Almost everyone is exposed to a small amount of asbestos as it is ubiquitous in the environment- in the air, soil, and water. Most asbestos fibers are microscopic and invisible to the human eye. This exposure is usually at a very low level. The asbestos-related diseases usually occur in people who have worked with fairly high levels of asbestos for a long time. High level of asbestos exposure is directly linked to development of an aggressive cancer, mesothelioma. It can also lead to a variety of non-cancerous condition like asbestosis (scarring of lung tissue) and formation of plaques in lung lining (pleural plaques). In addition, it is a risk factor for lung cancer (cancer of lung passages) and cancers of digestive tract (stomach and colon).