sentence: However , a recent study showed that from 2001 to 2003 , mean blood levels of total dioxins ( pg-TEQ / g lipid ) and 2,3,4,7,8 - penta-chlorodibenzofuran ( PeCDF ; picograms per gram lipid ) in Yusho patients were 3.4 – 4.8 and 11.6 – 16.8 times higher , respectively , than the mean levels in normal controls ( Furue et al. 2005 ) .