This text is missing some spaces, please add them: Therearemanyinvestigations,whichhavedocumentedcleanupfromabout2,000downtoabout200mgtotalPAH/kgwithtimescalesof6monthstoseveralyears.Generally,itisdifficulttocalculatethetimescaleforbiologicaltechniques.
There are many investigations, which have documented clean up from about 2,000 down to about 200 mg total PAH/kg with time scales of 6 months to several years. Generally, it is difficult to calculate the time scale for biological techniques.

This text is missing some spaces, please add them: HecontributedtomathematicalIntuitionismwhichhadbeenfoundedbyBrouwer.
He contributed to mathematical Intuitionism which had been founded by Brouwer .

This text is missing some spaces, please add them: continent:NA,country:UnitedStates(USA),city:SanFrancisco
continent: NA , country: United States (USA), city: San Francisco