Chemical products have improved life conditions of people. However, it has long been known that some chemicals that are marketed can have a negative effect on human health and the environment.

The effects of exposure to environmental contamination are usually long-term. It is associated with various neurological disorders, reproductive and developmental disorders, respiratory diseases, asthma and allergies, alterations of the hormonal system, immune system dysfunctions, obesity and cancer.

The U.S. Environmental Protection Agency (EPA) estimates that 72% of chemical exposure to humans occurs indoors. However, environmental pollution legislation focuses on outdoor air, which is subject to monitoring and strict control by the authorities.


Outdoor air in cities is often polluted by nitrogen dioxide and ozone.

In contrast, indoor environmental contamination tends to be more diverse: What are the most likely pollutants to be found?

When locating them, it is important to evaluate the following aspects:

  • Residents should reflect on whether health problems have arisen since they have moved to a new place of residence or since they have renovated it.
  • Analysis of the construction system and materials present, age of the house and subsequent renovations. For example, dangerous wood preservatives or heavy metals from industrial waste can be found in building materials in houses from the 1960s or 1970s. In more modern homes, however, the presence of solvents and other volatile contaminants in paints, foams, glues or varnishes may be suspected.
  • Occasional and apparently outdated problems such as a fire or pest or fungus extermination may have left toxic residues.
  • Home or office ventilation habits.


The detection of the main pollutants is possible by means of different measurements:

  • Air test for the detection of volatile substances. Air samples are taken by pumping and reacted in reactive media.
  • Dust tests with recent dust aspiration. It allows to know the presence of low volatile harmful substances and heavy metals.
  • Material testing can be used to identify sources of harmful substances.
  • Direct indication devices, only for some very specific toxicants.


Indoor air should contain no more harmful substances than those found outdoors.

There are hardly any legal limit values in dwellings. On the other hand, the existing limits for workplaces are not very demanding and are more oriented to workers’ safety than to their health.

There are multiple recommendations for harmful indoor concentrations, such as those of EUROPAEM or WHO. In bio-construction, the limit values of SBM-2015 of the Institut für Baubiologie, and those of the AGÖF (Working Group of the German Ecology Research Institutes), whose indicative values are more restrictive than the legal ones, are often used.