The high prevalence of smoking in adults in many developing countries (e.g. in China, 61% among men and 7% among women) results in many children being exposed to secondhand smoke (SHS). Although in 2001 the American Academy of Pediatrics recommended the promotion of proper smoking hygiene, (i.e. smoking away from the immediate environment of infants and children), similar recommendations in many developing countries are either scarce or non-existent. We hypothesize that implementation of a package of smoking hygiene intervention measures delivered by community health workers (CHWs) will reduce Chinese children's exposure to SHS and improve their respiratory health.

Inclusion Criteria:

1. household member has smoked one or more cigarettes daily for the past 30 days as self reported;
2. household smoker smokes a total of at least 10 cigarettes per week at home in the presence of the child, as self reported;
3. smoker household member and the child are living together in the same household and will live together during the entire period of the study;
4. residents of the study community;
5. able to communicate in Mandarin Chinese or local Shanghai dialect;
6. has signed an informed consent form or given verbal consent (for those who cannot read and write).

Exclusion Criteria:

1. reported residential coal burning and confirmed by the interviewer;
2. households with breast-feeding child;
3. household members do not smoke at home;
4. smoker member does not live in the same household as the under 5 child;
5. non-local community resident; and
6. not able to communicate in Mandarin Chinese or Shanghai dialect.