authority NSW (though this is unlikely with the WorkCover redundancy program in full swing).
It would seem that the most pressing research need to answer the health risk question in relation to other health risks from ceiling dust in Sydney is to look at the particulates issue (especially fine particulates (PM10) and ultra-fine particulates (PM2.5)). Ceiling dust is variously described as "like talcum powder" or "like flour" or, "you'd be amazed at the haze inside ceiling voids on a windy day!" The Whicker study referred to above, found that around 20% of the mass of ceiling dusts around Campbelltown was in the particle range of less than 53 microns [which is approximately the width of a human hair]. The lead concentration in this particle range was higher than for larger particles. According to a new brochure from The Australian Lung Foundation, called Wood Smoke, Air Pollution and Your Health:
"When you breathe in high levels of air-borne particles from burning wood, motor vehicle exhausts or industrial emissions, your health can be seriously affected. People who already suffer from conditions such as asthma, chronic bronchitis, emphysema or heart disease are especially at risk. So are the very young and very old. Each year in Australia, lung disease and ill-health resulting from air pollution, lead to 9 million lost days of work or social activity, and cause about 1000 preventable deaths."
Increased cancer risks due to cadmium and arsenic as have been found around the Boolaroo lead smelter, should also be investigated.
The possibility of asbestos fibres from in situ or since-removed asbestos cement roofs would seem to be a special health risk from some ceiling dusts. Asbestos is not a cumulative poison and even a single exposure should be avoided if at all possible.
As for which government agency is most appropriate for answering the question of whether ceiling dust is a health risk, this would be either the federal or state health or occupational health and safety agencies. See the "Ceiling Dust Removalist Case Study" for the clear answer from WorkCover NSW that exposure to ceiling dust (either by breathing it in, ingesting it or absorbing it through the skin) should be avoided. Anyone who observes a worker who has failed to protect himself from ceiling dust exposure is entitled to report the incident to WorkCover NSW (phone 131 050). Public Health Regulations may have something to say about ceiling dust. The National Occupational Health and Safety Commission (NOHSC - previously Worksafe) can write a standard or code of practice for, say, handling ceiling dust, but NOHSC cannot ensure that the code is followed. It would be up to the state agency to take it up.
10. Q: Is ceiling void dust an environmental problem and who controls this? A: When ceiling dust is permitted to escape from the void and enter the living space, or the outside of the building, there will then be opportunities for it to contaminate air, soil, street-dusts, sewage and stormwater. Councils have a mandate to control pollution of air, soil and stormwater, but council staff need evidence that it's happening (eg be called out and attend the site at the time) and evidence that the dust etc being dropped in gutters etc is contaminated. It is a violation of the Clean Waters Act to pollute waters at all, or to put something in a position where it might pollute stormwater. The NSW Environment Protection Authority (EPA) controls licences for waste facilities and the EPA has licensed the Australian Refined Alloys (ARA) secondary lead smelter in Alexandria (phone 9516 5099) to accept ceiling dust waste, as the lead in the dust can be recycled. Building debris needs to be separated out from the dust as it harms the ARA equipment.
11. Q: When
should ceiling void dust remain undisturbed?
When should ceiling void dust be removed?
Demolishing ceilings or cavity walls
Installing insulation or new electrical wiring
Working in the ceiling cavity for any reason
"Water damage may cause ceilings to crack or collapse "Assume dust in pre-1970 houses contains lead unless tests prove otherwise "Have lead dust removed from your house "Do-it-yourself ceiling dust removal is not recommended - it's dirty and dangerous and requires special equipment. Hire a professional."
13. Q: Is
there any government requirement that ceiling dust must be removed?
For houses in the Sydney Noise Insulation Project (SANIP) area, the project management (federal government agency) took advice from the environmental consultancy DASCHEM (Melbourne) that required that ceiling dust was removed in every house prior to house demolition and prior to installation of insulation. "All other building work resulting in penetrations to ceilings and/or walls is to be carried out after the dust removal had been completed", according to the Procedures Used in the Sydney Aircraft Noise Insulation Project (these specifications are only for the purpose of SANIP though the ceiling dust contractors who worked on SANIP tend to still use them).
"With the introduction of the Integrated Development Assessment Legislation in 1998, all NSW councils were obliged to review their standard conditions for DA's [Development Applications]", so in the case of work to be carried out which requires a DA, for instance, in the Southern Sydney Regional Organisation of Councils (SSROC) area, member councils are "strongly encouraged to adopt the conditions [Reference: SSROC - Standard Environmental Conditions for Development Applications] in as near to the current form as possible to encourage cross-regional consistency." The "Instructions for Use" section of the reference quoted above and below warns: "Under no circumstances should any of these conditions be placed on a DA without consideration as to whether they apply to the development proposed." Relevant SSROC standard conditions for residential properties (and all other properties) undergoing demolition/remediation include:
"13 Demolition and disposal
of materials incorporating lead paint Prior to demolition of buildings constructed
before 1970, the applicant shall submit a Work plan prepared in accordance with Australian
Standard AS2601 - 1991, Demolition of structure by a person with suitable expertise
and experience. The Work Plan should outline the identification of any hazardous
materials, including surfaces coated with lead paint, method of demolition, the
precautions to be employed to minimise any dust nuisance and the disposal methods for
"14 Lead contaminated material post-removal requirements Following demolition activities, soil must be tested by a person with suitable expertise, to ensure the soil lead levels are below acceptable health criteria for residential areas. Full certification is to be provided to Council prior to final inspection."
