( ( Lead ( in gasoline ) ) ( , ( however ( , ( ( has ( been ( drastically ( ( reduced , ) ( due ( to ( environmental considerations ) ) ) ) ) ) ) . ) ) ) ) )
(ROOT (S (NP (NP (JJ Lead)) (PP (IN in) (NP (NN gasoline)))) (, ,) (ADVP (RB however)) (, ,) (VP (VBZ has) (VP (VBN been) (VP (ADVP (RB drastically)) (VBN reduced) (, ,) (PP (JJ due) (TO to) (NP (JJ environmental) (NNS considerations)))))) (. .)))
Lead in gasoline, however, has been drastically reduced, due to environmental considerations.
(ROOT (S (NP (NNS People)) (VP (VBD stopped) (S (VP (VBG adding) (NP (NN lead)) (PP (TO to) (NP (NP (NN gasoline)) (PP (RB because) (IN of) (NP (JJ environmental) (NN pollution)))))))) (. .)))