What is formaldehyde?

Exposure routes: Inhalation

Where found: Manufacturing plants, prefabricated dwellings, hospitals, mortuaries, smog

At risk: Workers involved in tissue fixation and in manufacturing plastics, particleboard, wood paneling, and furniture; occupants of prefabricated dwellings

Etiology and symptoms of associated cancers:
When formaldehyde reacts with adjacent primary amine groups in proteins or other biomolecules, the resulting covalent bond prevents normal mobility and functioning of the joined molecules. Repeated or sustained exposure to high concentrations (greater than 15 parts per million) of inhaled formaldehyde is sufficient to cause tissue damage, mutations, and increased cell turnover, which can result in malignant transformation. Cells in the upper respiratory tract (the nasopharynx) are especially liable to formalin-induced cancers, which take the form of squamous cell carcinomas. Formaldehyde’s carcinogenicity has been demonstrated only in rodents exposed to very high gas concentrations over long periods of time, and extrapolation to human carcinogenicity was speculative as of 1981, when it was listed in the Second Annual Report on Carcinogens as "reasonably anticipated to be a human carcinogen." Between 1981 and 2011, studies in humans were published and it was listed for the first time in the Twelfth Report on Carcinogens (2011) as a known human carcinogen.

History: Formaldehyde was first described and chemically synthesized in the 1800s, although it exists in small quantities in the atmosphere naturally and is a product of amino acid metabolism in the body. Its widespread adoption in the chemical industry prompted several large studies to search for diseases associated with exposure. According to the Report on Carcinogens, Thirteenth Edition (2014), consistent findings in epidemiological studies have shown a causal relationship between formaldehyde exposure and human cancer, including myeloid leukemia, nasopharyngeal cancer, and sinonasal cancer. Because of its many other adverse health effects, formaldehyde is subject to occupational and residential monitoring, with variable exposure limits in different jurisdictions.

Bibliography

Agency for Toxic Substances and Disease Registry. Formaldehyde: CAS #50-00-0. Atlanta: ATSDR, 1999. Digital file.

Centers for Disease Control and Prevention. "Formaldehyde." CDC.gov. CDC, 3 Mar. 2012. Web. 28 Oct. 2014.

Marsh, Gary M., et al. "Issues of Methods and Interpretation in the National Cancer Institute Formaldehyde Cohort Study." Jour. of Occupational Medicine & Toxicology 9.1 (2014): 1–17. Digital file.

Natl. Cancer Inst. "Natl. Cancer Inst. FactSheet: Formaldehyde and Cancer Risk." Cancer.gov. NCI, 10 June 2011. Web. 28 Oct. 2014.

US Dept. of Health and Human Services Natl. Toxicology Program, Natl. Inst. of Environmental Health Sciences, Natl. Insts. of Health. "Formaldehyde: CAS No. 50-00-0." Report on Carcinogens, Thirteenth Edition. Washington, DC: GPO, 2 Oct. 2014. Digital file.

US Envirnomental Protection Agency. "An Introduction to Indoor Air Quality (IAQ): Formaldehyde." EPA.gov. EPA, 20 June 2012. Web. 28 Oct. 2014.