Pollution

Posted on March 27, 2008 by Rashid Faridi

Pollution is the addition to the ecosystem of someting which has a detrimental effect on it. One of the most important causes of pollution is the high rate of energy usage by modern, growing populations.

Different kinds of pollution are found. Some are

  1. Air Pollution.
  2. Water Pollution.
  3. Land Pollution.


Air Pollution

Air pollution is the accumulation in the atmosphere of substances that, in sufficient concentrations, endanger human health or produce other measured effects on living matter and other materials. Among the major sources of pollution are power and heat generation, the burning of solid wastes, industrial processes, and, especially, transportation. The six major types of pollutants are carbon monoxide, hydrocarbons, nitrogen oxides, particulates, sulfur dioxide, and photochemical oxidants.

Examples of Air Pollution

 

 

Noise pollution or unwanted sounds that are carried by the air, have an irritating and detrimental effect on humans and other animals. Careful planning of streets and biuldings in towns and better control over noisy vechiles may add to the control of noise pollution.

 

  • Tobacco Smoke

 

Tobacco smoke is one of the major forms of pollution in buildings. It is not only the smoker who is infected, but everyone who inhales the polluted air. There is a very strong connection between smoking and lung cancer. Bronchitis is common among smokers and unborn babies of mothers who smoke also suffer from the harmful effects of smoking.

 

  • Exhaust Gases of Vehicles

 

Pollution from exhaust gases of vehicles is reponsible for 60% of all air pollution and in cities up to 80%. There is a large variety of harmful chemicals present in these gases, with lead being one of the most dangerous.

 

  • Combustion of Coal

 

The combustion of caol without special precautions can have serious consequences. If winds do not blow away the poisonous gases, they can have fatal effects and may lead to death.

 

 

Acid rain is the term for pollution caused when sulfur and nitrogen dioxides combine with atmospheric moisture to produce highly acidic rain, snow, hail, or fog. The acid eats into the stone, brick and metal articles and pollutes water sources. Coal in South Africa is rich in sulphur and the power stations in the Mpumalanga Province could be reponsible for acid rain over other areas of our country.

Control Measures

Although individual people can help to combat air pollution in their own immediate environment, efficient control can be best achieved by legislation. Some commonly enforced control measures include

  • the establishment of more smokeless zones;
  • control over the kinds of fuel used in cars, aeroplanes, power stations, etc.
 

Water Pollution

Water pollution is the introduction into fresh or ocean waters of chemical, physical, or biological material that degrades the quality of the water and affects the organisms living in it. This process ranges from simple addition of dissolved or suspended solids to discharge of the most insidious and persistent toxic pollutants (such as pesticides, heavy metals, and nondegradable, bioaccumulative, chemical compounds).Ground Water Pollution is also a growing concern.

Examples of Water Pollution

 

  • Industrial affluents

 

 

    Water is discharged from after having been used in production processes. This waste water may contain acids, alkalis, salts, poisons, oils and in some cases harmful bacteria.

 

  • Mining and Agricultural Wastes

 

Mines, especially gold and coal mines, are responsible for large quatities of acid water. Agricultural pesticides, fertilisers and herbicides may wash into rivers and stagnant water bodies.

 

  • Sewage Disposal and Domestic Wastes

 

Sewage as wel as domestic and farm wastes were often allowed to pollute rivers and dams.

Control Measures

The following measures can be used to stop water pollution:

  • every intelligent people should be wise enough not to pollute water in any way;
  • by research and legislation the pollution of water bodies, even though not entirely prevented, must be effectively controlled.
 

Land Pollution

Land pollution is the degradation of the Earth’s land surface through misuse of the soil by poor agricultural practices, mineral exploitation, industrial waste dumping, and indiscriminate disposal of urban wastes. It includes visible waste and litter as well as pollution of the soil itself.

