Asbestos Exposure

Asbestos Exposure

Asbestos exposure has been linked to the development of serious respiratory diseases and cancers, including mesothelioma, lung cancer, asbestosis, and other conditions. Asbestos exposure is most commonly related to occupational, environmental and secondhand factors.
For nearly 100 years, it was one of the most commonly used materials in industries such as construction, shipbuilding and manufacturing.

It wasn't until the mid-20th century that researchers officially established the connection between asbestos exposure and serious respiratory conditions (although evidence was presented as early as the 1920s). But by then, millions of workers had already been exposed in the workplace and in other locations. While federal asbestos exposure limits were imposed in 1972, an estimated 10,000 people in the United States continue to pass away each year from related illnesses.

How Exposure Happens

Asbestos exposure occurs when someone inhales or swallows asbestos fibers. Just about everyone breathes in asbestos from the outside air, but these trace amounts rarely cause health problems. While no level of asbestos exposure is considered safe, most asbestos-related illnesses arise after heavy, repeated exposures.

Harmful exposures happen in a wide range of occupational settings. Construction work and home renovations can be especially hazardous because many common building materials contain asbestos. When asbestos products start to deteriorate, or someone cuts, sands, drills or otherwise disturbs them, microscopic fibers enter the air.

For instance, the sandblasting practices of Alaska-based shipbuilding and repair facility Seward Ship's Drydock have come under fire by the Alaska Department of Environmental Conservation (ADEC). The ADEC issued a notice of violation to Seward Ship's Drydock for uncontrolled "fugitive particulate emissions" at its sandblasting operations. If workers were sandblasting asbestos-containing materials such as paint, insulation or joint compounds off of a vessel, the asbestos fibers released were no longer confined to the sandblasted area and possibly inhaled by individuals elsewhere in the shipyard.

Fibers can remain airborne for hours, placing anyone nearby in danger. Once inhaled, they become trapped in the respiratory tract and lungs, where they may stay for life.

Who is at risk for an asbestos-related disease?
Everyone is exposed to asbestos at some time during their life. Low levels of asbestos are present in the air, water, and soil. However, most people do not become ill from their exposure. People who become ill from asbestos are usually those who are exposed to it on a regular basis, most often in a job where they work directly with the material or through substantial environmental contact.

Since the early 1940s, millions of American workers have been exposed to asbestos. Health hazards from asbestos fibers have been recognized in workers exposed in the shipbuilding trades, asbestos mining and milling, manufacturing of asbestos textiles and other asbestos products, insulation work in the construction and building trades, and a variety of other trades. Demolition workers, drywall removers, asbestos removal workers, firefighters, and automobile workers also may be exposed to asbestos fibers. Studies evaluating the cancer risk experienced by automobile mechanics exposed to asbestos through brake repair are limited, but the overall evidence suggests there is no safe level of asbestos exposure (3, 8). As a result of Government regulations and improved work practices, today’s workers (those without previous exposure) are likely to face smaller risks than did those exposed in the past.

Individuals involved in the rescue, recovery, and cleanup at the site of the September 11, 2001, attacks on the World Trade Center (WTC) in New York City are another group at risk of developing an asbestos-related disease. Because asbestos was used in the construction of the North Tower of the WTC, when the building was attacked, hundreds of tons of asbestos were released into the atmosphere. Those at greatest risk include firefighters, police officers, paramedics, construction workers, and volunteers who worked in the rubble at Ground Zero. Others at risk include residents in close proximity to the WTC towers and those who attended schools nearby. These individuals will need to be followed to determine the long-term health consequences of their exposure (10).

One study found that nearly 70 percent of WTC rescue and recovery workers suffered new or worsened respiratory symptoms while performing work at the WTC site. The study describes the results of the WTC Worker and Volunteer Medical Screening Program, which was established to identify and characterize possible WTC-related health effects in responders. The study found that about 28 percent of those tested had abnormal lung function tests, and 61 percent of those without previous health problems developed respiratory symptoms (11). However, it is important to note that these symptoms may be related to exposure to debris components other than asbestos.

Although it is clear that the health risks from asbestos exposure increase with heavier exposure and longer exposure time, investigators have found asbestos-related diseases in individuals with only brief exposures. Generally, those who develop asbestos-related diseases show no signs of illness for a long time after their first exposure. It can take from 10 to 40 years or more for symptoms of an asbestos-related condition to appear (2).

There is some evidence that family members of workers heavily exposed to asbestos face an increased risk of developing mesothelioma (6). This risk is thought to result from exposure to asbestos fibers brought into the home on the shoes, clothing, skin, and hair of workers. To decrease these exposures, Federal law regulates workplace practices to limit the possibility of asbestos being brought home in this way. Some employees may be required to shower and change their clothes before they leave work, store their street clothes in a separate area of the workplace, or wash their work clothes at home separately from other clothes (2).

Cases of mesothelioma have also been seen in individuals without occupational asbestos exposure who live close to asbestos mines