In this paper we extend the work of Elperin et al. [Phys. Rev. Lett. 80, 69 (1998)] by showing that a turbulent Dufour-type effect is also present in chemically nonreacting gaseous admixtures. This result is used to analyze the possibility of obtaining turbulent analogs of the Onsager relations, a fundamental result for molecular crossed effects in irreversible thermodynamics.