Do you really know what you are breathing when sitting at home? Europeans spend 90% of their time indoors. But closed environments are not always the healthiest. The latest studies on human exposure to indoor pollution, released today by the European Commission at its Joint Research Centre (JRC) facilities in Ispra (Italy), reveal that indoor environments pose their own threats to health and, in some cases, can be at least twice as polluting as outdoor environments.

Hundreds of volatile components have been detected and some of them are toxic, mutagenic or carcinogenic. The number of potential sources is enormous. For instance, up to 20% of Europeans suffer from asthma due to substances inhaled indoor. Tobacco smoke, asbestos, radon and benzene released inside buildings are prime suspects in the increase in cancer cases amongst the European population. The Commission is therefore developing sophisticated analytical methods to provide for a fingerprint of Volatile Organic Compounds (VOCs). Measurements are carried out, inter alia, at the EU INDOORTRON “environmental chamber”, and through a network of labs across Europe.

According to European Research Commissioner Philippe Busquin: “Traffic and smog are of course major causes of pollution, and we are studying and analysing their impact on human health. But unfortunately smoking and chemical substances sometimes follow us even behind closed doors – at home, at the office, in restaurants and bars. Under certain conditions, we can even be at risk while sitting in our sofa at home, not only while cycling downtown at the rush hour. We are therefore upgrading our indoor pollution monitoring and response capabilities, and we encourage policymakers and public authorities across Europe to address these issues and devise a consistent and effective strategy to solve the problem.”

Not safer at home

It is generally believed that buildings shelter us from most unpleasant and unhealthy outdoor conditions or pollutants. We spend, on average, 85-90% of our time indoors at home, in school, at work or during leisure time. However, reductions in ventilation rates to limit energy consumption and extensive use of new building materials are releasing chemical substances with unknown toxic properties.

Today the Joint Research Centre presented an insight into the potential causes of acute symptoms such as allergies, asthma, mucous irritation, headaches and tiredness. It is estimated, for instance, that up to 20% of the population suffers from asthma and other allergic diseases caused by substances typically present in indoor environments. In addition, indoor pollutants such as tobacco smoke, radon, asbestos and benzene may substantially contribute to the increase of cancer incidents in the population.

A breath of fresh air?

Results from measuring campaigns carried out by the Joint Research Centre in European cities clearly indicate that indoor concentrations of dangerous air pollutants (e.g. benzene) are often much higher than they are outdoors. Recent results indicate, for instance, that schoolchildren are exposed to high concentrations of pollutants (e.g. aromatic compounds), which might be particularly harmful for students with allergies, asthma or airway hyper-reactivity.

In the case of benzene and other aromatic compounds, overall exposure is at least twice that of urban pollution levels. This means that the indoor risk is doubled or even higher than that expected from existing levels of outdoor concentrations. This risk is increasingly associated with serious health problems for European citizens.

Tobacco still the main culprit

Environmental tobacco smoke (ETS), derived primarily from side-stream cigarette smoke emitted between puffs, is a major contributor to indoor air pollution wherever smoking occurs. Tests were undertaken to investigate the impact of various ventilation rates in indoor environments on the air concentration of tobacco components (burning products) during smoking at the Joint Research Centre’s environmental chamber, INDOORTRON

Preliminary evidence indicates that changes in ventilation rates during smoking do not have a significant influence on the air concentration of tobacco components. This means, in effect, that efforts to reduce indoor air pollution through higher ventilation rates in buildings and homes would hardly lead to a measurable improvement of indoor air quality.