The role of woodstoves in the etiology of nasal polyposis.

OBJECTIVE To determine the role of environmental pollutants in the etiology of nasal polyposis. DESIGN Case-control study. SETTING A community-based hospital practice in the Gaspesian peninsula in rural northeastern Quebec. PATIENTS Fifty-five case patients with nasal polyposis and 55 age-matched control subjects without nasal polyposis who were seen at one physician's practice (J.K.) from March 1, 1998, to December 19, 1998. INTERVENTIONS Exposure to woodstoves, indoor tobacco smoke, and pets and occupational exposures to noxious inhalant compounds. RESULTS Forty-five (82%) of the cases, but only 14 (25%) of the controls, reported using woodstoves, yielding a crude odds ratio (OR) of 13.1. The corresponding risk associated with occupational exposure to noxious inhalant compounds was also high (OR, 6.1). When adjusted in various ways for the presence of other factors, these ORs remained high and statistically significant. For woodstove use, the point estimates of the ORs were consistently above 10, with the lower limits of 95% confidence intervals above 5. For occupational exposures to noxious inhalant compounds, the various adjusted OR estimates were above 6, with the lower limits above 1.5. CONCLUSIONS There is a strong association between the use of woodstoves as a principal source of heating and the development of nasal polyposis. Occupational exposures to noxious inhalant compounds (other than tobacco smoke) also play an important role in its etiology.