<prompt> Translate the following text to SwahiliHowever, the relative roles of PM exposure duration and PM exposure level in inducing premature mortality remain unknown at this time.  <response>: Hata hivyo, majukumu ya jamaa ya muda wa mfiduo wa PM na kiwango cha mfiduo wa PM katika kusababisha vifo vya mapema bado haijulikani kwa wakati huu. 