Decomposing household rubbish is not just unsightly, it also produces dozens of highly toxic chemical substances that cause a number of pathological conditions such as gastroenteritis, nausea, shortness of breath, eye irritations and, in extreme cases, even cancer. As this process usually takes place in an urban setting, the effects are even more detrimental because of the interaction of chemicals with nitrogen oxides, the main products emitted from gasoline-powered engines that result in a rapid increase in ozone, more commonly referred to as smog. These substances are the number one threat to vulnerable population groups such as heart patients, the elderly and people with respiratory problems such as asthma. These findings come from a survey carried out by the Chemical Analysis and Field Technology group at the National Technical University of Athens on the contents of garbage dumpsters during a weeklong strike by municipal workers. The new data give greater cause for concern when municipal workers go on strike, as it shows the problem is not simply the risk of germs and bad smells; there is also a toxic threat. During the survey – the first worldwide one that focuses exclusively on garbage dumpsters – 155 chemicals were recorded, of which 30 were found in every sample, that is in every dumpster. They included all kinds of hydrocarbons as well as organic sulfur compounds. However, what caused particular concern was the fact that most of the chemicals are by-products of benzene, substances known to be responsible for the appearance of cancer. Concentrations of benzene around dumpsters ranged from 0.8 to 12.7 mgr per cubic meter. The World Health Organization has set a limit of exposure to this substance of 5 mg/m3. Equally disturbing were the traces of dimethylosulfide found. This substance has been linked with serious gastroenteric problems, nausea and irritation of the respiratory passages. It was found in concentrations of over 16mgr/3; the exposure limit has been set at 12 mgr/m3. «When garbage is collected on a daily basis there is no risk to public health, but during strikes, volatile organic substances are emitted from the dumpsters (gases produced from liquids and solids) which create a health hazard,» said Associate Professor Miltiadis Statheropoulos of the National Technical University of Athens (NTUA)’s chemical engineering department. After adding up the concentrations of 30 substances common to all samples, the researchers came up with a total concentration of 3,100 mgr/m. This means that, according to the monitoring indicators for the effect of volatile substances in concentrations of 200 to 3,000 mgr/m3, there is a major risk of symptoms including respiratory difficulties, eye irritations, nausea and heart problems. In the event that concentrations go over 3,000 mgr/m3, there is a clear risk of serious pathological problems. If they are over 25,000 mgr/m3 (usually at landfill sites) the volatile organic substances combine to make a deadly, toxic cocktail. «The production of volatile substances is a dynamic phenomenon, since it is affected by temperature, humidity levels and factors such as the contents of the dumpster. The first survey was carried out when the average temperature was 28 degrees Celsius (82F) and humidity levels 47.4 percent. The second one, completed recently, confirmed the findings and brought to light more large concentrations of sulfuric substances, added Statheropoulos. Meanwhile, scientists have expressed serious reservations as to the effectiveness of spraying garbage piled up in the streets (as during the last strike) to limit the risk of germs. They say that not only does this do nothing to reduce chemical risk, but because of the garbage’s chemical content, these disinfectants could speed up the decomposition process, increasing the concentrations of volatile organic substances. Meanwhile, the NTUA experts emphasized the need to disinfect the dumpsters after long strikes. Concentrations of substances released might be greatly reduced, but within the dumpsters considerable quantities of volatile substances remain intact and can create an unbearable stench. Sulfuric organic compounds, hydrocarbons, by-products of alcohol and benzene in small concentrations are not dangerous but are extremely malodorous.