Digest of terms
this is a threat to human purity which may traditionally arise from many different forms of contact - e.g. with a dead body, blood (including a menstruating woman), an outsider 'foreign' to the social group. Such taboos are variously elaborated within cultural and religious traditions, along with specified means of prevention and purification such as temporary seclusion, washing, and priestly mediation. Ritual prescriptions for both pollution avoidance and purification are set out and observed by for instance many Hindus, Orthodox Jews, Muslims and Zoroastrians. They are less evident in Christianity, although the ceremony for 'churching of women' after childbirth has been practised by some. Today there is a tendency to distinguish purity rituals from morality as such, yet in their traditional religious contexts they can be seen to function as morally binding requirements.
Over-sensitivity to the dangers of pollution is well documented in the performance of obsessive cleaning rituals and in the social avoidance of physical proximity to individuals who for whatever reason are strange in appearance. Documentary evidence of the correlation between hygienic hand washing and concern for moral propriety suggests that pollution awareness continues to be a powerful ingredient in everyday human behaviour.