Global ecological problems

Global Ecological
problems.
Urbanization-
hygienic
problems.

Urbanization

The expanding Los Angeles metropolitan
area is an early example of suburbanization.

Urbanization

Urbanization, urbanisation or
urban drift is the physical growth
of urban areas as a result of global
change. The United Nations
projected that half of the world's
population would live in urban
areas at the end of 2008.

Urbanization

Urbanization is closely linked to
modernization, industrialization, and the
sociological process of rationalization.
Urbanization can describe a specific
condition at a set time, i.e. the proportion of
total population or area in cities or towns, or
the term can describe the increase of this
proportion over time. So the term
urbanization can represent the level of urban
relative to overall population, or it can
represent the rate at which the urban
proportion is increasing.

Movement

Percentage of population which is urbanized,
by country, as of 2006.

Movement

As more and more people leave villages and
farms to live in cities, urban growth results.
The rapid growth of cities like Chicago in the
late 19th century and Mumbai a century later
can be attributed largely to rural-urban
migration. This kind of growth is especially
commonplace in developing countries. This
growth can also be attributed to new job
opportunities.

Movement

The rapid urbanization of the world‘s
population over the twentieth century is
described in the 2005 Revision of the UN
World Urbanization Prospects report. The
global proportion of urban population rose
dramatically from 13% (220 million) in 1900,
to 29% (732 million) in 1950, to 49% (3.2
billion) in 2005. The same report projected
that the figure is likely to rise to 60% (4.9
billion) by 2030.

Movement

Percentage of World Population: Urban vs. Rural.

Movement

According to the UN State of the World
Population 2007 report, sometime in the
middle of 2007, the majority of people
worldwide will be living in towns or cities, for
the first time in history; this is referred to as
the arrival of the "Urban Millennium" or the
'tipping point'. In regard to future trends, it
is estimated 93% of urban growth will occur
in developing nations, with 80% of urban
growth occurring in Asia and Africa.

Movement

Urbanization rates vary between
countries. The United States and
United Kingdom have a far higher
urbanization level than China,
India, Swaziland or Niger, but a
far slower annual urbanization
rate, since much less of the
population is living in a rural
area.

Movement

Urbanization in the United States never
reached the Rocky Mountains in locations
such as Jackson Hole, Wyoming; Telluride,
Colorado; Taos, New Mexico; Douglas
County, Colorado and Aspen, Colorado. The
state of Vermont has also been affected, as
has the coast of Florida, the Birmingham-
Jefferson County, AL area, the Pacific
Northwest and the barrier islands of North
Carolina.

Movement

In the United Kingdom, two major examples
of new urbanization can be seen in Swindon,
Wiltshire and Milton Keynes,
Buckinghamshire.These two towns show
some of the quickest growth rates in Europe.

Center of São Paulo, one of the largest metropolises in the world.

Causes

Population age comparison between rural Pocahontas County, Iowa and urban
Johnson County, Iowa, illustrating the flight of young adults (red) to urban
centers in Iowa.

Causes

The City of Chicago, Illinois is an example of
the early American grid system of
development. The grid is enforced even on
uneven topography.

Causes

Urbanization is not always attributed to high
density. In Manila, the cost of living has
forced residents to live in low quality slums
and shanty towns

Causes

Urbanization occurs naturally from
individual and corporate efforts to reduce
time and expense in commuting and
transportation while improving
opportunities for jobs, education, housing,
and transportation. Living in cities permits
individuals and families to take advantage of
the opportunities of proximity, diversity, and
marketplace competition.

Causes

People move into cities to seek economic
opportunities. A major contributing factor is
known as "rural flight". In rural areas, often on
small family farms, it is difficult to improve one's
standard of living beyond basic sustenance.
Farm living is dependent on unpredictable
environmental conditions, and in times of
drought, flood or pestilence, survival becomes
extremely problematic. In modern times,
industrialization of agriculture has negatively
affected the economy of small and middle-sized
farms and strongly reduced the size of the rural
labor market.

