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

An Overview of Literature Topics Related to Current Concepts, Methods, Tools, and Applications for Cumulative Risk Assessment (2007-2016)

Cumulative risk assessments (CRAs) address combined risks from exposures to multiple chemical and nonchemical stressors and may focus on vulnerable communities or populations. Significant contributions have been made to the development of concepts, methods, and applications for CRA over the past decade. Work in both human health and ecological cumulative risk has advanced in two different contexts. The first context is the effects of chemical mixtures that share common modes of action, or that cause common adverse outcomes. In this context two primary models are used for predicting mixture effects, dose addition or response addition. The second context is evaluating the combined effects of chemical and nonchemical (e.g., radiation, biological, nutritional, economic, psychological, habitat alteration, land-use change, global climate change, and natural disasters) stressors. CRA can be adapted to address risk in many contexts, and this adaptability is reflected in the range in disciplinary perspectives in the published literature. This article presents the results of a literature search and discusses a range of selected work with the intention to give a broad overview of relevant topics and provide a starting point for researchers interested in CRA applications.

Proximity to Industrial Food Animal Production and Asthma Exacerbations in Pennsylvania, 2005-2012

The research on industrial food animal production (IFAP) and asthma exacerbations in the United States has relied on small sample sizes and/or self-reported outcomes. We assessed associations of proximity to large-scale and densely stocked swine and dairy/veal IFAP with three types of asthma exacerbations: hospitalizations, emergency encounters, and oral corticosteroid (OCS) medication orders from Geisinger Clinic in Pennsylvania. We used a diagnosis code (International Classification of Diseases, 9th Revision, Clinical Modification code 493.x) and medication orders from electronic health records to identify these exacerbations among asthma patients (n = 35,269) from 2005-2012. We compared residential proximity to swine or dairy/veal IFAP (dichotomized as <3 miles (4.8 km) or ≥3 miles) among asthma patients with and without exacerbations and estimated odds ratios using multilevel logistic regression. In adjusted models, proximity to IFAP was associated (odds ratio (95% confidence interval)) with OCS orders (1.11 (1.04-1.19)) and hospitalizations (1.29 (1.15-1.46)), but not emergency encounters (1.12 (0.91-1.37)). This study contributes to growing evidence that IFAP may impact health, in this case clinically-documented asthma exacerbations. No prior study has evaluated the association of IFAP and clinically-documented asthma exacerbations in the United States.

Impact of Feed Delivery Pattern on Aerial Particulate Matter and Behavior of Feedlot Cattle

Fine particulate matter with less than 2.5 microns diameter (PM_2.5) generated by cattle in feedlots is an environmental pollutant and a potential human and animal health issue. The objective of this study was to determine if a feeding schedule affects cattle behaviors that promote PM_2.5 in a commercial feedlot. The study used 2813 crossbred steers housed in 14 adjacent pens at a large-scale commercial West Texas feedlot. Treatments were conventional feeding at 0700, 1000, and 1200 (CON) or feeding at 0700, 1000, and 1830 (ALT), the latter feeding time coincided with dusk. A mobile behavior lab was used to quantify behaviors of steers that were associated with generation of PM_2.5 (e.g., fighting, mounting of peers, and increased locomotion). PM_2.5 samplers measured respirable particles with a mass median diameter ≤2.5 μm (PM_2.5) every 15 min over a period of 7 d in April and May. Simultaneously, the ambient temperature, humidity, wind speed and direction, precipitation, air pressure, and solar radiation were measured with a weather station. Elevated downwind PM_2.5 concentrations were measured at dusk, when cattle that were fed according to the ALT vs. the CON feeding schedule, demonstrated less PM_2.5-generating behaviors (p < 0.05). At dusk, steers on ALT vs. CON feeding schedules ate or were waiting to eat (standing in second row behind feeding cattle) at much greater rates (p < 0.05). Upwind PM_2.5 concentrations were similar between the treatments. Downwind PM_2.5 concentrations averaged over 24 h were lower from ALT compared with CON pens (0.072 vs. 0.115 mg/m³, p < 0.01). However, dry matter intake (DMI) was less (p < 0.05), and average daily gain (ADG) tended to be less (p < 0.1) in cattle that were fed according to the ALT vs. the CON feeding schedules, whereas feed efficiency (aka gain to feed, G:F) was not affected. Although ALT feeding may pose a challenge in feed delivery and labor scheduling, cattle exhibited fewer PM_2.5-generating behaviors and reduced generation of PM_2.5 when feed delivery times matched the natural desires of cattle to eat in a crepuscular pattern.

Health conditions in rural areas with high livestock density: Analysis of seven consecutive years

Previous studies investigating health conditions of individuals living near livestock farms generally assessed short time windows. We aimed to take time-specific differences into account and to compare the prevalence of various health conditions over seven consecutive years. The sample consisted of 156,690 individuals registered in 33 general practices in a (rural) area with a high livestock density and 101,015 patients from 23 practices in other (control) areas in the Netherlands. Prevalence of health conditions were assessed using 2007-2013 electronic health record (EHR) data. Two methods were employed to assess exposure: 1) Comparisons between the study and control areas in relation to health problems, 2) Use of individual estimates of livestock exposure (in the study area) based on Geographic Information System (GIS) data. A higher prevalence of chronic bronchitis/bronchiectasis, lower respiratory tract infections and vertiginous syndrome and lower prevalence of respiratory symptoms and emphysema/COPD was found in the study area compared with the control area. A shorter distance to the nearest farm was associated with a lower prevalence of upper respiratory tract infections, respiratory symptoms, asthma, COPD/emphysema, allergic rhinitis, depression, eczema, vertiginous syndrome, dizziness and gastrointestinal infections. Especially exposure to cattle was associated with less health conditions. Living within 500m of mink farms was associated with increased chronic enteritis/ulcerative colitis. Livestock-related exposures did not seem to be an environmental risk factor for the occurrence of health conditions. Nevertheless, lower respiratory tract infections, chronic bronchitis and vertiginous syndrome were more common in the area with a high livestock density. The association between exposure to minks and chronic enteritis/ulcerative colitis remains to be elucidated.

Hydrogen sulfide concentrations at three middle schools near industrial livestock facilities

Safe school environments are essential for healthy development, yet some schools are near large-scale livestock facilities that emit air pollution. Hydrogen sulfide (H₂S) from decomposing manure is an indicator of livestock-related air pollution. We measured outdoor concentrations of H₂S at three public middle schools near livestock facilities in North Carolina. We used circular graphs to relate H₂S detection and wind direction to geospatial distributions of nearby livestock barns. We also used logistic and linear regression to model H₂S in relation to upwind, distance-weighted livestock barn area. Circular graphs suggested an association between upwind livestock barns and H₂S detection. The log-odds of H₂S detection per 1000 m² increased with upwind weighted swine barn area (School A: β-coefficient (β)=0.43, SE=0.06; School B: β=0.64, SE=0.24) and upwind weighted poultry barn area (School A: β=0.05, SE=0.01), with stronger associations during periods of atmospheric stability than atmospheric instability (School A stable: β=0.69, SE=0.11; School A unstable: β=0.32, SE=0.09). H₂S concentration also increased linearly with upwind swine barn area, with greater increases during stable atmospheric conditions (stable: β=0.16 parts per billion (p.p.b.), SE=0.01; unstable: β=0.05 p.p.b., SE=0.01). Off-site migration of pollutants from industrial livestock operations can decrease air quality at nearby schools.

