Dimitris Kotzias, head of the European Commission's Joint Research Centre Environment Institute, is leading an initiative to investigate the quality of the air we breathe indoors, writes Martin Ince.
The work began after Dr Kotzias spotted a legislative paradox. "The vast majority of legislation about air quality is concerned with the outdoors," he said, "but we spend 90 per cent of our time indoors."
At the JRC's centre at Ispra in Italy, Dr Kotzias and others decided to take a closer look at this conundrum. Before there can be community policy on indoor air, he said, there needed to be some proper science, which to date had been largely missing.
In an attempt to build up a knowledge base, his team measured human exposure to air pollution in homes, schools, offices and other settings across Europe.
They found variations. In the south, hazardous chemicals evaporate into the atmosphere faster because temperatures were higher. In the north, people stayed indoors more and exposed themselves to chemical hazards, especially in the winter months. But across the continent, there was inexplicably high exposure to a wide range of chemicals that were known health hazards.
Dr Kotzias said: "We cannot yet explain just where the high concentrations of indoor pollution are coming from. But we have identified some of the hazards. We know that a new computer or printer will give off high levels of emissions for some months."
Carpets sprayed with anti-fungal chemicals are another significant source of hazardous exposure, as are flame retardants, building materials, and what one JRC report terms "body effluents".
The Ispra scientists have studied a variety of indoor pollutants with a room-sized structure called the Indoortron, within which anything from curtains to televisions can be tested for emissions.
This work provided the scientific backing for the recent ban on phthalates - a class of chemicals used in the manufacture of plastics - from toys because of the high level of air pollution they were generating.
Ispra scientist Kaes van Leeuwen said that much of the work was designed to produce ways of reducing exposure, not just theoretical knowledge about its origin.
There are many unknowns, but, like others involved in the research, he was sure of one thing. "There is one hazard that appears on our present knowledge to be far more serious than all others - smoking."
Dr Kotzias said: "We have found that a cigarette is an exceptionally powerful point source of pollution. A lot is said about ventilation and no-smoking areas in workplaces. But our work on ventilation shows that the pollution from smoking is so intense and lasts so long that increasing ventilation does not help."
JRC director-general Barry McSweeney said: "With most forms of pollution it is possible to imagine ways of reducing exposure, which is a better approach than setting limits. But it turns out that with smoking, the only answer is to remove the pollution at source. This is a genuinely unexpected scientific finding in which we have a lot of confidence."
Mr McSweeney said that the Ispra research was likely to underpin moves to ban smoking in workplaces across the European Union. Some states, including his native Ireland, are already planning to ban smoking in restaurants and bars, a move that is regarded by many smokers as little short of an attack on their civil rights.
But he pointed out that the issue was not smokers' rights but those of the people who work in smoke-filled environments. In some countries, the fear of lost takings in pubs and bars has led trade unions representing staff to denounce the proposed smoking ban. In Ireland, health minister Michael Martin is in deep political trouble over the idea.
Mr McSweeney was adamant, however, that a ban was essential. "I did a radio interview in which a representative of the Irish pub trade opposed the ban.
I ended by wishing him a happy and short life."