Can Asbestos Exposure Cause Lymphoma?

Existing research on the connection between asbestos exposure and lymphoma, a systemic cancer of the immune system, is mixed.  Most research suggests that there is no causal link, or that there is as yet insufficient evidence to support this contention.

Scientific Research on Asbestos and Lymphoma

In one of the most comprehensive studies of asbestos exposed workers, researchers found 19 cases of lymphoma among a cohort of 17,800 members of the International Association of Heat and Frost Insulators and Asbestos Workers of the U.S. and Canada.  The rate of lymphoma among this confirmed asbestos-exposed population corresponds with that of the general American population, suggesting that asbestos exposure does not increase the risk of lymphoma.  Other, smaller studies reiterate this finding [1]

A meta-review of existing epidemiological research on asbestos exposure and non-Hodgkin’s lymphoma and other types of hematolymphoid cancers found that laboratory studies on animals have not found an increase in either of these forms of cancer among animals exposed to asbestos, and the vast majority of epidemiological studies of asbestos-exposed humans (as of 2002) similarly showed no increased risk.

On the other hand, several case-control studies have suggested some sort of relationship between asbestos exposure and lymphoma.  For example, one study of large-cell lymphoma patients found that they a significant number were likely to have experienced “substantial exposure” to asbestos.  The correlation was even more likely when the cancer affected the gastrointestinal tract and oral cavity than other areas of the body, and the researchers posit this may be a result of patients ingested and absorbed asbestos fibers through the mucosa.  Several other studies have suggested higher rates of non-Hodgkin’s lymphoma among asbestos exposed workers, with one finding twice as many deaths from the disease than expected based on the national average.

Law, Politics, and Asbestos Research

Unfortunately, asbestos research has been highly politicized, as companies with a history of exposing employees to asbestos fund research and pressure politicians in order to mitigate the costs of compensating former workers.  Lawsuits and workers compensation decisions related to claims that occupational exposure to asbestos resulted in lymphoma rely on the testimony of expert witnesses, and judges and workers compensation boards have been inconsistent in their rulings over whether there is a link between asbestos and lymphoma.

  1. Smaller Studies: