(S (S (S (BASENP (JJ Further) (NNS tests)) (VP (VBD were) (VP (VBN performed)))) (CONJP (COMMA ,) (CC but)) (S (S (BASENP (DT those) (NNS results)) (VP (VP (VBP are) (RB not)) (VP (ADVP (RB yet)) (VBN known)))) (CC and) (S (BASENP (NNS officials)) (VP (VP (VBP do) (RB n't)) (VP (VB believe) (SBAR (S (BASENP (EX there)) (VP (VBD was) (NP (BASENP (DT any) (NN danger)) (PP (TO to) (BASENP (DT the) (NN air)))))))))))) (PERIOD .))