Radon exposure

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Radiation exposure in Germany

The exposure to radon is the largest single contributor to the natural radiation exposure is of most people. Radon is a natural radioactive element in the natural decay chains occurs uranium and thorium. The gas, which mostly penetrates into houses from the underground, can, under unfavorable conditions, increase the activity of the room air so much that the risk of dying from lung cancer increases significantly.

Influence of radon on humans

Inhaling radon itself hardly increases the risk, because the noble gas is almost completely exhaled without having broken down in the body. The decays in indoor air are far more numerous. This also creates radioactive radon decay products , which attach to fine dust as heavy metal atoms, accumulate in the lungs and decay there.

Lung cancer from radon is a recognized occupational disease among uranium miners. In the early days of mining, it became known as Schneeberger Disease , which killed practically all miners in the area around Schneeberg in the Ore Mountains .

Mathematical estimates based on the incidence of lung cancer in miners have shown that radon causes around 5% of lung cancer deaths in Germany, in total that is around 1,900 deaths; for Europe, 9% of all lung cancer deaths and 2% of all cancer deaths are attributed to radon. This order of magnitude has since been proven by epidemiological studies. This means that 20,000 deaths from lung cancer in the EU and 300 to around 400 in Switzerland are caused by radon.

Investigations by the Swiss Tropical and Public Health Institute (Swiss TPH) as part of the Swiss National Cohort Study show that radon in living areas also increases the risk of developing malignant skin cancer (malignant melanoma).

There is also a risk in various medical applications such as radon balneology because of the associated radiation exposure.

burden

The following table with representative radon activities for Germany (given in Becquerel per cubic meter) shows that the majority of the radon comes from the soil.

Average Bq / m³
open air 15th
Indoor air 60
Drinking water 6,000
Ground clearance at a depth of 1 m 5,000-500,000

Radon is poorly soluble in water. In the open atmosphere, it dilutes greatly and disintegrates within a few days. The pollution is greater in houses, especially in basements with house wells. The load is lower on higher floors. Houses made of natural stone or clay ( half-timbered houses ) are more heavily polluted.

In Germany, the average indoor radon exposure is 59 Bq / m³. In 1984 a study in West Germany revealed a logarithmic normal distribution of pollution with a mean value of 40 Bq / m³ in the indoor air. However, the burden is very different from region to region. In areas of Bavaria and Saxony it is very high in places. This is due to the different occurrences of individual rock types and compositions. Regions where uranium was mined and regions with granite, bauxite and black shale deposits have high radon concentrations in the soil, in the air and in the water, higher than in soils made of limestone.

The regional differences are also evident in the drinking water: the average in Germany is 6 kBq / m³, in Sweden 15 kBq / m³ and in Finland 50 kBq / m³. When it comes into contact with the air, radon is released from the water. Employees of waterworks can be particularly exposed - 40,000 Bq / m³ air was found in one waterworks.

activities

The course of radon activity in a laboratory over a week, at night and on weekends, ventilation was reduced.

The radon concentration in buildings is subject to fluctuations of up to three orders of magnitude, depending on the type of use of the building and the habits of the residents. The diagram opposite shows the effect of reduced air exchange. A building waterproofing, for example in accordance with the German Energy Saving Ordinance , can lead to an increase in the radon concentration in areas where there is a significant health risk.

This mainly affects residents of houses that were built on building sites with a geologically increased radon concentration. The geogenically conditions existing radon potential under a building can be determined by an examination of the subsoil. In this context, it is advantageous to determine the radon concentration in the ground at a depth of one meter before building new buildings.

A remedy against rising radon is e.g. B. the installation of cavity elements in the lowest floor slab, which are connected to the outside world via pipes. Air suction just above the ground on the north or east side, suction under the ceiling on the opposite side or via a chimney that is no longer needed - this creates a chimney effect. This means that rising moisture as well as radon or mine gases are safely released into the open. Radon wells also help to divert radon-contaminated air before it gets into the apartments. Another method is to lay tightly welded aluminum composite foils on the floor of the living room. A parquet floor, screed or even just carpet can then be placed over it. As a result, the radon is guided at least into the outer walls, where it rises but partially diffuses back into the living space. Especially since buildings have been tightly packed to prevent energy loss, radon has not been able to escape through the external walls - as it used to be - and is therefore increasingly staying in living areas. Uninhabited basement rooms can and should be mechanically forced ventilation. A slight overpressure in the cellar prevents air from entering the floor, while a slight negative pressure prevents the living space from rising.

