Understanding Society User Support

I am little confused since I have read a lot about cross-sectional research using the understanding society data: since understanding society is a longitudinal survey- how is a valid cross-sectional analysis a possibility?
I am interested in looking at hours spent on doing housework for South Asians. A single wave does not allow me sufficient data for this analysis. So, if I pool different waves- will this be considered a true cross-secitonal analysis whereby the respondents are different in each wave?