The imbalance of the ecosystem and its effect on public health and livestock

The imbalance of ecosystems and their impact on public health and livestock
Karki Dr.Kedar MVST. (Preventive Veterinary Medicine)
Central Veterinary Laboratory Tripureshwor
The human health, like all living organisms depends of an ecosystem that supports life. Healthy ecosystems are the sine qua non for healthy bodies. However, there is considerable evidence that many support systems are very far from healthy living, impose a greater burden on human health. In some regions, gains in life expectancy and quality of life during the twentieth century is likely to be reversed XXI century. The consequences of ecosystem degradation to human health are numerous, including health risks of unsafe water, pollution air, climate change, the emergence of new diseases and resurgence of old diseases due to environmental imbalances. Reversing this damage is possible in some cases but not others. Preventing environmental damage is by far the most effective strategy.
DEFINITION OF THE ECOSYSTEM
An ecological system can be defined as a community of plants and animals that interact among themselves and with their abiotic, or natural environment. Typically, ecosystems are distinguished on the basis of vegetation dominant, topography, climate or other criteria. Boreal forests, for example, are characterized by the predominance of conifers, grasslands are characterized by the predominance grass, the tundra is partly determined by the harsh climatic zone. In most human of the world community is important, even essential to the ecosystem. Ecosystems are not only natural areas (eg forests, lakes, coastal and marine systems), but also human constructs systems (eg ecosystems urban, agro-ecosystems, dams). Human populations are increasingly concentrated in urban ecosystems, and it is estimated that in 2010, 50 percent of world population living in urban areas.
A landscape with a mosaic of ecosystems, including cities, rivers, lakes, agricultural systems, and so on. Precise limits between ecosystems are often difficult to establish. Often, the regions of each slide the other gradually over a long term "transition" zone, for example between the boreal and taiga regions of Canada.
Ecosystem health
It is important to recognize the difficulties inherent in the definition of "health", whether in the individual, population or ecosystem. The concept of health is something of an enigma, being easier to define in its absence (illness) in their presence. Perhaps partly for this reason, ecologists have resisted applying the notion of "health" of ecosystems. However, ecosystems can to be dysfunctional, particularly under conditions of chronic stress activity.Example rights for this may be cited for discharges of nutrients from sewage, industrial discharge and agricultural runoff into lakes or rivers affects the normal functioning of ecosystems, and may lead to a serious deterioration. Excessive inputs of nutrients from human activity is one of the main factors that have seriously compromise the health of the lower Laurentian Great Lakes (Lakes Erie and Ontario) and regions of the Great Lagos, the top (Lake Michigan). Unfortunately, ecosystem gradients are more the rule than the exception.
The characteristics of the study of degraded systems, and comparisons with systems that have not been modified by human activity, identifies the characteristics of healthy ecosystems. May Healthy ecosystems are characterized not only by the absence of signs of pathology, but also by the signs of health, including measures of force (productivity), organization and resistance.
Force can be evaluated in terms of metabolism (activity and productivity) system. Ecosystems are very different in their normal ranges of productivity. Estuaries are much more productive than open oceans, and marshes have higher productivity of deserts. Health is not valued by the application of a standard for all systems. Organization can be assessed by the structure of the biotic community that forms an ecosystem and the nature of interactions between species (plants and animals). Invariably, healthy ecosystems have more diversity of biota in danger of ecological systems. Resilience is the capacity of an ecosystem to maintain its structure and functions response to natural disturbances. Systems with a history of chronic stress are less likely to recover normal disturbances such as drought that systems which have been relatively less stressed.
Healthy ecosystems can also be characterized in terms of economic health, social and human development. Ecosystems support healthy to a certain level of economic activity. This does not mean that the ecosystem is necessarily self-sufficient, but supports economic productivity to enable human community to meet reasonable needs. Inevitably, ecosystem degradation affects in the long term, the human economy that is associated with it, although in the short term this may not be obvious, because the natural capital (eg, soils, non-renewable resources) can be exploited and temporary, increase economic returns. Similarly, with regard to welfare, Healthy ecosystems provide a basis for promoting integration and community. Historically, for example, groups of natives Hawaii won its ecosystem through a highly developed social cohesion, which provides a high degree of cooperation in agriculture fisheries.
Another reflection of ecosystem health is directly in the field of public health. In the spring of 2000, a deadly strain of the bacteria E-coli (0157: H7) entered into public water supply in Walkerton, Ontario, Canada, causing seven deaths and making thousands sick. This small town with a population of five thousand, is in an agricultural community. The management of manure from the cattle farm was the likely source inadequate this tragedy.
