There is no basis for rumors that cut cakes contain mercury. Mercury is actually very expensive. In terms of price, one kilogram of mercury is about 200 yuan. The most important thing is that mercury is toxic. The steam generated by mercury at high temperature is highly toxic. People who make these cakes will not wear gas masks to do it. Some people say that the cake is getting heavier because of mercury, which is also very unreliable. How much mercury do you have to put to obviously feel the cake getting heavier? So it is untrue that there is mercury in this online rumor.
Another netizen broke the news that there is 0.5 mg of mercury additive in every 500 grams of cut cake. A small amount of mercury can indeed polymerize sugar polymers and increase their density. But you won't react if you eat a catty of cut cake. Mercury cannot be metabolized out of the body. If it is eaten for a long time, it will deposit in the body, causing kidney diseases.