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Citizens
for the Environment and Future in Eastern Ontario |
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Citizens
for the Environment and Future in Eastern Ontario |
October 27, 2003
In response to a request from two communities in the five counties of Eastern Ontario, a cursory review of the literature looking at the effects of concentrated animal feeding operations (CAFOs) and the public health implications, was done.
Introduction
Many health hazards occur in hog farm operations, contaminants entering into the body by ingestion, inhalation, and skin absorption. Without knowledge of the potential hazard, people can be subjected to injury within a short time following an acute exposure or suffer from chronic condition over long-term exposure.
Historically swine operations have increased with growth of the human population; at the same time the public perception of health impacts related to hog operations has increased. Such concerns commonly arise because of extrapolation of risks to the general population from those observed in occupational workers, and population living near these facilities. A number of epidemiological investigations have been carried out by different public health authorities in United States and Canada to try to assess whether communities have experienced adverse outcomes as a result of exposures to swine operations.
Background
Modern hog facilities are more enclosed and tightly constructed compared to conventional livestock housing, and have much higher density of animals, usually for 24 hours a day from birth to shipment to the slaughter house. These buildings must include devices to ventilate and heat the buildings and to dispose of animal wastes. Often, feeding and watering operations are semiautomatic or automatic. Manure can be handled by one of two systems: it either drops through a slatted floor into a pit beneath the house where it remains until the manure slurry is pumped out to be distributed on fields (usually twice a year), or it is removed through any of several mechanisms to a storage pit or lagoon outside the building.
Based in environmental assessments and epidemiologic studies there are evidences of impacts of hog farms on water, air, human health, and quality of life. The impacts of swine operations on the environment and public health are listed below: 6
HEALTH IMPACT
Public Health
The health risks are measured on the probability that someone will experience health problems; exposures to toxic air pollutants from hog farms can take many forms and the risks are related to the proximity to the source of the toxic products. Swine waste is a source of nitrates and pathogens that can find their way in the ground and surface waters, which can directly impact human health. Breathing contaminated air increases the risk of getting health problems and also increases the risks of respiratory disease and reproductive disorders. In people already suffering from respiratory diseases, breathing of contaminated air can clearly exacerbate their symptoms.
Odour
Odours are generated from lagoons, spray fields, or swine houses. When odours are not confined to the property of the operations, they have the potential to cause health problems, heightened community tensions, and losses in property values. The most frequently reported health complaints include eye, nose, and throat irritation, hoarseness, cough, chest tightness, shortness of breath, and wheezing. Respiratory symptoms are increased in smokers and among people with pre-existing respiratory problems (hay fever, bronchitis), and in people who suffer from allergies. Other symptoms include headache, nausea, diarrhea, dizziness, and nasal congestion. A number of people also present psychological symptoms. Typically, these symptoms occur at the time of exposure and remit after a short period of time of avoidance. However, for sensitive individuals such as asthmatic patients, exposure to odours may induce health symptoms that persist for longer periods of time as well as aggravate existing medical conditions.13
Water
Water supplies can be endangered if manure is not managed properly, or is accidentally spilled. Bacteria and microorganisms from spilled manure or dead animals can contaminate groundwater. Microbes and nutrients from hog manure and land-applied wastes, leaking lagoons, and pit-buried carcasses can be transported by soil and can contaminate both the groundwater and surface waters, becoming potential sources of waterborne diseases. Waterborne cryptosporidiosis is of particular concern since a number of municipal water treatment plants still do not have any filtration and that these microorganism can sometimes find their way in the distribution system12 and cause disease in the population.
Surface Water. Surface water can be contaminated by discharges from the lagoons or run-off from spray fields. There are 107 documented discharges from swine facilities in USA with 31 of these reaching the surface waters.
Groundwater. Groundwater can be contaminated either through leaking lagoons or leaching of spray field-applied waste. If nutrients in ground water reach a well that supplies drinking water, they can pose a human health hazard. Soil below the root zone containing unusually high levels of nitrate nitrogen and other nutrients can affect ground water quality and pose human health hazard.
Consuming nitrate nitrogen can alter the body's ability to transport oxygen, causing a condition called methemoglobinemia, also known, as Blue Baby Syndrome.5 This syndrome can be fatal to infants. Children in the first six months of life are particularly vulnerable to high nitrates because fetal hemoglobin is more reactive than adult hemoglobin; also the flora found in the stomach of infants facilitates conversion of nitrate to nitrite.
