OBJECTIVE: To determine whether serum levels of chlorinated
hydrocarbons are elevated in patients with chronic fatigue
METHODS: Chlorinated hydrocarbon levels were
measured in 22 patients with chronic fatigue syndrome (CFS)
(as defined by the Centers for Disease Control [CDC]); in 17
patients with CFS symptoms whose history of exposure to toxic
chemicals excluded them from the research definition of CFS;
and in 34 non-CFS control subjects matched for age and sex.
RESULTS: DDE (1,1-dichloro-2,2-bis (p-chlorophenyl) ethene)
was detected in all serum samples at levels over 0.4 ppb. The
incidence of hexachlorobenzene (HCB) contamination (> 2.0 ppb)
was 45% in the CFS group, compared with 21% in the non-CFS
control group (P < 0.05). The CFS group had a significantly
higher total organochlorine level (15.9 ppb; SEM, 4.4) than
the control group (6.3 ppb; SEM, 1.1; P < 0.05). The toxic
exposure group also had a higher mean organochlorine level
(13.6 ppb; SEM, 6.2) than the control group, but the
difference was not statistically significant. DDE and HCB
comprised more than 90% of the total organochlorines measured
in each of the groups.
CONCLUSION: The results suggest that
recalcitrant organochlorines may have an aetiological role in
CFS. There were no significant differences in serum
organochlorine concentrations between CFS patients and chronic
fatigue patients with a history of toxic chemical exposure.
Therefore, exclusion of patients from the CDC research
definition of CFS on the basis of a reported history of known
exposure to toxic chemicals is not valid. The role of
low-level organochlorine bioaccumulation in the development of
CFS symptoms requires further investigation.
MCM: See also Editorial 96,018,934
Dunstan RH, Donohoe M, Taylor W, Roberts TK, Murdoch RN, Watkins JA,