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.
