On May 12 the National Cancer Institute published an updated report on its ongoing study of industrial workers with high formaldehyde exposure. The findings indicate a possible link between high formaldehyde exposure and increased risk of cancers of the blood and lymphatic system, most notably Hodgkin’s lymphoma, multiple myeloma, and myeloid leukemia.

"The overall patterns of risk seen in this extended follow-up of industrial workers, while not definitive, are consistent with a causal association between formaldehyde exposure and cancers of the blood and lymphatic system and warrant continued concern,” said the lead author of the report, Dr. Laura Beane-Freeman.

Initiated in the 1980s, the study tracked 25,169 workers who worked in industrial plants that produced formaldehyde or formaldehyde resin prior to 1966. In the resulting 40 years, the study found that workers with the highest peak exposure had a 37 percent increased risk of death from blood and lymphatic cancers, compared to those with the lowest levels of peak exposure. The report also indicated a significantly higher increased risk of death from myeloid leukemia. Workers with the highest peak exposure had a 78 percent increased risk of death from myeloid leukemia, compared to those with the lowest levels of peak exposure.

Although this new evidence suggests a link between formaldehyde exposure and increased risk of leukemia, scientists have not yet identified a mechanism for how normal white blood cells become leukemic. Prior studies have demonstrated that people with exposure to inhaled formaldehyde have higher rates of chromosomal damage, and it has been suggested that these formaldehyde-related chromosomal aberrations may cause leukemia.

In spite of these alarming statistics, Dr. Beane-Freeman insists that the recently published results are not definitive and warrant additional investigation. "Further studies are needed to evaluate risks of these cancers in other formaldehyde-exposed populations and to assess possible biological mechanisms,” said Dr. Beane-Freeman.

For more information, please read the press release at the National Cancer Institute Website or the published report at the Journal of the National Cancer Institute.