Maternal and fetal exposure to pesticides associated to genetically modified foods in Eastern Townships of Quebec, Canada
Aziz Aris (a,b,c,*), Samuel Leblanc (c)
(a) Department of Obstetrics and Gynecology, University of Sherbrooke
Hospital Centre, Sherbrooke, Quebec, Canada
(b) Clinical Research Centre of Sherbrooke University Hospital Centre,
Sherbrooke, Quebec, Canada
(c) Faculty of Medicine and Health Sciences, University of Sherbrooke,
Sherbrooke, Quebec, Canada
(*) Corresponding author at:Department of Obstetrics and Gynecology, University of Sherbrooke Hospital Centre, 3001, 12e Avenue Nord, Sherbrooke, Quebec, Canada
J1H 5N4. Tel.:+18198206868x12538; fax:+18195645302. E-mail address: firstname.lastname@example.org (A. Aris).
Pesticides associated to genetically modified foods (PAGMF), are engineered to tolerate herbicides such as glyphosate (GLYP) and gluphosinate (GLUF) or insecticides such as the bacterial toxin bacillus thuringiensis (Bt). The aim of this study was to evaluate the correlation between maternal and fetal exposure, and to determine exposure levels of GLYP and its metabolite amino methylphosphoricacid (AMPA), GLUF and its metabolite 3-methylphosphinicopropionicacid (3-MPPA) and Cry1Abprotein (a Bt toxin) in Eastern Townships of Quebec, Canada. Blood of thirty pregnant women (PW) and thirty-nine non pregnant women (NPW) were studied. Serum GLYP and GLUF were detected in NPW and not detected in PW. Serum 3-MPPA and CryAb1 toxin were detected in PW, their fetuses and NPW. This is the first study to reveal the presence of circulating PAGMF in women with and without pregnancy, paving the way for a new field in reproductive toxicology including nutrition and utero-placental toxicities.
Our results show that GLYP was not detected in maternal and fetal blood, but present in the blood of some non-pregnant women (5%), whereas its metabolite AMPA was not detected in all analyzed samples. This is may be explained by the absence of exposure, the efficiency of elimination or the limitation of the method of detection. Previous studies report that glyphosate and AMPA share similar toxicological profiles. Glyphosate toxicity has been shown to be involved in the induction of developmental retardation of fetal skeleton  and significant adverse effects on the reproductive system of male Wistar rats at puberty and during adulthood . Also, glyphosate was harmful to human placental cells [35,36] and embryonic cells . It is interesting to note that all of these animal and in vitro studies used very high concentrations of GLYP compared to the human levels found in our studies. In this regard, our results represent actual concentrations detected in humans and therefore they constitute a referential basis for future investigations in this field.
GLUF was detected in 18% of non pregnant women’s blood and not detected in maternal and fetal blood. As for GLYP, the non detection of GLUF may be explained by the absence of exposure, the efficiency of elimination or the limitation of the method of detection. Regarding the non-detection of certain chemicals in pregnant women compared with non pregnant women, it is assumed that the hemo dilution caused by pregnancy may explain, at least in part, such non-detection. On the other hand, 3-MPPA (the metabolite of GLUF) was detected in 100% of maternal and umbilical cord blood samples, and in 67% of the non pregnant women’s blood samples. This highlights that this metabolite is more detectable than its precursor and seems to easily cross the placenta to reach the fetus. Garcia et al.  investigated the potential teratogenic effects of GLUF in humans found and increased risk of congenital malformations with exposure to GLUF. GLUF has also been shown in mouse embryos to cause growth retardation, increased death or hypoplasia . As for GLYP, it is interesting to note that the GLUF concentrations used in these tests are very high (10ug/ml) compared to the levels we found in this study (53.6ng/ml).
Hence, our data which provide the actual and precise concentrations of these toxicants, will help in the design of more relevant studies in the future. On the other hand, Cry1Ab toxin was detected in 93% and 80% of maternal and fetal blood samples, respectively and in 69% of tested blood samples from non pregnant women. There are no other studies for comparison with our results.
However, trace amounts of the Cry1Ab toxin were detected in the gastrointestinal contents of livestock fed on GM corn [38–40], raising concerns about this toxin in insect-resistant GM crops; (1) that these toxins may not be effectively eliminated in humans and (2) there maybe a high risk of exposure through consumption of contaminated meat.
To our knowledge, this is the first study to highlight the presence of pesticides-associated genetically modified foods in maternal, fetal and non pregnant women’s blood. 3-MPPA and Cry1Ab toxin are clearly detectable and appear to cross the placenta to the fetus. Given the potential toxicity of these environmental pollutants and the fragility of the fetus, more studies are needed, particularly those using the placental transfer approach .
Thus, our present results will provide baseline data for future studies exploring a new area of research relating to nutrition, toxicology and reproduction in women. Today, obstetric-gynecological disorders that are associated with environmental chemicals are not known.
This may involve perinatal complications (i.e. abortion, prematurity, intra uterine growth restriction and preeclampsia) and reproductive disorders (i.e. infertility, endometriosis and gynecological cancer).
Thus, knowing the actual PAGMF concentrations in humans constitutes a cornerstone in the advancement of research in this area.