Water pollution

When toxic substances enter lakes, streams, rivers, oceans, and other water bodies, they get dissolved or lie suspended in water or get deposited on the bed. This results in the pollution of water whereby the quality of the water deteriorates, affecting aquatic ecosystems. Pollutants can also seep down and affect the groundwater deposits.

Water pollution has many sources. The most polluting of them are the city sewage and industrial waste discharged into the rivers. The facilities to treat waste water are not adequate in any city in India. Presently, only about 10% of the waste water generated is treated; the rest is discharged as it is into our water bodies. Due to this, pollutants enter groundwater, rivers, and other water bodies. Such water, which ultimately ends up in our households, is often highly contaminated and carries disease-causing microbes. Agricultural run-off, or the water from the fields that drains into rivers, is another major water pollutant as it contains fertilizers and pesticides.

Domestic sewage refers to waste water that is discarded from households. Also referred to as sanitary sewage, such water contains a wide variety of dissolved and suspended impurities.
Biochemical oxygen demand, or BOD

The amount of organic material that can rot in the sewage is measured by the biochemical oxygen demand. BOD is the amount of oxygen required by micro-organisms to decompose the organic substances in sewage. Therefore, the more organic material there is in the sewage, the higher the BOD. It is among the most important parameters for the design and operation of sewage treatment plants. BOD levels of industrial sewage may be many times that of domestic sewage. Dissolved oxygen is an important factor that determines the quality of water in lakes and rivers. The higher the concentration of dissolved oxygen, the better the water quality. When sewage enters a lake or stream, micro-organisms begin to decompose the organic materials. Oxygen is consumed as micro-organisms use it in their metabolism. This can quickly deplete the available oxygen in the water. When the dissolved oxygen levels drop too low, many aquatic species perish. In fact, if the oxygen level drops to zero, the water will become septic. When organic compounds decompose without oxygen, it gives rise to the undesirable odours usually associated with septic or putrid conditions.

It amounts to a very small fraction of the sewage by weight. But it is large by volume and contains impurities such as organic materials and plant nutrients that tend to rot. The main organic materials are food and vegetable waste, plant nutrient come from chemical soaps, washing powders, etc. Domestic sewage is also very likely to contain disease-causing microbes. Thus, disposal of domestic waste water is a significant technical problem. Sewage generated from the urban areas in India has multiplied manifold since 1947.

Today, many people dump their garbage into streams, lakes, rivers, and seas, thus making water bodies the final resting place of cans, bottles, plastics, and other household products. The various substances that we use for keeping our houses clean add to water pollution as they contain harmful chemicals. In the past, people mostly used soaps made from animal and vegetable fat for all types of washing. But most of today’s cleaning products are synthetic detergents and come from the petrochemical industry. Most detergents and washing powders contain phosphates, which are used to soften the water among other things. These and other chemicals contained in washing powders affect the health of all forms of life in the water.

Agricultural Run off

Eutrophication

When fresh water is artificially supplemented with nutrients, it results in an abnormal increase in the growth of water plants. This is known as eutrophication. The discharge of waste from industries, agriculture, and urban communities into water bodies generally stretches the biological capacities of aquatic systems. Chemical run-off from fields also adds nutrients to water. Excess nutrients cause the water body to become choked with organic substances and organisms. When organic matter exceeds the capacity of the micro-organisms in water that break down and recycle the organic matter, it encourages rapid growth, or blooms, of algae. When they die, the remains of the algae add to the organic wastes already in the water; eventually, the water becomes deficient in oxygen. Anaerobic organisms (those that do not require oxygen to live) then attack the organic wastes, releasing gases such as methane and hydrogen sulphide, which are harmful to the oxygen-requiring (aerobic) forms of life. The result is a foul-smelling, waste-filled body of water. This has already occurred in such places as Lake Erie and the Baltic Sea, and is a growing problem in freshwater lakes all over India. Eutrophication can produce problems such as bad tastes and odours as well as green scum algae. Also the growth of rooted plants increases, which decreases the amount of oxygen in the deepest waters of the lake. It also leads to the death of all forms of life in the water bodies.

