Epidemiology

Breathing formaldehyde causes cancer

Formaldehyde may look like an innocent clear liquid in the jars sitting on a lab shelf but it’s not. The substance used regularly by embalmers and pathologists has proven to cause leukemia and cancers of the nose and throat, nasal cavities and sinuses.

A group of 26 researchers who met over the summer at the International Agency for Research on Cancer (IARC), came to that very conclusion. The meeting of the World Health Organization agency brought researchers from 10 different countries to Lyons from June 2 nd to 8 th and was chaired by chemist Michel Gérin, head of the Université de Montréal’s Department of Environmental and Occupational Health. “Quebecers have heard a lot about urea formaldehyde insulating foam, which is now prohibited,” explains Michel Gérin. “But that doesn’t mean that formaldehyde is not being used much nowadays. In fact, many consumer items contain or release the chemical, albeit in small concentrations. These include particleboard, furniture, clothes and some resin-based products such as paints and glue.”

According to a recent survey, 40,000 Quebecers work in conditions where there is some exposure to formaldehyde. Embalmers, who preserve cadavers with formalin (of which formaldehyde is a derivative), are among those most exposed to the chemical, known to be an eye, nose and throat irritant,” according to Michel Gérin. But hospital pathologists, laboratory technicians, and researchers who are in contact with formalin, which is still used to preserve tissue, are also at risk. “People who are heavily exposed are two to five times more at risk of contracting some types of cancers than the general public,” said the specialist.

Michel Gérin, who has studied formaldehyde for 20 years, suspects the product causes various kinds of tumours, but has not found enough scientific proof to convince an agency like the IARC to put it at the top of its ‘black list.’ “When researchers meet, they give priority to epidemiological studies. Those are about human subjects. But toxicological studies of animals are also very important in the absence of indisputable human findings.”

Research conducted in various countries has built a case against formaldehyde. In a study in the United States, where 22,000 chemical industry workers were examined, those most exposed were two to three times more at risk of cancer of the rhinopharynx (ear, nose and throat), a relatively rare cancer. Other studies of different work environments have yielded similar results.

The researcher describes the IARC as a sort of ‘scientific court’ because its deliberations have much in common with a court of law. It does conduct a careful systematic examination of all evidence. However, if there is no consensus among scientists, the majority rules. And as in real life, often enough the suspect is acquitted due to a lack of evidence.