How healthy ecosystems are pathological
The stress of human activity is an important factor in transforming healthy ecosystems ecosystems for patients. Chronic stress from human activity differs from natural disturbances. Natural disturbances (fires, floods, periodic insect infestations) are part of the dynamics of most ecosystems. These processes help to "reset" the ecosystem by recycling nutrients and clean space for recolonization by biota that can be adapted better to changing environments. Therefore, natural disturbances help maintain healthy ecosystems. In contrast, acute and chronic stress on ecosystems resulting of human activity (eg, construction of large dams, the release of nutrients and toxic substances in air, water and land) generally results in the long-term ecological dysfunction.
Five major sources of anthropogenic (anthropogenic) stresses have been identified by the Report and friend DJ AM (1979): physical restructuring, overfishing, waste disposal, the introduction of alien species and global change.
Physical restructuring. Activities such as wetland drainage, removal of the banks in lakes, damming of rivers, and road construction and change the landscape and damage critical habitat. These activities also disrupt nutrient cycling, and cause loss of biodiversity.
Overexploitation. Overexploitation usual when it comes to harvesting of wildlife, fisheries and forests. For long periods of time, stocks of preferred species are reduced. For example, the giant redwoods that once thrived along the California coast that now exist on the extra patches due to overexploitation. When species dominant as the giant redwood tree larger (possibly the world and a sample was recorded at 110 meters high with a circumference of 13.4 meters) are lost, the entire ecosystem becomes. Overfishing is often reduced biodiversity of endemic species and facilitates the invasion of opportunistic species.
Waste residues. Discharges from air sources of municipal, industrial and agricultural, water and land have severely compromised many of the ecosystems Earth. The effects are particularly apparent in aquatic ecosystems. In some lakes that lack a natural buffering capacity, acid rain has eliminated the most fish and other organisms. Although the visual effect appears beneficial (water clarity goes up) the impact on ecosystem health is devastating. Systems, once contained a variety of organizations and have been very productive (biological) is devoid of most life forms, except for a few acid bacteria tolerant and benthic organisms.
Introduction of exotic species. The spread of invasive Alien has become a problem in almost every ecosystem on the world. Transportation of natural habitat to entirely new ecosystems can wreak havoc, such as new environments are often without natural checks and balances of new species. In the Great Lakes basin, the accidental introduction of two small pelagic fish, shad, smelt, combined with the simultaneous operation natural predators such as lake trout, led to a significant decline in native fish species. The introduction of the sea lamprey, an eel-like large predatory fish attack fish in Lake Erie and the upper Great Lakes further destabilized the native fish community. The sea lamprey contributed the disappearance of the community of benthic feeding fish in deep water lake trout, whitefish and burbot. This has contributed to a change in the community fish that had been dominated by large benthic organisms to one dominated by small pelagics (fish found in the layers higher profile of the lake). This change of groundfish (benthos) from surface-dwelling fish (pelagic) has been partially offset by another accidental introduction of exotic: zebra mussels. As zebra mussels filter is very effective both phtyoplankton and zooplankton, its presence has reduced food availability in surface waters of the pelagic fish. However, while the benthic fish community has gained back its dominance, the preferred species of groundfish have not yet regained by the degree of initial degradation. Overall, the increased prevalence of rare plants, not only altered the ecology, but also significantly reduce the value of commercial fishing.
Global Change. Rapid climate change (or global warming) is an emerging global potential of stress throughout the planet's ecosystem. At time evolutionary course, there are significant variations in climate. However, for the most part, these fluctuations have occurred gradually over long periods of time. The rapid Climate change is a very different import. By altering the mean and extremes of precipitation, temperature, and storms, and the destabilization of the Niño-Southern Oscillation (ENSO), which controls weather patterns in most of the region, the South Pacific, many ecosystem processes can become significantly altered. Long periods of drought or unusually heavy rains and floods exceed the tolerance of many species, thus changing the biotic composition. Flooding and unusually high winds contribute to soil erosion, and at the same time add to nutrient loading in rivers and coastal waters.
These limitations anthropogenic undermined the functioning of ecosystems in most regions of the world, resulting in distress syndrome of ecosystems (EDS). EDS characterized by a set of signs, including abnormalities in nutrient cycling, productivity, species diversity and richness, biotic structure, prevalence disease, soil fertility, and so on. The consequences of these changes for human health are not negligible. Impoverished biotic communities are ports natural pathogens affecting humans and other species.
