Kamis, 08 November 2012


FOOD ENVIRONMENT AND HEALTH
Water Pollution


The possible sources and causes of water pollution from the picture and what will happen to the quality of water in the river and people who live nearby, are:

Ø Fertilizer runoff

Fertilizers are a mixture of phosphate, potassium, and nitrogen. These are all naturally-occurring elements. Fertilizers are useful when soil is insufficient in one of these elements to strengthen its productivity. Although fertilizers are useful in many ways, too much can effect the environment negatively.
When runoff of fertilizer occurs, algae and other aquatic plants begin to take over aquatic environments. Nitrogen is normally in short supply in coastal ecosystems. This small supply limits the creation of new organic matter by phytoplankton, tiny plants at the bottom of the marine food chain. When an ecosystem has an increase in nitrogen, phytoplankton populations can increase drastically. This results in an 'algal bloom' and ruins the state of equilibrium between the environment itself and its resources. Oxygen-consuming bacteria consume the plankton that die and sink to the sea floor. When there is a greater amount of plankton sinking to the sea floor, such as following after an algal bloom, bacteria use oxygen more quickly than the water layers above can replace it. This creates low oxygen conditions, which are unsuitable for plant life.

Ø Industrial wastes

There are various wide-ranging effects, as well as serious consequences, of industrial pollution on the ecological balance of the atmosphere. One of them is water pollution. Dumping of various industrial waste products into water sources, and improper contamination of industrial wastes, often result in polluting the water. Such water pollution disturbs the balance of the ecosystem inside, resulting in the death of various animal and plant species present in the water.
Global warming is one of the most common and serious consequences of industrial pollution. The emission of various greenhouse gases such as CO2, methane (CH4), among others from various industries, increases the overall temperature of the earth, resulting in global warming. Global warming has various serious hazards, both on the environment as well as on human health. It results in melting of glaciers and snow-capped mountains, causing an increase of the water levels in seas and rivers, thereby increasing the chances of flood. Apart from this, global warming also has numerous health risks on humans, such as increase of diseases such as malaria and dengue, cholera, Lyme disease and plague, among others. Certain other common effects of industrial pollution include damaging buildings and structures, increasing the risk of various occupational hazards such as asbestosis, pneumoconiasis, among others.

Ø Livestock wastes

Manure, and wastewater containing manure, can severely harm river and stream ecosystems. Manure contains ammonia which is highly toxic to fish at low levels. Increased amounts of nutrients, such as nitrogen and phosphorus, that can cause algal blooms which block waterways and deplete oxygen as they decompose. This can kill fish and other aquatic organisms, devastating the entire aquatic food chain.
When contaminants from animal waste seep into underground sources of drinking water, the amount of nitrate in the ground water supply can reach unhealthy levels. Infants up to three months of age are particularly susceptible to high nitrate levels and may develop Blue Baby Syndrome (methemoglobinemia), an often fatal blood disorder.
The microorganisms found in animal wastes, such as cryptosporidium, can also pose significant public health threats. If the presence of these microorganisms exceeds the standards set by the Safe Drinking Water Act, community and private well owners will not only face health risks, but will also have to find new sources for their drinking water supplies. This can be extremely costly and impractical.

Ø Lanfill dump

A landfill is property set aside for the purpose of safe disposal of solid waste, either municipal (trash such as would come from homes) or hazardous (toxic chemicals, etc). "Hazardous waste" refers to any material that may pose an unreasonable risk to health, safety, or property, especially those materials that are toxic, corrosive, reactive, or ignitable. If harmful chemicals are present in the soil surrounding a water supply, they can seep into the water supply and cause harmful effects, even in small amounts.
Gases escaping from landfills contain toxic pollutants that can cause cancer, asthma, and other serious health effects. Studies link living near landfills with cancer, where escaping gases will typically carry toxic chemicals such as paint thinner, solvents, pesticides, and other hazardous volatile organic compounds. All dumps also leak toxic leachate; even “state-of-the-art” landfills will eventually leak and pollute nearby groundwater.