The use of land for agriculture and the practices followed in cultivation greatly affect the quality of groundwater. Intensive cultivation of crops causes chemicals from fertilizers (e.g. nitrate) and pesticides to seep into the groundwater, a process commonly known as leaching. Routine applications of fertilizers and pesticides for agriculture and indiscriminate disposal of industrial and domestic wastes are increasingly being recognized as significant sources of water pollution.

The high nitrate content in groundwater is mainly from irrigation run-off from agricultural fields where chemical fertilizers have been used indiscriminately.


Industrial effluents

Waste water from manufacturing or chemical processes in industries contributes to water pollution. Industrial waste water usually contains specific and readily identifiable chemical compounds. During the last fifty years, the number of industries in India has grown rapidly. But water pollution is concentrated within a few subsectors, mainly in the form of toxic wastes and organic pollutants. Out of this a large portion can be traced to the processing of industrial chemicals and to the food products industry. In fact, a number of large- and medium-sized industries in the region covered by the Ganga Action Plan do not have adequate effluent treatment facilities. Most of these defaulting industries are sugar mills, distilleries, leather processing industries, and thermal power stations. Most major industries have treatment facilities for industrial effluents. But this is not the case with small-scale industries, which cannot afford enormous investments in pollution control equipment as their profit margin is very slender.

Effects of water pollution

The effects of water pollution are not only devastating to people but also to animals, fish, and birds. Polluted water is unsuitable for drinking, recreation, agriculture, and industry. It diminishes the aesthetic quality of lakes and rivers. More seriously, contaminated water destroys aquatic life and reduces its reproductive ability. Eventually, it is a hazard to human health. Nobody can escape the effects of water pollution.

an adult body is made up of...

The human body is made up of a head, neck, torso, two arms and two legs. The average height of an adult human is about 5 to 6 feet tall. The human body is made to stand erect, walk on two feet, use the arms to carry and lift, and has opposoble thumbs (able to grasp).



The adult body is made up of:

* 100 trillion cells
* 206 bones
* 600 muscles
* 22 internal organs

Why do humans sweat?

Sweat is your body's natural way of cooling down. When you get really hot from the bright sun or from running around outside, the tiny pores on your body open up to let heat out – and this is when you sweat! And, as the sweat comes out of your body, you cool off!

Why is water good for you?

Glass of water

People, animals and plants all need clean water to live. Infact more plants and animals live in water than on land. Blood is mostly water, and your muscles, lungs, and brain all contain a lot of water. Your body needs water to regulate body temperature and to provide the means for nutrients to travel to all your organs. Water also transports oxygen to your cells, removes waste, and protects your joints and organs.

top 10 recycleing tips

Top Recycling Tips

1. First things first, a little R & R & R
The aphorism is so tired it almost might seem like “reduce, reuse, recycle” should go without saying. But in fact, most of us have only really heard the last third of the phrase, and they’re ranked in order of importance. Reducing the amount that we consume, and shifting our consumption to well-designed products and services, is the first step. Finding constructive uses for “waste” materials is next. And tossing it in the blue bin is last. (The garbage can is not on the list, for good reason.) Through a balance of these three principals you can easily see your landfill-destined waste dwindle fast. A good example of recycling is setting your empty water bottles in the bin on the curb. But by using a water filter and reusable container you can reduce or completely eliminate your need for disposable plastic bottles.

2. Know what you can and can't recycle
Read up on the recycling rules for your area and make sure you don't send anything in that can't be processed. Each city has its own specifics, so try to follow those guidelines as best you can.

3. Buy recycled
The essence of recycling is the cyclical movement of materials through the system, eliminating waste and the need to extract more virgin materials. Supporting recycling means feeding this loop by not only recycling, but also supporting recycled products. We can now find high recycled content in everything from printer paper to office chairs.

