Formaldehyde concentrations inside private residences: a mail-out approach to indoor air monitoring.

During 1984, the California Indoor Air Quality Program undertook two studies aimed at evaluating the feasibility of using passive monitors, in combination with a mail-out approach, to measure formaldehyde concentrations inside a large sample of private residences. A pilot study in 51 nonmanufactured dwellings preceded an indoor formaldehyde survey in more than 500 mobile homes from throughout California. In the mobile home study, 663 residences were included in the summer phase (July/August 1984) and 523 in the winter phase (February/March 1985). Four hundred and seventy-two of these mobile homes were monitored twice, once in both the summer and winter phases of the study. Each investigation was carried out entirely by mail, including solicitation of volunteers, placement and recovery of monitors, collection of data on occupant- and housing-characteristics, and communication of test results. Results of formaldehyde measurements in both manufactured and nonmanufactured dwellings are presented and the feasibility of monitoring indoor air quality by mail is discussed.