Ø Mining pollutants

Mining can have adverse effects on surrounding surface and ground water if protective measures are not taken. The result can be unnaturally high concentrations of some chemicals, such as arsenic, sulfuric acid, and mercury over a significant area of surface or subsurface. Runoff of mere soil or rock debris -although non-toxic- also devastates the surrounding vegetation. The dumping of the runoff in surface waters or in forests is the worst option here. Submarine tailings disposal is regarded as a better option (if the soil is pumped to a great depth). Mere land storage and refilling of the mine after it has been depleted is even better, if no forests need to be cleared for the storage of the debris. There is potential for massive contamination of the area surrounding mines due to the various chemicals used in the mining process as well as the potentially damaging compounds and metals removed from the ground with the ore. Large amounts of water produced from mine drainage, mine cooling, aqueous extraction and other mining processes increases the potential for these chemicals to contaminate ground and surface water. In well-regulated mines, hydrologists and geologists take careful measurements of water and soil to exclude any type of water contamination that could be caused by the mine's operations.
Water-pollution problems caused by mining include acid mine drainage, metal contamination, and increased sediment levels in streams. Sources can include active or abandoned surface and underground mines, processing plants, waste-disposal areas, haulage roads, or tailings ponds. Sediments, typically from increased soil erosion, cause siltation or the smothering of streambeds. This siltation affects fisheries, swimming, domestic water supply, irrigation, and other uses of streams.
Acid mine drainage (AMD) is a potentially severe pollution hazard that can contaminate surrounding soil, groundwater, and surface water. The formation of acid mine drainage is a function of the geology, hydrology, and mining technology employed at a mine site. The primary sources for acid generation are sulfide minerals, such as pyrite (iron sulfide), which decompose in air and water. Many of these sulfide minerals originate from waste rock removed from the mine or from tailings. If water infiltrates pyrite-laden rock in the presence of air, it can become acidified, often at a pH level of two or three. This increased acidity in the water can destroy living organisms, and corrode culverts, piers, boat hulls, pumps, and other metal equipment in contact with the acid waters and render the water unacceptable for drinking or recreational use.

Ø Nuclear plant

The use of nuclear power as a source of domestic energy has increased significantly over the past decade and is expected to continue to do so in the years to come. However, the use of this form of energy does not come without a unique set of consequences. These can range from environmental impact, altering to a great extent the balance in the flora and fauna of a region, to causing social problems to do with social consensus and risk perceptions of people living in the vicinity of such a plant. Nuclear power plant operation emits no or negligible amounts of carbon dioxide. However, all other stages of the nuclear fuel chain (mining, milling, transport, fuel fabrication, enrichment, reactor construction, decommissioning and waste management) use fossil fuels and hence emit carbon dioxide.
Perhaps the impact which is easiest to notice is the effect on the environment, particularly in terms of flora and fauna. To start with, the setting up of a nuclear plant requires a large area, preferably situated near a natural water body. This is usually accompanied with clearing of forests which disturbs the natural habitat of several creatures and gradually upsets the ecological balance of the region. Another significant effect is the increased amount of sulfur dioxide in the air which causes acid rain to form which then leads to contamination of surface water bodies of the region, reduction of productivity of the soil, and has several other negative effects on the region's vegetation and human health.

Ø Oil pollution

Oil compounds are mostly just carbon (C) and hydrogen (H), which forms hydrocarbons, but the C and H combine in ways that can be toxic to plant and animal life.  Oil inhibits metabolic activity, interferes with animal membranes and disturbs fishes’ ability to regulate water. The aromatic compounds cause the greatest problems, especially poly-cyclic aromatic hydrocarbons (PAHs). PAHs can originate naturally from oil seeps, or can be the result of human activity. They are present, for example, in engine exhausts, furnace smoke, run-off from municipal storm sewers, and oil refinery cooling water. These compounds can cause long-term effects in fish such as cancers and can damage developing fish embryos. And while laws are in place to protect the environment, sometimes there are accidents. 
Oil is persistent--both in its desirability in our modern age and its damaging effects in the environment when it spills. It sticks around. When crude oil ends up in water, it forms a buoyant layer on the water. That layer spreads into a thin slick but in weeks can weather into thick, tarry globs--a tough “skin” trapping fresher oil inside. Storms and weather also break up oil into small drops that can disperse as small oil particles. As these particles collide in the water with suspended sediment, they form “tarballs” of oil, sand, algae and other debris. And while slicks and tarballs can be broken down by light and by micro-organisms and plants, it takes a long time. Floating oil can become stuck onto shorelines, or oil particles can collect enough sediment to sink to the water bottom and remain there.
Oil affects wildlife by coating their bodies with a thick layer.  Many oils also become stickier over time (this is called weathering) and so adheres to wildlife even more.  Since most oil floats o nthe surface of the water it can effect many marine animals and sea birds.  Unfortunately, birds and marine mammals will not necessarily avoid an oil spill.  Some marine mammals, such as seals and dolphins, have been seen swimming and feeding in or near an oil spill.  Some fish are attracted to oil because it looks like floating food.  This endangers sea birds, which are attracted to schools of fish and may dive through oil slicks to get to the fish. Oil that sticks to fur or feathers, usually crude and bunker fuels, can cause many problems. 