For the problem of ventilation there are now windows that have a small flap in the frame, which causes continuous ventilation when there is no wind. In the event of strong wind movements, this flap closes and the window is as tight as a conventional window manufactured in accordance with current guidelines. The seasonal fluctuations in the house are related to a change in ventilation behavior in summer compared to the winter months. But the weather situation is also responsible for the fluctuations. For example, the radon concentration can increase in poor weather conditions.

Radon Protection Act

Europe

The European Commission recommends limiting the maximum indoor radon concentration. The following limit values ​​are recommended:

According to the EU, these limit values ​​must be implemented in national law by February 6, 2018 at the latest. From then on, these limit values ​​apply as an annual average as the maximum permissible value. If apartments are sold or rented, this value must also be attested by the tenant or buyer upon request. Intervention level: 400 Bq / m³ applies to buildings that were built before 1996. Planning guideline value: 200 Bq / m³ applies to buildings that were built after 1996

In its statement of July 14, 2004, the Radiation Protection Commission established a statistical significance of the additional lung cancer risk from radon from 150 Bq / m³. It is therefore recommended to reduce the indoor radon concentration to below 100 Bq / m³. This value is also recommended by the WHO.

In December 2013 the European Union published a new guideline 2013/59 / Euratom, in which it was stipulated that the member states must set a reference value for the radon activity concentration in indoor workplaces (Art. 54) and in common rooms (Art. 74) should be set in the air, which must not be higher than 300 Bq / m³ in the annual mean.

Germany

The Federal Ministry for the Environment, Nature Conservation and Nuclear Safety presented a draft law in March 2005 that was supposed to set limit values ​​for the radon concentration in buildings. The planned target value was 100 Becquerel per cubic meter of air for new and old buildings. Due to the early elections to the Bundestag on September 18, 2005, the proposed law could not be completed and the proposed law lapsed when the Bundestag was dissolved. In the following legislative periods , no law has been passed on this topic so far (as of April 2012). For the time being, 400 Bq / m³ also apply as the maximum value for Germany - as for the entire EU.

On December 31, 2018, the Radiation Protection Act (StrlSchG) and the new Radiation Protection Ordinance (StrlSchV) came into force in Germany with regard to protection against radon. Section 124 of the StrlSchG specifies the reference value for the annual average radon-222 activity concentration in the air c (Rn-222) in common rooms of 300 Bq / m³. The same reference value applies to workplaces in accordance with Section 126 StrlSchG. According to Section 5, Paragraph 29 of the StrlSchG, the reference value is “a fixed value that serves as a benchmark for testing the appropriateness of measures. A reference value is not a limit value! "The radiation protection authorities responsible in the federal states are to define and publish areas by the end of 2020 for which it is expected that the annual mean radon-222 activity concentration in the air in a considerable number of buildings with lounges or Jobs exceeds the reference value according to § 124 or § 126 StrlSchG.

Switzerland

In the Radiation Protection Ordinance of 1994, the following limit values ​​for radon-222 were set: 1000 Bq / m³ for living and recreation rooms and 3000 Bq / m³ for work rooms. A guideline value of 400 Bq / m³ applies to new buildings. The 2017 revised Radiation Protection Ordinance will replace these limit values ​​from January 1, 2018 with a reference value of 300 Bq / m³ for the general population and a point-of-entry value of 1000 Bq / m³ for work-related exposure.

Guide values

Radon is the decay product of radium-226 and thorium-232. Their activity in building materials should be less than 260 Bq / kg (7 nCi / kg). If it is higher, good ventilation must be ensured to prevent excessive radon accumulation. As a guideline, the radon flow ( exhalation rate ) should be less than 2 Bq / m²h and the concentration in the air should be less than 50 Bq / m³.

WHO Radon Manual

The World Health Organization (WHO) published a handbook on the lung cancer risks from radon in indoor areas in September 2009. According to this, radon is one of the most common causes of lung cancer. The WHO calls, among other things, to reduce the individual risks of those affected. In the longer term, the population is to be protected through preventive structural measures and renovation of old buildings. According to the WHO, 100 Becquerel per cubic meter should be the maximum permissible radon concentration in new and old buildings.