4. Encourage an artist
If you know someone interested in making art from recycled materials, offer to provide supplies. Many school children need items like paper towel tubes for art projects. Older artists use everything from rubber bands to oven doors. If you know someone who teaches art classes, suggest that an emphasis be put on making art from trash. While you're at it, remind them to use recycled paper and biodegradable, earth-friendly glues, paints, and pencils whenever possible. See below for inspiration and groups that connect artists and students with useful “trash.”

5. Recycle your water
If you're a homeowner, consider rearranging your plumbing so that rainwater or wastewater from your shower and tub is used to flush your toilet. If you have a garden, water it with leftover bathwater or dishwashing water (as long as you use a biodegradable soap). For more on water recycling see How to Go Green: Water.

6. Recycle your greenery
William McDonough and Michael Braungart, authors of the groundbreaking Cradle to Cradle, envision so-called “waste” divided into two categories: technical nutrients and biological nutrients. Biological nutrients are those that, at the end of their useful life, can safely and readily decompose and return to the soil. Composting is one of the simplest and most effective recycling methods. Both your garden cuttings and your green kitchen waste can go into an outdoor or indoor composter (with or without entertaining a population of worms). If you don't have a garden yourself, find neighbors or a community garden that can make use of your soil. Composting food scraps will mean your regular kitchen wastebasket fills up more slowly and also won’t smell. Hotter, more active compost heaps can also consume tougher stuff like newspaper and paper napkins. After Christmas, many cities also have programs for turning your tree into mulch.

7. Recycle your robots
Electronics recycling is becoming more common in many urban areas, battery recycling is ubiquitous (rechargeable batteries are ecologically sounder, but even they wear out after a while), and there are a number of non-profit organizations that will take computer parts and turn them into working computers for others. Companies like Ebay have also developed programs to help your electronics find new homes. Other groups will gladly recycle your cell phone or give it to a senior citizen, as even without a contract it can still make emergency calls. If you have a major appliance that doesn't work and you'd rather replace it than try to fix it, offer it to local repair shops, trade schools, or hobbyists to tinker with. Many cities now offer hazardous waste recycling days when they will take not only hazardous waste, but electronics.

8. Anticipate recycling
In addition to buying recycled goods, keep a keen eye out for recyclable goods. Whenever you purchase something packaged, think about how you can reuse the packaging, return it to a shipping store for reuse, or try to otherwise recycle it. If you get something likely to run down or wear out over time, such as an electronic component, give preference to the model that can be easily upgraded or cannibalized for parts so that you don't have to junk the whole thing if one part breaks. Products that are impossibly fused together are often called “monstrous hybrids” and are, while often cheaper up front, frequently unfixable and unrecyclable.

9. If you don’t love something, let it go
Lots of charities welcome your donations. Groups like Freecycle and Recycler's Exchange exist to help you get rid of useful objects that you just don't want to make use of. If you're in a Craigslist city, make use of the "free stuff" section. Give away clothes that don't fit, the boxes you used in your last house move, or scented soaps that don't appeal to your sensibilities. Make it a rule in your house that nothing useable goes in the trash until you've given the community a fair shot at it.

10. Become a waste-stream analyst
To better understand the kind of materials that enter and leave your home, office, or school, consider conducting a waste audit. Set a span of time like a week or a month, and separate your waste categories. Weigh the different kinds of material flows that go out the door (landfill waste, organic compost, aluminum, recyclable plastic, reusable material, etc.). Design a “material recovery” program that minimizes the amount going to the landfill. This is a great exercise to do with kids but can be very convincing to corporate higher-ups, too, especially since most companies pay to have their trash hauled away and can get money for recycled paper, containers, toner cartridges, corrugated cardboard, and such.

why is blood red?

Why is blood red?