The U.S. Environmental Protection Agency (EPA) in 2001 claimed that groundwater in two Oklahoma counties was contaminated by high levels of nitrates and that the sources was factory hog operations linked to Seaboard Farms; in consequence five hog farms in Kingfisher and Major were sanctioned by the EPA. 4
Atmospheric Deposition
A study from Department of Environment and Natural Resource of USA estimates that swine facilities produce 20% total atmospheric nitrogen compounds that react with other constituents in the air and is deposited to land, vegetation, and water bodies in one of the largest facilities in USA (Eastern North Carolina). Around 2/3 of the nitrogen in the swine excretions is emitted to the air in accordance with the design of a lagoon and spray field system. 6
Research has demonstrated that neighbours residing near hog facilities can be exposed to hazardous agents through a number of pathways such as inhalation. Hazardous dusts and gases induce the strongest and most frequent human respiratory responses in swine confinement buildings, which can be distributed into outdoor air by building ventilation fans and spray application of slurried wastes 1. Toxic air pollutants are emitted into the atmosphere and that can travel some miles causing health concerns.11 Since dusts include both breathing (10 microns) and larger (10-50 microns) particles, lung tissues, large airway, and small airways may all be affected.2
Dusts from the animals, their feed, and their feces, ammonia (NH3) from urine and feces, and hydrogen sulfide (H2S) from manure pits, especially during agitation and emptying, can rise to harmful levels. 1
Toxic air pollutants can cause health problems by interfering with normal body functions. Most commonly they change chemical reactions within individual cells. These changes can impair cell function, resulting in damaged organs, birth defects, or other diseases. 21
According to a Iowa Center for Agricultural Health and Safety report presented by James A. Zahn Ph .D 15 there are adverse environmental and off-site human health effects from airborne emissions from concentrated animal feeding operations. This report indicated that air pollutants emitted from concentrated animal feeding operations included: ammonia (NH3), dinitrogen (N2), nitrous dioxide (NO2), hydrogen sulfide (H2S), carbon dioxide (CO2), methane (CH4), non-methane organic compounds (certain Volatile and non volatile organic compounds), and particulate matter.
Ammonia (NH3) the most important gas health wise found in swine buildings that accumulates on the slats, rooms, and equipment surfaces can be irritant to the respiratory system. Ammonia can adsorb to breathing particles and be drawn deep into the lungs; it can also cause eye irritation. NH3 vaporizing from manure sources can be carried with precipitation. High levels of nitrogen and other nutrients in slow-moving or stagnant surface waters can cause a phenomenon called eutrophication. The nutrients fuel the growth of algae, which consume oxygen in the water. As the algae die and decompose, even more oxygen is consumed. Without oxygen, fish and other marine animals die by asphyxiation altering ecosystems in natural areas. During rainfall ammonia can largely remain in the water in the dissociated forms as ammonium due to its highly water-soluble properties.
Methane (CH4)
It is a colourless, odourless gas escaping from degrading manure, which contributes to greenhouse gases. These gases may affect or accelerate the rate of climate change, such as declining water levels in lakes, high levels of smog in urban areas, hotter summer, more ice storms, increasing number and intensity of heat waves and related health problems putting at risk the population health.
Hydrogen Sulfide (H2S)
This colourless gas with a strong odour of rotten eggs can cause nausea, dizziness, possibly sudden collapse, respiratory distress, and may cause toxic effects on neighbours. At moderately high concentrations (100-400 ppm) it produces rhinitis, cough, dyspnea, tracheobronchitis, and possibly pulmonary edema 1. Brain function studies found that hydrogen sulfide can cause neuro-physiological abnormalities such as slower reaction times, color discrimination and mood alterations. 7
It is a colourless, odourless gas, about 3 percent lighter than air, and is poisonous to all warm-blooded animals and to many other forms of life. When inhaled it combines with hemoglobin in the blood, preventing absorption of oxygen and resulting in asphyxiation. It reduces the ability of blood to transport oxygen to muscles and organs, due to its strong affinity for hemoglobin. People with cardiovascular disease are more at risk. High concentrations can injure the vision; diminish work capacity, learning ability and performance of difficult tasks. Carbon monoxide is eliminated from lungs when cleaner air is inhaled.
Population at risk
Individual’s susceptibility is tempered by existing respiratory conditions (including allergies and asthma), reactivity of the bronchi, and smoking history. Although, inhalation of dust and gases brings a complex set of respiratory responses and each person has different response, the more vulnerable groups are children, pregnant women, the elderly and persons with respiratory problems or immune deficiencies.
Human studies
Based on different studies, researchers concluded that residential exposure to air contaminants generated by industrial swine operations had both physical and mental ill effects.
