A recent Australian study examined the association between asbestos exposure from residential insulation and the risk of cancers such as mesothelioma.
Until the nineties, asbestos-contaminated material was the main insulators in most homes in countries such as Australia, Canada, and the United States. There is substantial evidence to prove that asbestos causes mesothelioma and certain other cancers like cancer of the lung, ovary and larynx. This evidence was mostly obtained from those exposed at their place of work such as mine workers, those in manufacturing and construction industries as well as their family members, and those who live close to asbestos-related industries. Little is known about the link between asbestos exposure in residential properties and risk of cancer.
Does Living in an Affected House Increase the Chance of Cancer?
To determine the association between the risk of mesothelioma and other cancers and living in a house insulated with loose-fill asbestos, Korda and colleagues conducted a cohort study in the Australian Capital Territory (ACT). This study was published in The Lancet Public Health and included all those who were enrolled in the Australian universal health insurance provider from the Australian Capital Territory between November 1, 1983 and December 31, 2013.
The study classified individuals as either exposed (those who had lived at a residential property that has asbestos insulation during the study period) or unexposed (those that have never lived in an asbestos-affected residential property). The outcome of interest for this cohort was the development of cancer. The cancers that were examined included mesothelioma (the primary cancer of interest), lung (including bronchus, lung, and trachea), ovarian, laryngeal, pharyngeal, stomach, and colorectal. Four other common cancers with little or no evidence of association with asbestos (bladder cancer, kidney cancer, melanoma, and prostate cancer) were also examined.
During the study period, 1,035,578 individuals were identified as those who have ever lived in the ACT, of which, 17,248 were exposed (had lived in affected residential property). A total of 285 people (all men) had mesothelioma – seven of whom had lived at an affected residential property before their diagnosis.
Mesothelioma Levels Related to Asbestos
A thorough analysis showed that the incidence of mesothelioma in unexposed males was 2.25 cases per 100 000 while in exposed males it was 8.26 cases per 100, 000, indicating a 2.5 times increase in the risk of mesothelioma in exposed males. No evidence of association was found between asbestos exposure and risk of lung, ovarian, laryngeal, pharyngeal and stomach cancers. There was an increase in colorectal cancer in both male and female residents of the ACT who had ever lived in an affected residential property compared to those who had never lived in an affected property. However, the increase for males was not statistically significant. For bladder and kidney cancer, no difference was found between exposed and unexposed population, however, prostate cancer was found to be higher in exposed men than unexposed men.
This study is the first to evaluate the evidence of a cancer risk with living in a house with asbestos insulation. These results show that asbestos exposure in domestic dwellings can lead to an increase in the risk of mesothelioma, colorectal, and prostate cancer. Despite being an excellent insulator, asbestos is not likely to be safe for use in both occupational and domestic settings and as such the government should consider the health, legal, and social implications of the use of such materials in these settings.
Written by Asongna T. Folefoc
Reference: Korda RJ, Clements MS, Armstrong BK, Law HD, Guiver T, Anderson PR, Trevenar SM, Kirk MD. Risk of cancer associated with residential exposure to asbestos insulation: a whole-population cohort study. Lancet Public Health 2017; 2: e522–28