ECOSYSTEM HEALTH AND HUMAN HEALTH
An important aspect of ecosystem degradation is the increased risk to human health. Traditionally, concern has been polluting including industrial chemicals that can have negative impacts on the human development, neurological functions, reproductive functions, which appear to be pathogenic in a variety of cancers. In addition to these serious concerns about the environment (where resources are often technological, including technical solutions to reduce discharges of pollutants), there are many other health risks Ecological imbalance derived from human.
Syndrome Ecosystem danger of loss of ecosystem services evaluated, including flood control, water quality, air quality, fish and diversity of wildlife and recreation. One of the major signs of EDS is the impact of enhanced disease in both humans and other species. The human population health should be considered in an ecological context, expressing integrity and health of the life sustaining capacity the environment.
Ecological imbalances caused by climate change and other causes are responsible for the increased risks to human health.
Climate change and vector-borne diseases. The global burden of infectious diseases is the order of several hundred million cases annually. Vector of many diseases are climate sensitive. Malaria, dengue, hantavirus pulmonary syndrome, and various forms of viral encephalitis are all in this category. All these diseases are the result of the virus carried by arthropods (arboviruses) are transmitted to humans following the bite of bloodsucking arthropods.
Global climate change in particular because of its impact on temperature and precipitation is strongly correlated with the prevalence of vector-borne diseases. For example, viruses transmitted by mosquitoes, ticks and other bloodsucking arthropods generally have increased transmission rates increase with temperature. St. Louis encephalitis (SLE) is an example. The Culex tarsalis mosquito carrying the virus. The percentage of bites that result in transmission of SLE is dependent on temperature, with greater transmission at high temperatures.
The temperature dependence of vector-borne diseases is also well illustrated by malaria. Malaria is endemic in tropical regions with high prevalence in Africa, the Indian subcontinent, Southeast Asia and parts of South and Central America and Mexico. About 2.4 million people live in risk areas, with some 350 million of new infections each year, causing about 2 million deaths, mostly among young children. Untreated malaria can become life-long pain, general symptoms are fever, headache and malaise.
The climate sensitivity of malaria because of the nature of interactions between parasites of vectors and hosts, the final impact types of transmission to humans. The gestation period required for the parasite to become fully developed within the mosquito host (a process called sporogony) is from eight to thirty-five days. When temperatures are in the range of 20 ° C 27 ° C, the gestation period is reduced. The rain and humidity also play a role. Both drought and heavy rains tend to reduce the mosquito population which act as vectors of malaria. In the drier areas of the tropics, low rainfall and humidity limit mosquito survival. Severe flooding can cause the drag of rivers and destruction of breeding habitats for the mosquito vector, while intermediate rainfall enhances vector production.
Ecological imbalances. Cholera is a severe and potentially fatal, is caused by the bacterium Vibrio cholerae. Although not as widespread as cases of malaria, however, are numerous. In 1993, there were 296,206 new cases of cholera reported in South America, 9280 cases were reported in Mexico, where 62,964 Africa, and 64,599 cases in Asia. Most of the outbreaks in Asia, Africa and South America have their origin in coastal areas. The symptoms of cholera are explosive watery diarrhea, vomiting and abdominal pain. The most recent pandemic of cholera involves the regions than at any time before the twentieth century. The disease remains endemic in India, Bangladesh and Africa. Vibrio cholerae has also been observed in the United States in the region of the Gulf Coast of Texas, Louisiana and Florida, the region Chesapeake Bay and the coast of California.
The increasing prevalence of V. cholerae has been closely linked to degradation coastal marine environments. The warming of nutrients rich coastal waters as a result of a combination of climate change and the use of fertilizers, providing an ideal environment for reproduction and dissemination of V. cholerae. Recent outbreaks of cholera in Bangladesh, for example, are closely related to better protection of surface temperatures. V. cholerae attach to the surface of freshwater and marine copepods (crustaceans) as well as to roots and exposed surfaces of macrophytes (aquatic plants) such as hyacinth water, abundant aquatic plants in Bangladesh. Nutrient enrichment and warmer temperatures lead to algae blooms and an abundance of macrophytes. Algal blooms provide abundant food for copepods, and population growth of copepods, and macrophytes provide V. habitat cholerae. After the dispersion of the V. cholerae into estuaries and fresh water bodies allows contact with humans who use these waters for drinking and bathing. Distribution global marine pathogens such as V. cholerae is facilitated by ballast water of ships. Ballast water contains a virtual cocktail of pathogens, including including V. cholerae.