Spatial and temporal variation in endotoxin and PM10 concentrations in ambient air in a livestock dense area

Several studies have reported associations between farming and respiratory health in neighboring residents. Health effects are possibly linked to fine dust and endotoxin emissions from livestock farms. Little is known about levels of these air pollutants in ambient air in livestock dense areas. We aimed to explore temporal and spatial variation of PM10 and endotoxin concentrations, and the association with livestock-related spatial and meteorological temporal determinants. From March till September 2011, one week average PM10 samples were collected using Harvard Impactors at eight sites (residential gardens) representing a variety of nearby livestock-related characteristics. A background site was included in the study area, situated at least 500m away from the nearest farm. PM10 mass was determined by gravimetric analysis and endotoxin level by means of Limulus-Amebocyte-Lysate assay. Data were analyzed using mixed models. The range between sites of geometric mean concentrations was for PM10 19.8-22.3µg/m³ and for endotoxin 0.46-0.66EU/m³. PM10 concentrations and spatial variation were very similar for all sites, while endotoxin concentrations displayed a more variable pattern over time with larger differences between sites. Nonetheless, the temporal pattern at the background location was highly comparable to the sites mean temporal pattern both for PM10 and endotoxin (Pearson correlation: 0.92, 0.62). Spatial variation was larger for endotoxin than for PM10 (within/between site variance ratio: 0.63, 2.03). Spatial livestock-related characteristics of the surroundings were more strongly related to endotoxin concentrations, while temporal determinants were more strongly related to PM10 concentrations. The effect of local livestock-related sources on PM10 concentration was limited in this study carried out in a livestock dense area. The effect on endotoxin concentrations was more profound. To gain more insight in the effect of livestock-related sources on ambient levels of PM10 and endotoxin, measurements should be based on a broader set of locations.

Materializing Exposure: Developing an Indexical Method to Visualize Health Hazards Related to Fossil Fuel Extraction

How can STS researchers collaborate with communities to design environmental monitoring devices that more effectively express their experiences and address gaps in regulation? This paper describes and shows the results of a novel method of visualizing environmental emissions of corrosive gases such as hydrogen sulfide (H₂S) exposure using photographic paper. H₂S is a neurotoxic and flammable gas that smells like rotten eggs and is frequently associated with oil and natural gas extraction. Communities living with oil and gas development in Wyoming report odors of rotten eggs and describe symptoms of H₂S exposure. H₂S is recognized as an acute and chronic threat to human and environmental health and oil and gas companies are required to have plans in place to prevent and respond to accidental, high concentration releases of H₂S. They are not, however, required to monitor, report or prevent routine daily emissions. Yet 15-25% of the oil and gas wells in the US are predicted to contain H₂S, and some communities surrounded by multiple wells report chronic, routine exposure. Chronic exposure is difficult to represent with current tools for monitoring H₂S because they are designed to measure acute workplace exposure. Informed by STS theories of black boxes and regimes of imperceptibility that focus on the need to revise not only regulations but also material tools of science, this paper describes the development of an indexical approach to visualizing this hazard. In indexical design, the reactive sensing element of a scientific instrument is brought to the foreground. The silver in the photopaper is an index as it tarnishes with H₂S exposure. Discolored tests strips can be arranged together to form data-rich maps of the exposure landscape where this discoloration both represents how the gas spreads through a space and is a physical trace of the gas. Preliminary results in the form of data-rich maps show that regulating H₂S emissions as primarily accidental is inappropriate and fails to adequately protect human health.

Panel studies of air pollution in patients with COPD: Systematic review and meta-analysis

BACKGROUND

Epidemiological studies have shown an increase in morbidity and mortality rates in patients with chronic obstructive pulmonary disease (COPD) following exposure to elevated levels of air pollution. Panel studies have been used to assess short-term effects of air pollution which are not detected by registry studies, specifically lung function and symptoms. The aim of this systematic review was to assess the evidence of panel studies on acute effects of air pollution among patients with COPD.

METHODS

We searched the PubMed database, and identified additional studies by inspecting reference lists and literature reviews. We identified and summarized 25 panel studies that were published between 1993 and February 2016. Results were presented in forest plots and effect estimates of sufficiently comparable outcomes and pollutants were summarized by a random-effects meta-analysis.

RESULTS

Meta-analysis showed that a 10µg/m³ increase in ambient levels of particles less than 10µm in diameter (PM₁₀) had a small, but statistically significant impact on FEV₁ (-3.38mL, 95% CI -6.39 to -0.37) and PEF (-0.61L/min, -1.20 to -0.01). There was significant heterogeneity across the included studies. A forest plot showing associations between PM₁₀ and respiratory symptoms was also suggestive of an adverse effect of particulate air pollution, but this was not formally tested in a meta-analysis due to the heterogeneity of outcomes. Results for gaseous pollutants were inconsistent for lung function or symptoms.

CONCLUSIONS

Evidence from the identified panel studies indicated statistically significant associations of particulate matter air pollution with lung function in patients with COPD.

Characterization of exposure in epidemiological studies on air pollution from biodegradable wastes: Misclassification and comparison of exposure assessment strategies

The assignment of exposure is one of the main challenges faced by environmental epidemiologists. However, misclassification of exposures has not been explored in population epidemiological studies on air pollution from biodegradable wastes. The objective of this study was to investigate the use of different approaches for assessing exposure to air pollution from biodegradable wastes by analyzing (1) the misclassification of exposure that is committed by using these surrogates, (2) the existence of differential misclassification (3) the effects that misclassification may have on health effect estimates and the interpretation of epidemiological results, and (4) the ability of the exposure measures to predict health outcomes using 10-fold cross validation. Four different exposure assessment approaches were studied: ammonia concentrations at the residence (Metric I), distance to the closest source (Metric II), number of sources within certain distances from the residence (Metric IIIa,b) and location in a specific region (Metric IV). Exposure-response models based on Metric I provided the highest predictive ability (72.3%) and goodness-of-fit, followed by IV, III and II. When compared to Metric I, Metric IV yielded the best results for exposure misclassification analysis and interpretation of health effect estimates, followed by Metric IIIb, IIIa and II. The study showed that modelled NH₃ concentrations provide more accurate estimations of true exposure than distances-based surrogates, and that distance-based surrogates (especially those based on distance to the closest point source) are imprecise methods to identify exposed populations, although they may be useful for initial studies.

