A study on shark fin conducted by the Department of Ecology and Taxonomy of the University of Hong Kong found that shark fin contains more mercury or other heavy metals than other fish. This is because human beings constantly discharge industrial wastewater into the ocean, which makes the content of heavy metals such as mercury in seawater high and marine life also affected. Sharks are at the top of the marine food chain and often accumulate a lot of pollution toxins in their bodies. In addition to the possibility of male infertility, high levels of mercury in the human body can also damage the central nervous system and kidneys. Eating more shark meat and shark fins may be harmful to human health.

Trent revealed that "wildaid" also conducted an investigation, and randomly sampled 10 shark fins in a street, and found that 7 of them contained 0.57-2 1.02 ppm of mercury, which exceeded the edible concentration (0.5ppm). This is an unexpected result.

The relevant departments of our country have also made a series of investigations on the heavy metal content of shark fin: cadmium, lead, arsenic and other metal elements have been found in the tissue samples of shark species in the eastern Mediterranean; Spot check of shark fin in Chinatown market in Bangkok, Thailand shows that 70% of shark fin contains mercury that can be absorbed by human body, and the highest proportion exceeds the normal allowable amount by 42 times. A sample survey in Hong Kong market found that 8 shark fins in 10 contained high content of methylmercury, and the highest content was four times the allowable amount.

Dr. Liao Xianping, Dean of Guangdong Armed Police Corps Hospital, said that excessive intake of mercury is more harmful to pregnant women and will affect the generation of fetal brain and nerve cells. "When you spend a lot of money on shark fin soup, what you buy is probably only harm to yourself." He said. Although this risk is not too great for ordinary people who eat shark fin several times a year, it needs to be taken seriously for people who like to eat shark fin or often attend dinner parties.