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

BACKGROUND: Industrial swine operations emit odorant chemicals including ammonia, hydrogen sulfide (H2S), and volatile organic compounds. Malodor and pollutant concentrations have been associated with self-reported stress and altered mood in prior studies. OBJECTIVES: We conducted a repeated-measures study of air pollution, stress, and blood pressure in neighbors of swine operations. METHODS: For approximately 2 weeks, 101 nonsmoking adult volunteers living near industrial swine operations in 16 neighborhoods in eastern North Carolina sat outdoors for 10 min twice daily at preselected times. Afterward, they reported levels of hog odor on a 9-point scale and measured their blood pressure twice using an automated oscillometric device. During the same 2- to 3-week period, we measured ambient levels of H2S and PM10 at a central location in each neighborhood. Associations between systolic and diastolic blood pressure (SBP and DBP, respectively) and pollutant measures were estimated using fixed-effects (conditional) linear regression with adjustment for time of day. RESULTS: PM10 showed little association with blood pressure. DBP [ß (SE)] increased 0.23 (0.08) mmHg per unit of reported hog odor during the 10 min outdoors and 0.12 (0.08) mmHg per 1-ppb increase of H2S concentration in the same hour. SBP increased 0.10 (0.12) mmHg per odor unit and 0.29 (0.12) mmHg per 1-ppb increase of H2S in the same hour. Reported stress was strongly associated with BP; adjustment for stress reduced the odor-DBP association, but the H2S-SBP association changed little. CONCLUSIONS: Like noise and other repetitive environmental stressors, malodors may be associated with acute blood pressure increases that could contribute to development of chronic hypertension.

Depressive symptoms in women working in a poultry-processing plant: a longitudinal analysis.

BACKGROUND: Work in poultry-processing plants is physically demanding, and a number of studies have documented the effects of such work on the physical health of workers. Few studies, however, have examined the potential effects on mental health. METHODS: Longitudinal data were collected on 223 women who worked in two poultry-processing plants in northeastern North Carolina. Effects on depressive symptoms of demographic variables, work tenure at baseline, musculoskeletal pain, psychosocial job characteristics, coping style, and health-related quality of life were examined using mixed models. RESULTS: Psychosocial job characteristics were not associated with depressive symptoms as measured by the Center for Epidemiologic Studies Depression scale (CES-D) in this cohort of workers. CES-D scores decreased with increasing work tenure at the plant, which suggests a healthy worker survivor effect (HWSE). CONCLUSIONS: These exploratory analyses draw attention to the need to more carefully explore the possibility that the HWSE may extend to mental health outcomes as well as physical ones.

Air pollution, lung function, and physical symptoms in communities near concentrated Swine feeding operations.

BACKGROUND: Concentrated animal feeding operations emit air pollutants that may affect health. We examined associations of reported hog odor and of monitored air pollutants with physical symptoms and lung function in people living within 1.5 miles of hog operations. METHODS: Between September 2003 and September 2005, we measured hydrogen sulfide (H2S), endotoxin, and particulate matter (PM10, PM2.5, and PM2.5-10) for approximately 2-week periods in each of 16 eastern North Carolina communities. During the same time periods, 101 adults sat outside their homes twice a day for 10 minutes, reported hog odor and physical symptoms, and measured their lung function. Conditional fixed-effects logistic and linear regression models were used to derive estimates of associations. RESULTS: The log odds (±1 standard error) of acute eye irritation following 10 minutes outdoors increased by 0.53 (±0.06) for every unit increase in odor, by 0.15 (±0.06) per 1 ppb of H2S, and by 0.36 (±0.11) per 10 µg/m of PM10. Odor and H2S were also associated with irritation and respiratory symptoms in the previous 12 hours. The log odds of difficulty breathing increased by 0.50 (±0.15) per unit of odor. A 10 µg/m increase in mean 12-hour PM2.5 was associated with increased log odds of wheezing (0.84 ± 0.29) and declines in forced expiratory volume in 1 second (-0.04 ± 0.02 L). A 10 EU/mg increase in endotoxin was associated with increased log odds of sore throat (0.10 ± 0.05), chest tightness (0.09 ± 0.04), and nausea (0.10 ± 0.05). CONCLUSIONS: Pollutants measured near hog operations are related to acute physical symptoms in a longitudinal study using analyses that preclude confounding by time-invariant characteristics of individuals.

