. "chemical load on the environment"@en . . _:b1 . _:b1 "2009-11-18" . _:b1 "fo" . _:b2 . _:b2 "fo" . _:b2 "2009-11-18" . "chemical load on the environment"@en . _:b4 . _:b4 . _:b4 _:b5 . _:b5 . _:b5 . _:b5 _:b6 . _:b6 . _:b6 . _:b6 _:b7 . _:b7 . _:b7 . _:b7 . _:b4 .