Tuesday, September 24, 2002

As a preliminary, just what does 'saline water' mean? If water contains more than 1,000 milligrams of dissolved solids, such as salt, per liter then the water is called saline. More simply, if 1/1,000 th (or more) of the weight of a liter of water (also referred to as "parts per thousand") is from salt, then the water is saline. By far, most of the water used in the United States is fresh water. Certainly, water that is used for household (domestic), agricultural, irrigation, and public-supply puropses is almost all fresh. There are some uses for saline water, mainly in industry, mining, and in producing power: Here is a table of fresh and saline water use in 1990 for the U.S. Numbers are in million gallons of water used per day. Industry Mining Power Production Total Water Use Fresh Saline Fresh Saline Fresh Saline Fresh Saline ----------------- ---------------- ---------------- ----------------- 19,300 3,270 3,310 1,650 131,000 64,500 339,000 69,400 It is possible to remove the salts from sea water and thus produce fresh water available for drinking. This is an expensive process and is not used much at the moment. But this will become a feasable method of supplying thirsty areas in the future in places that just cannot naturally supply fresh water for human purposes 3:37:12 PM    comment []

Periodic Water Fact: "A promising method to desalinate seawater is the "reverse osmosis" method. Right now, the high cost of desalinization has kept it from being used more often, as it can cost over $1,000 per acre-foot to desalinate seawater as compared to about $200 per acre-foot for water from normal supply sources. Desalinization technology is improving and costs are falling, though, and Tampa Bay, FL is currently desalinizing water at a cost of only $650 per acre foot" 3:35:05 PM    comment []

Water Supply of the World Water Supply of the World The Antarctic Icecap is the largest supply of fresh water, nearly 2% of the world's total of fresh and salt water. As can be seen from the table below, the amount of water in our atmosphere is over ten times as much as the water in all the rivers taken together. The fresh water actually available for human use in lakes and rivers and the accessible ground water amounts to only about one-third of 1% of the world's total water supply.   Surface area (sq mi) Volume (cu mi) Percentage of total1 Salt water   The oceans 139,500,000 317,000,000 97.2%   Inland seas and saline lakes 270,000 25,000 0.008   Fresh water   Freshwater lakes 330,000 30,000 0.009     All rivers (average level) — 300 0.0001     Antarctic Icecap 6,000,000 6,300,000 1.9     Arctic Icecap and glaciers 900,000 680,000 0.21     Water in the atmosphere 197,000,000 3,100 0.001     Ground water within half    a mile from surface — 1,000,000 0.31     Deep-lying ground water — 1,000,000 0.31     Total (rounded) — 326,000,000 100.00   1. All figures are estimated. Source: Department of the Interior, Geological Survey. 3:23:26 PM    comment []

The Greenhouse Gas Effect U.S. Greenhouse Gas Emissions In 1990, total greenhouse gas emissions in the United States were 1,618 million metric tons carbon equivalent, according to 1997 estimates published by the Energy Information Administration (EIA). Of this total, 1,346 million metric tons, or 83 percent, was due to carbon emissions from the combustion of energy fuels—the focus of this report. By 1996, total U.S. greenhouse gas emissions had risen to 1,753 million metric tons carbon equivalent, including 1,463 million metric tons of carbon emissions from energy combustion. EIA's Annual Energy Outlook 1998 (AEO98) projects that energy-related carbon emissions will reach 1,577 million metric tons in 2000, 17 percent above the 1990 level. Projected emissions continue to rise at an average annual rate of 1.5 percent a year from 1996 to 2010, reaching 1,803 million metric tons of carbon emissions in 2010, 34 percent above the 1990 level. Because energy-related carbon emissions are a large portion of total greenhouse gas emissions, any efforts to reduce greenhouse gas emissions will likely have a significant impact on the energy sector; however, as discussed later, there are a number of factors outside the domestic energy market that also affect emissions levels. To put U.S. emissions in a global perspective, the United States produced about 24 percent of the worldwide energy-related carbon emissions in 1996, which totaled 6.6 billion metric tons, as noted in EIA's International Energy Outlook 1998 (IEO98). Although continued increases in carbon emissions are expected for the United States and other industrialized countries, much more rapid increases are projected for the developing countries of Asia, the Middle East, Africa, and Central and South America. As a result, global carbon emissions from energy use are expected to increase at an average annual rate of 2.4 percent from 1996 through 2010, reaching 8.3 billion metric tons, to which the United States would contribute about 22 percent. 3:02:12 PM    comment []

