Abstract
OBJECTIVES: Since waste from swine industrial livestock operations (ILOs) produces air pollutants associated with negative health outcomes among nearby residents, we assessed the impact of odorant emissions on sleep duration and awakenings. DESIGN: A repeated-measures design. SETTING: Sixteen residential communities in eastern North Carolina hosting swine ILOs. PARTICIPANTS: Eighty participants residing in eastern North Carolina from 2003 to 2005. INTERVENTION (IF ANY): Not applicable. MEASUREMENTS: Study participants completed twice-daily diaries in which they rated the strength of hog odors and indicated whether they were asleep or awake per hour for 2 weeks. Simultaneously, a monitoring trailer placed in a central location in each community measured the atmospheric concentration of hydrogen sulfide (H(2)S). Subject-conditional fixed-effects regression models were used to estimate associations between 2 markers of swine ILO pollutant exposures (H(2)S and swine odor) and 2 self-reported sleep outcomes (nightly sleep duration and awakening from sleep). RESULTS: Among 80 participants, nightly (across a 12-hour period) swine odor was associated with lower nightly sleep duration (mean difference = -14.3 minutes, 95% confidence interval -25.0 to -3.3 minutes) compared to odor-free nights and detection of nightly hydrogen sulfide was associated with an increased risk of awakening (hazard ratio = 1.23, 95% confidence interval 0.98 to 1.55) compared to nights with no detection of hydrogen sulfide. CONCLUSIONS: These results suggest that environmental odorants are important considerations for sleep health and highlight the importance of sleep as a potential mediator between environmental air pollution and health outcomes impacted by poor sleep.