Causes

Cities, in contrast, are known to be places where
money, services and wealth are centralized.
Cities are where fortunes are made and where
social mobility is possible. Businesses, which
generate jobs and capital, are usually located in
urban areas. Whether the source is trade or
tourism, it is also through the cities that foreign
money flows into a country. It is easy to see why
someone living on a farm might wish to take
their chance moving to the city and trying to
make enough money to send back home to their
struggling family.

Causes

There are better basic services as well as other
specialist services that aren't found in rural areas.
There are more job opportunities and a greater
variety of jobs. Health is another major factor.
People, especially the elderly are often forced to
move to cities where there are doctors and hospitals
that can cater for their health needs. Other factors
include a greater variety of entertainment
(restaurants, movie theaters, theme parks, etc.) and
a better quality of education, namely universities.
Due to their high populations, urban areas can also
have much more diverse social communities allowing
others to find people like them when they might not
be able to in rural areas.

Causes

These conditions are heightened during
times of change from a pre-industrial society
to an industrial one. It is at this time that
many new commercial enterprises are made
possible, thus creating new jobs in cities. It is
also a result of industrialization that farms
become more mechanized, putting many
labourers out of work. This is currently
occurring fastest in India.

Economic effects

One of the last housebuildings in the growing city
of Kstovo, such as the one in the background

Economic effects

As cities develop, effects can include a dramatic
increase and change in costs, often pricing the local
working class out of the market, including such
functionaries as employees of the local
municipalities. For example, Eric Hobsbawm's book
The age of revolution: 1789–1848 (published 1962
and 2005) chapter 11, stated "Urban development in
our period [1789–1848] was a gigantic process of
class segregation, which pushed the new labouring
poor into great morasses of misery outside the
centres of government and business and the newly
specialised residential areas of the bourgeoisie. The
almost universal European division into a 'good' west
end and a 'poor' east end of large cities developed in
this period

Economic effects

" This is likely due the prevailing south-west
wind which carries coal smoke and other
airborne pollutants downwind, making the
western edges of towns preferable to the eastern
ones. Similar problems now affect the
developing world, rising inequality resulting
from rapid urbanisation trends. The drive for
rapid urban growth and often efficiency can lead
to less equitable urban development, think tanks
such as the Overseas Development Institute have
even proposed policies that encourage labour
intensive growth as a means of absorbing the
influx of low skilled and unskilled labour.

Economic effects

Urbanization is often viewed as a negative
trend, but can in fact, be perceived simply as
a natural occurrence from individual and
corporate efforts to reduce expense in
commuting and transportation while
improving opportunities for jobs, education,
housing, and transportation. Living in cities
permits individuals and families to take
advantage of the opportunities of proximity,
diversity, and marketplace competition.

Environmental effects

The urban heat island has become a growing
concern and is increasing over the years. The
urban heat island is formed when industrial and
urban areas are developed and heat becomes
more abundant. In rural areas, a large part of the
incoming solar energy is used to evaporate water
from vegetation and soil. In cities, where less
vegetation and exposed soil exists, the majority
of the sun‘s energy is absorbed by urban
structures and asphalt. Hence, during warm
daylight hours, less evaporative cooling in cities
allows surface temperatures to rise higher than
in rural areas.


Additional city heat is given off by vehicles
and factories, as well as by industrial and
domestic heating and cooling units. This
effect causes the city to become 2 to 10 °F (1
to 6 °C) warmer than surrounding
landscapes. Impacts also include reducing
soil moisture and intensification of carbon
dioxide emissions.


In his book Whole Earth Discipline, Stewart
Brand argues that the effects of urbanization
are on the overall positive for the
environment. Firstly, the birth rate of new
urban dwellers falls immediately to
replacement rate, and keeps falling. This can
prevent overpopulation in the future.
Secondly, it puts a stop to destructive
subsistence farming techniques, like slash
and burn agriculture. Finally, it minimizes
land use by humans, leaving more for nature.

Changing forms

 Different forms of urbanization can be classified
depending on the style of architecture and planning
methods as well as historic growth of areas.
 In cities of the developed world urbanization
traditionally exhibited a concentration of human
activities and settlements around the downtown
area, the so-called in-migration. In-migration refers
to migration from former colonies and similar
places. The fact that many immigrants settle in
impoverished city centres led to the notion of the
"peripheralization of the core", which simply
describes that people who used to be at the periphery
of the former empires now live right in the centre.

