The Reliability of Full-Band Signal Blockers: A Closer Look at the Controversy

In an effort to prevent cheating during the national college entrance examination, many examination management agencies across the country have installed full-band signal blockers, which have signal interference capabilities, in various examination halls. However, a widely circulated article titled “Founder of Full-Band Signal Blocker Claims Harmful Effects on Humans” has raised concerns about the safety of these devices. In response, the Ministry of Education officially stated that the claims lack scientific evidence and that the expert from Tsinghua University, who made the statement in the media, is not an employee of the university. While the Ministry of Education does not mandate the use of full-band signal blockers in examination halls, they believe that these devices are the most effective means of preventing widespread cheating. The ministry has already issued safety requirements for schools using full-band signal blockers and plans to release guidelines on the use of these devices in the near future. This article aims to examine the reliability of the claims regarding the harmful effects of full-band signal blockers on the human body.

The Relationship between Radiation and Distance:

According to the responsible person from the Ministry of Education’s Student Affairs Department, the harmfulness of full-band signal blockers to the human body cannot be generalized as either harmful or harmless. The level of radiation depends on the distance from the device; the farther away, the smaller the impact, whereas close proximity, such as holding it against the ear, can have a significant effect. To gain further insight into the matter, the journalist interviewed a professional who has been involved in the research and sales of full-band signal blockers for over a decade. The professional stated that the damage caused by full-band signal blockers is similar to that of mobile phones. Despite daily exposure to these devices, they have not experienced any significant adverse reactions.

Comparing Radiation Levels:

The professional further explained that the electronic power value of the mobile phones currently in use is 2 watts, while the power of full-band signal blockers is required to be less than 2 watts. If the harmful effects were as significant as claimed, it would be unlikely for people to continue using mobile phones. Additionally, the full-band signal blockers produced and distributed by their company have undergone testing at the Electronic Institute of the Ministry of Public Security before being promoted, and no abnormalities were found. Moreover, out of the 136 cinemas in Beijing, 70% have installed these full-band signal blockers, and there have been no reports of discomfort among individuals in the covered areas.


In conclusion, the claims regarding the harmful effects of full-band signal blockers on the human body lack scientific evidence. The Ministry of Education emphasizes that the level of radiation depends on the distance from the device, and while close proximity may have a significant impact, the overall risk is minimal. The professional interviewed, who has extensive experience in the research and sales of full-band signal blockers, also attests to the safety of these devices. With the Ministry of Education planning to release guidelines on the use of full-band signal blockers, it is evident that these devices are considered an effective means of preventing cheating on a large scale. As long as the devices are used in accordance with safety requirements, concerns about their potential harm to individuals can be alleviated.