Animal studies and a study of 99 twins showed there is a "lot of circumstantial evidence" that exposure to tetrachloroethylene increases the risk of developing Parkinson's disease ninefold.
Dyrestudier og studier af 99 tvillinger viste "masser af indicier" på at udsættelse for tetraklorethen øger risikoen for at udvikle Parkinsons sygdom ni gange.