Changing forms

Recent developments, such as inner-city
redevelopment schemes, mean that new arrivals
in cities no longer necessarily settle in the centre.
In some developed regions, the reverse effect,
originally called counter urbanisation has
occurred, with cities losing population to rural
areas, and is particularly common for richer
families. This has been possible because of
improved communications, and has been caused
by factors such as the fear of crime and poor
urban environments. It has contributed to the
phenomenon of shrinking cities experienced by
some parts of the industrialized world.

Changing forms

When the residential area shifts outward, this is
called suburbanization. A number of researchers
and writers suggest that suburbanization has
gone so far to form new points of concentration
outside the downtown both in developed and
developing countries such as India. This
networked, poly-centric form of concentration is
considered by some an emerging pattern of
urbanization. It is called variously exurbia, edge
city (Garreau, 1991), network city (Batten, 1995),
or postmodern city (Dear, 2000). Los Angeles is
the best-known example of this type of
urbanization.

Changing forms

Rural migrants are attracted by the possibilities that
cities can offer, but often settle in shanty towns and
experience extreme poverty. In the 1980s, this was
attempted to be tackled with the urban bias theory
which was promoted by Michael Lipton who wrote:
"...the most important class conflict in the poor
countries of the world today is not between labour
and capital. Nor is it between foreign and national
interests. It is between rural classes and urban
classes. The rural sector contains most of the poverty
and most of the low-cost sources of potential
advance; but the urban sector contains most of the
articulateness, organization and power. So the urban
classes have been able to win most of the rounds of
the struggle with the countryside...".

Changing forms

 Most of the urban poor in developing countries
able to find work can spend their lives in
insecure, poorly paid jobs. According to research
by the Overseas Development Institute pro-poor
urbanisation will require labour intensive
growth, supported by labour protection, flexible
land use regulation and investments in basic
services.'
 Urbanization can be planned urbanization or
organic. Planned urbanization, i.e.: planned
community or the garden city movement, is
based on an advance plan, which can be
prepared for military, aesthetic, economic or
urban design reasons.

Changing forms

Examples can be seen in many ancient cities;
although with exploration came the collision
of nations, which meant that many invaded
cities took on the desired planned
characteristics of their occupiers. Many
ancient organic cities experienced
redevelopment for military and economic
purposes, new roads carved through the
cities, and new parcels of land were cordoned
off serving various planned purposes giving
cities distinctive geometric designs.

Changing forms

UN agencies prefer to see urban
infrastructure installed before urbanization
occurs. Landscape planners are responsible
for landscape infrastructure (public parks,
sustainable urban drainage systems,
greenways etc.) which can be planned before
urbanization takes place, or afterward to
revitalize an area and create greater livability
within a region. Concepts of control of the
urban expansion are considered in the
American Institute of Planners.

Urbanization As A
Social Problem

Urbanization as a Social Problem How is
urbanization negatively effecting our society?

The answer to this question is not a simple
one. This essay will not only break down the
problems of urbanization in the United
States, but it will also tell you some of the
attempts made to fix the problem and give
some solutions as to how it could possibly be
solved in the future. Also when answering
this question one must understand that
urbanization, can not be stopped, but only
contained in a manner that will help the
United States to function better as a country.


The more densely populated and more
heterogeneous a community is, the more
accentuated characteristics can be associated
with urbanism. Urbanism causes decrease in per
capita, and promotes urban violence, political
instability, crime and aggressive behavior. Rapid
population growth in urban areas also
perpetuates poverty. Another major issue being
created by this social problem is the breaking of
the traditional family structure. Our cities are
not working well! Sanitation, safety,
transportation, housing, education and even
electricity are failing.


These are all responsibilities of the
government or it is at least their job to
regulate these services deemed to be
monopolies. And it is a known fact that
monopolies deem toward inefficiency.
Functionalist look at our cities as a means to
profit. Cities are a place where everybody
visits, and therefor vendors can raise their
prices and profit more on their products.