Examples of Land Pollution

Soil Pollution
Soil pollution is mainly due to chemicals in herbicides (weed killers) and pesticides (poisons which kill insects and other invertebrate pests). Litter is waste material dumped in public places such as streets, parks, picnic areas, at bus stops and near shops.

Waste Disposal
The accumulation of waste threatens the health of people in residential areas. Waste decays, encourages household pests and turns urban areas into unsightly, dirty and unhealthy places to live in.

Control Measures

The following measures can be used to control land pollution:

 

  • anti-litter campaigns can educate people against littering;
  • organic waste can be dumped in places far from residential areas;
  • inorganic materials such as metals, glass and plastic, but also paper, can be reclaimed and recycled.

Source:http://www.botany.uwc.ac.za

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Safe Water in Peril

Posted on March 27, 2008 by Rashid Faridi

More than one billion people lack access to safe drinking water, and more
than two billion people live without improved sanitation. While these dire
conditions already pose the greatest threat to environmental health around
the world, global warming is set to make matters even worse. More frequent
and more serious droughts and floods will increase water shortages and
cause more widespread water contamination and sanitation challenges. To
avoid an outright global water catastrophe, local, national, and global leaders
must urgently pursue a two-part strategy of reducing pollution to minimize
further climate change while preparing vulnerable communities to deal with
the changes in climate that are already occurring or are unavoidable.

The Most Vulnerable Will Be Hit Hardest
by the Water Crisis
Although developed countries are most responsible
for causing global warming, it is the poor in
developing countries that face the greatest risks
from a warmer climate. Without bold policy
action from the international community,
vulnerable nations in Africa, Asia, and Latin
America are likely to face the most devastating
shocks from global warming. For example,
although Sub-Saharan Africa currently contributes
little to the causes of climate change (producing
less than four percent of the world’s greenhouse
gases1) the IPCC predicts that by 2020, between
75 and 250 million people in Africa will suffer
increased water stress due to climate change. In
East Africa, snow is already disappearing from
mountains like Mt. Kenya and Mt. Kilimanjaro,
affecting the local communities who depend on
the rivers and streams fed by these mountain
snows.
In heavily-populated Asia, up to one billion
people could face reduced access to water and
more extreme weather events such as flooding and
droughts, even with a small rise in temperature.
Already, Chinese scientists have blamed global
warming for reducing the water flow in China’s
major rivers to historic lows. Low river flows last
summer led to severe drinking water shortages that
afflicted 18 million people.
In Latin America and the Caribbean, global
warming is expected to change precipitation
patterns, resulting in too little water in some areas
and too much in others. Increasingly severe and
frequent storms will lead to more flooding and
damaged infrastructure, particularly along the
coastal areas, where 60 of the region’s 77 largest
cities are situated.

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Bringing Safe Water to the World

Posted on March 27, 2008 by Rashid Faridi

Almost every day, Sarah and her best friend walk to a deep hole dug into a dry riverbed in Sudan to fetch water for their families. It’s a seven-and-a-half-hour journey in brutal heat, the return trip made even more arduous by the weight of the 5-gallon water container, which Sarah carries on her head — a load of about 45 pounds of water of questionable quality.

Sarah’s journey was captured in real time in the documentary The Long Walk, by Alice Hobbs. But her story is by no means unique. One billion people around the world don’t have access to clean, safe water. Developed countries have essentially eradicated diseases such as cholera, typhoid and malaria, but in developing nations, these and other waterborne illnesses kill 5 million people each year — 6,000 children every day. And global warming is exacerbating this crisis as severe, prolonged droughts dry up water supplies in arid regions and heavy rains cause sewage overflows. In terms of the sheer number of people affected, the lack of access to safe water and basic sanitation is a massive problem. Yet it is a problem with proven solutions.

What Makes Water Unsafe?

