(S (S (S (NP (DT This) (NP (ADJP (ADJP (JJ soft)) (CONJP (COMMA ,) (CC but)) (ADJP (JJ heavy) (CC and) (JJ poisonous))) (NN metal))) (VP (MD can) (VP (VB be) (ADJP (JJ fatal))))) (SBAR (WHADVP (WRB when)) (S (BASENP (EX there)) (VP (VP (VBZ is) (NP (QP (ADVP (RBR more) (IN than)) (NN 10)) (BASENP (NN μg) (CC /) (NN dL)))) (PP (IN in) (BASENP (DT the) (NN blood))))))) (PERIOD .))