Ambient Ammonia Exposures in an Agricultural Community and Pediatric Asthma Morbidity

BACKGROUND

Large-scale animal feeding operations compromise regional air quality in the rural US through emission of pollutants, such as ammonia gas. Exposure to airborne pollution from animal feeding operations may cause pediatric asthma exacerbations in surrounding communities.

OBJECTIVES

To describe spatial and temporal patterns in ambient ammonia concentrations in an agricultural region, and to investigate associations between short-term fluctuations in ammonia and subsequent changes in respiratory health in children with asthma.

METHODS

For 13 months in the Yakima Valley of Washington State, 14 monitors sampled ammonia in outdoor air for 24-hour periods every 6 days. School-age children with asthma (n = 51) were followed for two health outcomes: biweekly reports of asthma symptoms and quick relief medication usage, and daily measurements of forced expiratory volume in 1 second. We assessed associations between each outcome and ammonia using generalized estimating equations.

RESULTS

Twenty-four-hour ammonia concentrations varied from 0.2 to 238.1 μg/m during the study period and displayed a strong correlation with proximity to animal feeding operations. The percentage of forced expiratory volume in 1 second was 3.8% lower (95% confidence interval = 0.2, 7.3) per interquartile increase in 1-day lagged ammonia concentration and 3.0% lower (95% confidence interval = 0.5, 5.8) for 2-day lagged concentration. We observed no associations between self-reported asthma symptoms or medication usage and estimated ammonia exposure.

CONCLUSIONS

Ammonia concentrations were elevated in this community and strongly predicted by proximity to animal feeding operations. Ammonia's association with acute lung function decrements in children with asthma in the surrounding community may be causal or, alternatively, ammonia may be a marker for other pollutants from animal feeding operations associated with respiratory effects.

Association between Daily Hydrogen Sulfide Exposure and Incidence of Emergency Hospital Visits: A Population-Based Study

BACKGROUND

The adverse health effects of high concentrations of hydrogen sulfide (H2S) exposure are well known, though the possible effects of low concentrations have not been thoroughly studied. The aim was to study short-term associations between modelled ambient low-level concentrations of intermittent hydrogen sulfide (H2S) and emergency hospital visits with heart diseases (HD), respiratory diseases, and stroke as primary diagnosis.

METHODS

The study is population-based, using data from patient-, and population-registers from the only acute care institution in the Reykjavik capital area, between 1 January, 2007 and 30 June, 2014. The study population was individuals (≥18yr) living in the Reykjavik capital area. The H2S emission originates from a geothermal power plant in the vicinity. A model was used to estimate H2S exposure in different sections of the area. A generalized linear model assuming Poisson distribution was used to investigate the association between emergency hospital visits and H2S exposure. Distributed lag models were adjusted for seasonality, gender, age, traffic zones, and other relevant factors. Lag days from 0 to 4 were considered.

RESULTS

The total number of emergency hospital visits was 32961 with a mean age of 70 years. In fully adjusted un-stratified models, H2S concentrations exceeding 7.00μg/m3 were associated with increases in emergency hospital visits with HD as primary diagnosis at lag 0 risk ratio (RR): 1.067; 95% confidence interval (CI): 1.024-1.111, lag 2 RR: 1.049; 95%CI: 1.005-1.095, and lag 4 RR: 1.046; 95%CI: 1.004-1.089. Among males an association was found between H2S concentrations exceeding 7.00μg/m3, and HD at lag 0 RR: 1.087; 95%CI: 1.032-1.146 and lag 4 RR: 1080; 95%CI: 1.025-1.138; and among those 73 years and older at lag 0 RR: 1.075; 95%CI: 1.014-1.140 and lag 3 RR: 1.072; 95%CI: 1.009-1.139. No associations were found with other diseases.

CONCLUSIONS

The study showed an association between emergency hospital visits with HD as primary diagnosis and same day H2S concentrations exceeding 7.00μg/m3, more pronounced among males and those 73 years and older than among females and younger individuals.

Associations between proximity to livestock farms, primary health care visits and self-reported symptoms

BACKGROUND

Living in a neighbourhood with a high density of livestock farms has been associated with adverse respiratory health effects, but less is known about healthcare utilisation. This study aimed at investigating the associations between livestock exposure and primary health care visits and self-reported symptoms. In addition, we examined the potentially confounding effect of distance from home to general practice.

METHODS

Contact data between 2006 and 2009 were obtained from electronic medical records of 54,777 persons registered within 16 general practices in an area with a high density of livestock farms in the Netherlands. Data on self-reported symptoms were used from a cross-sectional sample of 531 patients in 2010. Livestock presence in a 500 m radius from home was computed using Geographic Information System data.

RESULTS

In general, livestock exposure was associated with fewer contacts and self-reported symptoms for respiratory and other conditions. The number of poultry within 500 m was positively associated with the number of contacts. A longer distance to general practice was associated with fewer contacts, but did not confound associations.

CONCLUSIONS

People living close to livestock farms less often see their general practitioner and report symptoms.

Doctor-diagnosed health problems in a region with a high density of concentrated animal feeding operations: a cross-sectional study

BACKGROUND

There is growing interest in health risks of residents living near concentrated animal feeding operations (CAFOs). Previous research mostly focused on swine CAFOs and self-reported respiratory conditions. The aim was to study the association between the presence of swine, poultry, cattle and goat CAFOs and health of Dutch neighbouring residents using electronic medical records from general practitioners (GPs).

METHODS

Data for the year 2009 were collected of 119,036 inhabitants of a rural region with a high density of CAFOs using information from GIAB (high exposed population). A comparison was made with GP data from 78,060 inhabitants of rural areas with low densities of CAFOs (low exposed population). Associations between the number of CAFOs near residents' homes and morbidity were determined by multilevel (cross-classified) logistic regression.

RESULTS

In 2009, the prevalence of most respiratory and gastrointestinal conditions was similar in the high and low exposed population. Exceptions were pneumonia, atopic eczema and unspecified infectious diseases with an increased prevalence, and sinusitis with a decreased prevalence in the high exposed population. Within the high CAFO density region, the number of poultry, cattle and swine CAFOs near residents' homes was not associated with allergic, respiratory or gastrointestinal conditions. Conversely, each additional goat CAFO within the postal code area of residents' homes significantly increased the odds of unspecified infectious disease and pneumonia by 87 and 41 percent, respectively.

CONCLUSIONS

Using GP records, pneumonia and unspecified infectious diseases were positively associated with the number of goat CAFOs near residents' homes, but no association was found between swine, cattle, and poultry CAFOs and respiratory, allergic or gastrointestinal conditions.