Drinking water contaminated with chemicals or bacteria can make people sick, especially children and the elderly. Water can be contaminated with bacteria when it comes into contact with untreated human waste. Nearly half the people on the planet — most of them in China and India — don’t have a system to safely dispose of human waste and keep it away from areas where people can come into contact with it. As a result, disease-causing bacteria can enter the water supply and spread through a population. Children are particularly vulnerable to these waterborne diseases. Their small bodies take in a disproportionately large quantity of water and its contaminants, and their immune systems are not equipped to fight off invaders such as E. coli, giardia and the typhoid bacteria. More than 2 million children are killed by such diarrheal diseases each year, and 90 percent of them are kids under five.

Chemicals from industrial waste, pesticides that wash off from farms, or naturally occurring arsenic can also contaminate drinking water. Millions of people drink arsenic-laced well water every day, mostly in Bangladesh, West Bengal (India), China, Taiwan, Nepal and pockets of South America. The footprint of a contaminated well is painfully easy to spot: an epidemic of skin lesions, vascular and cardiac problems, and widespread bladder, lung, and skin cancer in affected areas.

Safe Water: Keystone of Environment, Health, Economy and Security

People who fall ill from waterborne diseases can’t work. Women and girls like Sarah who travel hours to fetch clean water for their families can’t go to school or hold on to a job. Without proper sanitation, human waste pollutes waterways and wildlife habitat. Global warming and population pressures are drying up water supplies and instigating conflict over scarce resources. Expanding access to clean water and sanitation will have ripple effects throughout local economies and societies.

The U.N. estimates that if the proportion of people without access to safe water and basic sanitation were halved, countries around the world would save $7.3 billion per year in health care costs, and the annual global value of adult working days gained because of less illness would be almost $750 million. Relocating wells or boreholes closer to users, installing piped water supply in houses, and building latrines closer to home would yield annual time savings worth $64 billion.

Simple Solutions Can Make Water Safer

Simple sanitation improvements, like digging pit latrines and treating drinking water with chlorine, filters and other simple, existing technologies can save millions of lives. The challenge is to put the right strategies to use in the right places, as needs vary from country to country.

The long-term goal is to provide safe sources of treated drinking water and improved sanitation for all. In the meantime, simple, shorter-term strategies can save millions of lives. The list of successful safe drinking water projects is growing, using simple household approaches, such as:

  • Household chlorination or other chemical treatment
  • Solar disinfection — leaving transparent bottles of water in the sun to kill microbes
  • Hygiene education and promoting hand-washing
  • Boiling water using excess heat from cooking
  • Filtering water using sand, cloth, ceramics or other existing materials.

Chemical contamination such as arsenic pollution can be more difficult to solve, but strategies like these have been successful in particular regions:

  • Accessing low-arsenic water through shallow groundwater or deeper aquifers
  • Rainwater harvesting
  • Pond-sand filtration
  • Household chemical treatment
  • Piping in water from safe or treated sources.

Safe Water by 2015: How to Get it Done

Safe water is a critical environmental and public health issue, as well as a means to lift people out of poverty and ensure human security. Yet the number of people without safe water is increasing. Water supply and sanitation programs can’t be developed in isolation from other development issues. Global warming is affecting water supplies, creating shifts in agriculture and where people live. AIDS patients especially need access to clean water so they don’t fall ill from common waterborne germs that healthy adults can fend off. Integrating safe water programs into larger development strategies often involves complex, many-sided reforms, which requires high-level coordination and firm political will to get the job done.

The United Nations included safe water in its Millennium Development goals, with the intention of reducing by half the proportion of people without sustainable access to safe drinking water and basic sanitation.

In 2005, the United States Congress codified the goal into law by passing the Senator Paul Simon Water for the Poor Act. The act made the provision of safe water and sanitation a cornerstone of U.S. foreign aid by integrating water sanitation into all U.S. development programs. However, Congress has failed to designate any funds for its implementation.