In the United States, the breaking of the
traditional family structure is an issue that
has become increasingly noticeable in recent
years, particularly in urbanized areas. The
traditional, mom and dad, and children are
rarely seen in the inner cities any more.
There is a weakened bond of kinship, and
declining social family significance as
America has transferred industrial,
educational and recreational activities to
specialized institutions outside of the home.


It is depriving families of their most
characteristic, historical functions. While
individuals pursue their own diverging
interests in their educational, vocational,
religious and recreational life. With divorce
rates rising, delinquency is also becoming
more of a problem than before. With single
parent families, children lack in the authority
department due to the lack of the amount of
time their parents have free to raise them.


These specialized institutions often help, but
can not replace the role of a child‘s guardian.
As long as the divorce rate continues to
increase, delinquency will continue to
increase in these areas as well. The density of
people reinforces effect of numbers in
diversifying people and their activities and
increasing the complexity of the social

7 Environmental Problems That
Are Worse Than We Thought

7 Environmental Problems That Are Worse Than We Thought

With as much attention as the environment has been getting lately, you‘d think that we‘d
be further along in our fight to preserve the world‘s species, resources and the beautiful
diversity of nature. Unfortunately, things aren‘t nearly that rosy. In fact, many of the
environmental problems that have received the most public attention are even worse
than we thought – from destruction in the rain forest to melting glaciers in the Arctic.
We‘ve got a lot of work to do.


7. Mammal Extinction

Image via National Wildlife Federation


One in four mammals is threatened with
extinction. That‘s 25%, a huge number that
will totally change the ecology of every corner
of the earth. We could see thousands of
species die out in our lifetime, and the rate of
habitat loss and hunting in crucial areas like
Southeast Asia, Central Africa and Central
and South America is growing so rapidly,
these animals barely have a chance.


If you think the extinction of an animal like the
beautiful Iberian Lynx is no big deal, and
wouldn‘t have that much of an effect on the
planet, think again. Not only would we be losing
– mostly due to our own disregard for our
surroundings – so much of the awe-inspiring
diversity of nature, mass extinctions like this
would cause a serious imbalance in the world‘s
food chain. When a predator disappears, the
prey will multiply. When prey dies out, the
predator will see its ranks decrease as well.
Many people fail to realize just how
interconnected all species on this planet really
are.


6. The Ocean Dead Zones

Image via NASA


In oceans around the world, there are eerie areas
that are devoid of nearly all life. These ‗dead zones‘
are characterized by a lack of oxygen, and they‘re
caused by excess nitrogen from farm fertilizers,
emissions from vehicles and factories, and sewage.
The number of dead zones has been growing fast –
since the 1960‘s, the number of dead zones has
doubled every 10 years. They range in size from
under a square mile to 45,000 square miles, and the
most infamous one of all is in the Gulf of Mexico, a
product of toxic sludge that flows down the
Mississippi from farms in the Midwest. These
‗hypoxic‘ zones now cover an area roughly the size of
Oregon.


Spanish researches recently found that many
species die off at oxygen levels well above the
current definition of ‗uninhabitable‘,
suggesting that the extent of dead zones in
coastal areas that support fishing is much
worse than previously thought. Robert Diaz,
a Virginia Institute of Marine Science
biologist, said ―Everything is pointing
towards a more desperate situation in all
aquatic systems, freshwater and marine.
That‘s pretty clear. People should be worried,
all over the world.‖


As if that weren‘t bad enough,
global warming will likely
aggravate the problem. A rise in
carbon dioxide in the atmosphere
will change rainfall patterns,
which could create an increase in
runoff from rivers into the seas in
many areas.


5. Collapsing Fish Stock

Image via Pew Environment Group


Millions of people across the world depend
upon fish as a major staple in their diet. As
such, commercial fishermen have been
pulling such a huge quantity of fish from the
oceans that we‘re heading toward a global
collapse of all species currently fished –
possibly as soon as the year 2048. Like large-
scale mammal extinction, the collapse of fish
species would have a major impact on the
world‘s ecosystems.


