The EU legislation requests post-market environmental monitoring (PMEM) of a genetically modified (GM) organism even if its pre-market risk assessment indicated negligible risks. It has been claimed that the monitoring of the only currently commercially cultivated GM plant in the EU, Bt MON810 maize, has not revealed any adverse effects. However, the implementation of its PMEM has been criticised repeatedly by the European Food Safety Authority (EFSA).

Although EFSA agreed with the monitoring plan consisting of four tools, as proposed by the company which markets MON810, in practice PMEM has relied on famers’ questionnaires, a farmers’ complaint system, and a literature survey. The fourth approach, environmental surveillance networks, has not been utilised yet. Furthermore, PMEM requires that farmers plant a refuge of non-Bt maize in order to sustain the efficiency of the plant in combating the targeted pest.

This paper aims to contribute to improved PMEM by means of a critical evaluation of its implementation in the Czech Republic based on interviews and a questionnaire survey of farmers who cultivated MON810. The results indicate that a quarter of the farmers who were surveyed did not comply with the refuge requirement. Moreover, farmers often lacked the knowledge, time, and motivation to observe and report the potential impacts of Bt maize on biodiversity, which is supposed to be monitored by the PMEM farmers’ questionnaire.

The findings of this study compound the previous criticism and suggest that the current practice of PMEM limits its aim of detecting unanticipated adverse effects of MON810 maize cultivation on human and animal health and the environment. The PMEM plan should be revised before the approval process of the application for the renewal of the authorisation for MON810 cultivation in the EU continues.

欧盟立法要求对转基因（GM）生物进行上市后环境监测（PMEM），即使其上市前风险评估表明风险可以忽略不计。据称，对欧盟目前唯一商业化种植的转基因植物Bt MON810玉米的监测并未发现任何不利影响。但是，其PMEM的实施遭到欧洲食品安全局（EFSA）的一再批评。

尽管EFSA同意监测MON810的公司提出的由四个工具组成的监测计划，但实际上PMEM依赖于​​农民的问卷，农民的投诉系统和文献调查。第四种方法，即环境监视网络，尚未使用。此外，PMEM要求农民种植非Bt玉米的避难所，以维持植物对抗目标害虫的效率。

本文旨在通过访谈和对种植MON810的农民进行问卷调查，对捷克共和国实施的PMEM进行严格评估，从而为PMEM的改进做出贡献。结果表明，接受调查的农民中有四分之一不符合庇护要求。此外，农民通常缺乏观察和报告Bt玉米对生物多样性的潜在影响的知识，时间和动力，应该通过PMEM农民调查表进行监测。

这项研究的发现加剧了先前的批评，并表明PMEM的当前实践限制了其检测MON810玉米种植对人类和动物健康及环境的意外不良影响的目的。在继续进行欧盟MON810种植许可更新申请的批准程序之前，应修改PMEM计划。