Researchers at the National Food Administration (Livsmedelsverket) in Uppsala and Karolinska Institute confirmed the find in a new study published in the latest edition of Environmental Research, Uppsala Nya Tidning (UNT) writes.
The study is based on the analysis of PCB, dioxins and several brominated flame retardants in samples taken from 335 randomly selected women in Uppsala county who gave birth to children between 1996-2006.
During the period levels of PCB declined by between four-nine percent each year. For the dioxins PCDD and PCDF the corresponding figures were a five-seven percent decline per annum.
"This shows that the ban on chlorine bleaching of paper and other measures to eradicate chlorine pollutants from the environment seem to have paid off," said Anders Glynn, a toxicologist at the administration to UNT.
The study shows however that progress has not been as positive with regard to brominated flame retardants with no established trend towards lower levels.
The levels of certain substances have declined, while others have remained constant and some even increased since the mid-1990s.
PCBs are a group of industrial chemicals found to be damaging both to the environment and to health developed in the 1920s.
The use of PCBs was banned in Sweden in 1972 but traces remain in the environment due to the long degradation process.