Breathing asbestos fibres can be dangerous.

When disturbed, asbestos breaks down into fibres up to 1,200 times thinner than a human hair. When inhaled, they become trapped in lung tissues. Medical research tells us that up to 30 years after inhalation, asbestos fibres can cause lung cancer or mesothelioma, a related terminal cancer of the tissue lining the chest cavity.

Because asbestos is a naturally occurring mineral and has been so widely used in manufactured products, including automobile brake linings, it can be found almost everywhere. Trace amounts are in the air we breathe every day. Most of us have asbestos fibres in our lungs.

On the other hand, there's no known safe level of asbestos exposure. That's why medical, environmental health and regulatory organizations stress the need to protect health by minimizing exposure to airborne asbestos fibres accumulate at elevated levels. Elevated levels result from uncontrolled disturbances and removals of asbestos-containing materials.

Asbestos is not always an immediate hazard. In fact, if asbestos can be maintained in good condition, it is recommended that it be left alone and periodic surveillance performed to monitor it’s condition. It’s only when asbestos containing materials are disturbed or the materials become damaged that it becomes a hazard. When the materials become damaged, the fibres separate and may then become airborne. In the asbestos industry, the term ‘friable’ is used to describe asbestos that can be reduced to dust by hand pressure. ‘Non-friable’ means asbestos that is too hard to be reduce to dust by hand. Non-friable materials, such as transit siding and floor tiles are not regulated provided it does not become friable. Machine grinding, sanding and dry-buffing are ways of causing non-friable materials to become friable.

How concerned should I be?

If the asbestos is in good condition and stable, your risk on health effects is relatively low. However, if the asbestos is damaged, there are three things seem to determine your likelihood of developing one of these asbestos related diseases:

1. The amount and duration of exposure - the more you are exposed to asbestos and the more fibres that enter your body, the more likely you are to develop asbestos related problems. While there is no "safe level" of asbestos exposure, people who are exposed more frequently over a long period of time are more at risk.
2. Whether or not you smoke - if you smoke and you have been exposed to asbestos, you are far more likely to develop lung cancer than someone who does not smoke and who has not been exposed to asbestos. If you work with asbestos or have been exposed to it, the first thing you should do to reduce your chances of developing cancer is to stop smoking.
3. Age - cases of mesothelioma have occurred in the children of asbestos workers whose only exposures were from the dust brought home on the clothing of family members who worked with asbestos. The younger people are when they inhale asbestos, the more likely they are to develop mesothelioma. This is why enormous efforts are being made to prevent school children from being exposed.

Because each exposure to asbestos increases the body burden of asbestos fibres, it is very important to reduce and minimize your exposure. Removing or stabilizing the asbestos is the best way to minimize the risk. However, it can be dangerous for the homeowner to do this without proper equipment and skills. The homeowner should be fully informed before trying to


Chronic Effects (Noncancer):

• Chronic inhalation exposure to asbestos in humans can lead to a lung disease called asbestosis, which is a diffuse fibrous scarring of the lungs. Symptoms of asbestosis include shortness of breath, difficulty in breathing, and coughing.  Asbestosis is a progressive disease, i.e., the severity of symptoms tends to increase with time, even after the exposure has stopped.  In severe cases, this disease can lead to death, due to impairment of respiratory function.
  Other effects from asbestos exposure via inhalation in humans include pulmonary hypertension and immunological effects.
  Feeding studies in animals exposed to high doses of asbestos have not detected any evidence of adverse toxic effects.

Reproductive/Developmental Effects:

• No studies were located on the developmental or reproductive effects of asbestos in animals or humans via inhalation.
  Birth defects were not noted in the offspring of animals exposed to asbestos in the diet during pregnancy.
• No effects on fertility were observed in animals exposed to asbestos in the diet during breeding, pregnancy, and lactation.