What are the occupational health and safety protocols for ceiling dust extraction?
As mentioned above, if ceiling dust is to be removed as a result of a DA involving demolition in which a council officer determines that a condition such as SSROC's Standard Condition 13 is required, then respiratory devices would be worn and work practices from WorkSafe's Control of Inorganic Lead at Work would be adopted.
According to the Procedures Used in the Sydney Aircraft Noise Insulation Project [SANIP] (which specifications are only for the purpose of SANIP), in addition to the respiratory device being worn (after the worker is trained in its use), the following specifications are used during ceiling dust removal:-
All employees directly involved in the removal shall wear disposable overalls fitted with hoods and must at all times keep their suits fully on and in good condition;
Personal monitoring of all employees directly involved with the removal conforming to AS3640 Workplace Atmospheres method for sampling and Gravimetric Determination of Inspirable Dust;
The entire ceiling space and bagged wastes are to be sprayed with a PVA solution applied by an airless spray prior to removal from the ceiling space:
Personal decontamination procedures are to be followed and will involve spraying down of disposable suits with the PVA solution in the ceiling space, and washing hands and face with clean water outside the building with all waste water directed to sewer;
All employees involved in dust removal shall adopt good hygiene practices and ensure hands and faces are thoroughly washed before leaving the site and prior to smoking or eating;
All employees entering the ceiling space within 1 hour of dust removal shall wear approved respiratory protection conforming to AS1716;
15. Q: What
special equipment is needed to safely remove ceiling dust?
What are the potential health risks to people carrying out ceiling dust removal?
17. Q: What are
the potential health risks to people working in ceiling voids or cutting into ceilings if
the dust is not first removed?
18. Q: What are
the potential health risks to residents when ceiling dust is removed?
What are the government requirements regarding disposal of ceiling dust?
20. Q: Can
the lead in ceiling dust be recycled?
21. Q: When
and why did the ceiling dust extraction industry begin?
22. Q: How
big is the ceiling dust extraction industry in Sydney?
23. Q: How many houses have had their ceiling dust extracted? A: A conservative estimate would be 5000, over half of which were paid for by the Federal Government in the SANIP.
24. Q: What
are the government requirements regarding licensing of ceiling dust contractors?
25. Q: What
do you need to do to set yourself up as a ceiling dust removalist?
26. Q: How
would licensing of ceiling dust removalists help the home-owner?
27. Q: Could
ceiling dust removalists be licensed by the EPA, WorkCover, or Department of Fair Trading
28. Q: What
do government departments do when they need to employ ceiling dust contractors?
The Sydney Aircraft Noise Insulation Project (SANIP), a federal government project, has resulted in one ceiling dust removal company being on a list of approved contractors for SANIP work and 5 other ceiling dust removal companies being sub-contracted by approved contractors on the SANIP list.
The Broken Hill Environmental Lead Centre project (part of the NSW Health Department) has approved of 3 companies to carry out lead removal work in the lead mining town of Broken Hill but most of the ceiling dust work is sub-contracted by the three companies, to Nobac Cleaning Pty Ltd.
The Hunter Region office of the NSW Department of Public Works and Services (Hunter DPWS) has accredited 6 companies to carry out ceiling dust removal work around the lead zinc smelter in Boolaroo, in a remediation program being managed by the North Lake Macquarie Environmental Health Centre (part of the NSW Health Department). Hunter DPWS specifies in the contracts, the procedures to be used for the ceiling dedusting.
Other government departments are still overcoming the problem, for example:
29. Q: Is
Standards Australia currently writing or planning to write a standard on ceiling dust
removal, including WHEN to remove dust and how to test it?
30. Q: Is there an industry association for ceiling dust removalists and what does it say about standards and licensing? A: [This answer was revised in July 2005] Yes, The LEAD Group mentored the development of the Australian Dust Removalists Association (ADRA) which began in 1999 and was incorporated as an association on 17 November 2000. See www.adra.com.au for their Code of Practice and Contact Details of Member Companies to find an ADRA member near you. If there is no ADRA member near you, try to find a contractor who will remove ceiling dust by looking in the phone book or local newspaper ads and let them know about ADRA so that ADRA can determine if they comply with the Association's criteria for membership and invite them to join if compliant. Potential new members of ADRA should Email the Association or Phone ADRA: (02) 9716 0966 Or Contact Global Lead Advice & Support Service Freecall 1800 626 086 Email
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Updated 10 October 2011