Industrial Food Animal Production and Community Health

Industrial food animal production (IFAP) is a source of environmental microbial and chemical hazards. A growing body of literature suggests that populations living near these operations and manure-applied crop fields are at elevated risk for several health outcomes. We reviewed the literature published since 2000 and identified four health outcomes consistently and positively associated with living near IFAP: respiratory outcomes, methicillin-resistant Staphylococcus aureus (MRSA), Q fever, and stress/mood. We found moderate evidence of an association of IFAP with quality of life and limited evidence of an association with cognitive impairment, Clostridium difficile, Enterococcus, birth outcomes, and hypertension. Distance-based exposure metrics were used by 17/33 studies reviewed. Future work should investigate exposure through drinking water and must improve exposure assessment with direct environmental sampling, modeling, and high-resolution DNA typing methods. Investigators should not limit study to high-profile pathogens like MRSA but include a broader range of pathogens, as well as other disease outcomes.

Risk of exacerbations in COPD and asthma patients living in the neighbourhood of livestock farms: Observational study using longitudinal data

OBJECTIVE

Living in an area with a high density of livestock farms has been associated with adverse respiratory health effects in some studies. As patients with COPD and asthma already have a compromised respiratory function and chronic airway inflammation, they are expected to be at increased risk for adverse respiratory health effects. The objective of this study was to assess the association between livestock exposure and exacerbations in COPD and asthma.

METHODS

899 COPD and 2546 asthma patients from 15 general practices in a rural area with a high livestock density and 933 COPD and 2310 asthma patients from 15 practices in a control area in the Netherlands were included. Occurrence of exacerbations was based on the pharmaceutical treatment of exacerbations in COPD and asthma patients using 2006-2012 prescription data of electronic medical records. Farm exposure was assessed by comparing the study area with the control area, and with individual exposure estimates in the study area using Geographic Information System data.

RESULTS

The exacerbation rate was higher in the study area compared with the control area in COPD (IRR: 1.28; 95%CI: 1.06-1.55), but not in asthma patients (IRR: 0.87; 95%CI: 0.72-1.05). In general, individual exposure estimates in the study area were not associated with exacerbations. COPD patients living within a 500m radius of up to12,499 chickens had a 36% higher exacerbation rate (IRR: 1.36; 95%CI: 1.03-1.79).

CONCLUSIONS

Living in an area with a high livestock density is a risk factor for exacerbations in COPD patients. The environmental exposure responsible for this increased risk remains to be elucidated.

Effect of environmental exposure to hydrogen sulfide on central nervous system and respiratory function: a systematic review of human studies

BACKGROUND

Assessment of the health effects of low-level exposure to hydrogen sulfide (H2S) on humans through experiments, industrial, and community studies has shown inconsistent results.

OBJECTIVE

To critically appraise available studies investigating the effect of H2S on the central nervous system (CNS) and on respiratory function.

METHODS

A search was conducted in 16 databases for articles published between January 1980 and July 2014. Two researchers independently evaluated potentially relevant papers based on a set of inclusion/exclusion criteria.

RESULTS

Twenty-seven articles met the inclusion criteria: 6 experimental, 12 industry-based studies, and 10 community-based studies (one article included both experimental and industry-based studies). The results of the systematic review varied by study setting and quality. Several community-based studies reported associations between day-to-day variations in H2S levels and health outcomes among patients with chronic respiratory conditions. However, evidence from the largest and better-designed community-based studies did not support that chronic, ambient H2S exposure has health effects on the CNS or respiratory function. Results from industry-based studies varied, reflecting the diversity of settings and the broad range of H2S exposures. Most studies did not have individual measurements of H2S exposure.

DISCUSSION

The results across studies were inconsistent, justifying the need for further research.

Association between use of warfarin with common sulfonylureas and serious hypoglycemic events: retrospective cohort analysis

STUDY QUESTION

Is warfarin use associated with an increased risk of serious hypoglycemic events among older people treated with the sulfonylureas glipizide and glimepiride?

METHODS

This was a retrospective cohort analysis of pharmacy and medical claims from a 20% random sample of Medicare fee for service beneficiaries aged 65 years or older. It included 465,918 beneficiaries with diabetes who filled a prescription for glipizide or glimepiride between 2006 and 2011 (4,355,418 person quarters); 71,895 (15.4%) patients also filled a prescription for warfarin (416,479 person quarters with warfarin use). The main outcome measure was emergency department visit or hospital admission with a primary diagnosis of hypoglycemia in person quarters with concurrent fills of warfarin and glipizide/glimepiride compared with the rates in quarters with glipizide/glimepiride fills only, Multivariable logistic regression was used to adjust for individual characteristics. Secondary outcomes included fall related fracture and altered consciousness/mental status.

SUMMARY ANSWER AND LIMITATIONS

In quarters with glipizide/glimepiride use, hospital admissions or emergency department visits for hypoglycemia were more common in person quarters with concurrent warfarin use compared with quarters without warfarin use (294/416,479 v 1903/3,938,939; adjusted odds ratio 1.22, 95% confidence interval 1.05 to 1.42). The risk of hypoglycemia associated with concurrent use was higher among people using warfarin for the first time, as well as in those aged 65-74 years. Concurrent use of warfarin and glipizide/glimepiride was also associated with hospital admission or emergency department visit for fall related fractures (3919/416,479 v 20,759/3,938,939; adjusted odds ratio 1.47, 1.41 to 1.54) and altered consciousness/mental status (2490/416,479 v 14,414/3,938,939; adjusted odds ratio 1.22, 1.16 to 1.29). Unmeasured factors could be correlated with both warfarin use and serious hypoglycemic events, leading to confounding. The findings may not generalize beyond the elderly Medicare population.

WHAT THIS STUDY ADDS

A substantial positive association was seen between use of warfarin with glipizide/glimepiride and hospital admission/emergency department visits for hypoglycemia and related diagnoses, particularly in patients starting warfarin. The findings suggest the possibility of a significant drug interaction between these medications.

FUNDING, COMPETING INTERESTS, DATA SHARING

JAR and DPG receive support from the National Institute on Aging, the Commonwealth Fund, and the Leonard D. Schaeffer Center for Health Policy and Economics at the University of Southern California. ABJ receives support from the NIH Office of the Director. No additional data are available.

Increased respiratory symptoms in COPD patients living in the vicinity of livestock farms

Several studies have investigated the effect of livestock farm emissions on the respiratory health of local residents, but results are inconsistent. This study aims to explore associations between the presence of livestock farms and respiratory health in an area of high-density livestock farming in the Netherlands. We focused especially on associations between farm exposures and respiratory symptoms within subgroups of potentially susceptible patients with a pre-existing lung disease.In total, 14 875 adults (response rate 53.4%) completed a questionnaire concerning respiratory health, smoking habits and personal characteristics. Different indicators of livestock farm exposures relative to the home address were computed using a geographic information system.Prevalence of chronic obstructive pulmonary disease (COPD) and asthma was lower among residents living within 100 m of a farm (OR 0.47, 95% CI 0.24-0.91 and OR 0.65, 95% CI 0.45-0.93, respectively). However, >11 farms in 1000 m compared to fewer than four farms in 1000 m (fourth quartile versus first quartile) was associated with wheezing among COPD patients (OR 1.71, 95% CI 1.01-2.89). Using general practitioners' electronic medical records, we demonstrated that selection bias did not affect the observed associations.Our data suggest a protective effect of livestock farm emissions on the respiratory health of residents. Nonetheless, COPD patients living near livestock farms reported more respiratory symptoms, suggesting an increased risk of exacerbations.