It‘s not too late – yet – if overfishing and
other threats to fish populations are reduced
as soon as possible. Marine systems are still
biologically diverse, but catastrophic loss of
fish species is close at hand. 29 percent of
species have been fished so heavily or have
been so affected by pollution that they‘re
down to 10 percent of their previous
population levels. If we continue the way we
are fishing today, there will be a 100 percent
collapse by mid-century, so we‘ve got to turn
this around fast.


4. Destruction of the Rain Forest

Image via Encyclopedia Britannica


‗Saving the rain forest‘ has been at the
forefront of the environmental movement for
decades, yet here we are facing huge losses in
the Amazon all the same. You might have
thought that, with all the attention the rain
forest has gotten, it wouldn‘t need so much
saving anymore – but unfortunately, global
warming and deforestation mean that half of
the Amazon rain forest will likely be
destroyed or severely damaged by 2030.


 The World Wildlife Fund concluded this summer that
agriculture, drought, fire, logging and livestock
ranching will cause major damage to 55 percent of
the Amazon rain forest in the next 22 years. Another
4 percent will see damage due to reduced rainfall,
courtesy of global warming. These factors will
destroy up to 80 percent of the rain forest‘s wildlife.
Losing 60 percent of the rain forest would accelerate
global warming and affect rainfall in places as far
away as India. Massive destruction to the rain forest
would have a domino effect on the rest of the world.
 The WWF says that the ‗point of no return‘, from
which recovery will be impossible, is only 15 to 25
years away.


3. Polar Sea Ice Loss

Image via National Snow and Ice Data Center


Polar sea ice is melting at an unprecedented
rate, and it‘s not showing any signs of slowing
down. It‘s perhaps the most dramatic,
startling visual evidence of global warming,
and it‘s got scientists rushing to figure out
just how big of an effect the melting is going
to have on the rest of the world.


British researchers said last week that the
thickness of sea ice in the Arctic decreased
dramatically last winter for the first time
since records began in the early 1990s. The
research showed a significant loss in
thickness on the northern ice cap after the
record loss of ice during the summer of 2007.


Scientific American warns that ―human
fingerprints have been detected‖ on both the
Arctic and Antarctic regions. Antarctica had
previously appeared to be the only continent
on the planet where humanity‘s impact on
climate change hadn‘t been observed. The
collapse of the Larsen B and Wilkins ice
shelves in the Antarctic Peninsula shows just
how fast the region is warming.


2. CO2 Levels in the Atmosphere

Image via Visible Earth


The aforementioned polar sea ice loss is yet
another sinister sign of carbon dioxide levels
building up in the atmosphere – the main
force behind global warming. Greenhouse
gas emissions caused by our modern way of
life – vehicles, power plants, factories, giant
livestock farms – will bring devastating
climate change within decades if they stay at
today‘s levels.


Average temperatures could increase by as
much as 12 degrees Fahrenheit by the end of
the century if emissions continue to rise, a
figure that would easily make the world
virtually uninhabitable for humans. A global
temperature rise of just 7.2 degrees
Fahrenheit would cause a catastrophic
domino effect, bringing weather extremes
that would result in food and water shortages
and destructive floods.


The most recent report by the
Intergovernmental Panel on Climate Change
represents ―the final nail in the coffin‖ of
climate change denial, representing the most
authoritative picture to date that global
warming is caused by human activity.
According to the panel, we must make a swift
and significant switch to clean, efficient and
renewable energy technologies in order to
prevent the worst-case scenario


1. Population Explosion

Image via Wikimedia Commons


Whether we like to admit it or not, our very
own rapidly multiplying presence on this
planet is the biggest environmental problem
there is, and it‘s getting bigger by the minute.
We voraciously consume resources, pollute
the air and water, tear down natural habitats,
introduce species into areas where they don‘t
belong and destroy ecosystems to the point of
causing millions of species to become
endangered and, all too often, go extinct.


