A room where people smoke contains dozens or hundreds of times higher air concentrations of endotoxins than smoke-free indoor air. This has been shown by a research team from Lund University.
Endotoxin is the name of a group of poisonous substances produced by bacteria and naturally occurring in the air and elsewhere. In normal low concentrations, endotoxins are not dangerous; indeed, they might play a role in protecting us against allergies. But at higher levels of concentration they induce serious inflammatory reactions in the respiratory tract.
Endotoxins have long been known for their powerful capacity to cause inflammations. Dust rich in endotoxins constitutes a health risk in many workplaces and is seen as a key explanation for the high incidence of chronic bronchitis among farmers. Endotoxins from construction materials, dust, plants, etc. in the home can also contribute to asthma. On the other hand, it had not been clearly shown previously that cigarette smoke contains true endotoxins, i.e. bacterial lipopolysaccharides.
In its experiments, the Lund team, headed by Associate Professor Lennart Larsson, has tried to simulate both passive and active smoking. For the latter, they set up equipment that “smoked” a cigarette in 8-10 minutes and captured the contents of the smoke in a filter. For passive smoking, they “smoked” one cigarette every half hour in an unventilated room for seven hours and compared it with a similar room without smoke. The results, presented in the international journal Indoor Air, show that the level of the toxic substances in the air of the smoky room was a full 120 times higher than in a smoke-free room. Moreover, the tobacco endotoxin seemed to be the most aggressive sort among the various forms that exist.