Challenges and benefits of conducting environmental justice research in a school setting

Environmental justice (EJ) research requires attention to consequences for research participants beyond those typically considered by institutional review boards. The imbalance of power between impacted communities and those who create and regulate pollution creates challenges for participation, yet research can also benefit those involved. Our community-academic partnership designed the Rural Air Pollutants and Children's Health (RAPCH) study to provide positive impacts while measuring health effects at three low-resource public middle schools near concentrated animal feeding operations (CAFOs) in North Carolina. We evaluated perceived benefits and challenges of study involvement by interviewing school staff and community liaisons who facilitated data collection. Reported benefits included enhancement of students' academic environment and increased community environmental awareness; challenges were associated mainly with some participants' immaturity. Leadership from a strong community-based organization was crucial to recruitment, yet our approach entailed minimal focus on EJ, which may have limited opportunities for community education or organizing for environmental health.

Investigation of hydrogen sulfide exposure and lung function, asthma and chronic obstructive pulmonary disease in a geothermal area of New Zealand

Background

Results have been conflicting whether long-term ambient hydrogen sulfide (H₂S) affects lung function or is a risk factor for asthma or chronic obstructive pulmonary disease (COPD). Rotorua city, New Zealand, has the world’s largest population exposed to ambient H₂S—from geothermal sources.

Objectives

We investigated associations of H₂S with lung function, COPD and asthma in this population.

Methods

1,204 of 1,639 study participants, aged 18–65 years during 2008–2010, provided satisfactory spirometry results. Residences, workplaces and schools over the last 30 years were geocoded. Exposures were estimated from data collected by summer and winter H₂S monitoring networks across Rotorua. Four metrics for H₂S exposure, representing both current and long-term (last 30 years) exposure, and also time-weighted average and peak exposures, were calculated. Departures from expected values for pre-bronchodilator lung function, calculated from prediction equations, were outcomes for linear regression models using quartiles of the H₂S exposure metrics. Separate models examined participants with and without evidence of asthma or COPD, and never- and ever-smokers. Logistic regression was used to investigate associations of COPD (a post-bronchodilator FEV₁/FVC < 70% of expected) and asthma (doctor-diagnosed or by FEV₁ response to bronchodilator) with H₂S exposure quartiles.

Results

None of the exposure metrics produced evidence of lung function decrement. The logistic regression analysis showed no evidence that long-term H₂S exposure at Rotorua levels was associated with either increased COPD or asthma risk. Some results suggested that recent ambient H₂S exposures were beneficially associated with lung function parameters.

Conclusions

The study found no evidence of reductions in lung function, or increased risk of COPD or asthma, from recent or long-term H₂S exposure at the relatively high ambient concentrations found in Rotorua. Suggestions of improved lung function associated with recent ambient H₂S exposures require confirmation in other studies.

Food System Policy, Public Health, and Human Rights in the United States

The US food system functions within a complex nexus of social, political, economic, cultural, and ecological factors. Among them are many dynamic pressures such as population growth, urbanization, socioeconomic inequities, climate disruption, and the increasing demand for resource-intensive foods that place immense strains on public health and the environment. This review focuses on the role that policy plays in defining the food system, particularly with regard to agriculture. It further examines the challenges of making the food supply safe, nutritious, and sustainable, while respecting the rights of all people to have access to adequate food and to attain the highest standard of health. We conclude that the present US food system is largely unhealthy, inequitable, environmentally damaging, and insufficiently resilient to endure the impacts of climate change, resource depletion, and population increases, and is therefore unsustainable. Thus, it is imperative that the US embraces policy reforms to transform the food system into one that supports public health and reflects the principles of human rights and agroecology for the benefit of current and future generations.

Odors from sewage sludge and livestock: associations with self-reported health

OBJECTIVES

Class B treated sewage sludge (TSS) contains microbes and toxicants and is applied to land in areas where livestock wastes may be present. We evaluated relationships of reports of TSS and livestock odors with acute symptoms and excessive flies.

METHODS

A total of 158 adults living near liquid TSS application sites, 85 living near cake TSS application sites, and 188 living in comparison areas responded to a household survey regarding odors, health, and demographics. We identified symptom groups using factor analysis. We used generalized estimating equations to fit linear models for associations between factor scores and odors, and Poisson models for associations with specific symptoms.

RESULTS

Most factor scores were similar between exposure groups. Covariate-adjusted z-scores for lower respiratory symptoms were 0.28 (95% confidence interval [CI] -0.10, 0.65) higher among residents who reported moderate to very strong liquid TSS odor than among residents in comparison areas, and 0.28 (95% CI 0.05, 0.50) higher among residents who reported moderate to very strong livestock odor compared with residents reporting no or faint livestock odor. The factor score for dermatologic conditions was higher among residents who reported higher liquid sludge odor (0.27, 95% CI -0.13, 0.68), primarily due to skin rash (prevalence ratio = 2.21, 95% CI 1.13, 4.32). Excessive flies were reported twice as commonly among respondents who reported moderate to very strong TSS odor than among other residents.

CONCLUSIONS

Reported odors from TSS and livestock were associated with some acute symptoms. Health departments should monitor land applications of human and animal wastes and conduct surveillance of health problems reported by neighbors.

Seasonal variability in airborne biotic contaminants in swine confinement buildings

Little is known about the seasonal dynamics of biotic contaminants in swine confinement buildings (SCBs). The biotic contaminants of seven SCBs were monitored during one visit in the winter and one during the summer. Paired-end Illumina sequencing of the 16S rRNA gene, V3 region, was used to examine seasonal shifts in bacterial community composition and diversity. The abundances of 16S rRNA genes and six tetracycline resistance genes (tetB, tetH, tetZ, tetO, tetQ, and tetW) were also quantified using real-time PCR. Bacterial abundances, community composition and diversity all showed strong seasonal patterns defined by winter peaks in abundance and diversity. Microclimatic variables of SCBs, particularly air speed, PM2.5 and total suspended particles (TSP) were found significantly correlated to abundances, community composition, and diversity of bacterial bioaerosols. Seasonal fluctuations were also observed for four tetracycline resistance genes, tetH, tetO, tetQ, and tetW. The frequency of occurrences of these resistance genes were significantly higher in samples collected during winter and was also significantly correlated with air speed, PM2.5 and TSP. Overall, our results indicate that biotic contaminants in SCBs exhibit seasonal trends, and these could be associated with the microclimatic variables of SCBs. The correlations established in the current study could be helpful in establishing better management strategies to minimize the potential health impacts on both livestock and humans working in this environment.

