Industrial Formaldehyde Exposure Linked to Increased Risk for Blood and Lymphatic System Cancers

The latest results from a long-term study of the effects of formaldehyde exposure on a group of 25,619 industrial workers indicates a possible link between the chemical and deaths from cancers of the blood and lymphatic system, according to researchers at the National Cancer Institute.

For almost 25 years, the NCI has studied the cancer deaths among a group of workers employed before 1966 in 10 industrial plants that produced formaldehyde and formaldehyde resin and that used the chemical to produce molded-plastic products, decorative laminates, photographic film or plywood, an NCI press release stated.

The chemical already is associated with nasopharyngeal cancer, which led the International Agency for Research on Cancer to classify it as a human carcinogen. By 1995, an estimated 2.1 million workers had been exposed to formaldehyde in the United states, according to the U.S. Occupational Safety and Health Administration.

In this study, the researchers found a statistically significant association between peak formaldehyde exposure and death from all blood and lymphatic cancers combined.

The workers who experienced the highest peak exposures had a 37 percent increased risk of death compared to the ones exposed to the lowest levels, the researchers noted. This represents an excess risk of death from several specific cancers, including Hodgkin's lymphoma, multiple myeloma, and myeloid leukemia, which is the cancer most often tied with chemical exposure.

Risk of death from myeloid leukemia in this study was 78 percent higher among the industrial workers with the highest peak exposures.

“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. Further studies are needed to evaluate risks of these cancers in other formaldehyde-exposed populations and to assess possible biological mechanisms," said lead author of the report, Laura E. Beane Freeman, Ph.D., NCI Division of Cancer Epidemiology and Genetics.

Currently, scientists can’t identify the mechanism that turns normal white cells leukemic when exposed to formaldehyde. However, other studies have shown that inhaled formaldehyde damages chromosomes in a certain type of mature white blood cell.

The study is the first to report a statistically significant association between chemical exposure and increased risk of death from Hodgkin lymphoma. The results are from the aticle, “Lymphohematopoietic Malignancies Among Workers in Formaldehyde Industries: The National Cancer Institute Cohort,” published online on May 20, 2009, JNCI, Vol. 101, No. 10.