Arsenic 2:38:07 PM    comment []

The table that follows presents EPA information on major pollutants, their many sources and their potential effects. Click here to learn even more about the effect of pollutants on human health and the environment. Pollutant Sources Potential Effects Ozone A colorless gas that is the major constituent of photochemical smog at the Earth's surface. In the upper atmosphere (stratosphere), however, ozone is beneficial, protecting us from the sun's harmful rays. Ozone is formed in the lower atmosphere as a result of chemical reactions between oxygen, volatile organic compounds and nitrogen oxides in the presence of sunlight, especially during hot weather. Sources include vehicles, factories, electric generating plants, landfills, industrial solvents and many small sources such as gas stations, farm and lawn equipment, etc. Ozone causes significant health and environmental problems at the Earth's surface, where we live. It can irritate the respiratory tract, produce impaired lung function such as inability to take a deep breath, and cause throat irritation, chest pain, cough, lung inflammation and possible susceptibility to lung infection. Smog components may aggravate existing respiratory conditions like asthma. It can also reduce yield of agricultural crops and injure forests and other vegetation. Ozone is the most injurious pollutant to plant life. Carbon monoxide Odorless and colorless gas emitted in the exhaust of motor vehicles and other kinds of engines where there is incomplete fossil fuel combustion. Cars, buses, trucks, small engines and some industrial processes. High concentrations can be found in confined spaces like parking garages, poorly ventilated tunnels or along roadsides during heavy traffic. Reduces the ability of blood to deliver oxygen to vital tissues, affecting primarily the cardiovascular and nervous systems. Lower concentrations have been shown to adversely affect individuals with heart disease (angina) and to decrease maximum exercise performance in young, healthy men. Higher concentrations can cause dizziness, headaches and fatigue. Nitrogen dioxide Light brown gas at lower concentrations becomes an important component of unpleasant-looking brown, urban haze. Result of burning fuels at electric generating plants, industrial boilers, cars and trucks. One of the major pollutants that causes smog and acid rain. Can harm humans and vegetation when concentrations are sufficiently high. In children, may cause increased respiratory illness such as chest colds and coughing with phlegm. For asthmatics, can cause increased breathing difficulty. Particulate matter Solid matter or liquid droplets from smoke, dust, fly ash and condensing vapors that can be suspended in the air for long periods of time. Industrial processes, smelters, electric generating plants, cars, burning industrial fuels, woodsmoke, dust from paved and unpaved roads, construction and agricultural ground breaking. These microscopic particles can affect breathing, causing increased respiratory disease and lung damage and possible premature death. Children, the elderly and people suffering from heart or lung disease (like asthma) are especially at risk. Also damages paint, soils clothing and reduces visibility. Sulfur dioxide Colorless gas, odorless at low concentrations but pungent at very high concentrations Emitted largely from industrial, utility, institutional and apartment-house furnaces and boilers, as well as petroleum refineries, smelters, paper mills and chemical plants. One of the major pollutants that causes smog. Can also, at high concentrations, affect human health, especially among asthmatics (who are particularly sensitive to respiratory track problems and breathing difficulties that sulfur dioxide can produce). Can also harm vegetation and metals. The pollutants it produces can impair visibility and acidify lakes and streams. Lead Can adversely affect human health through ingestion of lead-contaminated soil, dust, paint, etc., or paint inhalation. Transportation sources using lead in their fuels, coal combustion, smelters, car battery plants and combustion of garbage containing lead products. A particular risk for young children, whose normal hand-to-mouth activities can result in greater ingestion of lead-contaminated soils and dusts. Young tissues and organs have increased sensitivity to lead. Elevated lead levels can adversely affect mental development and performance, kidney function and blood chemistry. Toxic Air Pollutants Includes pollutants such as arsenic, asbestos and benzene Chemical plants, industrial processes, motor vehicle emissions and fuels, and building materials Known or suspected to cause cancer, respiratory effects, birth defects, and reproductive and other serious health effects. Some can cause death or serious injury if accidentally released in large amounts. Stratospheric Ozone Depleters Chemicals such as chlorofluorocarbons (CFCs), halons, carbon tetrachloride and methyl chloroform that are used in refrigerants and other industrial processes. Industrial household refrigeration, cooling and cleaning processes, car and home air conditioners, some fire extinguishers, and plastic foam products These chemicals linger in the air, rising to the upper atmosphere where they destroy the protective ozone layer that screens out harmful ultraviolet (UV) radiation before it reaches the Earth's surface. Increased exposure to ultraviolet radiation could potentially cause an increase in skin cancer, increased cataract cases, suppression of the human immune response system and environmental damage. Greenhouse gases Gases that build up in the atmosphere and may induce global climate change or the "greenhouse effect." They include carbon dioxide, methane and nitrous oxide. The main man-made source of carbon dioxide emissions is fossil fuel combustion for electricity generation and transportation. Methane comes from landfills, cud-chewing livestock, coal mines and rice paddies. Nitrous oxide results from industrial processes, such as nylon fabrication. The extent of the effects of climate change on human health and the environment is believed to include increased global temperature, increased severity and frequency of storms and other weather extremes, melting of the polar ice cap and sea-level rise.     2:36:05 PM    comment []