Water quality and nitrogen mass loss from anaerobic lagoon columns receiving pretreated influent

Control methods are needed to abate NH losses from swine anaerobic lagoons to reduce the contribution of confined swine operations to air pollution. In a 15-mo meso-scale column study, we evaluated the effect of manure pretreatment on water quality, reduction of N losses, and sludge accumulation in swine lagoons using (i) enhanced solid-liquid separation with polymer (SS) and (ii) solid-liquid separation plus biological N treatment using nitrification-denitrification (SS + NDN). A conventional anaerobic lagoon was included as a control. Concentrations of total Kjeldahl N (TKN), total ammoniacal N (TAN), and NO-N were monitored during the course of the study, and the volumes of column liquid and sludge were used to estimate N mass flows. At the end of the study, TKN and TAN concentrations in the liquid of SS columns were 35 and 37% lower than the control, respectively, and TKN and TAN concentrations in SS + NDN were 97 and 99% lower than the control. The N mass flow analysis revealed that SS reduced total N inflow by 30% and SS + NDN by 82% compared with the control. The SS was ineffective at reducing NH losses compared with the control. Instead, SS + NDN effectively reduced total NH losses by 50%, most of which occurred during the first 6 mo of the study. Although both pretreatments can stop the mass accumulation of total N in sludge, SS + NDN had the advantage of improving water quality and abating NH emissions from treated lagoons. As an additional environmental benefit, SS + NDN effluents could be used for crop irrigation without the risk of NH losses during land application.

Human exposure to endotoxins and fecal indicators originating from water features

Exposure to contaminated aerosols and water originating from water features may pose public health risks. Endotoxins in air and water and fecal bacteria in water of water features were measured as markers for exposure to microbial cell debris and enteric pathogens, respectively. Information was collected about wind direction, wind force, distance to the water feature, the height of the water feature and the tangibility of water spray. The mean concentration of endotoxins in air nearby and in water of 31 water features was 10 endotoxin units (EU)/m(3) (Geometric Mean (GM), range 0-85.5 EU/m(3) air) and 773 EU/mL (GM, range 9-18,170 EU/mL water), respectively. Such mean concentrations may be associated with respiratory health effects. The water quality of 26 of 88 water features was poor when compared to requirements for recreational water in the Bathing Water Directive 2006/7/EC. Concentrations greater than 1000 colony forming units (cfu) Escherichia coli per 100 mL and greater than 400 cfu intestinal enterococci per 100 mL increase the probability of acquiring gastrointestinal health complaints. Regression analyses showed that the endotoxin concentration in air was significantly influenced by the concentration of endotoxin in water, the distance to the water feature and the tangibility of water spray. Exposure to air and water near water features was shown to lead to exposure to endotoxins and fecal bacteria. The potential health risks resulting from such exposure to water features may be estimated by a quantitative microbial risk assessment (QMRA), however, such QMRA would require quantitative data on pathogen concentrations, exposure volumes and dose-response relationships. The present study provides estimates for aerosolisation ratios that can be used as input for QMRA to quantify exposure and to determine infection risks from exposure to water features.

Investigating the role of state permitting and agriculture agencies in addressing public health concerns related to industrial food animal production

Objectives

Industrial food animal production (IFAP) operations adversely impact environmental public health through air, water, and soil contamination. We sought to determine how state permitting and agriculture agencies respond to these public health concerns.

Methods

We conducted semi-structured qualitative interviews with staff at 12 state agencies in seven states, which were chosen based on high numbers or rapid increase of IFAP operations. The interviews served to gather information regarding agency involvement in regulating IFAP operations, the frequency and type of contacts received about public health concerns, how the agency responds to such contacts, and barriers to additional involvement.

Results

Permitting and agriculture agencies’ responses to health-based IFAP concerns are constrained by significant barriers including narrow regulations, a lack of public health expertise within the agencies, and limited resources.

Conclusions

State agencies with jurisdiction over IFAP operations are unable to adequately address relevant public health concerns due to multiple factors. Combining these results with previously published findings on barriers facing local and state health departments in the same states reveals significant gaps between these agencies regarding public health and IFAP. There is a clear need for regulations to protect public health and for public health professionals to provide complementary expertise to agencies responsible for regulating IFAP operations.

Chronic ambient hydrogen sulfide exposure and cognitive function

BACKGROUND

Exposures to hydrogen sulfide gas (H2S) have been inconclusively linked to a variety of negative cognitive outcomes. We investigated possible effects on cognitive function in an urban population with chronic, low-level exposure to H2S.

METHODS

Participants were 1637 adults, aged 18-65 years from Rotorua city, New Zealand, exposed to ambient H2S from geothermal sources. Exposures at homes and workplaces were estimated from data collected by summer and winter H2S monitoring networks across Rotorua in 2010/11. Metrics for H2S exposure at the time of participation and for exposure over the last 30 years were calculated. H2S exposure was modeled both as continuous variables and as quartiles of exposure covering the range of 0-64 ppb (0-88 μg/m(3)). Outcomes were neuropsychological tests measuring visual and verbal episodic memory, attention, fine motor skills, psychomotor speed and mood. Associations between cognition and measures of H2S exposure were investigated with multiple regression, while covarying demographics and factors known to be associated with cognitive performance.

RESULTS

The consistent finding was of no association between H2S exposure and cognition. Quartiles of H2S exposure had a small association with simple reaction time: higher exposures were associated with faster response times. Similarly, for digit symbol, higher H2S exposures tended to be marginally associated with better performance.

CONCLUSION

The results provide evidence that chronic H2S exposure, at the ambient levels found in and around Rotorua, is not associated with impairment of cognitive function.

Availability of information about airborne hazardous releases from animal feeding operations

Introduction

Air from animal feeding operations (AFOs) has been shown to transport numerous contaminants of public health concern. While federal statutes like the Emergency Planning and Community Right-to-Know Act (EPCRA) generally require that facilities report hazardous releases, AFOs have been exempted from most of these requirements by the U.S. Environmental Protection Agency (EPA). We assessed the availability of information about AFO airborne hazardous releases following these exemptions.

Methods

We submitted public records requests to 7 states overlapping with or adjacent to the Chesapeake Bay watershed for reports of hazardous releases made by AFOs under EPCRA. From the records received, we calculated the proportion of AFOs in each state for which ≥1 reports were available. We also determined the availability of specific types of information required under EPCRA. The numbers of AFOs permitted under the Clean Water Act (CWA) or analogous state laws, as determined from permitting databases obtained from states, were used as denominators.

Results

We received both EPCRA reports and permitting databases from 4 of 7 states. Across these 4 states, the mean proportion of AFOs for which ≥1 EPCRA reports were available was 15% (range: 2-33%). The mean proportions of AFOs for which the name or identity of the substance released, ≥1 estimates of quantity released, and information about nearby population density and sensitive populations were available were 15% (range: 2-33%), 8% (range: 0-22%), and 14% (range: 2-8%), respectively.

Discussion

These results suggest that information about the airborne hazardous releases of a large majority of AFOs is not available under federal law in the states that we investigated. While the results cannot be attributed to specific factors by this method, attention to multiple factors, including revision of the EPA’s exemptions, may increase the availability of information relevant to the health of populations living or working near AFOs.