Two other examples of how ecological imbalances lead to prevalence-related human health costs Increased Lyme disease and hantavirus pulmonary disease. Lyme disease, Sonam because it has been positively identified in Lyme, Connecticut is the cessation of a type of arthritis disease transmitted by spirochete-infected Ixodes ticks (deer ticks). Ticks become infected rodents, and spend part of their life cycle of deer. Three factors have combined to increase the risk to humans of contracting Lyme disease, especially in North America: (1) elimination of natural predators of deer, including wolves, (2) reforestation of abandoned farmland has created more favorable habitat for deer and (3) the creation of suburban areas, where deer find ideal habitat for navigation. The net result is higher deer population, which increases the chances of human contact closer to ticks.
In 1995 in the southern United States, hantavirus infection was confirmed in eighty fourteen people in twenty states, with 48 cent mortality. Variants of the strain that causes hantavirus pulmonary syndrome has also been found elsewhere in the country and in Asia and Europe. The virus appears to be asymptomatic rodents and is spread through saliva and feces. In the human being has a flu-like presentation, which is followed by acute respiratory distress syndrome. The main reservoir of the Four Corners region of the southwestern United States is the deer mouse. Climatic shocks, which in recent years have been designed which is exacerbated by human activity (eg global warming), appear to establish the conditions that trigger outbreaks. In the 1990s, ENSO events initially caused drought conditions develop in the southern United States. This led to a low plant and animal populations, including natural predators deer mice. Heavy rains followed by drought in 1993 led to a pinon nut harvest exceptional, an important food source for deer mice. Subsequently, the deer mouse population greatly increased, resulting in greater contact with humans and trigger the onset of hantavirus.
Resistance to antibiotics and agricultural practices antibiotic resistance is a growing threat to public health. Antibiotic-resistant strains of Streptococcus pneumoniae, a common pathogen in humans and the main cause of many infections, including chronic bronchitis, pneumonia and meningitis, have increased the prevalence since the 1970s. In some regions, 70 percent of bacterial isolates taken from patients proved resistant to penicillin and other b-lactams. The use of large quantities of antibiotics in agriculture and aquaculture seem to have been a key factor in the development of antibiotic resistance of pathogens to farm animals that later can also infect humans. One of the most serious risk to human health damage from these practices is resistant enterococci vancomycin. The use of avoparcin, a growth promoter, appears to have compromised the utility of vancomycin, an antibiotic effective against the latest of several bacteria drug-resistant. In areas where avoparcin was used as farms in Denmark and Germany, vancomycin-resistant bacteria were detected in meat sold in the supermarkets. Avoparcin was subsequently banned by the European Union. Another example is the use of ofloxacin to protect chickens against infection and improve growth. This drug is closely related to ciprofloxacin, an antibiotic used most in the year 2000. There have been cases of resistance to ciprofloxacin directly related with veterinary use. In the UK, ciprofloxacin resistance developed in strains of Campylobacter, a common cause of diarrhea. Multi-resistant strains of salmonella have attributed to the European egg production.
Food security and water. Agricultural practices are also responsible for a growing number of threats to public health. Some of them are related to inadequate waste management, which resulted in the parasites and bacteria that enter the water supply. Other origins are completely different and involve the transfer manifest in all species of pathogens that affect animals and humans. The latest and most spectacular is the BSE, known as Creutzfeldt-Jakob disease in humans, a neuro-degenerative, in humans, the fatal outcome. The first case of mad spongiform encephalopathy (BSE), the animal form of the disease was identified in southern England in November 1981. In the fall of 2000, an outbreak took place in France, and Isolated cases have occurred in Germany, Switzerland and Spain. More than a hundred deaths in Europe were attributed to what has become commonly known as disease mad cow disease.
Improper handling of manure is the likely source of the outbreak of EE coli 0157: H7 in Walkerton, Ontario, Canada. Health hazards associated with malfunctioning agricultural ecosystems are periodic outbreaks of cryptosporidiosis, a parasitic disease spread by surface runoff contaminated by feces of infected cattle. This parasite causes fever and diarrhea in immunocompetent individuals and severe diarrhea and even death in immunocompromised individuals.