Providing safe water is an essential step for human health and development. Global awareness of this issue is rising, but our leaders need to take concrete action in order to solve this crisis in the next decade. NRDC is urging the U.S. Congress to fully fund the Senator Paul Simon Water for the Poor Act, and is helping provide concrete recommendations to implement the act successfully. By encouraging leadership and generating momentum for solutions, we can save millions of lives over the next 10 years.

source:http://www.nrdc.org

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NASA Satellite Measures Pollution From East Asia To North America

Posted on March 26, 2008 by Rashid Faridi
In a new NASA study, researchers taking advantage of improvements in satellite sensor capabilities offer the first measurement-based estimate of the amount of pollution from East Asian forest fires, urban exhaust, and industrial production that makes its way to western North America.
China, the world’s most populated country, has experienced rapid industrial growth, massive human migrations to urban areas, and considerable expansion in automobile use over the last two decades. As a result, the country has doubled its emissions of man-made pollutants to become the world’s largest emitter of tiny particles called pollution aerosols that are transported across the Pacific Ocean by rapid airstreams emanating from East Asia.

Hongbin Yu, an associate research scientist of the University of Maryland Baltimore County working at NASA’s Goddard Space Flight Center in Greenbelt, Md., grew up in China and taught there as a university professor, where he witnessed first-hand and studied how pollution from nearby power plants in China affected the local environment.

Early this decade, scientists began using emerging high-accuracy satellite data to answer key questions about the role tiny particles play in the atmosphere, and eventually expanded their research to include continent-to-continent pollution transport. So Yu teamed with other researchers to take advantage of the innovations in satellite technology and has now made the first-ever satellite-based estimate of pollution aerosols transported from East Asia to North America.

The new measurements from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on NASA’s Terra satellite substantiate the results of previous model-based studies, and are the most extensive to date. The new study will be published this spring in the American Geophysical Union’s Journal of Geophysical Research-Atmospheres.

“We used the latest satellite capabilities to distinguish industrial pollution and smoke from dust transported to the western regions of North America from East Asia. Looking at four years of data from 2002 to 2005 we estimated the amount of pollution arriving in North America to be equivalent to about 15 percent of local emissions of the U.S. and Canada,” Yu said.

“This is a significant percentage at a time when the U.S. is trying to decrease pollution emissions to boost overall air quality. This means that any reduction in our emissions may be offset by the pollution aerosols coming from East Asia and other regions.”

Yu and his colleagues measured the trans-Pacific flow of pollution in teragrams, a unit of measurement of the mass of pollution aerosol (1 teragram is about 2.2 billion pounds). Satellite data confirmed 18 teragrams — almost 40 billion pounds — of pollution aerosol was exported to the northwestern Pacific Ocean and 4.5 teragrams – nearly 10 billion pounds — reached North America annually from East Asia over the study period.

Yu points out, however, that the matter of pollution transport is a global one. “Our study focused on East Asian pollution transport, but pollution also flows from Europe, North America, the broader Asian region and elsewhere, across bodies of water and land, to neighboring areas and beyond,” he said. “So we should not simply blame East Asia for this amount of pollution flowing into North America.”

In fact, in a model study published last November in the Journal of Atmospheric Chemistry and Physics, Mian Chin, also a co-author of this study and an atmospheric scientist at NASA Goddard, suggests that European pollution also makes a significant contribution to the pollution inflow to North America.

“Satellite instruments give us the ability to capture more accurate measurements, on a nearly daily basis across a broader geographic region and across a longer time frame so that the overall result is a better estimate than any other measurement method we’ve had in the past,” said study co-author Lorraine Remer, a physical scientist and member of the MODIS science team at NASA Goddard.

The MODIS instrument can distinguish between broad categories of particles in the air, and observes Earth’s entire surface every one to two days, enabling it to monitor movement of the East Asian pollution aerosols as they rise into the lower troposphere, the area of the atmosphere where we live and breathe, and make their way across the Pacific and up into the middle and upper regions of the troposphere.