Air pollution from livestock farms, and asthma, allergic rhinitis and COPD among neighbouring residents

OBJECTIVES

There is an ongoing debate regarding environmental health risks of exposures to dust and microbial agents from livestock farming in the Netherlands. The aims of the study were (1) to investigate associations between indicators of air pollution from livestock farms and asthma, allergic rhinitis and chronic obstructive pulmonary disease (COPD) among neighbouring residents; and (2) to assess associations between farm exposures and endotoxin levels in participants' homes.

METHODS

Electronic medical records of all 92 548 patients of 27 general practices in a rural area with a high density of animal farms were analysed, followed up by a case-control component using a subsample of the full population. Distance between livestock farms and home address, presence of livestock within 500 m, and particulate matter (PM)10 emissions from farms within 500 m were computed as proxies for farm exposure. Potential confounding was investigated through a case-control questionnaire study in 269 adult patients with asthma and 546 controls. Endotoxin levels were assessed in 493 homes.

RESULTS

Modelled PM10 emission was inversely associated with asthma, allergic rhinitis and COPD (p<0.05). A smaller distance to the nearest farm, and the presence of swine, goat and sheep farms were also inversely related to respiratory morbidity, whereas mink farms showed positive associations with asthma and allergic rhinitis. Adjustment for confounding in the case-control study did not change results. Farm exposures were not associated with endotoxin levels in neighbouring residents' homes.

CONCLUSIONS

In conclusion, indicators of air pollution from livestock farms were inversely associated with respiratory morbidity among neighbouring residents.

Passive monitors to measure hydrogen sulfide near concentrated animal feeding operations

Hydrogen sulfide (H2S) is one of many airborne pollutants emitted by concentrated animal feeding operations (CAFOs). However, few studies have characterized ambient H2S levels near these facilities, largely due to the lack of low-cost, reliable, and easily transportable instrumentation available to researchers. We determined intermediate environmental H2S exposure near CAFOs using Radiello passive monitors. First, a laboratory study was performed to determine the accuracy of the device. Next, a total of eight passive H2S monitors were deployed bi-weekly in close proximity (<40 m) to a medium-sized swine confinement for seven months in order to determine the temporal and spatial variability of H2S. Finally, we measured H2S concentrations across two rural Iowa counties to characterize ambient exposure near thirteen CAFOs and two schools. The value of the temperature-adjusted H2S passive diffusion rate provided by the supplier was 29% larger than the 24 h rate determined experimentally. Concentrations of H2S measured near the medium-sized confinement were varied and ranged from 0.2 to 48.6 ppb depending on the sampling period and proximity to a lagoon on the property. Two-week concentrations near the schools were low (<1 ppb), while concentrations near the thirteen CAFOs ranged from 0.1 to 42.9 ppb. The passive monitors were effective in measuring H2S concentrations near a swine CAFO as long as they were exposed for a sufficient period of time (two weeks). Radiello passive monitors are a promising new device in measuring intermediate H2S exposure in rural populations. Measured values in excess of an Iowa state limit of 30 ppb (24 h average) suggest that enforcement actions are needed to mitigate H2S migration from swine CAFOs.

Land application of treated sewage sludge: community health and environmental justice

BACKGROUND

In the United States, most of the treated sewage sludge (biosolids) is applied to farmland as a soil amendment. Critics suggest that rules regulating sewage sludge treatment and land application may be insufficient to protect public health and the environment. Neighbors of land application sites report illness following land application events.

OBJECTIVES

We used qualitative research methods to evaluate health and quality of life near land application sites.

METHODS

We conducted in-depth interviews with neighbors of land application sites and used qualitative analytic software and team-based methods to analyze interview transcripts and identify themes.

RESULTS

Thirty-four people in North Carolina, South Carolina, and Virginia responded to interviews. Key themes were health impacts, environmental impacts, and environmental justice. Over half of the respondents attributed physical symptoms to application events. Most noted offensive sludge odors that interfere with daily activities and opportunities to socialize with family and friends. Several questioned the fairness of disposing of urban waste in rural neighborhoods. Although a few respondents were satisfied with the responsiveness of public officials regarding sludge, many reported a lack of public notification about land application in their neighborhoods, as well as difficulty reporting concerns to public officials and influencing decisions about how the practice is conducted where they live.

CONCLUSIONS

Community members are key witnesses of land application events and their potential impacts on health, quality of life, and the environment. Meaningful involvement of community members in decision making about land application of sewage sludge will strengthen environmental health protections.

Associations of ambient hydrogen sulfide exposure with self-reported asthma and asthma symptoms

BACKGROUND

Whether long-term, low-level hydrogen sulfide (H2S) gas is a cause of health effects, including asthma, is uncertain. Rotorua city, New Zealand, has the largest population exposed, from geothermal sources, to relatively high ambient levels of H2S. In a cross-sectional study, the authors investigated associations with asthma in this population.

METHODS

A total of 1637 adults, aged 18-65 years, were enrolled during 2008-2010. Residences and workplaces were geocoded. H2S exposures at homes and workplaces were estimated using city-wide networks of passive H2S samplers and kriging to create exposure surfaces. Exposure metrics were based on (1) time-weighted exposures at home and work; and (2) the maximum exposure (home or work). Exposure estimates were entered as quartiles into regression models, with covariate data.

RESULTS

Neither exposure metric showed evidence of increased asthma risk from H2S. However, some suggestion of exposure-related reduced risks for diagnosed asthma and asthma symptoms, particularly wheezing during the last 12 months, emerged. With the maximum exposure metric, the prevalence ratio for wheeze in the highest exposure quartile was 0.80 (0.65, 0.99) and, for current asthma treatment, 0.75 (0.52, 1.08). There was no evidence that this was caused by a "survivor effect".

CONCLUSIONS

The study provided no evidence that asthma risk increases with H2S exposure. Suggestions of a reduced risk in the higher exposure areas are consistent with recent evidence that H2S has signaling functions in the body, including induction of smooth muscle relaxation and reduction of inflammation. Study limitations, including possible confounding, preclude definitive conclusions.

Investigating the role of state and local health departments in addressing public health concerns related to industrial food animal production sites

Objectives

Evidence of community health concerns stemming from industrial food animal production (IFAP) facilities continues to accumulate. This study examined the role of local and state health departments in responding to and preventing community-driven concerns associated with IFAP.

Methods

We conducted semi-structured qualitative interviews with state and county health department staff and community members in eight states with high densities or rapid growth of IFAP operations. We investigated the extent to which health concerns associated with IFAP sites are reported to health departments, the nature of health departments’ responses, and barriers to involvement.

Results

Health departments’ roles in these matters are limited by political barriers, lack of jurisdiction, and finite resources, expertise, and staff. Community members reported difficulties in engaging health departments on these issues.