Ø Pesticide crop dusting

Pesticides are the only toxic substances released intentionally into our environment to kill living things. This includes substances that kill weeds (herbicides), insects (insecticides), fungus (fungicides), rodents (rodenticides), and others. Pesticides are used almost everywhere, not only in agricultural fields, but also in homes, parks, schools, buildings, forests, and roads. It is difficult to find somewhere where pesticides aren't used, from the can of bug spray under the kitchen sink to the airplane crop dusting acres of farmland, our world is filled with pesticides. In addition, pesticides can be found in the air we breathe, the food we eat, and the water we drink.
As with pesticide application in general, crop dusting is associated with a number of environmental concerns, including spray drift, soil contamination, water pollution, and occupational disease, often in the form of increased risk of cancer to those involved. In addition to their impact on human health, there is also concern that the use of pesticides can lead to the development of resistance among insects. Environmental and human rights issues associated with crop dusting are greatest in developing countries, where government oversight is weaker or absent, few safety practices are used, and chemicals are used that are banned in most developed countries.
Pesticides have been linked to a wide range of human health hazards, ranging from short-term impacts such as headaches and nausea to chronic impacts like cancer, reproductive harm, and endocrine disruption. There is also mounting evidence that exposure to pesticides disrupts the endocrine system, wreaking havoc with the complex regulation of hormones, the reproductive system, and embryonic development. Endocrine disruption can produce infertility and a variety of birth defects and developmental defects in offspring, including hormonal imbalance and incomplete sexual development, impaired brain development, behavioral disorders, and many others.

Ø Precipation

Generally, precipitation will fall to the surface; an exception is Virga which evaporates before reaching the surface. Precipitation forms as smaller droplets coalesce via collision with other rain drops or ice crystals within a cloud. Rain drops range in size from oblate, pancake-like shapes for larger drops, to small spheres for smaller drops. Unlike raindrops, snowflakes grow in a variety of different shapes and patterns, determined by the temperature and humidity characteristics of the air the snowflake moves through on its way to the ground. While snow and ice pellets require temperatures close to the ground to be near or below freezing, hail can occur during much warmer temperature regimes due to the process of its formation.
In cold air way up in the sky, rain clouds will often form.  Rising warm air carries water vapor high into the sky where it cools, forming water droplets around tiny bits of dust in the air. Some vapor freezes into tiny ice crystals which attract cooled water drops.  The drops freeze to the ice crystals, forming larger crystals we call snowflakes. When the snowflakes become heavy, they fall. When the snowflakes meet warmer air on the way down, they melt into raindrops. In tropical climates, cloud droplets combine together around dust or sea salt particles.  They bang together and grow in size until they're heavy enough to fall.
  If snowflakes completely melt in the warmer air, but temperatures are below freezing near the ground, rain may freeze on contact with the ground or the streets. This is called freezing rain, and a significant freezing rain is called an ice storm. Ice storms are extremely dangerous because the layer of ice on the streets can cause traffic accidents.  Ice can also build up on tree branches and power lines, causing them to break and our lights to go out.  There is another kind of precipitation that comes from thunderstorms called hail. Rainfall in a thunderstorm can be very heavy. Cumulonimbus clouds contain huge amounts of moisture. Several inches of rain can fall in a short time. That's why thunderstorms sometimes result in flooding.

