Results from ten years of post-market environmental monitoring of genetically modified MON 810 maize in the European Union.

In European regulations for the deliberate release into the environment of genetically modified organisms (GMO), the objective of General Surveillance in Post-Market Environmental Monitoring is defined as the identification of the occurrence of adverse effects of the GMO or its use which were not anticipated in the environmental risk assessment (ERA). Accompanying the commercial cultivation in the EU of maize event MON 810, General Surveillance was implemented by Monsanto, the authorization holder, on a voluntary basis. We carried out a statistical analysis on the pooled results of ten years of farmer questionnaires, which were a part of this General Surveillance, amounting to 2,627 farmer fields in eight European countries in the period 2006-2015. This analysis did not reveal any unexpected adverse effects associated with the cultivation of MON 810. Results from farmer questionnaires confirmed that the cultivation of MON 810 resulted in a significant reduction in the use of pesticides, efficient protection against the target pests, and healthier, higher yielding crops compared to conventional maize. MON 810 also had reduced susceptibility to disease and pests when compared to conventional maize. Monitoring characteristics related to environment and wildlife revealed no significant differences between MON 810 and conventional maize. Literature searches, that were also conducted as part of General Surveillance, identified a comprehensive set of publications addressing environmental safety as well as food and feed safety aspects of MON 810. None of the publications indicated any adverse effect of MON 810 that was not anticipated in the initial ERA, nor did they lead to a change in the conclusions of the initial risk assessment that demonstrated the safety of MON 810. The development of resistance by the target pests (Ostrinia nubilalis, ECB and Sesamia nonagrioides, MCB) was the only potential adverse effect identified in the ERA of MON 810 cultivation in the EU. The extensive safety data package for MON 810, the robust weight of evidence demonstrating both its safety and benefits, and the history of safe use of MON 810 for 15 years in the EU, indicates that focussing the General Surveillance of MON 810 on literature searches and farmer complaint systems would be appropriately protective. This will allow the identification of potential adverse effect not anticipated in the initial ERA without the intensive effort and organizational challenges of farmer questionnaires.

Impact of polychlorinated biphenyls contamination on estrogenic activity in human male serum.

Polychlorinated biphenyls (PCBs) are thought to cause numerous adverse health effects, but their impact on estrogen signaling is still not fully understood. In the present study, we used the ER-CALUX bioassay to determine estrogenic/antiestrogenic activities of the prevalent PCB congeners and PCB mixtures isolated from human male serum. The samples were collected from residents of an area with an extensive environmental contamination from a former PCB production site as well as from a neighboring background region in eastern Slovakia. We found that the lower-chlorinated PCBs were estrogenic, whereas the prevalent higher-chlorinated PCB congeners 138, 153, 170, 180, 187, 194, 199, and 203, as well as major PCB metabolites, behaved as antiestrogens. Coplanar PCBs had no direct effect on estrogen receptor (ER) activation in this in vitro model. In human male serum samples, high levels of PCBs were associated with a decreased ER-mediated activity and an increased dioxin-like activity, as determined by the DR-CALUX assay. 17beta-Estradiol (E2) was responsible for a major part of estrogenic activity identified in total serum extracts. Significant negative correlations were found between dioxin-like activity, as well as mRNA levels of cytochromes P450 1A1 and 1B1 in lymphocytes, and total estrogenic activity. For sample fractions containing only persistent organic pollutants (POPs), the increased frequency of antiestrogenic samples was associated with a higher sum of PCBs. This suggests that the prevalent non-dioxin-like PCBs were responsible for the weak antiestrogenic activity of some POPs fractions. Our data also suggest that it might be important to pay attention to direct effects of PCBs on steroid hormone levels in heavily exposed subjects.