Known occupational and environmental caricongens (visit http://www.lung-cancer.com/causes.html) that increase lung cancer risk, include exposure to;
hard metal dust
polycyclic aromatic hydrocarbons
Several of these exposures work synergistically with tobacco smoke, leading to the onset of lung cancer. Some of these exposures act as independent risk factors among non smokers.
Arsenic in water
A Chilean study focusing on cancer mortality between 1950 and 1997, found a mortality risk ratio of lung cancer of 3 to 4 in one region, where drinking water had a high percentage of inorganic arsenic.
This conclusion could not be explained on the basis of tobacco use patterns. The potential link between exposure to arsenic and lung cancer is substantiated by a Taiwanese study that noted progressive reduction in mortality rate of lung cancer when arsenic was eliminated from a communal water supply.
Radon exposure in uranium mining
Public health experts have been concerned about the risk of lung cancer among the general population due to radon exposure. (Visit http://www.lung-cancer.com/radon.html)
Radon, a gaseous decay product of radium-226 and uranium-238, can damage respiratory epithelium through emission of alpha particles.
Uranium miners who face occupational exposure to radon and its decay products, have an increased lung cancer risk. An interactive effect between cigarette smoking and exposure to radon has been noted.
Radon is found in soil, groundwater and rock, and was shown to accumulate in homes. Due to conflicting data, the risk associated with radon exposure remains unclear.
A meta-analysis in 2005 covered 13 European case control studies, and demonstrated that a linear relationship existed between the amount of radon found in a home, and lung cancer risk.
Although small, the increased risk was significant statistically, and it was estimated by the authors that around 2% of deaths in Europe may be due to radon exposure.
Wood smoke exposure
Wood smoke or charcoal smoke exposure is also a contributing cause to lung cancer. In many areas of the world, wood or charcoal is frequently burned for heating or cooking. A number of studies have demonstrated that exposure to smoke from burning of wood is linked with an increased lung cancer risk.
Lung cancer accounts for a million deaths per year, more than any other form of cancer, says the World Health Organisation.