Ø Sediments

Sediment refers to the fine-grained particles that are sometimes transported in water. Sediment often results from work projects in or around water and can harm fish habitat. Sediment is the fine-grained particles that are sometimes transported in water. Turbidity refers to the cloudiness of the water because of the sediment suspended in it. Sediment and turbidity can result in a variety of harmful impacts to fish. For example, sediment and turbidity interfere with feeding for visual feeders such as trout and bass. Some of the negative effects of turbid water are:
  • abrasion of gill membranes.
  • impairment of feeding.
  • fatal impacts to small aquatic animals that are food for fish.
Suspended sediment results in turbid water that can harm fish. Deposited sediment can also be harmful to fish habitat.

Ø Septic tank

Properly maintained septic tanks have a minimal effect on the environment. Most harmful bacteria, viruses and contaminants are digested by microbes in the soil under the septic system's drainage field before they reach the groundwater. A septic tank should be properly designed, sited in the right place and maintained regularly. Otherwise, when a septic tank malfunctions, it can have a serious impact on the environment and public health.
If the septic tank has not been inspected and pumped out regularly, the sewage can back up. Once the drainage field gets clogged it stops functioning properly. Heavy metals and toxic chemicals can get into the household wastewater when toxic household products are flushed down the drain. Wastewater containing contaminants such as harmful bacteria, viruses and toxic chemicals can seep into the groundwater, which is an important source of drinking water. People and animals can get diseases and infections from drinking contaminated water.
Contaminated discharge from a septic tank can flow into lakes, rivers, streams and saltwater. Lakes that are used for drinking-water reservoirs can become contaminated. When people swim in contaminated water they can get eye and ear infections, gastrointestinal illnesses and hepatitis. When a septic system backs up, sludge and wastewater can end up on the surface of the ground. Contact with contaminated sludge and water can expose people and animals to diseases and infections.

Ø Sewage treatment plant

Sewage treatment plants neutralize and deactivate the chemicals found in the sewage water. They work by relying on the bacteria that is found in our colons, which eat away the nitrates, phosphates and organic matter that is found in sewage. These plants can be expensive to build and operate for many governments, but there are cheaper alternative which rely on nature to do most of the work. This is done by rebuilding or restoring wetlands,  because the plants and bacteria found in the wetlands will do the same thing that bacteria in standard sewage treatment plants do. This helps the environment in two ways: restoring wetlands and treating human waste water before it pollutes the natural waterways.
When sewage is not properly collected and transported to sewage treatment plant in a sanitary way, sewage emanates foul odour causing air pollution and gives room for mosquito breeding leading to spread of diseases. And also, when sewage is discharged into river bodies without proper treatment, organic matters present in sewage causes depletion of dissolved oxygen which in turn affect aquatic eco system existing in the water bodies. Some gases like methane, carbon-di-oxide, sulphur-di-oxide, etc. are formed in sewage and escape into atmosphere causing air pollution and acclerating global warming by green house gases.

Ø Urban wastes

The urban waste landfills that are not waterproof often represent sources of groundwater pollution by nitrates and nitrites, as well as other pollutants. Landfill exfiltration and water leakage on the slopes affect adversely the quality of the adjoining soils, which brings along consequential effects to their utilization.
Statutory water and sewerage companies, which own and operate the public sewerage system and the treatment works are affected by this directive. The directive mainly affects the statutory water and sewerage companies since they own and operate the public sewerage system and the treatment works.  To meet the requirements of the directive the water companies have had to make a very large investment in building and improving treatment works and improving sewerage systems.
Most of the industrial discharges controlled by the directive already met the treatment levels.  The directive lays down uniform emission standards, or percentage reductions in pollutant concentrations, for discharges from sewage treatment works. It also requires that the sludge arising from the treatment of waste water is re-used whenever appropriate, and that its use or disposal minimises the risks to the environment. A different directive deals specifically with the use of sludge on agricultural land.
An important aspect of the urban waste water treatment directive is the protection of the water environment from nutrients, (specifically compounds of nitrogen and phosphorus), and/or nitrates present in waste water where these substances have adverse impacts on the ecology of the water environment or abstraction source waters.

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