Indoor air in offices is an important source of worker exposure to potentially toxic substances released by carpeting, furniture, paint and other items, a new study has revealed. In a first-of-its-kind study, scientists have described a link between levels of polyfluorinated compounds (PFCs) in office air and in the blood of workers. Michael McClean and colleagues explain that PFCs, used in water-repellent coatings on carpet and furniture, may have adverse effects on human health. The substances are widespread in the environment and in humans around the world. Scientists know that potential sources of exposure include food, water, indoor air, indoor dust and direct contact with PFC-containing objects. But the link between levels in air and blood had not been explored previously, so McClean's group set out to fill that gap with a study of 31 office workers in Boston. They found concentrations of a PFC called fluorotelomer alcohol (FTOH) in office air that were 3-5 times higher than those reported in previous studies of household air, "suggesting that offices may represent a unique and important exposure environment." In addition, the study found a strong link between concentrations of FTOH in office air and perfluorooctanoic acid (a metabolite of FTOH) in the blood of office workers. The results also suggested that workers in newly renovated office buildings might receive considerably higher doses of PFCs than workers in older buildings. The study appeared in ACS' journal Environmental Science and Technology.