A sub-group of the Yunlin County Council said Monday they want a chemical plant owned by Formosa Plastics Group (FPG) in the southwestern Taiwan county to suspend operations immediately to prevent locals from being further inflicted with cancer-causing air pollution from the plant. The Sixth Naphtha Cracking Plant in Mailiao, Yunlin has been in operation since 1999. Naphtha cracking plants produce the raw materials for plastics. Cracking is a refining process using heat and pressure. The sub-group formed by Yunlin councilors from the opposition Democratic Progressive Party (DPP) cited results of an investigation conducted by professor Chan Chang-chuan with National Taiwan University which indicated that cancer rates in the areas near the plant had grown substantially since the factory was opened. According to the investigation report, cancer incidents have grown noticeably among residents in Mailiao township and four other adjacent townships of Taisi, Dongshih, Lunbei and Sihhu since the cracking plant began to emit volatile organic compounds (VOCs) in 1999. Infliction rates of liver cancer have grown 30 percent in Taisi township over the past nine years, according to the investigation conducted by Chan under the consignment of the Yunlin County Environmental Protection Bureau. Noting that the Yunlin residents' cancer infliction rate is now 1.7 times higher than the average of residents in other cities and counties around Taiwan, DPP Councilor Liao Ching-hsiang said measures must be taken immediately to address the issue. Meanwhile, the Formosa office in Mailiao said that the Yunlin County Environmental Protection Bureau had conducted testing of the air in the areas near the cracking plant many times over the past several years and that the air quality was found to be normal. 'It's hard to pinpoint one single factor as the culprit of cancers since factors that may cause cancers are so many, ' said a Formosa staff member. 