Of Pregnant Women
Have Pesticides In Their Placenta
beings are directly responsible for more than 110,000 chemical
substances which have been generated since the Industrial Revolution.
Every year, we "invent" more than 2,000 new substances, most of
them contaminants, which are emitted into the environment and
which are consequently present in food, air, soil and water.
Nonetheless, human beings are also victims of these emissions,
and involuntarily (what is known in this scientific field as "inadvertent
exposure"), every day humans ingest many of these substances which
cannot be assimilated by our body, and are accumulated in the
fatty parts of our tissues.
This is especially worrying for pregnant women. During the gestation
period, all the contaminants accumulated in the organism have
direct access to the microenvironment where the embryo/foetus
develops. The doctoral thesis "Maternal-child exposure via the
placenta to environmental chemical substances with hormonal activity",
written by María José López Espinosa, from the Department of
Radiology and Physical Medicine of the University of Granada,
analyzes the presence of organochlorine pesticides -normally used
as pesticides- in the organisms of pregnant women. The analysis
was developed at San Cecilio University Hospital , in Granada,
with 308 women who had given birth to healthy children between
2000 and 2002. The results are alarming: 100% of these pregnant
women had at least one pesticide in their placenta, but the average
rate amounts to eight different kinds of chemical substances.
Fifteen different pesticides in the organisms of pregnant women
In her study, through the analysis of the placentas, López studied
the presence of 17 endocrine disruptive organochlorine pesticides
(i.e., pesticides which interfere with the proper performance
of the hormonal system). The results showed that the most frequent
pesticides present in the placenta tissue are DDE (92.7%), lindane
(74.8%), endosulfan diol (62.1%) y endosulfan-I (54.2%). Among
these, the most prevalent was endosulfan-diol, with an average
concentration of 4.15 nanograms per gram of placenta (156.73 ng/g
lipid). Surprisingly, the UGR
researcher discovered that some patients' placentas contained
15 of the 17 pesticides analyzed.
A total of 668 samples from pregnant women were used in this study,
which was approved by the Ethical Commission of San Cecilio University
Hospital . Mothers were informed of the study's goals before giving
their express consent.
Thanks to gynaecologists, the nurses and the midwives who participated
in the study, biological samples were extracted from the blood,
the umbilical cord and the placenta during childbirth. The following
day, an epidemiological survey was carried out by trained survey
statisticians. The survey contained questions on the general data
of the parents, their places of residence, profession, medical
history, anthropometric information, age, tobacco habits, lifestyle
and diet during pregnancy, among other factors.
The study made at the UGR has facilitated research into the association
of the characteristics of parents, newborn babies and childbirth
with exposure to pesticides found in the mothers' placenta. Among
the aspects associated with a higher presence of pesticides we
find an older age, higher body mass index, less weight gained
during pregnancy, lower educational level, higher workplace exposure,
first-time motherhood and lower weight in babies.
"Serious effects on the baby"
According to María José López, "we do not really know the consequences
of exposure to disruptive pesticides in children, but we can predict
that they may have serious effects, since this placenta exposure
occurs at key moments of the embryo's development".
The research group to which María José López belongs, directed
by Prof. Nicolás Olea Serrano, has conducted several studies which
associate exposure to pesticides with neonatal malformations
if the genito-urinary system, such as cryptorchidism (undropped
testicles) and hypospadias (total fusion of the urethral folds).
The UGR researcher underlines the fact that, in spite of "inadvertent
exposure", "it is possible to control pesticide ingestion by means
of a proper diet, which should be healthy and balanced, through
consumption of food whose chemical content is low. Moreover, daily
exercise and the avoidance of tobacco (which could also be a source
of inadvertent exposure) are very important habits which help
to control the presence of pesticides in our organisms.
The UGR researcher's work is framed within the objectives established
in the research project "Increasing incidence of human male reproductive
health disorders in relation to environmental effects on growth-and
sex steroid-induced alterations in programmed development" (Environmental
Reproductive Health), directed and carried out by a multidisciplinary
group of clinicians, basic researchers and epidemiologists at
several institutions from countries such as Denmark, Finland or
England and financed by the European Union (QLK4-1999-01422).