Exposure to tainted Chinese drywall did not cause 11 deaths in the South, according to a recent report by the Center of Disease Control and Prevention. The CDC found the residents of  Florida, Louisiana and Virginia had "preexisting chronic health conditions unrelated to imported drywall" that caused their deaths. According to the federal report, seven people who died had cancer and most had heart problems. All the individuals were between the ages of 59 and 86. "Based on the reviews of the records and available information by the state public health authorities exposure to imported drywall was not believed to be a contributing factor in these deaths," the CDC report said, noting that all the deceased had one or more severe illnesses. Defective Chinese drywall and the health problems associated with it have become a major issue in recent years. After Hurricane Katrina hit in 2005, many homes around the Gulf of Mexico were rebuilt using the material after a shortage in U.S.-produced drywall. As of Jan. 7, there were 3,770 incidents reported of defective drywall, according to the Consumer Product Safety Commission. Florida has the most with 2,137 cases, followed by Louisiana with 704 cases and Alabama with 215. Since the issue has come to light, there have been a number of debates on how fix the problem and mitigate infected homes. The process can often be lengthy and extremely expensive. In November, Fannie Mae began offering borrowers in homes built with the toxic drywall a forbearance extension of their mortgage payments. This followed an already initiated six-month forbearance the agency offered. In October, plans were announced to remove Chinese drywall from up to 300 homes in a pilot program funded by the believed maker of defective Chinese drywall, Knauf Plasterboard Tianjin. Earlier this year, several homebuilders were held liable for using the building material, costing millions in consumer lawsuits. One court resolution in Florida, however, relieved homebuilders of some liability because they did not manufacture the product and were not involved in the chain of distribution. The CPSC continues to investigate imported drywall and has created a website for the public to keep up with agency research and findings. Write to Christine Ricciardi. Follow her on Twitter @HWnewbieCR.