Various pollutants are likely to be found in indoor air, including chemical pollutants, organic contaminants, particles or fibres. The air we breathe may affect our comfort and health to various degrees, ranging from minor troubles such as unpleasant odours, drowsiness or irritation of the eyes or skin to the onset or aggravation of serious diseases such as respiratory allergies, asthma, cancer and disabling or fatal poisoning. Until recently, the quality of air inside buildings was not a major health concern, as was, on the other hand, the quality of outside air. Yet, in temperate climates we spend on average 85% of our time in enclosed environments, and a majority of that time in the home.
To address the issue of indoor air quality, and provide public authorities with useful tools for managing this risk, ANSES has been working since 2004 to develop Indoor Air Quality Guidelines (IAQGs). The values they stipulate are defined as airborne concentrations of a chemical substance below which no health effects or harmful impact on health is expected for the general population as current knowledge stands. These guidelines provide health targets to aim for in order to protect the general public.
ANSES has just published its IAQGs for nitrogen dioxide (NO2), a gas generated by various combustion sources. Indoor sources include smoking, flueless water and space heaters, gas stoves, in addition to transfer of outdoor air pollution from road traffic or industrial sources, for example. It is extremely irritating to the respiratory tract and may lead, in humans, to shortness of breath, obstruction of bronchial air flow, asthma attacks or bronchitis.
The first guideline is designed to protect the public from the effects of short-term exposure (200 µg.m-3 for one hour), and the second, from the effects of long-term exposure (20 µg.m-3 for over one year). The IAQGs for nitrogen dioxide follow the broad outlines of the World Health Organization’s guidelines for indoor air quality (2010)(1).
ANSES also recommends collecting data to quantify the health benefits to be gained from implementing NO2 IAQGs.
Indoor Air Quality Guidelines (IAQGs) stipulate values defined as airborne concentrations of a chemical substance below which no health effects or harmful impact on health is expected for the general population as current knowledge stands. IAQGs are designed to define and propose a reference framework for protecting the population from the health effects associated with exposure to air pollution by inhalation. The purpose is to contribute to the development of recommendations that will ultimately eliminate—or reduce to an “acceptable” public health level—contaminants that have been proven or assumed to be detrimental to human health and welfare.
(1) WHO guidelines for indoor air quality: selected pollutants (2010)