(Yicai Global) March 8 -- Authorities in Hunan have ordered all betel nut processors in the central Chinese province to stop advertising across the country amid health concerns.

The companies were told to cancel all ads by March 15, state-backed news outlet the Paper reported, citing the Hunan Betel Food Industry Association. The ban covers newspapers, radio, television, subways, buses, online platforms, electronic screens, shop signboards, cinemas, and taxi ranks.

The State Food and Drug Administration listed betel nut as a first grade carcinogen in 2017. Most cases of mouth cancer in Hunan and Hainan, provinces noted for high consumption of the fruit, were caused by betel nut addiction, Xinhua News Agency reported on Feb. 26.

The secretary of the Hunan Betel Food Industry Association did not comment on whether the order was related to health worries, but said the sanction will greatly impact the sector.

The Chinese Stomatological Association and the Chinese Center for Disease Control and Prevention conducted a survey on the status of betel nut eaters and oral cancer in Hunan last year. They found that 45 patients among 50 on the oral and maxillofacial surgery ward of Central South University's Xiangya Hospital in Changsha had oral cancer. Of them, 44 had eaten large quantities of the nuts over a long period of time.