The Beijing News reports that an experiment by Zhang Hao, a grade-six pupil in Beijing, found that more than 90 percent of fresh mushrooms on the market were tainted with fluorescent brightener, a compound considered a potential cause of cancer.
His results were backed by microbiologist Gao Ruifang, of the China Agricultural University, who called the pupil’s method 100% reliable.
Zhang, a member of the "science exploration group" at the Xicheng District Youth Science and Technology Museum in Beijing, tested 16 kinds of mushrooms from retail and wholesale markets using ultraviolet light, which would cause the brightener to shine.
Only three of the 16 samples were untainted – organic needle mushrooms and two types of dried mushroom, CRIEnglish.com reported.
The results showed most of the fresh mushrooms were tainted. The dried mushrooms, with their long shelf life, were clean because they didn’t need brighteners to keep their freshness.