Asbestos: dangerous and still present
Water pipes made of asbestos concrete - a real danger?
Deaths after over 40 years and serious occupational diseases: Asbestos, once a much vaunted material, has been banned for years and yet has lost none of its horror. It still occurs in the environment. And time and again, old drinking water pipes made of asbestos cement make the headlines. A major problem is the disposal of old pipes, which can only be carried out by specialists. But what about pipes that have been in operation for decades and are still in use?
What is asbestos?
Asbestos is a collective term. The heat- and acid-resistant mineral comprises six different fibrous silicate minerals that occur naturally in rock. They were used by man for building materials, including asbestos cement. Typical for this material are the tiny fibres that can remain in the human body for a very long time.
The high danger of asbestos has been known since the last century, but it was only in 2005 that this substance was banned. It must be disposed of under strict occupational safety regulations. Asbestos is to be completely removed in the EU by 2035.
Why is asbestos dangerous?
Already in 1900, the so-called pulmonary asbestosis, a fatal lung hardening, was proven. The cause of this is the inhalation of fine asbestos fibres, which remain in the lungs for years. The irritation of the lung tissue leads to its hardening and endangers the lung function. Asbestos also causes cancer. Certain asbestos fibres, such as crocidolite, are even considered extremely carcinogenic. This poses an enormous health hazard.
Four diseases caused by asbestos are recognised occupational diseases: pulmonary asbestosis, pleural asbestosis, lung cancer and so-called mesotheliomas. These are tumours in the pleura and peritoneum that can arise from even brief exposure to asbestos and offer little chance of survival. Asbestos is also suspected to cause other types of cancer. For this reason it is being discussed whether the ingestion of asbestos fibres through drinking or eating can possibly cause cancer. This question has not been clearly answered.1
How and where was asbestos used in water pipes?
Especially in the 50s and 60s of the last century asbestos cement was used for the laying of drinking water pipes. An estimated 30,000 km of drinking water pipes made of asbestos were used, mainly in Schleswig-Holstein. Today, this material may no longer be used.
What are the possible dangers?
The question of whether drinking water pipes made of asbestos cement pose a current health risk is a matter of ongoing debate. The fact that cement can be dissolved in soft water by mechanical contact with water and by dissolved salts and acids speaks for a danger.
As a result, large quantities of asbestos fibres could contaminate drinking water. This assumption is based on a drinking water analysis carried out by the Fraunhofer Institute in 1983, which found up to 1.57 million freely dissolved asbestos fibres per litre in drinking water (umweltanalytic.com).
The study did indeed have consequences: The German Federal Health Office developed a method for avoiding asbestos fibres in drinking water that was proposed by the highest environmental authority in the USA as the "best available technique". 2
Doubts remain, however. It is still unclear whether orally ingested asbestos fibres are as dangerous as inhaled fibres. It is debatable whether the asbestos fibres are excreted by the gastrointestinal tract or whether they migrate in the body. 3
In any case, however, the laying of new asbestos-cement pipes has been prohibited since January 1, 1995. Older pipes may continue to be operated. 4
To this day, the WHO and the Federal Health Office are of the opinion that the operation of asbestos cement pipes does not pose a risk if the "transported water complies with the Drinking Water Ordinance". Therefore, water must not be too "soft".
The Drinking Water Ordinance requires that the pH value of the water at the waterworks outlet must be greater than 7.7. The highest possible pH value should keep the lime solubility (calcite dissolving capacity) as low as possible. In this way the risk of asbestos fibres being released can be minimised. 4
In contrast to Germany, in the USA there are limit values for asbestos in water set by the environmental authority EPA to protect the health of the population.
Danger when showering
If there is indeed a concentration of asbestos fibres in the water, there could also be a risk from inhaling asbestos fibres: The American Environmental Protection Agency (EPA) classifies showering with asbestos-contaminated water as highly damaging to health. Asbestos fibres could float in the air (source: umweltanalytic.com).
Caution with blocked drains!
It can become critical if pipes made of asbestos cement have been used in the domestic area. If damage should occur here, for example due to a blocked drain pipe, it is essential that a specialist company be commissioned. If pipes have to be cut, they know the strict occupational safety regulations for asbestos removal. 6
Where can I find help?
The local water supplier can provide information about the presence of water pipes made of asbestos cement. If property owners or businesses want more detailed information on how to deal with the hazardous substance asbestos cement in drinking water pipes, they can get help from the German Association of the Gas and Water Industry (dvgw), which has compiled recommendations on how to deal with drinking water pipes made of asbestos cement in an information sheet 2011.
What protects against asbestos?
Asbestos fibres in drinking water can be retained by nanofiltration. Activated carbon filters also protect against possible asbestos fibres in water. In areas where there are older drinking water pipes made of asbestos cement, the use of an activated carbon filter can therefore be useful. Reverse osmosis can also be used to remove asbestos fibres.
Asbestos in cement pipes is considered largely harmless as long as the pipes are intact and are not decomposed by mechanical influences or lime-dissolving water. There are different opinions about the danger of asbestos fibres in water. Filtration, for example by activated carbon filters, can remove asbestos fibres from the water.
Related articles and products
- Final report on the research project Handling of asbestos cement pipes, IKT Institute for Underground Infrastructure, https://www.ikt.de/website/down/f0078langbericht.pdf
- German Bundestag, printed matter http://dipbt.bundestag.de/doc/btd/11/056/1105604.pdf
- Der Spiegel, 1989, https://www.spiegel.de/spiegel/print/d-13495344.html
- lfu Bavaria, https://www.lfu.bayern.de/wasser/merkblattsammlung/teil1_grundwasserwirtschaft/doc/nr_187.pdf
- German Wave, https://www.dw.com/de/asbest-krebsgefahr-kann-in-jeder-wand-lauern/a-45484320