Workers in steel industry are working.[Photo/IC]

The boiler you use is made of manganese steel that can make you stupid.

The sweet balls in bubble tea are made of polymers. If you have one cup every day, you will get intestinal cancer.

Switch off the WiFi router! Or the radioactive wave will kill you!

These are just three of the strong rumors doing the rounds. Unlike the ones about social incidents, they have one thing in common: fabricating the negative effects certain modern technological breakthroughs have on human health. And they are often more widespread than rumors about social incidents.

The manganese-steel-boiler rumor has been so strong that people in Guangzhou, capital of South China's Guangdong province, have made a beeline to buy glass boilers to replace them.

Such rumors are rather persistent. For example, the rumor about WiFi harming people's health has been on the top-10 annual rumor list since 2013 that guokr.com updates every year.

Why are there so many rumors against technological breakthroughs? And why is it so difficult to extinguish them?