SIX MAJOR AIR POLLUTANTS The U.S. Environmental Protection Agency has developed health-based national air quality standards for six pollutants. They are: 1. Carbon Monoxide Carbon monoxide (CO) is an odorless, colorless, poisonous gas that comes mainly from motor vehicles and other combustion exhaust. Health effects: Carbon monoxide interferes with the blood's ability to carry oxygen to the brain, heart and other tissues, and it is particularly dangerous for people with existing heart disease, and unborn or newborn children. 2. Ozone Ozone (O3) is the major harmful ingredient in smog. It is not emitted directly into the air but produced in the atmosphere when gases or vapors of organic chemicals called hydrocarbons combine with nitrogen oxide compounds in the presence of sunlight. Organic hydrocarbon gases, one of the raw ingredients of ozone, are released from a variety of sources related to human activities. Major sources include refineries, gas stations, motor vehicles, chemical plants, paints and solvents. Harmful ozone in the lower atmosphere should not be confused with ozone in the upper atmosphere, which protects us from ultraviolet radiation. Health effects: Ozone reacts with lung tissue. It can inflame and cause harmful changes in breathing passages, decrease the lungs' working ability and cause both coughing and chest pains. Ozone air pollution, found at unhealthful levels in nearly all of the nation's major urban areas, may particularly affect millions of otherwise healthy Americans who, for currently unknown reasons, are especially sensitive to it. People who exercise are also more vulnerable to the effects of ozone, suffering symptoms and a reduced ability to breathe at relatively low ozone levels. Ozone pollution, even at low levels, has also been linked to increased hospital admissions and emergency room visits for respiratory problems. 3. Nitrogen Dioxide Nitrogen dioxide (NO2) and related nitrogen oxides (NOx) are produced when fuel is burned, especially in power plants and motor vehicles. These oxides of nitrogen compounds contribute to ozone formation, and are a health problem themselves. NO2 also changes in the atmosphere to form acidic particles and liquid nitric acid. Health effects: Both NO2 and NOx may threaten human health. Nitrogen dioxide seems to act on the body like both ozone and sulfur dioxide. 4. Sulfur Dioxide Sulfur dioxide (SO2) is created when sulfur-containing fuel is burned, primarily in powerplants and diesel engines. Like NO2, sulfur dioxide can also change in the atmosphere into acidic particles and into sulfuric acid. Health effects: Sulfur dioxide constricts air passages, making it a problem for people with asthma and for young children whose small lungs need to work harder than adult lungs. Even brief exposure to relatively low levels of sulfur dioxide can cause an asthma attack. 5. Particulate Matter Particulate matter (PM) includes microscopic particles and tiny droplets of liquid. These particles come from the burning of fuels by industry and diesel vehicles and from earth-moving activities such as construction and mining. Health effects: Larger particles can be stopped in the nose and upper lungs by the body's natural defenses. The smallest particles escape the body's defenses and go deep into the lungs, where they may become trapped. Exposure to particulate pollution can cause wheezing and other symptoms in people with asthma or sensitive airways. Particulate pollution has been linked to increased hospital admissions and emergency room visits for respiratory problems and to a substantial increase in premature deaths. 6. Lead Lead (Pb) has been known as a poisonous substance for many years. Due to past major reductions and now the elimination of lead in gasoline, there has been a significant decrease in public exposure to lead in outdoor air. Remaining air pollution sources include lead smelters, incineration of lead batteries, and burning lead-contaminated waste oil. However, the most common sources of current lead exposure are indoors from old lead-containing paint and soil. Health effects: Exposure to high levels of lead can damage the blood, brain, nerves, kidneys, reproductive organs and the immune system. Lower levels that are more commonly associated with current exposures can result in impaired mental functioning and development in children and raising blood pressure in middle-aged men. Lead accumulates in the body, so repeated small doses can be harmful. 2:31:44 PM    comment []