MENTAL HEALTH
Research has demonstrated that odours from swine facilities had an impact on the mental health of people living near the facilities; the symptoms observed are depression, tension, anger, fatigue, and confusion 18. Research in North Carolina 8 (Schiffman et al., 1995) reported that persons living near large-scale swine operations exhibited significantly higher rates of mood disorders than did matched control participants as measured by a Profile of Mood States (POMS) scale. The study of mood was considered important not only to better understand the psychological impacts but additionally because negative mood can depress the body's immune response. Unpleasant odours can thus influence physical health. Brain structures broadly involved in smell can affect immune responses via physical connections between olfactory and immune systems. Some studies suggest that sensory stimulation of the limbic forebrain, hypothalamus, and other odour projection brain areas can directly alter immune status (Schiffman et al., 1995). 12
PHYSICAL HEALTH
A study in eastern North Carolina 7 revealed health effects of community living near to swine operations. This study compared three rural communities: a rural community without livestock facilities within 2 miles; a group within 2 miles of a dairy facility; and another group within 2 miles of a swine operation. Community differences in the mean number of episodes were compared with adjustment for age, sex, smoking, and employment status. The households more affected were those living within 2 miles of the swine operation, reporting symptoms such as headaches, runny nose, sore throat, excessive coughing, burning eyes, and diarrhea. This study supports previous finding that community members experience health problems due to airborne emissions from intensive swine operations.
Long-term physical and mental health impacts could not be investigated in this study.
Another study conducted by University of Iowa 10 showed that neighbours of large-scale swine operations had higher rates of respiratory related problems compared with those living near minimal livestock production. These health related problems are the same as those reported in earlier research on swine confinement workers. These symptoms included headaches, respiratory problems, eye irritation, nausea, weakness, and chest tightness.
According to publication from The University of South Carolina at Chapel Hill 12 we found the same conclusions about human adverse effects from Swine operations as in Carolina and Iowa studies.
Cardiovascular effects of odours
The literature suggests that odour intolerance has been associated with increased cardiopulmonary risk including increased sympathetic tone in the cardiovascular system at rest, different EEG alpha rhythms, lower rapid-eye-movement (REM) sleep, and greater prevalence of chronic cough, phlegm, wheeze, chest tightness, exertional dyspnea, acute respiratory illnesses, hay fever, child respiratory trouble, and physician confirmed asthma. 12
In addition, negative mood, stress, and environmental worry can potentially lead to a number of physiological and biochemical changes with subsequent health consequences. These include elevations in blood pressure, both in normotensives and in patients with hypertension, immune impairment, increased levels of peripheral catecholamines, increased glucocorticoids, increased secretion of adrenocorticotropic hormone (ACTH) from the pituitary, decreased gastric motility, increased scalp muscle tension in patients with muscle tension headaches, and even hippocampal damage.12 Thus, if odorous stimuli are sufficiently stressful, this could potentially elevate the catecholamines epinephrine and norepinephrine to levels that produce adverse cardiovascular effects including increased heart rate and increased tendency of blood to clot. 12
Persons who report symptoms from odours generally find problems with many different types of odorous compounds. A review of recent studies suggests that the main complaints of health symptoms from odours are eye, nose, and throat irritation, headache, and drowsiness. Odours can also potentially affect mood and memory. Further research is required to assess fully the health impact of odours in order to establish recommendations for air quality guidelines based on scientific data.
QUALITY OF LIFE
According to a study in eastern North Carolina 7 the quality of life of the neighbourhood was affected, as indicated by the number of times residents could not open their windows or go outside even in nice weather; similar results were assumed in the control community and the community in the vicinity of the cattle operation but greatly reduced compared to residents near the hog operation. In reference to a study conducted by University of Iowa 10 many participants believed that these operations were having negative impacts on their community.
Furthermore, a study in Quebec 24 showed that the presence of odours was sickening and that it already affected the quality of life of the neighbourhood. This investigation was based on the results of social- health investigation 1992-1993 among the residents of swine operation. The frequency of the persons having a high level of psychological distress in the population was established for each of the categories of municipalities, intensity of hog production and season. In addition, these data were collected without the responders knowing that they were serving to link up the pork production operations and psychological distress. The results demonstrated high levels of changes with large-scale hog productions for the period of spring and summer, where the production is higher than other seasons, showing that CAFOs could be associated with psychological distress of the residents.
