EPA has released a draft risk assessment, or scientific evaluation of the potential human health risks associated with the presence of toxic per- and polyfluoroalkyl substances chemicals in biosolids, also known as sewage sludge. The findings show that there may be human health risks associated with exposure to PFOA or PFOS with all three methods of using or disposing of sewage sludge – land application of biosolids, surface disposal in landfills, or incineration.