Trial Information

Studies of Myeloid Progenitor Cells in Workers Exposed to Formaldehyde, a Putative Leukemogen

Research in industrial workers and professionals exposed to formaldehyde suggests that
occupational exposure to this important chemical is associated with increased risk for
myeloid leukemia. The significance, however, of these observations for occupational and
environmental health is uncertain because of inconsistencies among epidemiologic studies and
lack of a demonstrated mechanism through which formaldehyde can cause leukemia. Cytogenetic
damage is one potential leukemogenic mechanism, but there are few studies of
formaldehyde-exposed humans. Some experimental data suggest that epigenetic changes in
myeloid cells could also be involved. We plan to study 40 workers exposed to high levels of
formaldehyde and 40 unexposed controls to examine the hypothesis that formaldehyde is
associated with these changes. To determine formaldehyde exposure, we will incorporate a
number of methods, including questionnaires to determine potential past exposure and on-site
monitoring to determine current average and peak intensities of exposure. We will then
examine differences in aneuploidy and structural abnormalities in myeloid progenitor cells
cultured from peripheral blood. We will specifically look for differences in genes
associated with myeloid leukemia such as monosomy 7 and trisomy 8 using interphase and
Octochrome FISH. We will also determine whether aberrant methylation in progenitor cells,
specifically hypermethylation of genes associated with myeloid leukemia, is higher in those
exposed to formaldehyde. This study will substantially contribute to our understanding of
the leukemogenic potential of formaldehyde, which has important public health and regulatory
implications.