In addition, the existence of swine industry results in loss of property values. It reduces the attractiveness of those locations for other types of economic and social improvements that could impact both on the individual and community public health, especially in poor and underdeveloped regions; it may stop other types of economic development and industrialization; it may impact local ownership, which are critical to keep profits in local community. Properties located near CAFO will be negatively impacted by this externality; some of these losses in value may be attributable to stigmatization of the area since there are unknowns and potential risks associated with ownership of the property. The degree of impairment depends on proximity and property type and use. Properties with higher unimpaired values are probably impacted more than otherwise lower-valued properties. 22
In view of the fact that CAFOs is associated with noxious and obvious problems, such as increasing of community pollution and environment exposure in communities; many states in U.S.A. have enacted severe restrictions on permits. For example, in 1997 Oklahoma’s legislature mandated setbacks and other pollution controls, and in 1998 that legislature enacted a moratorium on new livestock permits. Kansas has enacted too a moratorium on CAFOs, and it is considering legislation to end CAFOs. In 1998, the North Carolina legislature, faced with unregulated establishment of CAFOs, enacted House Bill 1480, which mandated the registration of growers for integrators, extended a moratorium, and mandated substantial elimination of both atmospheric emission of ammonia and odour beyond the boundary of existing CAFOs. Minnesota enacted similar odour control legislation in 1997 and established both a complaint control protocol and an enforcement response protocol specific to CAFOs. 23 The province of Quebec has recently reviewed the status of hog production and their jurisdiction, and decided in the prolongation of the current moratorium on further development.
Concentrated animal feeding operations are responsible for numerous health complaints from community neighbours. There have been few health studies to evaluate the physical, mental and quality of life of those residents, but the few studies completed so far have demonstrated a negative impact on the physical, mental and social health of the population affected. One study showed adverse altered mood states, and another showed evidence of respiratory illness similar to what workers experience (North Carolina and Iowa studies respectively).
Much remains to be learned about the actual acute and long-term health consequences of pollution from swine facilities. In consequence, it is important to consider all sources and pathways that can be affected from swine pollution. In addition to emission sources of pollutants, it is essential to identify the prevailing winds and weather conditions of the municipality, in determining pollution patterns and effects of theses kind of facilities. More research is needed to address how H2S, ammonia, dust and the more than 400 volatile organic compounds found in manure impact on human health 15.
The hazardous substances present in hog odour, such as formaldehyde, are routinely released into the environment and as a result the vulnerable persons can development asthma- like symptoms. Therefore, people living or working in communities surrounding such releases may be exposed to hazardous substances from hog facilities. Research does show that many odours, both those generally considered pleasant and offensive, can have an impact on asthmatics. In Eastern Ontario the prevalence of asthma and chronic obstructive pulmonary diseases (COPD) has been increasing over the years. 16 No research to date focused on those vulnerable residents. Further study is needed to find out the effect the exposure to air emissions on asthmatics and people with respiratory problems to determine if chronic exposure to these gases can result in potential toxicity and if the emissions form hog are having any effect on the health of nearby asthmatic populations, especially among children under 18 years of age.
Because water is a natural resource of substantial size and economic value, it requires management and protection. Basic on scientific studies it appears that to minimize the water contamination additional research will be needed to describe the impact of potential contaminants from hog industries on human health. A better understanding of what happens to nutrients within entire watersheds, not just the relatively small plots of land of hog farms, is necessary, if effective water quality protection strategies are to be developed. It becomes visible that technology and knowledge is not sufficient to operate concentrated animal feeding operations, it is important to understand that they alone are not enough to protect water, air and human health. We need to encourage the research to deal with nutrients from hog manure while protecting water quality and human population. Because of the complexity, plans for surface and groundwater management zones must be incorporated to predict water contamination using sophisticated tools and software such as GIS.
A larger population- based study is needed to include the population at risk, and neighbours of a cross-section of various sizes, types of swine operations, and to quantify health symptoms from the types of exposure experienced by neighbours. Only through solid research can we determine what limits are and how swine feeding operations may affect them. It is particularly appropriate that such studies take place where exist concentrate of operations and we would prove their impacts on neighbouring residents.
CAFOs impact the land value of proximities properties bringing in limitation of economic development of communities and reducing the ability of communities to attract and maintain educational, industrial, and medical facilities – community resources that are essential to positive public health development. Moreover, CAFOs reduce the quality of life of individuals and their community and on long-term affect mental and physical health in the community
Official supports from Canadian Medical Association (CMA) confirmed the current recommendation regarding concentrated animal feeding operation by adopting the following resolutions:
Furthermore, the American Public Health Association expressed an interest in using these resolutions as a basic for similar policy motions. These resolutions were also cited in public advocacy activities in New Brunswick, Saskatchewan, Manitoba, and Quebec.
In eastern North Carolina seventy-five physicians of the medical staff of Craven Regional Medical Center signed a petitioning letter endorsing a one-year countywide moratorium on new and expanding hog operations for Craven County in February of 1997. The petitioning letter read: “Our role as physicians requires that we be vocal advocates for our patients' health and well being. We believe that the issues of agricultural and industrial waste disposal pose a health risk to our patient population. We therefore petition the Board to grant the moratorium, which will allow these areas of concern to be addressed more fully."12
It appears clear there is too much to be learned about the effect of large hog farms on human health. It is vital that research continue in this area to assure the health and safety of our communities, who could live near hog intensive livestock operations.