Spontaneous sister chromatid exchanges (SCEs) were counted
in blood lymphocytes from samples drawn from soldiers of the 11th Armored
Cavalry Regiment before, during, and after their deployment from Germany
to Kuwait in 1991. Frequencies of SCE for the three periods were 4.41,
5.11, and 5.29 per cell, respectively. The statistically significant increase
persisted for at least one month following return to Germany. This study
was prompted by concerns that the smoke from burning oil wells may have
contained potentially carcinogenic polycyclic aromatic hydrocarbons (PAH).
SCE has been employed as an indicator of genotoxic exposure to environmental
agents. The authors cite other literature which has linked increased SCEs
with: stress, noise, electric shock, sleep deprivation, measles vaccination,
alpha quartz, and pesticides. Limitations of the study: because there
are many possible causes for increases in SCE beyond those cited by the
authors, the meaning, if any, of the results is unknown; the long term
health implications of SCE frequencies have not been established.