Red blood cells

Red blood cells are red only because they contain a protein chemical called hemoglobin which is bright red in color. Hemoglobin contains the element Iron, making it excellent for transporting oxygen and carbon dioxide.

do plant sweat

Do Plants Sweat Like People Do?
Advanced-Level Science Projects

* Biology
* Do Plants Sweat Like People Do?
* What Types of Bacteria Are Found in Your House?

You know that plants need water to survive, just like people and animals do.

But did you ever wonder whether plants sweat, like people do? Well, they don't sweat, exactly, but they do something similar. It's called transpiration, and it's when plants release water through their leaves.

This experiment isn't very difficult, and it's a good way to see some transpiration, firsthand.
Basic Elements

Transpiration is a process that occurs in plants when they release unnecessary water through their leaves.

What you need to do is break off a piece of a healthy geranium plant. If you're doing this at home, make sure it's okay with the adult in your house. You'll only need a piece of stem and one or two leaves.

Cut out a rectangle about four by six inches from a piece of thin cardboard, such as a shoebox lid. Poke a hole in the middle of the rectangle that's just big -enough for the geranium stem to poke through. Poke the bottom stem through the hole.

Fill a water glass about three-quarters full. Put the cardboard rectangle on top of the water glass, with the stem in the water and the leaf on top of the cardboard. Rub a small amount of Vaseline around the hole. That seals the hole and prevents evaporated water from escaping.

Get a glass that's the same size and type as the first one, and place it upside down over the geranium leaf onto the cardboard. The mouth of one glass should match up with that of the other.

Put the glasses on a bright windowsill and let them sit for at least four hours. Then check out what's happened inside the top glass. You should see little drops of water on the inside of the glass. You know that the water didn't travel up through the hole in the cardboard, because you sealed that off. Look at the underside of the geranium leaf. The little dots you'll see there are called stomates, and they are the source for this water. The water passes through the stem, into the leaf, and what isn't needed is released through the stomates

water cycle

The earth has a limited amount of water. That water keeps going around and around and around and around and (well, you get the idea) in what we call the "Water Cycle".

This cycle is made up of a few main parts:

* evaporation (and transpiration)
* condensation
* precipitation
* collection

What YOU can do at Home

Turn off your computer AND computer monitor when not in use
graphic of computer

Replace the incandescent light bulbs in your house with compact fluorescent light bulbs - they use about 40% less electricity
graphic of light bulb

Conserve water & whenever possible USE COLD water, NOT HOT
graphic of faucet

global warming

Washington, Jun 8 -- As if overfishing and coastal pollution were not destructive enough, global warming posed a potentially lethal threat to many marine species, two major environmental organisations reported Tuesday.

From tropical coral reefs to polar-ice edge communities, and from tiny zooplankton to polar bears, scientists have documented worrying declines in marine life which they believed could be at attributed, at least partly, to the impact of global warming.

The new report, "Turning Up the Heat: How Global Warming Threatens Life in the Sea" - compiled by the World Wildlife Fund (WWF) and the Marine Conservation Biology Institute (MCBI) - warned that whole species could be wiped out by warmer waters.

The report was based on an extensive review of studies and a meeting earlier this year of some of the world's leading marine researchers. It said that warmer surface air temperatures, which most scientists blamed on the emission of greenhouse gases, also were gradually warming the world's oceans.

Surface water temperature had risen by about one degree Celsius over the past century and were expected to increase by up to

another three degrees in the next 100 years if emissions - caused mainly by the burning of fossil fuels like oil and gas - continued at current rates.

Marine life already was threatened by a number of human activities, the report pointed out. Overfishing had resulted in the collapse of major fisheries, and destructive fishing practices like bottom trawling had devastated the habitat of the sea floor.

Coastal development and other activities that resulted in the pollution of coastal waters had converted whole ares of the oceans into so-called "dead zones," while the invasion of alien species, often carried in ships' ballast water to distant habitats, has wiped out many native marine species around the world.