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

OBJECTIVES: We evaluated malodor and air pollutants near industrial hog operations as environmental stressors and negative mood triggers. METHODS: We collected data from 101 nonsmoking adults in 16 neighborhoods within 1.5 miles of at least 1 industrial hog operation in eastern North Carolina. Participants rated malodor intensity, stress, and mood for 2 weeks while air pollutants were monitored. RESULTS: Reported malodor was associated with stress and 4 mood states; odds ratios (ORs) for a 1-unit change on the 0-to-8 odor scale ranged from 1.31 (95% confidence interval [CI] = 1.16, 1.50) to 1.81 (95% CI = 1.63, 2.00). ORs for stress and feeling nervous or anxious were 1.18 (95% CI = 1.08, 1.30) and 1.12 (95% CI = 1.03, 1.22), respectively, for a 1 ppb change in hydrogen sulfide and 1.06 (95% CI = 1.00, 1.11) and 1.10 (95% CI = 1.03, 1.17), respectively, for a 1 microg/m(3) change in semivolatile particulate matter less than 10 microm in aerodynamic diameter (PM(10)). CONCLUSIONS: Hog odor, hydrogen sulfide, and semivolatile PM(10) are related to stress and negative mood in disproportionately low-income communities near industrial hog operations in eastern North Carolina. Malodor should be considered in studies of health impacts of environmental injustice.

Data completeness and quality in a community-based and participatory epidemiologic study.

BACKGROUND: The principles of community-based participatory (CBPR) research challenge traditional scientific standards of objectivity and neutrality. Little work has been done to evaluate the quality of data obtained from CBPR studies. OBJECTIVES: We examined factors associated with the completeness and quality of data that participants collected for the Community Health Effects of Industrial Hog Operations (CHEIHO) study, a community-based, participatory, longitudinal, epidemiologic investigation. METHODS: Twice daily for 2 weeks, 101 eastern North Carolina residents collected data on odor from industrialized hog operations, physical health, and mood. Data collected at a single point in time constitute a record. For each record, participant responses were classified as error free or not and missing or not. We used mixed models to quantify associations between errors or missing values and time of day, odor rating, week-in-participation, and presence of a person to assist with data collection. RESULTS: Participants collected data out of order in 2% of 2,949 total records. On average, individual variables were incomplete in 2% of records. Errors and missing data were most common for lung function measurements. Missing data for lung function and blood pressure were less common after the first week of participation (odds ratio [OR], 0.41; 95% confidence interval [CI], 0.20-0.84). Saliva samples were more frequently missing when participants reported odor than when they did not (OR, 1.59; 95% CI, 0.97-2.59). For women, the odds that yes/no variables were missing in week 2 records were higher relative to week 1 (OR, 1.46; 95% CI, 1.01-2.12). CONCLUSIONS: Community members collected relatively complete and consistent data. Better training in use of mechanical devices and more frequent input from researchers could help to improve data quality in CBPR studies.

Air pollution and odor in communities near industrial swine operations.

BACKGROUND: Odors can affect health and quality of life. Industrialized animal agriculture creates odorant compounds that are components of a mixture of agents that could trigger symptoms reported by neighbors of livestock operations. OBJECTIVE: We quantified swine odor episodes reported by neighbors and the relationships of these episodes with environmental measurements. METHODS: Between September 2003 and September 2005, 101 nonsmoking volunteers living within 1.5 mi of industrial swine operations in 16 neighborhoods in eastern North Carolina completed twice-daily odor diaries for approximately 2 weeks. Meteorological conditions, hydrogen sulfide, and particulate matter 6.75 miles per hour. The odds of reporting a change in daily activities due to odor increased 62% for each unit increase in average odor during the prior 12 hr (t-value = 7.17). CONCLUSIONS: This study indicates that malodor from swine operations is commonly present in these communities and that the odors reported by neighbors are related to objective environmental measurements and interruption of activities of daily life.

Integrating epidemiology, education, and organizing for environmental justice: community health effects of industrial hog operations.

The environmental justice movement has stimulated community-driven research about the living and working conditions of people of color and low-income communities. We describe an epidemiological study designed to link research with community education and organizing for social justice. In eastern North Carolina, high-density industrial swine production occurs in communities of low-income people and people of color. We investigated relationships between the resulting pollution and the health and quality of life of the hog operations' neighbors. A repeat-measures longitudinal design, community involvement in data collection, and integration of qualitative and quantitative research methods helped promote data quality while providing opportunities for community education and organizing. Research could affect policy through its findings and its mobilization of communities.