See also

literature

  • GSF Research Center for Environment and Health: Radiation in Everyday Life . Munich 1991, ISSN  0175-4521 .
  • Eckhard Ettenhuber and others: Limiting radiation exposure to radon in common rooms. In: Strahlenschutzpraxis (Organ of the Association for Radiation Protection) 1/2005, pp. 52–58.

Web links

Individual evidence

  • EU Directive 2013/59 / Euratom of the Council of 5 December 2013 laying down basic safety standards for protection against the dangers of exposure to ionizing radiation and repealing EU Directives 89/618 / Euratom, 90/641 / Euratom, 96 / 29 / Euratom, 97/43 / Euratom and 2003/122 / Euratom. - Official Journal of the European Union L 13/1; 17th January 2014.
  • Law on protection against the harmful effects of ionizing radiation - Radiation Protection Act (StrlSchG). - Article 1 of the law on the reorganization of the right to protection against the harmful effects of ionizing radiation of June 27, 2017; Federal Law Gazette 2017 Part I No. 42, issued in Bonn on July 3, 2017.
  • Ordinance on protection against the harmful effects of ionizing radiation (Radiation Protection Ordinance - StrlSchV). - Article 1 of the ordinance on the further modernization of radiation protection law of 29 November 2018; Federal Law Gazette 2018 Part I No. 41, issued in Bonn on December 5, 2018.
  1. ↑ Federal Office for Radiation Protection (Ed.): This is how radon affects health. Retrieved August 25, 2019 .
  2. ↑ Federal Office for Radiation Protection (Ed.): Health effects of radon in homes. July 1, 2009, archived from the original on August 8, 2009 ; Retrieved on August 25, 2019 (with reference to: Menzler S., Schaffrath-Rosario A., Wichman HE, Kreienbrock L .: Assessment of the attributable lung cancer risk in Germany due to radon in apartments . Ecomed-Verlag, Landsberg, 2006.).
  3. ↑ Martin Röösli et al: Effects of Radon and UV Exposure on Skin Cancer Mortality in Switzerland. In: Environmental Health Perspectives 125/6. June 2017, accessed on August 30, 2017 .
  4. ↑ Karl Hübner: Radon cure: Researchers explore the tunnel air. In: ÄrzteZeitung . January 7, 2013, accessed August 25, 2019 .
  5. ^ Karl Wolfgang Evers: Water as food: drinking water - mineral water - spring water - table water . Behr's 2009, ISBN 978-3-89947-528-9 , limited preview in Google Book Search.
  6. ↑ Hans Kiefer, Winfried Koelzer: Radiation and radiation protection: From the responsible handling of the invisible . Springer 1987, ISBN 978-3-540-17679-4 , limited preview in Google book search.
  7. ↑ Ralf Allgaier: Radiation can lurk in the waterworks. In: Kölnische Rundschau . October 14, 2007, accessed August 25, 2019 .
  8. ↑ Federal Ministry for the Environment, Nature Conservation and Nuclear Safety: Environmental Policy: Radon. (pdf, 2.2 MB) In: Leaflets on lowering the radon concentration in residential buildings. December 2, 2004, archived from the original on August 1, 2011 ; accessed on August 25, 2019 .
  9. ↑ The Effects of Radon on Health. In: was-ist-radon.de. Archived from the original on October 6, 2014 ; accessed on August 25, 2019 .
  10. ^ Henning von Philipsborn: Radioactivity and radiation measurement. ISBN 3-910088-01-5 .
  11. ↑ Swiss Federal Council : Radiation Protection Ordinance (StSV). (pdf, 8.2 MB) Chapter 3: Radon, Section 1: General Provisions, Art. 155–156. April 26, 2017. Retrieved April 26, 2017 .
  12. ↑ M. Rosenkranz: Tables. In: radontest.de. Archived from the original on August 26, 2011 ; accessed on August 25, 2019 . Federal Office for Radiation Protection (Ed.): Natural radionuclides in building materials. (pdf, 128 kB) June 21, 2002, archived from the original on February 3, 2013 ; accessed on August 25, 2019 .
  13. ↑ Suminory Akiba1, William J. Angell, Thomas Jung, among others: Who Handbook on Indoor Radon: A Public Health Perspective. (pdf, 596 kB) WHO, accessed on August 25, 2019 (English).