The health risks associated with nail polish are disputed. According to the U.S. Department of Health and Human Services, "The amount of chemicals used in animal studies is probably a couple of hundred times higher than what you would be exposed to from using nail polish every week or so. So the chances of any individual phthalate producing such harm humans is very slim." A more serious health risk is faced by professional nail technicians, who perform manicures over a workstation, known as a nail table, on which the client's hands rest – directly below the technician's breathing zone. In 2009, Susan Reutman, an epidemiologist with the U.S. National Institute for Occupational Safety and Health's Division of Applied Research and Technology, announced a federal effort to evaluate the effectiveness of downdraft vented nail tables (VNTs) in removing potential nail polish chemical and dust exposures from the technician's work area. These ventilation systems have potential to reduce worker exposure to chemicals by at least 50%. Many nail technicians will often wear masks to cover their mouth and nose from inhaling any of the harsh dust or chemicals from the nail products.