EN
Polychlorinated biphenyls (PCBs) and dioxins
(PCDDs/Fs) are well-known endocrine disrupters. This
paper strives to elucidate the data on reproductive
consequences of perinatal dioxin and PCB exposure in
men and women. We focused on the following end-points:
sex-ratio, endometriosis, menstrual cycle characteristics,
sperm quality, and prematurity. We summarize 46 papers
and compare their results including effects seen after
exposure to background concentrations. Seven of twelve
studies showed a decrease in sex-ratio after parental dioxin
or PCB exposure. In three of the seven studies, effects were
seen after paternal exposure and in three after maternal
exposure. In eight of the nine studies on menstrual cycle
characteristics, abnormalities were associated with
PCB or dioxin exposure, however the results differed. In
three studies PCB and TCDD were associated with longer
menstrual cycles, while three studies indicated that an
increase in PCB/PCDF exposure was associated with
shorter cycles. Five studies showed effects on menstrual
bleeding with higher PCB or dioxin exposure. A higher rate of irregular menstrual cycles in exposed women was
seen in four studies. The conflicting outcomes probably
result from variability in study design, timing of exposure
and endocrine disrupting properties of the measured
congeners. Nine of sixteen studies detected higher PCB or
dioxin exposure in women with endometriosis. However,
the manner of diagnosing endometriosis and the character
of the studies varied from prospective to retrospective. Five
of eight studies focusing on sperm quality showed that
men, with higher serum concentrations of PCBs and/or
PCB congeners and/or PCDFs, had reduced sperm quality,
including increased abnormal morphology and reduced
motility. The exposure timeframe seemed important here.
There are two studies addressing preterm birth in relation
to PCBs, one mentioned a shortening of three days of
gestational age, two other studies did not find a relation.
Recently one study related a shorter gestational age of
half a week with overall dioxin activity measured with
the CALUX method in cord blood, particularly in boys. In
conclusion, exposure to PCBs and dioxins has a negative
effect on the reproductive systems of human populations.
Although some speculations have been made, the exact
mechanism of these effects and the interactions of these
compounds with other endocrine disruptors are not yet
known. Age at exposure and congener specific properties
are probably crucial in interpreting the observed results.