A dangerous cocktail of substances floats on indoor air, making the polluted urban environment outdoors a potentially safer place than home, reports Dick Ahlstrom
The air in our homes, schools and workplaces is awash with a staggering collection of chemicals, including known toxins and carcinogens. These have an unknown impact on human health because they have largely been ignored, according to new research.
The shocking findings, released this morning, suggest it may now be safer in the polluted urban environment outdoors than in your own home.
The Physical and Chemical Exposure Unit of the EU's Joint Research Centre (JRC) in Ispra, Italy, carried out its own experiments, backed up by research from other member-states.
The study reveals indoor environments pose their own threats to health. They can be at least twice as polluting as outdoor environments for particularly dangerous substances such as the carcinogen benzene.
Indoor air contains literally hundreds of volatile chemical compounds, some of them toxic, mutagenic or carcinogenic. The report argues that up to 20 per cent of Europeans suffer from asthma due to substances inhaled while indoors. Tobacco smoke, asbestos, radon and benzene released inside buildings are prime suspects in the increase in cancer cases across Europe.
We retreat into our homes and air-conditioned offices and schools, spending up to 90 per cent of our time there and hoping to avoid outdoor pollution, the report states.
"However reductions in ventilation rates to limit energy consumption and extensive use of new building materials are releasing chemical substances with unknown toxic properties," it says.
Environmental tobacco smoke (ETS) remains a key contributor to indoor air pollution, the report says. Smoking discharges thousands of noxious compounds into the air, chemicals that become trapped because of low ventilation levels.
Unexpectedly, the research team found these dangerous chemicals are not cleared even when higher ventilation rates are used. "This means efforts to reduce indoor air pollution by ETS through higher ventilation rates in buildings and homes would hardly lead to a measurable improvement of indoor air quality," the report says.
While ETS is a major pollution source, a bewildering array of materials found in most homes contribute to the dangerous cocktail of substances floating on the air indoors. These include plastics, synthetic carpets, indoor paints, home-cleaning products, artificial lemon scent, modern building materials and processed wood products. Computers and office equipment release chemicals, and cooking and heating also contribute to the pollution load, the report indicates.
These can release volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), semi-volatile organic compounds, carbon monoxide, nitric oxide, benzene, toluene, formaldehyde and acetaldehyde, amongst others.
The JRC outlines a new effort to develop comprehensive information about 13 of the most dangerous and plentiful of the compounds afloat on indoor air, known as the "INDEX" project. It includes only those known to have health effects.
"We know that for several chemicals, indoor air concentrations exceed outdoor air concentrations. In addition, we breathe significantly more indoor air than outdoor mainly because we are staying indoors approximately 90 per cent of the time."
The report cites an alarming collection of health effects. These include a direct effect on the respiratory and cardiovascular systems. "Increased mortality, morbidity and impaired pulmonary function have been associated with elevated levels of sulphur dioxide and particulate matter."
Effects include cancers of the lungs, skin and bladder associated with PAHs, sensory irritation, neurotoxic, hepatoxic and genotoxic effects from VOCs, irritation of eyes, nose and throat from formaldehyde and dozens of other symptoms.
The report makes the link between "sick building syndrome" and chemical substances found on indoor air. "Exposure to mixtures of VOCs may be an important factor for sick building syndrome complaints."
It cited a study of 19 Dutch government buildings that showed six to seven times higher levels of endotoxins and airborne bacterial contamination in "sick" buildings, where more than 15 per cent of staff reported symptoms, compared to "healthy" buildings were less than 15 per cent reported symptoms.
The findings warranted quick action by the Commission and all member-states, according to the head of the Physical and Chemical Exposure Unit at the JRC, Dr Dimitrius Kotzias. "Our research now tries to educate the policy-makers and Commission about the importance of indoor pollution." The Commission should make use of existing controls to force companies to provide comprehensive information about chemical emissions and their levels. This would allow researchers to begin to assemble data on health risks, he said.
There is hard information on some chemicals such as benzene and toluene. "We have little information about long-term, low-dose exposures of the other materials," he added. "There is a lot of research needed to see \ exposures of low concentrations lead to serious health effects. For that reason we should be precautionary."