Inclusion Criteria:  Eligibility criteria include male and female, poorly controlled asthma, likely to stay in the area over the course of the study, having only one residence, no smokers in the household and residential proximity to dairy operations/crop production (<400 meters) determined by the telephone screening questionnaire.  Exclusion Criteria:  Prior participation in the Asthma Home Visiting Program, not from the northern third of the lower Yakima Valley, well controlled asthma, unlikely to stay in the are over the course of the study, smokers in the household, no residential proximity to dairy operations or crop production, having more than one residence and inability to communicate over the phone.