People & the Planet > water > overview > freshwater: lifeblood of the planet: "The world's 6 billion people are already appropriating just over half of all the accessible freshwater contained in rivers, lakes, and underground aquifers. By 2025 humankind's share will be at least 70 per cent - a conservative estimate that reflects the impact of population growth alone. If per capita consumption of water resources continues to rise at its current rate, humankind could be using over 90 per cent of all available freshwater by 2025." 2:06:13 PM    comment []

People & the Planet > water > overview > freshwater: lifeblood of the planet: "China's Yellow River is a classic example of this. The river is so over-used that, for an average of 70 days a year for the past decade, its waters have dried up before reaching the Bohai Sea. In 1995, the dry period lasted for 122 days, withering crops in the once rich delta so that upstream factories and farms could take all the water." 2:05:26 PM    comment []

People & the Planet > water > overview > freshwater: lifeblood of the planet: "The world's 6 billion people are already appropriating just over half of all the accessible freshwater contained in rivers, lakes, and underground aquifers. By 2025 humankind's share will be at least 70 per cent - a conservative estimate that reflects the impact of population growth alone. If per capita consumption of water resources continues to rise at its current rate, humankind could be using over 90 per cent of all available freshwater by 2025." 2:03:27 PM    comment []

People & the Planet > water > overview > freshwater: lifeblood of the planet: "As of 1999, some 400 of 600 major Chinese cities were suffering from severe water shortages. Of these, 30 cities in northern China, including Beijing, will face long-term shortages severe enough to limit their economic development. Elsewhere, in rapidly growing cities such as in Bangkok, Dhaka, Jakarta, Lagos, Manila, and New Delhi, freshwater is so short that water theft has become widespread." 1:52:38 PM    comment []

People & the Planet > water > overview > freshwater: lifeblood of the planet: "China, for example, has 22 per cent of the world's population but only 7 per cent of all freshwater runoff. China's freshwater supplies have been estimated to be capable of supporting 650 million people on a sustainable basis - only half the country's population. " 1:51:57 PM    comment []

People & the Planet > water > overview > freshwater: lifeblood of the planet: "The 20 countries of the Near East and North Africa face the worst prospects. In fact, the Near East "ran out of water" in 1972 in the sense that, since then, the region has withdrawn more water from its rivers and aquifers every year than is being replenished. Currently, for example, Jordan and Yemen withdraw 30 per cent more water from groundwater supplies every year than is replenished, and Israel's annual water use exceeds the renewable supply by 15 per cent. Inevitably, this means that water tables are falling and aquifers are slowly being sucked dry. Africa also faces serious water problems. Currently, some 206 million Africans live in water stressed or water scarce countries. By 2025 the number will rise to about 700 million, as population continues to grow rapidly. Of these, roughly 440 million will live in countries with acute water scarcity (less than 1000 cubic metres per person per year). " 1:51:01 PM    comment []

People & the Planet > water > overview > freshwater: lifeblood of the planet: "The results are startling: in 1995, PAI estimated that 31 countries, home to nearly half a billion people, regularly faced either water stress or water scarcity. In 2025, 48 countries containing about 3 billion people will face water shortages. By 2050 the figures will be 54 countries containing 4 billion people, or 40 per cent of the projected world population of 9.4 billion (see Table 1)." 1:50:13 PM    comment []

People & the Planet > water > overview > freshwater: lifeblood of the planet: "Globally, the annual population increase of nearly 80 million per year implies an increased demand for freshwater of about 64 billion cubic metres a year - an amount equivalent to the entire annual flow rate of the Rhine River. A country is said to experience water stress when annual water supplies drop below 1,700 cubic metres per person. When supplies drop below 1,000 cubic metres per person per year, the country faces water scarcity for all or part of the year. " 1:49:23 PM    comment []

People & the Planet > water > overview > freshwater: lifeblood of the planet: "Two-thirds of the world's population - around 4 billion people - live in areas receiving only one-quarter of the world's annual rainfall." 1:42:59 PM    comment []