It took nearly all of human history – from the
first days of man on earth until the early 1800‘s –
to reach a global population of 1 billion. In just
200 years, we‘ve managed to reach 6.5 billion.
That means the population has grown more since
1950 than in the previous four million years.
We‘re adding roughly 74 million people to the
planet every year, a scary figure that will
probably continue to increase. All of those
mouths will need to be fed. All of those bodies
will need clean water and a place to sleep. All of
the new communities created to house those
people will continue to encroach upon the
natural world.


All seven environmental problems detailed
above are very serious, and we‘ve got to start
treating them that way. We may not have easy
solutions, but the fact is, we simply can‘t
continue living our lives as if everything is
peachy. These problems aren‘t going to magically
solve themselves. We should have begun acting
generations ago, but we can‘t go back in time,
and that means we have to step up our efforts. If
we want to keep this planet a healthy place for
humans to live – for our grandchildren to enjoy
– it‘s time to buckle down and do everything in
our power to reverse the damage we‘ve done.

List of environmental issues
This is a list of environmental issues. As such they relate to the anthropogenic effects on
the natural environment.

 Climate change — Global warming • Global
dimming • Fossil fuels • Sea level rise •
Greenhouse gas • Ocean acidification • Shutdown
of thermohaline circulation • Environmental
impact of the coal industry
 Conservation — Species extinction • Pollinator
decline • Coral bleaching • Holocene extinction •
Invasive species • Poaching • Endangered species
 Energy — Energy conservation • Renewable
energy • Efficient energy use • Renewable energy
commercialization • Environmental impact of
the coal industry


 Environmental degradation —
Eutrophication • Habitat destruction •
Invasive species
 Environmental health — Air quality • Asthma
• Environmental impact of the coal industry •
Electromagnetic fields • Electromagnetic
radiation and health • Indoor air quality •
Lead poisoning • Sick Building Syndrome
 Genetic engineering — Genetic pollution •
Genetically modified food controversies


 Intensive farming — Overgrazing • Irrigation
• Monoculture • Environmental effects of
meat production • Slash and burn • Pesticide
drift • Plasticulture
 Land degradation — Land pollution •
Desertification
 Soil — Soil conservation • Soil erosion • Soil
contamination • Soil salination
 Land use — Urban sprawl • Habitat
fragmentation • Habitat destruction


 Nanotechnology — Nanotoxicology •
Nanopollution
 Nuclear issues — Nuclear fallout • Nuclear
meltdown • Nuclear power • Nuclear
weapons • Nuclear and radiation accidents •
Nuclear safety • High-level radioactive waste
management.
 Overpopulation — Burial • Water crisis •
Overpopulation in companion animals •
Tragedy of the commons


 Ozone depletion — CFC
 Pollution — Environmental impact of the coal industry •
Nonpoint source pollution • Point source pollution • Light
pollution • Noise pollution • Visual pollution
 Water pollution — Environmental impact of the coal
industry • Acid rain • Eutrophication • Marine pollution •
Ocean dumping • Oil spills • Thermal pollution • Urban
runoff • Water crisis • Marine debris • Microplastics •
Ocean acidification • Ship pollution • Wastewater • Fish
kill • Algal bloom • Mercury in fish
 Air pollution — Environmental impact of the coal industry
• Smog • Tropospheric ozone • Indoor air quality • Volatile
organic compound • Particulate matter


 Reservoirs — Environmental impacts of reservoirs
 Resource depletion — Exploitation of natural resources •
Overdrafting
 Consumerism — Consumer capitalism • Planned
obsolescence • Over-consumption
 Fishing — Blast fishing • Bottom trawling • Cyanide
fishing • Ghost nets • Illegal, unreported and unregulated
fishing • Overfishing • Shark finning • Whaling
 Logging — Clearcutting • Deforestation • Illegal logging
 Mining — Acid mine drainage • Hydraulic fracturing •
Mountaintop removal mining • Slurry impoundments


 Toxins — Chlorofluorocarbons • DDT •
Endocrine disruptors • Dioxin • Toxic heavy
metals • Environmental impact of the coal
industry • Herbicides • Pesticides • Toxic
waste • PCB • Bioaccumulation •
Biomagnification
 Waste — Electronic waste • Litter • Waste
disposal incidents • Marine debris • Medical
waste • Landfill • Leachate • Environmental
impact of the coal industry • Incineration •
Great Pacific Garbage Patch

