Environmental hazards are responsible for as much as a quarter of the total burden of disease world-wide, and more than one-third of the burden among children. Heading that list are diarrhea, lower respiratory infections, various forms of unintentional injuries and malaria. The disease burden is much higher in the developing world, although in the case of certain non-communicable diseases, such as cardiovascular diseases and cancers, the per capita disease burden is larger in developed countries. Health impacts of environmental hazards run across more than 80 diseases and types of injury. Well-targeted interventions can prevent much of this environmental risk.

To learn more, visit the World Health Organization website: www.who.int

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About residential radon

Radon is a radioactive gas produced naturally by the decay of uranium in the earth's crust. It is present everywhere in the world but its emission and concentration are not uniform. Radon can seep into buildings through cracks and other underground openings.

The presence of radon in outdoor air (1 to 10 Bq/m3) is not significant because it is extremely dilute. If it seeps into public and residential buildings, radon may be more concentrated in indoor air. Usually, radon levels vary between 30 and 100 Bq/m3.

In general, radon can seep into a home through different routes:

  • dirt floors;
  • cracks in the concrete slab;
  • cracks in foundation walls;
  • sump pits;
  • crawl spaces;
  • joints;
  • space around drain pipes (eg. pipe fittings).

The presence of radon gas inside homes is the result of the following conditions:

  • concentration of radon in soil (importance of the source);
  • poor ventilation of the premises (rate of air exchange);
  • air tightness of the house;
  • negative pressure within the building.

Radon can be present in drinking water and be emitted as a gas in the shower. However, in most cases, the concentration is not high enough to pose a health threat.

To read the full text, visit the Ministère de la Santé et des Services sociaux website.