Ecosystem Restoration
The pathology of ecosystems, in some cases can be reversed by simply removing the source of stress. In this case, for example, where ecosystem degradation is the result point source nutrient additions or toxic chemicals, removal of these constraints can cause substantial restoration of ecosystem health. A classic case is Lake Washington (near Seattle, Washington). This lake had become highly anoxic (oxygen deficiency) due to a sewage outfall in the lake. Redirecting the sewage outfall at Lake spent many signs of pathology.
Where it is possible to eliminate a source of stress, the solutions innovative engineering have been tried. For example, in the Lestijoki Kyrönjoki and rivers in western Finland, spring and fall runoff leads to acidity peaks. Runoff from melting snows of spring, the release of acid soil cultivated or dug was particularly damaging to fish during the critical period of the year for spawning. Reproduction of fish is severely limited if not eliminated all together in the acidity of water. Furthermore, there massive fish kills resulted in highly acidic water. A possible solution is to replace the original water runoff drains into rivers with new limed drains that can neutralize the acidity. This solution was applied on an experimental basis and appears to significantly reduce acid runoff.
The most radical treatment damaged ecosystem is "the surgery of ecosystems". In some cases, invasive exotic vegetation (such as mangroves in Hawaii) were withdrawn areas and natural vegetation has been replanted. In regions of North America where wetlands were severely damaged due to agriculture, urbanization and industrial activity, efforts were made to establish new wetlands.
More often, however, the condition of ecosystems is reversing possible. Efforts to restore native grasslands of the Jornada Experimental Range in southern United States is an example. Overgrazing by cattle has severely degraded landscape and led to the replacement of native grasses by largely edible shrubs, dominated by mesquite. Erosion by wind and heavy rains have areas the bush is largely sand exposed and subsequently developed in the dunes behind the fashion as in much of the area. Mesquite dunes result proved highly resistant to efforts to restore native grasslands, although almost all interventions have been tried, as highly toxic defoliants (Agent Orange) fire and burned.
Even when you can restore some of the ecological functions of degraded ecosystems, and improve the health of ecosystems, restoration often results in the restoration of the primitive community biotic community. The best that can be achieved in most cases is the restoration of function ecological key ecosystem services needed, such as water regulation, primary and secondary productivity, nutrient cycle and pollination. In all these efforts, key indicators of ecosystem health (vigor, productivity and resilience) are essential to monitor progress. Standard Indicators Green can be used for this purpose (for example, measures of productivity, species composition, nutrient flows, soil fertility) and the socio-economy and human health.
Experience in the efforts to restore damaged ecosystems highly available suggest that prevention of ecosystem health is much more effective than restoration. For marine ecosystems, setting aside protected areas provide a refuge for fish and wildlife is very promising. Many countries adopt policies to establish such zones in the prospect that these healthy regions can serve as a reservoir for biota that have been depleted in unprotected areas. However, this resource is not unlimited. Restoration of ecosystem health is not simply a question of reconstruction of lost or damaged biota. It is also an issue to restore the complex interactions between life forms of the ecosystem. Having a ready source of healthy biota that could recolonize damaged ecosystems is important, but this is only part of the solution.
PREVENTION OF ECOSYSTEM CHANGES
Given the difficulty of reversing the degradation of ecosystems and the many risks human health that arise in the loss of ecosystem health, the most effective method is simply to avoid the disruption of ecosystems. However, as many common sense approaches, is easier said than done. In developed and developing countries in development, there is a strong desire to continue growth economic, even at the expense of severe environmental damage. Apart from selfish motives, the argument advanced is that economic growth has many obvious advantages for health, for example, providing more efficient means of distributing food, providing more abundant food and providing better health services and research funding to improve living standards. These are in fact the benefits of economic development, and resulted in substantial increases in global health.
However, at the dawn of the XXI century, the past is not necessarily the best guide for the future. The human population is at record levels, and pressures associated human activities have led to increased degradation of the ecosystems on Earth. Ultimately, healthy ecosystems are essential to life of all organisms living, including human beings, global and regional trends are ominous. In these circumstances, a compromise between immediate material gains and sustainability long-term human activities on the planet may be the only option. If so, the solution to maintain the health of human health and ecosystems becomes one development of a new policy that places the maintenance of the systems of life support as a prerequisite for improving the human condition.
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About the Author

Senior Vet.Officer,Central Veterinary Laboratory Kathmandu Nepal M.V.St. Preventive Veterinary Mrdicine

Fort Worth texasi-35 and Western Center / Big Rig Accident