Elsevier

Sleep Health

Volume 7, Issue 5, October 2021, Pages 528-534
Sleep Health

Relation of repeated exposures to air emissions from swine industrial livestock operations to sleep duration and awakenings in nearby residential communities

https://doi.org/10.1016/j.sleh.2021.05.001Get rights and content

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 (H2S). Subject-conditional fixed-effects regression models were used to estimate associations between 2 markers of swine ILO pollutant exposures (H2S 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.

Introduction

Swine Industrial Livestock Operations (ILOs) are a prevalent source of air pollutants in eastern North Carolina. Today, nearly all of the pork consumed and exported by the United States is produced by ILOs1 and North Carolina is a leading producer, with over 2000 permitted operations and 9 million swine.47 The industry is highly concentrated in the southeastern part of the state,2 where the 2 top-producing counties are also the 2 top-producing counties in the entire United States.48

This context has produced an environment where residential communities hosting swine ILOs can face concentrated industrial air emissions not typically associated with rural areas. Rural areas consistently score poorly on population health indicators,2 and rural communities are experiencing social transitions that create health challenges:3 a shift to corporate agriculture, job loss, outmigration of young and working people, and poorer access to nutritious food.4 Air pollution produced by swine ILOs contains complex mixtures of particulate matter, aerosols, and gasses that can vary by facility, time of day, weather, and season. A large proportion of these air pollutants are produced by lagoon-and-sprayfield systems, which are used for waste management at swine ILOs in North Carolina.5 In this system, wet swine wastes flow through the slatted floors of confinement buildings into open pits where they decompose anaerobically to produce mixtures of microbial metabolites including ammonia and hydrogen sulfide.6 These wastes are sprayed onto adjacent fields to encourage aerobic decomposition, but this process also produces waste aerosols that spread liquid pollutants into the air and groundwater.

In ethnographic research conducted in communities near swine ILOs, neighbors have reported that swine ILO air pollutants interfere with sleeping7 and time outdoors8 but these associations have not been statistically quantified. ILO air pollutant exposures could be linked to sleep disruption through several mechanisms: awakenings could be caused by olfactory or trigeminal nerve excitation by chemical components of the emissions mixture, exposures to the emissions mixture may produce disease symptoms like airway restriction that could increase the risk of sleep apnea or making falling asleep more difficult, or the psychological impacts of uncontrollable malodor could lead to stress and impair activities that enhance sleep. Exposure to ammonia odorants like those found in swine ILO pollutants have long been known to cause awakenings from sleep;7,9 this property has been leveraged in the clinical context through the use of smelling salts.10 Many of the disease symptoms linked to swine ILO air emissions in past research are known to cause sleep impairment. Disrupted breathing can make falling asleep difficult,11 cause awakenings from sleep,12 interfere with outdoor activities,13 and produce psychological stress.14 Respiratory disease symptoms,15 the cultural and psychological meanings of malodor,14 and stress resulting from the inability to control odors could make falling asleep more difficult.

Poor sleep is associated with a host of poor health outcomes that have also been connected to air pollution, including obesity, hypertension, type 2 diabetes, cardiovascular disease, and premature mortality.16., 17., 18., 19. This study seeks to expand the understanding of the transient exposure-response dynamics of ILO pollutant exposures by assessing their impact on sleep. Associations between 2 exposure markers (swine odors and atmospheric hydrogen sulfide concentration) and 2 outcome measures (nightly sleep duration and awakening from sleep) are estimated. We leverage the unique design of the CHEIHO (Community Health Effects of Industrial Hog Operations) study,14,20., 21., 22., 23. which aimed to capture the acute impacts of exposures to hog operation emissions. The repeated measures of exposures and outcomes recorded as part of the CHEIHO study enable each participant to act as his or own control in assessments of potential sleep disruption, eliminating bias due to factors that remain constant over time (e.g., sex, race/ethnicity, co-exposures, and pre-existing conditions) and allowing adjustment for other measured time-varying factors.

Section snippets

Study population

We used data collected as part of the CHEIHO study, a community-engaged project combining environmental health education with mixed-methods qualitative and quantitative research in 16 communities in North Carolina. Potential CHEIHO communities were identified in collaboration with community organizations and had at least 4 residents interested in study participation.

One-hundred and one CHEIHO participants were recruited from 16 North Carolina residential communities hosting industrial swine

Results

Among the 80 eligible adult participants, 65% were female, 85% were Black, and 35% had an odor sensitivity threshold at or below 40 parts per million. Demographic characteristics of the 80 study participants are shown in Table 1.

