This is often associated primarily with religious conservatives in the context of moral imperatives of God's word - specific to sexuality. That is how the word is typically employed.  For instance, Jonathan Haidt speaks of "sanctity" or "purity" as one of the primary values differentiating liberal and conservative mindsets - reflecting a resistance and repulsion for disgusting things, foods, actions, etc.  While conservatives are framed as valuing "purity" more highly - it could be argued that this is only primarily true along the social, moral and sexual dimensions of the word.  When it comes to purity of body - from chemicals, for instance - it seems to be a central feature of progressive concern in American society.