Britain’s mesothelioma rate is the highest in the world, which makes it an ideal location to study environmental exposure to asbestos. In the UK, incidents of the disease are especially prevalent among those over age 70. It often takes more than 35 years after initial exposure to asbestos for cancer to develop.
In The Inhaled Particle Study (TIPS), South Thames Multicentre Research Committee looked at the link between asbestos exposure and mesothelioma risks among construction workers and the general population in the UK.
Researchers conducted interviews and analyzed lung samples of cancer patients. The purpose of the interviews was to document participants’ work histories and assess their potential asbestos exposure. By the 1980s, asbestos was no longer used in construction, so researchers anticipated fewer incidents of mesothelioma and related cancers among study subjects who were younger and therefore less likely to have worked in contaminated buildings.
Those who participated in the telephone interviews were born between 1918 and 1996, while those who agreed to submit lung samples were born in 1940 or later. The study included members of the general population and workers believed to be at higher risk for exposure– carpenters, plumbers, painters, and the like.
What they discovered
The researchers concluded that, among those born in Britain after 1965, the average lifetime mesothelioma risk stemming from environmental or occupational asbestos exposure will be about 1 in 10,000, considerably less than the rate among older workers, especially carpenters born in the 1940s. Risks are likely higher among workers exposed to the material during construction, with carpenters having the highest concentrations of the carcinogen in their lungs. Plumbers and electricians were also considered high-risk. Exposure rates were moderate among factory workers.
In older buildings, workers have an increased chance of coming into contact with the cancer-causing fibers when asbestos is removed or disturbed. Similarly, members of the general population who have spent time in highly-contaminated buildings may also have greater opportunities for exposure.
Because airborne asbestos concentrations are too low and variable to measure reliably, mesothelioma risks of current exposure cannot be established, although asbestos particles can still pose occupational hazards, especially amosite and crocidolite (brown and blue asbestos, respectively).
So is environmental asbestos declining?
Because exposure risks are not fully understood, more research is needed to determine whether asbestos hazards remain consistent or are really declining. This is especially a concern in schools, as researchers investigate whether environmental exposure begins in childhood or upon entering the workforce.