Remer added that the research team also found that pollution movements fluctuate during the year, with the East Asian airstream carrying its largest “load” in spring and smallest in summer. The most extensive East Asian export of pollution across the Pacific took place in 2003, triggered by record-breaking wildfires across vast forests of East Asia and Russia. Notably, the pollution aerosols also travel quickly. They cross the ocean and journey into the atmosphere above North American in as little as one week.

“Using this imaging instrument, we cannot determine at what level of elevation in the atmosphere pollution travels. So, we do not have a way in this study to assess the degree of impact the pollution aerosols from China have on air quality here once they cross over to North America. We need improved technology to make that determination,” said Remer. “Nevertheless, we realize there is indeed impact.

For example, particles like these have been linked to regional weather and climate effects through interactions between pollution aerosols and the Sun’s heat energy. Since pollution transport is such a broad global issue, it is important moving forward to extend this kind of study to other regions, to see how much pollution is migrating from its source regions to others, when, and how fast,” said Remer.

According to measurements taken with a satellite instrument, vast quantities of industrial aerosols and smoke from biomass burning in East Asia and Russia are traveling from one side of the globe to another. Explosive economic growth in Asia has profound implications for the atmosphere worldwide. Data collected by a NASA satellite shows a dense blanket of polluted air over the Northwestern Pacific.

This brown cloud is a toxic mix of ash, acids, and airborne particles from car and factory emissions, as well as from low-tech polluters like coal-burning stoves and from forest fires. This image generated by data from NASA’s instrument called MODIS (Moderate Resolution Imaging Spectroradiometer) onboard the Terra satellite demonstrates how large and pervasive this transport phenomenon is across vast areas.

In this picture, heavy aerosol concentrations appear in shades of brown, with darker shades representing greater concentrations. Areas lined in black on the land surface represent human population. Notice how heavy aerosol production and dense population areas correspond.

Also notice how there are dense patches of red points in East Asia. These correspond with intense forest fires, sending vast quantities of aerosols into the atmosphere. Although this image gives the impression that the fires and plumes of aerosols may not be connected, in fact they are. There’s a direct relationship between those fire point and the brown patches appearing to the East.

China’s exports fill shelves around the world, but according to a new NASA research paper, China also heavily exports pollution. This week, space agency scientists reveal how Chinese industrialization and Russian forest fires in combination with pollution transported eastward from Europe send roughly 18 teragrams – almost 40 billion pounds-of pollution aerosols into the atmosphere over the Northwestern Pacific every year.

The MODIS instrument on NASA’s Terra satellite has been tracking the particulate pollution for more than seven years, gathering data as most of it drifted east across the Pacific Ocean. About 4.5 teragrams of particulate pollution each year could reach the western boundary of North America, which is about 15% of local emissions of particulate pollutants from the U.S. and Canada.

In the last two decades, China has more than doubled its pollution production. This boom may be contributing to substantial changes in climate and weather in places far from the origin of the particulates. Never in human history-anywhere-has there been industrial growth like that in modern China. But with fast growth comes unintended consequences, and from space evidence of those consequences is starting to emerge.

The research relies on measurements of something called “aerosol optical thickness”. It’s a quantitative measurement about how well a slice of atmosphere transmits light. The greater the value of optical thickness for a given location, the less light of a particular wavelength can pass through it.

Measurements of aerosol optical thickness describe quantities of tiny particles in a given volume. By measuring how much light can penetrate a region of atmosphere across a variety of wavelengths, scientists can make certain inferences about the quantity and type of particles blocking that light.

This visualization shows the seasonal variations of transport of pollution aerosols across the North Pacific. The East Asian airstream carries its largest pollution loading in spring and smallest in summer and fall. With heavy concentrations of aerosols represented by shades of brown, scientists can track the origins and distribution of the particles as they travel in the atmosphere.

The sequence also shows a trail of substantial aerosol concentrations from a variety of sources. These sources include heavy industrial activity in East Asia associated with high population density represented in this sequence by gradations of black covering the land surface, and intense Russian forest fires in high latitudes.

Source : http://www.terradaily.com/

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