On coming home from work through the city smog and closing the door, people think they have left the polluted air outside. Not so, since the atmosphere inside our homes is often even worse than what’s outside. Air conditioning, synthetic surfaces and chipboard, electrical wires, and a number of other materials and appliances used in the modern home are a threat to our health and together contribute a new condition: the sick building syndrome. According to Michail Petrakis, of the Institute for Environmental Research and Sustainable Development at the National Observatory of Athens, modern homes contain more pathogens than when they were made of natural materials. Stone and timber have been replaced by synthetic materials that release dangerous chemical substances into the atmosphere. A survey by the European Research Institute has found hundreds of airborne substances, many of which are toxic or carcinogenic, inside buildings. These include asbestos, radon and benzene. Plasterboard, parquet floors and liquid floor waxes release whole hydrocarbons. Waxes emit trimethyl pentene and dodecane isomers. Formaldehyde is released from chipboard, along with acetone, from cigarette smoke, heating systems and additives to water-based paints. Cheap, adhesive carpeting pollutes the air with dichloroethylene, tricholorethylene, dichlorobenzene and decane, among other pollutants. Carpets are particularly bad sources of pollution since they collect dust and minute particles. Work spaces are even more polluted, due to the use of cheaper materials and dangerous appliances such as photocopying machines. Cigarette smoke Without a doubt, cigarette smoke is the most dangerous pollutant of interior spaces. It is also extremely resistant as it sticks to filters and other surfaces, and resists ventilation. According to Panayiotis Siskos, associate professor at the chemistry faculty of Athens University, recent studies show that cigarette smoke acts like a magnet to germs which adhere to the smoke particles and then enter the human body. Cigarette smoke is now indisputably linked to an increase in the chances of developing cancer and is also known to irritate mucous membranes because of the hundreds of chemical compounds it contains, many of which are toxic. These findings are confirmed in a study by Siskos and his colleague at Athens University’s chemical faculty, Maria Bayia. The two professors took readings inside 25 homes, divided into various categories such as smokers and non-smokers’ residences, distance from main roads, and whether the homes were old or new (or renovated). The measurements were taken over a 12-month period in order to get a picture of the pollution load throughout the year. The first conclusion drawn was that concentrations of chemical substances are far higher in winter months. In fact, as the effects are cumulative, the greatest concentrations are recorded in March, when the average reading is 350 micrograms per cubic meter, compared to just 60 in August. In December, the reading is 250 mg/cm, in January 280 and in February 300. In June the reading is just 75 and in August 65. Thus it is clear that the concentration is directly proportional to the amount of time spent at home, accompanied by bad ventilation and most probably by cigarette smoke. This is also evident from the average for the days of the week, with the highest readings at the weekend. In smokers’ homes, the concentrations of benzene are one-third higher than in the homes of non-smokers. As expected, houses near main roads also have higher concentrations of pollutants. New and renovated homes have higher indicators for a number of chemical compounds than older homes. Petrakis emphasized that these threats are very real. «For example, according to unquestioned clinical studies, for every single unit that benzene levels rise, it multiplies the chance of developing leukemia eight times over. Naturally, this happens over time, not immediately. The disease could develop 20 to 40 years later. And these are not the only dangers. Within a sick environment, people feel tired and unable to concentrate, they are troubled by coughs and headaches. People feel stifled by the dense atmosphere and unpleasant smells.» According to Siskos, the human body is a chemical laboratory. We inhale over 7 cubic meters of air every day, and with them a number of harmful substances. Immediate solutions include proper ventilation and the avoidance of smoking – at least indoors. In the long term, marble and mosaic should be preferred (rather than synthetic tiles), along with environmentally friendly paints. Filters on air-conditioning units should be changed frequently, and a combination of old materials and new, from the so-called «healthy materials,» should be used.