The distributions of sleep and odorant exposures are described in Table 2. Hydrogen sulfide was above the detection threshold for 8.2% of all study hours and participants reported odors 14.5% of their time awake. Evening outdoor odorants were higher on average than

Discussion

In this study we estimated the effect of exposures to swine ILO pollutants on sleep using 2 measures of odor perception and ambient outdoor H2S concentration. Episodes of nightly hydrogen sulfide exposure and odor, 2 markers of swine ILO pollutant exposures, decreased participants' sleep by 14.3 minutes on average and increased the risk of awakening from sleep by 23%. In the context of chronic daily exposures, these impacts could lead to substantial sleep losses over time.

Observed associations

Conclusion

Ultimately, the night-time ILO pollutant exposures investigated were associated with adverse sleep outcomes, which suggests that emissions reductions and odor abatement are important public health goals. Although we focused on odor and hydrogen sulfide from ILOs, environmental odorants from industrial sources in other areas could also be important for sleep hygiene and the secondary health effects associated with sleep. From a public health perspective, greater community control over local

Declaration of conflict of interest

The authors declare they have no actual or potential competing financial interests.

Funding

This work was funded, in part, by the Intramural Program at the NIH, National Institute of Environmental Health Sciences (Z1A ES103325-01, CLJ) and by the Environmental Biostatistics Training Grant (NIH 2T32ES007018­36, NSM).

References (48)

  • CD Phillips et al.

    Health in rural America: remembering the importance of place

    Am J Public Health

    (2004)
  • LW Morton et al.

    Starved for access: life in rural America's food deserts

    Rural Real

    (2007)
  • Lado ME, D'Ambrosio J. Complaint under title VI of the Civil Rights Act of 1964, 42 U.S.C. § 2000d, 40 C.F.R. Part 7....
  • S Wing et al.

    Air pollution and odor in communities near industrial swine operations

    Environ Health Perspect

    (2008)
  • M Tajik et al.

    Impact of odor from industrial hog operations on daily living activities

    New Solut

    (2008)
  • P. McCrory

    Smelling salts

    Br J Sports Med

    (2006)
  • DJ Gottlieb et al.

    Relation of sleepiness to respiratory disturbance index: the Sleep Heart Health Study

    Am J Respir Crit Care Med

    (1999)
  • P Lavie et al.

    Breathing disorders in sleep associated with “microarousals” in patients with allergic rhinitis

    Acta Otolaryngol

    (1981)
  • GC Donaldson et al.

    Exacerbations and time spent outdoors in chronic obstructive pulmonary disease

    Am J Respir Crit Care Med

    (2005)
  • RA Horton et al.

    Malodor as a trigger of stress and negative mood in neighbors of industrial hog operations

    Am J Public Health

    (2009)
  • BO Baumert et al.

    0463 pesticide exposure and sleep apnea in the agricultural lung health study

    J Sleep Sleep Disord Res

    (2017)
  • L Gallicchio et al.

    Sleep duration and mortality: a systematic review and meta-analysis

    J Sleep Res

    (2009)
  • M Gerber et al.

    Energy balance and cancers

    Eur J Cancer Prev

    (1999)
  • S Wing et al.

    Air pollution from industrial swine operations and blood pressure of neighboring residents

    Environ Health Perspect

    (2013)
  • Cited by (6)

    • Residential open space and the perception of health benefits: How much is the public willing to pay?

      2022, Journal of Environmental Management
      Citation Excerpt :

      Specifically, the current results revealed that individuals who believe landscape plays an important role in improving the quality of sleep are willing to pay more for ROS. Previous studies have demonstrated that outdoor air pollution and traffic noise decrease sleep quality, especially if they are close to areas where people live (Smith et al., 2019; MacNell et al., 2021; Yu et al., 2021). Meanwhile, evidence suggested that higher residential greenery coverage can attenuate adverse effects on sleep quality, while a higher land-use mix is associated with shorter sleep duration (Chum et al., 2015; Astell-Burt and Feng, 2020).

    • The Need for Social and Environmental Determinants of Health Research to Understand and Intervene on Racial/Ethnic Disparities in Obstructive Sleep Apnea

      2022, Clinics in Chest Medicine
      Citation Excerpt :

      As a result of historical discriminatory housing practices and environmental racism, minoritized racial/ethnic groups are more likely to live in lower SES neighborhoods and are exposed to more environmental hazards.48 For example, ambient air pollution is associated with disturbed sleep and OSA.49–56 Air pollution can negatively affect the nervous system, and can cause oxidative stress or inflammatory damage, which contributes to disturbed sleep.57

    • Residents’ experiences during a hydrogen sulfide crisis in Carson, California

      2024, Environmental Health: A Global Access Science Source
    View full text