Effects
Human health

Pollution

Overview of main health effects on humans from some common types of pollution.[26][27][28]

Human health

Adverse air quality can kill many organisms including
humans. Ozone pollution can cause respiratory disease,
cardiovascular disease, throat inflammation, chest pain,
and congestion. Water pollution causes approximately
14,000 deaths per day, mostly due to contamination of
drinking water by untreated sewage in developing
countries. An estimated 700 million Indians have no
access to a proper toilet, and 1,000 Indian children die of
diarrhoeal sickness every day. Nearly 500 million Chinese
lack access to safe drinking water. 656,000 people die
prematurely each year in China because of air pollution.
In India, air pollution is believed to cause 527,700
fatalities a year.[31] Studies have estimated that the
number of people killed annually in the US could be over
50,000.

Human health

Oil spills can cause skin irritations and rashes.
Noise pollution induces hearing loss, high blood
pressure, stress, and sleep disturbance. Mercury
has been linked to developmental deficits in
children and neurologic symptoms. Older people
are majorly exposed to diseases induced by air
pollution. Those with heart or lung disorders are
under additional risk. Children and infants are
also at serious risk. Lead and other heavy metals
have been shown to cause neurological
problems. Chemical and radioactive substances
can cause cancer and as well as birth defects.

Environment

Pollution has been found to be present widely in
the environment. There are a number of effects
of this:
 Biomagnification describes situations where
toxins (such as heavy metals) may pass through
trophic levels, becoming exponentially more
concentrated in the process.
 Carbon dioxide emissions cause ocean
acidification, the ongoing decrease in the pH of
the Earth's oceans as CO2 becomes dissolved.

Environment

 The emission of greenhouse gases leads to global
warming which affects ecosystems in many ways.
 Invasive species can out compete native species
and reduce biodiversity. Invasive plants can
contribute debris and biomolecules (allelopathy)
that can alter soil and chemical compositions of
an environment, often reducing native species
competitiveness.
 Nitrogen oxides are removed from the air by rain
and fertilise land which can change the species
composition of ecosystems.

Environment

 Smog and haze can reduce the amount of
sunlight received by plants to carry out
photosynthesis and leads to the production of
tropospheric ozone which damages plants.
 Soil can become infertile and unsuitable for
plants. This will affect other organisms in the
food web.
 Sulfur dioxide and nitrogen oxides can cause
acid rain which lowers the pH value of soil.

Environment
Environmental health information

 The Toxicology and Environmental Health
Information Program (TEHIP)[33] at the United States
National Library of Medicine (NLM) maintains a
comprehensive toxicology and environmental health
web site that includes access to resources produced
by TEHIP and by other government agencies and
organizations. This web site includes links to
databases, bibliographies, tutorials, and other
scientific and consumer-oriented resources. TEHIP
also is responsible for the Toxicology Data Network
(TOXNET)[34] an integrated system of toxicology and
environmental health databases that are available
free of charge on the web.

Environment
Environmental health information

TOXMAP is a Geographic Information
System (GIS) that is part of TOXNET.
TOXMAP uses maps of the United States to
help users visually explore data from the
United States Environmental Protection
Agency's (EPA) Toxics Release Inventory and
Superfund Basic Research Programs.

Regulation and monitoring

To protect the environment from
the adverse effects of pollution,
many nations worldwide have
enacted legislation to regulate
various types of pollution as well
as to mitigate the adverse effects
of pollution.

Pollution control

A litter trap catches floating rubbish in the
Yarra River, east-central Victoria, Australia

A litter trap catches floating rubbish in the Yarra River, east-central Victoria, Australia

Pollution control

A dust collector in Pristina, Kosovo

Pollution control

Gas nozzle with vapor recovery

Pollution control

A Mobile Pollution Check Vehicle in India.