Cancer Risk:

• A large number of occupational studies have reported that exposure to asbestos via inhalation can cause lung cancer and mesothelioma (a rare cancer of the membranes lining the abdominal cavity and surrounding internal organs). 
• Individuals who smoke and are also exposed to asbestos have a greater than additive increased risk of developing lung cancer. 
• Several occupational studies have reported an increase in gastrointestinal cancer from inhalation exposure to asbestos and subsequent oral ingestion. 
• Long- and intermediate-range asbestos fibres (>5 micrometers (µm)) appear to be more carcinogenic than short fibres (<5 µm). 
• Several epidemiological studies have found an association between asbestos in drinking water and cancer of the esophageus, stomach, and intestines; however confounding factors and the short follow-up time relative to the long latent period for tumour formation make it difficult to interpret the results. 
• A series of large-scale lifetime feeding studies in animals reported that intermediate-range asbestos fibres increased the incidence of a benign tumour of the large intestine in male rats, while short-range asbestos fibres showed no significant increase in tumour incidence.
• EPA considers asbestos to be a human carcinogen (cancer-causing agent) and has ranked it in EPA's Group A.
• EPA uses mathematical models, based on human and animal studies, to estimate the probability of a person developing cancer from breathing air containing a specified concentration of a chemical. EPA calculated an inhalation unit risk estimate of 2.3 × 10^-1 (fibers/cm³)^-1. EPA estimates that, if an individual were to continuously breathe air containing asbestos at an average of 0.000004 fibers/cm³ over his or her entire lifetime, that person would theoretically have no more than a one-in-a-million increased chance of developing cancer as a direct result of breathing air containing this chemical. Similarly, EPA estimates that breathing air containing 0.00004 fibers/cm³ would result in not greater than a one-in-a-hundred thousand increased chance of developing cancer, and air containing 0.0004 fibers/cm³ would result in not greater than a one-in-ten-thousand increased chance of developing cancer. 

Hazardous Substances Safety Link

Asbestos Walls and Roof Sheets

Background

1.    From the 1940 until early 1980 asbestos was a constituent of many popular building materials in Queensland.

2.  It most common use was in the manufacture of asbestos-cement corrugated and flat sheets for roofing and
    walls. This product is more commonly known as fibro.
3.  Today, many Queenslanders are concerned about the health risk caused by fibro in old houses.
4.  Medical experts maintain that intact fibro in roofing and walls poses no health risks to occupants.
5.  In most circumstances, when fibro is in good condition it is best left undisturbed so as to avoid the possibility
    of releasing asbestos fibres into the air.
6.  Any person contemplating removing fibro sheets in old Queensland houses should exercise caution.
7.  A health risk is created when these sheets are damaged, generating asbestos fibres which can be inhaled.

Health Risks

1.   Asbestos presents a health risk only when it is in the form of airborne dust which can be inhaled.

2.  Inhalation of asbestos fibres has been linked to respiratory diseases such as asbestosis, mesothelioma and
    lung cancer. These diseases are characterised by long latency periods. It may take up to 40 years between
    initial exposure and the onset of disease.
3.  The risk is related to the dose. Most people who suffer from asbestos-related illnesses are usually those who
    have worked with asbestos products and been exposed to asbestos dust over a number of years.
    Nevertheless, it is good practice to minimise exposure to asbestos by taking precautions when asbestos
    products are handled.

1.       To inhibit the release of asbestos fibres, the fibro sheets should be wet with water once they are removed, stacked, and then wrapped in plastic. Wall sheets can be sprayed with water prior to removal.

2.       Any asbestos-cement residue remaining in the building should be cleaned using an industrial vacuum cleaner approved for asbestos use.

3.       Once removed, the fibro sheets should be disposed of as soon as possible.

4.       Prior to removing fibro sheets, homeowners and contractors should get advice from the local council about the correct procedure for disposing of the material.

Where else asbestos cement is found

1.       Asbestos cement is found in flat sheets, profiled sheets, corrugated sheets, shingles, compressed sheets, rigid board insulation and building products such as pipes and guttering containing asbestos in cement.

In most Queensland homes, asbestos is found only in fibro roofs, walls and soffits. In old brick houses fibro was also popular for soffits and internally for kitchens and bathrooms.

For more information contact Workplace Health and Safety Queensland- Phone: 1300 369 915

                                               Or Email us at smartroofing@optusnet.com.au

         

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