People & the Planet > water > overview > freshwater: lifeblood of the planet: "Globally, between 12.5 and 14 billion cubic metres of water are available for human use on an annual basis. In 1989, this amount equaled about 9,000 cubic metres per person per year and by 2000 had dropped to around 7,800 cubic metres per person. In 2025 the amount of water per capita is expected to fall to 5,100 cubic metres per person as the world's population grows from 6 billion to over 8 billion." 1:41:51 PM    comment []

People & the Planet > pollution > overview > the price of pollution: " More than 1 billion people in developing countries live without adequate shelter or in unacceptable housing, more than 1.4 billion lack access to safe water, and more than 2.9 billion people have no access to adequate sanitation â013 all of which are essential for good health. Unable to afford clean fuels or efficient stoves, the poor rely instead on smoky biomass fuels for cooking and heating." 1:40:54 PM    comment []

Exhaust Pollutants HYDROCARBONS Hydrocarbon emissions result when fuel molecules in the engine do not burn or burn only partially. Hydrocarbons react in the presence of nitrogen oxides and sunlight to form ground-level ozone, a major component of smog. Ozone irritates the eyes, damages the lungs, and aggravates respiratory problems. It is our most widespread and intractable urban air pollution problem. A number of exhaust hydrocarbons are also toxic, with the potential to cause cancer. NITROGEN OXIDES (NOx) Under the high pressure and temperature conditions in an engine, nitrogen and oxygen atoms in the air react to form various nitrogen oxides, collectively known as NOx. Nitrogen oxides, like hydrocarbons, are precursors to the formation of ozone. They also contribute to the formation of acid rain. CARBON MONOXIDE Carbon monoxide (CO) is a product of incomplete combustion and occurs when carbon in the fuel is partially oxidized rather than fully oxidized to carbon dioxide (CO ). Carbon monoxide reduces the flow of oxygen in the bloodstream and is particularly dangerous to persons with heart disease. CARBON DIOXIDE In recent years, the U.S. Environmental Protection Agency (EPA) has started to view carbon dioxide, a product of "perfect" combustion, as a pollution concern. Carbon dioxide does not directly impair human health, but it is a "greenhouse gas" that traps the earth's heat and contributes to the potential for global warming Evaporative Emissions Hydrocarbon pollutants also escape into the air through fuel evaporation. With today's efficient exhaust emission controls and today's gasoline formulations, evaporative losses can account for a majority of the total hydrocarbon pollution from current model cars on hot days when ozone levels are highest. Evaporative emissions occur several ways: DIURNAL: Gasoline evaporation increases as the temperature rises during the day, heating the fuel tank and venting gasoline vapors. RUNNING LOSSES: The hot engine and exhaust system can vaporize gasoline when the car is running. HOT SOAK: The engine remains hot for a period of time after the car is turned off, and gasoline evaporation continues when the car is parked. REFUELING: Gasoline vapors are always present in fuel tanks. These vapors are forced out when the tank is filled with liquid fuel. 12:43:38 PM    comment []

The Combustion Process Gasoline and diesel fuels are mixtures of hydrocarbons, compounds which contain hydrogen and carbon atoms. In a "perfect" engine, oxygen in the air would convert all the hydrogen in the fuel to water and all the carbon in the fuel to carbon dioxide. Nitrogen in the air would remain unaffected. In reality, the combustion process cannot be "perfect," and automotive engines emit several types of pollutants. "Perfect" Combustion: FUEL (hydrocarbons) + AIR (oxygen and nitrogen) ==>> CARBON DIOXIDE + water + unaffected nitrogen Typical Engine Combustion: FUEL + AIR ==>> UNBURNED HYDROCARBONS + NITROGEN OXIDES + CARBON MONOXIDE + CARBON DIOXIDE + water 12:32:38 PM    comment []

For example, in 1990, there were 59 cities in Africa, 118 in Latin America and 359 in Asia with over one million people each. By 2015, it is estimated that there will be 225 cities in Africa, 225 in Latin America and 903 in Asia respectively with over a million people. At least 27 cities will have a population of 8 million or more. This implies that about 1,300 cities will account for a population of 1.5 to 2.0 billion people. These clusters may represent about 1.0 billion BOP consumers served primarily by the informal economy in clearly identifiable and restricted locales. Access to these markets can be very efficient. 12:32:04 PM    comment []