Health Risks of Asbestos Exposure

Chronic exposure to asbestos may increase the risk of lung cancer, mesothelioma, and nonmalignant lung and pleural disorders. Evidence in humans comes from epidemiologic studies as well as numerous studies of workers exposed to asbestos in a variety of occupational settings. Tremolite asbestos exposure has been associated with an increased incidence of disease in vermiculite miners and millers from Libby, Montana.

This evidence is supported by reports of increased incidences of nonmalignant respiratory diseases, lung cancer, and mesothelioma in villages in various regions of the world that have traditionally used tremolite-asbestos whitewashes in homes or have high surface deposits of tremolite asbestos and by results from animal studies.

Mesothalmia results in mesothelioma cancer, a disease that is a result of exposure to airborne asbestos fibers. If asbestos fibers are breathed in, they travel to the ends of the small air passages and cause lung cancer and various asbestos related diseases. There are no known cures for mesothelioma.

There are treatment options that you can avail of to fight against this asbestos related disease. You can opt for surgery, radiation therapy, chemotherapy and clinical trials. Surgery is a common treatment for malignant mesothelioma. Part of the lining of the chest may be removed, as also a lung.

In therapy radiation, the doctor may drain the fluid out of the body. Chemotherapy is another option. Most people with malignant mesothelioma have worked on jobs where they breathed asbestos like miners, shipyard workers and construction fields.

Disease from Asbestos

Macrophages normally engulf small particles in the lung. Asbestos particles, however, tend to rupture the macrophage on contact, releasing its contents into the surrounding lung tissue. This condition is characteristic of people suffering from asbestosis, a disease caused by the inhalation of asbestos fibers.

Significant exposure to any type of asbestos will increase the risk of lung cancer, mesothelioma and nonmalignant lung and pleural disorders, including asbestosis, pleural plaques, pleural thickening, and pleural effusions. This conclusion is based on observations of these diseases in groups of workers with cumulative exposures ranging from about 5 to 1,200 fiber-year/mL. Such exposures would result from 40 years of occupational exposure to air concentrations of 0.125 to 30 fiber/mL.

Diseases from asbestos exposure take a long time to develop. Most cases of lung cancer or asbestosis in asbestos workers occur 15 or more years after initial exposure to asbestos. Tobacco smokers who have been exposed to asbestos have a "far greater-than-additive" risk for lung cancer than do nonsmokers who have been exposed, meaning the risk is greater than the individual risks from asbestos and smoking added together.

The time between diagnosis of mesothelioma and the time of initial occupational exposure to asbestos commonly has been 30 years or more. Cases of mesotheliomas have been reported after household exposure of family members of asbestos workers and in individuals without occupational exposure who live close to asbestos mines.

Forms of Environmental diseases

Environmental diseases can affect any organ system of the body. How the diseases are expressed depends on how the particular environmental agent enters the body, how it is metabolized, and by what route it is excreted.

The skin, lungs, liver, kidneys, and nervous system are commonly affected by different agents in different settings. Of particular concern is the capacity of many environmental agents to cause various cancers, birth defects or spontaneous abortions (through fetal exposure), and mutations in germ cells, the last-named raising possibilities of environmentally caused genetic diseases in later generations.

Environmental illnesses can be mild or severe and can range from transient to chronic, depending on the doses of toxin received. Some diseases occur abruptly after a toxic exposure, whereas the time of onset of other diseases varies after exposure. Environmentally induced cancers, for example, commonly involve latency periods of 15 to 30 years or more.

Those illnesses that occur directly after a distinct toxic exposure are usually easily identified as being environmentally or occupationally caused. If the exposure is not clear-cut or illness is delayed, however, the cause is difficult to identify, as clinical features alone are usually nonspecific.
In addition, many different causes, environmental or otherwise, may produce identical illnesses. In such instances, epidemiological studies of exposed populations can help relate exposures to the illnesses they cause.

Radiation

Radiation therapy is used to fight many types of cancer. Radiation targets rapidly dividing cells like cancer cells. Radiation prevents cell division and the replication of DNA (the genetic building blocks).

Intravenous Radiation Theraphy (left)
Machine Radiation (right)

Ionizing and nonionizing radiation can produce both acute and chronic health effects, depending on dose levels. The effects of nonionizing radiation at lower dose levels are uncertain at present. Ionizing radiation at high doses causes both acute disease and delayed effects such as cancer. Victims include workers exposed to various occupational use of X rays or radioactive materials.

Although the disease-producing potential of ionizing radiation at low doses is also uncertain, an increase in chromosome damage has been observed in workers in nuclear shipyards.

Causes of Environmental diseases

Environmental diseases are caused by chemical agents, radiation, and physical hazards. The effects of exposure, in both natural and work settings, are greatly influenced by the exposure routes: primarily air pollution and water pollution, contaminated food, and direct contact with toxins.

Synergistic effects—two or more toxic exposures acting together—are also important, as illustrated by the greatly increased risk of lung cancer in asbestos workers who smoke cigarettes. The potential interaction of multiple hazardous chemicals at toxic waste dumps poses a current public health problem that is of unknown dimensions.

Industrial society has introduced or increased human exposure to thousands of chemicals in the environment. Examples are inorganic materials such as lead, mercury, arsenic, cadmium, and asbestos, and organic substances such as polychlorinated biphenyls (PCBs), vinyl chloride, and the pesticide DDT.

Of particular concern is the delayed potential for these chemicals to produce cancer, as in the cases of lung cancer and mesothelioma caused by asbestos, liver cancer caused by vinyl chloride, and leukemia caused by benzene. Minamata disease, caused by food contaminated with mercury, and Yusho disease, from food contaminated with chlorinated furans, are examples of acute toxic illnesses occurring in nonoccupational settings.

The full toxic potential of most environmental chemicals has not been completely tested. The extent and frequency of an illness are related to the dose of toxin, in degrees depending on the toxin. For chronic or delayed effects such as cancer or adverse reproductive effects, no “safe” dose threshold may exist below which disease is not produced. Thus, the cancer-producing potential of ubiquitous environmental contaminants such as DDT or the PCBs remains undefined.

Environmental and Occupational Diseases

Environmental and Occupational Diseases, illnesses caused by exposure to disease-causing agents in the environment, as opposed to illnesses related primarily to an individual's genetic makeup or to immunological malfunctions.

In everyday use, the term environmental disease is confined to noninfectious diseases and to diseases caused largely by exposures beyond the immediate control of the individual; the latter restriction eliminates diseases related to personal habits such as smoking or to the use or abuse of medications or drugs such as alcohol. Occupational disease, a major category of environmental disease, refers to illness resulting from job-related exposures.

Historically, awareness of environmental diseases began with the recognition of occupational illnesses, because exposures are usually more intense in work settings than in the general environment and therefore can more readily produce overt illnesses.

Examples include silicosis, a lung disease of miners, industrial workers, and potters exposed to silica dust; scrotal skin cancer in chimney sweeps exposed to soot; neurological disease in potters exposed to lead glazes; and bone disease in workers exposed to phosphorus in the manufacture of matches. Many such diseases first gained public attention during the Industrial Revolution in the 19th century.