"Global climate change is an additional stress on already stressed species and ecosystems, and may be the 'straw that breaks the camel's back' for many types of marine life," according to the 47-page report.

The increasingly frequent appearance of the El Nino weather phenomenon during the past 20 years provided a glimpse into the impact that can be expected from long-term global warming, the report said.

El Nino results from changes in atmospheric pressure in the Pacific Ocean and is associated with higher sea surface temperatures and sea levels, lower nutrients, and increased intensity of storms and storm surges.

Recent El Ninos have proved lethal to marine life, with the death of up to 98% of coral reefs in some regions. El Nino also has wreaked havoc in stocks of sardines and anchovies in Perua, marine iguanas and kelp forests off California and some species of seals, sea lions and seabirds.

Some scientists believe that global warming itself may be increasing the frequency of El Nino.

It occurred in five of the first seven years of the 1990's, a sharp increase from its pattern of the previous 7,000 years of every two to 8.5 years. The 1997-98 El Nino was the strongest on record.

Rising marine temperatures, according to the report, influence all kinds of ocean conditions, including sea levels, critical to the survival of microscopic phytoplankton, the base of the food web; and the circulation of the deep ocean between the poles and the tropics.

Because polar regions will experience the greatest overall temperature change from global warming, the biological impacts - many of which have already been observed - will be greatest there.

Sea ice, which provides a platform for many marine mammals and penguins, as well as a surface for algae that produce phytoplankton, is diminishing in both the Arctic and the Antarctic, according to the report.

"As this area diminishes, so does the food available to each higher level on the web, from zooplankton to seabirds," the report says. Penguins in Antarctica and Crabeater seals are already declining in some areas as the ice recedes.

Reef fish and intertidal invertebrates , such as anemones, crabs and snails in California provide evidence that fish and other species are shifting toward the poles in response to ocean warming, the report said.

In Europe, researchers also have observed a trend of species of butterflies and birds to gradually move north to live out their live cycle. A University of Leeds study found that many bird species in Britain had moved an average of 12 miles to the north over the past 20 years.

Coral reefs have proved to be particularly sensitive to warming.

As surface temperatures have risen in recent years, many reefs have bleached - meaning they expel the colourful algae that produce the foods on which they rely - and, if temperatures remain too high for too long and bleaching persists, the corals die.

That is happening around the world, according to the report. "In 1998, the hottest year in at least six centuries, coral suffered the most extensive and severe bleaching and subsequent mortality in the modern record."

New studies have found that Pacific salmon, especially sockeye, are particularly vulnerable to temperature changes which affect their metabolism. The warmer the water, the more food they need to stay alive.

In 1997-1998, higher sea temperatures during the winter may have led to the collapse of western Alaskan salmon populations, according to the report which concluded that the Pacific sockeye and other salmon species may soon be at risk of extinction.

Similarly, reductions in phytoplankton caused by warmer sea temperatures have devastating effects on predators, such as seabirds and marine mammals, at the top of the food web.

Scientists already have established a connection between warmer water and declining reproduction and increased mortality among different species of seabirds and seals and sea lions along the US Pacific coast affected by the El Nino phenomenon. (IPS)

The above article by the Inter Press Service appeared in the South-North Development Monitor (SUNS).

Why is it hot in summer

Because the earth's axis is tilted.

It is all about the tilt of the Earth's axis. Many people believe that the temperature changes because the Earth is closer to the sun in summer and farther from the sun in winter. In fact, the Earth is farthest from the sun in July and is closest to the sun in January!

During the summer, the sun's rays hit the Earth at a steep angle. The light does not spread out as much, thus increasing the amount of energy hitting any given spot. Also, the long daylight hours allow the Earth plenty of time to reach warm temperatures.

During the winter, the sun's rays hit the Earth at a shallow angle. These rays are more spread out, which minimizes the amount of energy that hits any given spot. Also, the long nights and short days prevent the Earth from warming up. Thus, we have winter!