Blogger Yulie Qige posted a video on September 18 documenting his entire process of tracking down unscrupulous merchants in Qingyuan, Guangdong, who use sulfur to fumigate ma bamboo shoots. He said tests showed sulfur dioxide levels exceeded the limit by dozens or even hundreds of times, and pointed out that long-term consumption of sulfur-fumigated shoots containing arsenic and heavy metals carries a cancer risk. The Qingyuan Market Supervision Bureau subsequently issued a report confirming that individual dens had illegally used sulfur fumigation; the dens involved have been sealed off, and the distribution of the tainted bamboo shoots is being traced.