Pollution control

Pollution control is a term used in
environmental management. It means the
control of emissions and effluents into air, water
or soil. Without pollution control, the waste
products from consumption, heating,
agriculture, mining, manufacturing,
transportation and other human activities,
whether they accumulate or disperse, will
degrade the environment. In the hierarchy of
controls, pollution prevention and waste
minimization are more desirable than pollution
control. In the field of land development, low
impact development is a similar technique for
the prevention of urban runoff.

Practices

 recycling
 reusing
 reducing
 mitigating
 preventing

Pollution control devices

 Dust collection systems
 Baghouses
 Cyclones
 Electrostatic precipitators

 Scrubbers
 Baffle spray scrubber
 Cyclonic spray scrubber
 Ejector venturi scrubber
 Mechanically aided scrubber
 Spray tower
 Wet scrubber


 Sewage treatment
 Sedimentation (Primary treatment)

 Activated sludge biotreaters (Secondary treatment;
also used for industrial wastewater)
 Aerated lagoons

 Constructed wetlands (also used for urban runoff)


 Industrial wastewater treatment
 API oil-water separators[15][35]

 Biofilters

 Dissolved air flotation (DAF)

 Powdered activated carbon treatment

 Ultrafiltration

 Vapor recovery systems

Perspectives

The earliest precursor of pollution generated by life
forms would have been a natural function of their
existence. The attendant consequences on viability
and population levels fell within the sphere of
natural selection. These would have included the
demise of a population locally or ultimately, species
extinction. Processes that were untenable would
have resulted in a new balance brought about by
changes and adaptations. At the extremes, for any
form of life, consideration of pollution is superseded
by that of survival.

Perspectives

For humankind, the factor of technology is a
distinguishing and critical consideration, both as an
enabler and an additional source of byproducts.
Short of survival, human concerns include the range
from quality of life to health hazards. Since science
holds experimental demonstration to be definitive,
modern treatment of toxicity or environmental harm
involves defining a level at which an effect is
observable. Common examples of fields where
practical measurement is crucial include automobile
emissions control, industrial exposure (e.g.
Occupational Safety and Health Administration
(OSHA) PELs), toxicology (e.g. LD50), and medicine
(e.g. medication and radiation doses).

Perspectives

"The solution to pollution is dilution", is a
dictum which summarizes a traditional
approach to pollution management whereby
sufficiently diluted pollution is not
harmful.[36][37] It is well-suited to some other
modern, locally scoped applications such as
laboratory safety procedure and hazardous
material release emergency management.
But it assumes that the dilutant is in virtually
unlimited supply for the application or that
resulting dilutions are acceptable in all cases.

Perspectives

Such simple treatment for environmental pollution
on a wider scale might have had greater merit in
earlier centuries when physical survival was often
the highest imperative, human population and
densities were lower, technologies were simpler and
their byproducts more benign. But these are often no
longer the case. Furthermore, advances have enabled
measurement of concentrations not possible before.
The use of statistical methods in evaluating outcomes
has given currency to the principle of probable harm
in cases where assessment is warranted but resorting
to deterministic models is impractical or unfeasible.
In addition, consideration of the environment
beyond direct impact on human beings has gained
prominence.

Perspectives

Yet in the absence of a superseding principle,
this older approach predominates practices
throughout the world. It is the basis by which
to gauge concentrations of effluent for legal
release, exceeding which penalties are
assessed or restrictions applied. The
regressive cases are those where a controlled
level of release is too high or, if enforceable,
is neglected. Migration from pollution
dilution to elimination in many cases is
confronted by challenging economical and
technological barriers.

Greenhouse gases and global warming

Historical and projected CO2 emissions by country.
Source: Energy Information Administration.

Greenhouse gases and global warming

Carbon dioxide, while vital for photosynthesis, is
sometimes referred to as pollution, because
raised levels of the gas in the atmosphere are
affecting the Earth's climate. Disruption of the
environment can also highlight the connection
between areas of pollution that would normally
be classified separately, such as those of water
and air. Recent studies have investigated the
potential for long-term rising levels of
atmospheric carbon dioxide to cause slight but
critical increases in the acidity of ocean waters,
and the possible effects of this on marine
ecosystems.

Global ecological problems

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