Conclusions

Our investigation suggests that health departments frequently lack resources or jurisdiction to respond to health concerns related to IFAP sites, resulting in limited engagement. Since agencies with jurisdiction over IFAP frequently lack a health focus, increased health department engagement may better protect public health.

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 [β (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.

Environmental and non-infectious factors in the aetiology of pharyngitis (sore throat)

OBJECTIVES

The aim of this review is to examine the causes, pathophysiology and experimental models of non-infectious pharyngitis (sore throat).

INTRODUCTION

The causes of sore throat can be infectious (viruses, bacteria, and fungi) or non-infectious, although the relative proportion of each is not well documented.

METHODS

A PubMed database search was performed for studies of non-infectious sore throat.

RESULTS AND CONCLUSIONS

Non-infectious causes of sore throat include: physico-chemical factors, such as smoking, snoring, shouting, tracheal intubation, medications, or concomitant illness; and environmental factors including indoor and outdoor air pollutants, temperature and humidity, and hazardous or occupational irritants. The pathophysiology underlying non-infectious sore throat is largely uncharacterised, although neurogenic inflammation looks to be a promising candidate. It is likely that there will be individual disposition factors or the coincidence of more than one irritant with possible--up to now unknown--interactions between them. Therefore, experimental models with defined conditions and objective endpoints are needed. A new model using cold dry air to directly induce pharyngeal irritation in humans, with pharyngeal lavage to measure biomarkers, may provide a useful tool for the study of mechanisms and treatment of non-infectious sore throat.

Q fever and pneumonia in an area with a high livestock density: a large population-based study

Concerns about public health risks of intensive animal production in the Netherlands continue to rise, in particular related to outbreaks of infectious diseases. The aim was to investigate associations between the presence of farm animals around the home address and Q fever and pneumonia.

Electronic medical record data for the year 2009 of all patients of 27 general practitioners (GPs) in a region with a high density of animal farms were used. Density of farm animals around the home address was calculated using a Geographic Information System. During the study period, a large Q fever outbreak occurred in this region. Associations between farm exposure variables and pneumonia or ‘other infectious disease’, the diagnosis code used by GPs for registration of Q fever, were analyzed in 22,406 children (0–17 y) and 70,142 adults (18–70 y), and adjusted for age and sex. In adults, clear exposure-response relationships between the number of goats within 5 km of the home address and pneumonia and ‘other infectious disease’ were observed. The association with ‘other infectious disease’ was particularly strong, with an OR [95%CI] of 12.03 [8.79–16.46] for the fourth quartile (>17,190 goats) compared with the first quartile (<2,251 goats). The presence of poultry within 1 km was associated with an increased incidence of pneumonia among adults (OR [95%CI] 1.25 [1.06–1.47]).

A high density of goats in a densely populated region was associated with human Q fever. The use of GP records combined with individual exposure estimates using a Geographic Information System is a powerful approach to assess environmental health risks.

Occupational exposure to particulate matter and endotoxin for California dairy workers

Occupational exposure of dairy workers to particulate matter (PM) and endotoxin has been considered by some to be of potential concern. This paper reports personal exposure concentrations of PM (μg/m3) and endotoxin (EU/m3) for 226 workers from 13 California dairies. Arithmetic mean personal concentrations for PM2.5, inhalable PM and endotoxin were 48 μg/m3 (N = 222), 987 μg/m3 (N = 225) and 453 EU/m3 (N = 225), respectively. Using mixed effects models, time spent re-bedding of freestall barns versus any other job conducted on a dairy led to the highest exposure for PM2.5, inhalable PM, and endotoxin. Personal exposure concentrations were found to be greater than those reported for ambient area based concentrations at the same dairies. A pseudo R-square approach revealed that one area based measure combined with time spent performing tasks explained a significant portion of variation in personal exposure concentrations.

Relation between malodor, ambient hydrogen sulfide, and health in a community bordering a landfill

BACKGROUND

Municipal solid waste landfills are sources of air pollution that may affect the health and quality of life of neighboring communities.

OBJECTIVES

To investigate health and quality of life concerns of neighbors related to landfill air pollution.

METHODS

Landfill neighbors were enrolled and kept twice-daily diaries for 14d about odor intensity, alteration of daily activities, mood states, and irritant and other physical symptoms between January and November 2009. Concurrently, hydrogen sulfide (H(2)S) air measurements were recorded every 15-min. Relationships between H(2)S, odor, and health outcomes were evaluated using conditional fixed effects regression models.

RESULTS

Twenty-three participants enrolled and completed 878 twice-daily diary entries. H(2)S measurements were recorded over a period of 80d and 1-h average H(2)S=0.22ppb (SD=0.27; range: 0-2.30ppb). Landfill odor increased 0.63 points (on 5-point Likert-type scale) for every 1ppb increase in hourly average H(2)S when the wind was blowing from the landfill towards the community (95% confidence interval (CI): 0.29, 0.91). Odor was strongly associated with reports of alteration of daily activities (odds ratio (OR)=9.0; 95% CI: 3.5, 23.5), negative mood states (OR=5.2; 95% CI: 2.8, 9.6), mucosal irritation (OR=3.7; 95% CI=2.0, 7.1) and upper respiratory symptoms (OR=3.9; 95% CI: 2.2, 7.0), but not positive mood states (OR=0.6; 95% CI: 0.2, 1.5) and gastrointestinal (GI) symptoms (OR=1.0; 95% CI: 0.4, 2.6).

CONCLUSIONS

Results suggest air pollutants from a regional landfill negatively impact the health and quality of life of neighbors.

Suitability of public records for evaluating health effects of treated sewage sludge in North Carolina

BACKGROUND

Exposure to potentially harmful agents because of waste disposal practices is receiving increased attention. Treated sewage sludge (TSS), or biosolid material, is the solid waste generated during domestic sewage treatment after it has undergone processes to reduce the number of pathogens and vector attractants. Application of TSS to land, which is the most common method for disposal, is promoted as a soil amendment and fertilizer. Few studies have examined the effects of land application on the health and quality of life of neighboring populations. We describe and summarize publicly available records that could be used to study the public health impact of practices associated with land application in North Carolina.

METHODS

We abstracted public records from the North Carolina Department of Natural Resources Division of Water Quality, to determine the following activities associated with land application of TSS in 8 counties in central North Carolina: the process for obtaining permits, reported applications, violations, documented concerns of residents, and penalties assessed.

RESULTS

The Division of Water Quality routinely collects records of permits and approvals for land application of TSS, amounts applied, and reported pollutant levels. Documentation was useful in summarizing land application practices, but lack of standardization in reporting was a concern. Research into the public health impacts of the land application program is hindered by inconsistency in documenting inspections and resident concerns.

LIMITATIONS

We were not able to validate state records with direct observation of land application of TSS.

CONCLUSIONS

Records from the Division of Water Quality would be of limited use in epidemiologic studies of the health effects of land application of biosolids. Information about locations, amounts, and dates of application are relevant to exposure potential, but additional information is needed for health investigations.