Air

Human beings need quality air for health and well-being.

Air composition

Air is a mixture of nitrogen, oxygen CO2 and some inert gases.

It also consists of water vapours of varying quantity.

Air also contains numerous harmful substances: natural pollutants such as dust and volcanic ash, and pollutants that are by-products of human activity.

Atmosphere

The atmosphere consists of layers of air  covering the Earth.

Plants and animals rely on the gases in the atmosphere.

Plants need CO2 for the process of photosynthesis and release oxygen as a result.

Animals -- including human beings -- need oxygen to live and

release CO2 as they exhale.

The CO2 is then taken up again by plants, forming a cycle of life in the biosphere.

• In the modern world, however, industrial activity, the burning of fossil fuels, waste treatment, intensive agriculture and many other economic activities lead to air pollution.

• Air pollution is harmful to humans, as well as to plants, animals and their natural habitats.

• It even brings about changes in the Earth's climate.

• It was long believed that air pollutants, once released, were diluted to negligible concentrations in the atmosphere.

• Measurements have shown this belief to be flawed, if not misleading.

High concentrations of primary pollutants can occur within and around emission areas.

• Nearly all large particles are deposited locally. • Local weather is an important factor in determining short-

term pollution levels. • However, local emissions may have regional and global

implications.• For example, CFCs emitted at the surface are responsible

for ozone layer depletion that occurs at an altitude of 20-30 kilometres in the stratosphere. 

Ambient air pollutants

Chemical compounds present in the atmosphere are considered ambient air pollutants when they occur in unnaturally high concentrations and have the potential to cause harm to the environment and human health.

The traditional air pollutants include SO2, NOx, CO, lead, particulate matter (PM) and VOCs.

• Hazardous air pollutants include:

• metals and metalloids, such as cadmium, mercury and arsenic;

• respirable mineral fibres, such as asbestos and glass micro-fibres;

• inorganic gases, such as fluorides, chlorine, cyanide and phosgene; and

• organic compounds, such as aldehydes, aromatic and polycyclic aromatic hydrocarbons, and dioxins.

Efectos en la salud de contaminates del aire

•  Ozone cause pulmonary damage, nose and throat irritation and headaches

• Fine particles and heavy metals cause irritation and damage to respiratory functions and can possess mutagenic and carcinogenic properties

• VOC have wide-ranging impacts, from olfactory irritations to mutagenic and carcinogenic effects (benzene).

• CO affects tissue oxygenation.

• NOxcause acid rain.,have respiratory effects and inhibit plant growth

• SO2 exacerbates respiratory pathology and causes acid rain.

• Exposure to dioxins increases the risk of cancer.

• Scientists believe that dioxins hinder the immune system and alter the concentration of reproductive hormones.

Tipos de contaminación aerea

• Summer smog

When the sun shines, the gases exhausted from cars (such as NOx and VOCs) combine to form ozone. Although the Earth needs ozone in the upper atmosphere, its effects at low altitudes are extremely harmful; more than 100 million people are affected in Europe alone.

Winter smog

Winter smog is created when pollutants are trapped by a mass of cold air hovering over a city, causing them to build up (especially SO2, NOx and particles).

• The worst pollution tends to occur in urban environments, where two of every three Europeans live today.

Severe winter smog episodes frequently create health hazards in parts of Central and Eastern Europe in the densely populated areas of, for example, the Czech Republic, eastern Germany and Poland

• Combustion processes, including residential heating, power production and industry, are the main sources of pollution.

Urban air pollution

Urban areas are growing worldwide, as are their air-pollution levels.

Europe, for example, is a highly urbanised continent, with more than 70 percent of its inhabitants living in urban areas.

Traffic, combustion and industrial production lead to airborne emissions with elevated concentrations of pollutants.

This pollution gives rise to a range of problems such as health risks, accelerated deterioration of building materials, damage to historical monuments and harm to vegetation within and around cities.

Air pollution from transport *Smog occurrences and long-term average

concentrations of harmful compounds such as lead, benzene, particulate matter and benzopyrene are significantly increased by road-transport emissions.

Road transport also contributes more than half of NOx emissions and 35 percent of VOC emissions.

• Diesel-engine vehicles also produce very fine particulate matter, which is extremely harmful to human health.

A significant air pollution problem in Scandinavian countries results from the use of studded tyres in winter.

• These tyres wear down the surfaces of roads and produce grit, which becomes suspended in the air.

Air pollution from industry • Air pollution is also caused by industry. • The level of impact of the emission source depends

on the height of the smokestack and the prevailing wind direction.

• Primary pollutants with longer residence times include acidifying compounds (such as SO2, NOx and ammonia) and aerosol-bound pollutants (such as dust, heavy metals and persistent organic pollutants).

• "Hot spot" air pollution is a term used to describe high, short-term pollution concentrations.

• Populations near pollution sources are at risk of exposure.

• Hot spot pollution includes urban streets with busy traffic and the impact of industrial stacks in cities.

Regional air pollution

• Pollutants originating from sulphur and nitrogen oxides, as well as ammonia emissions, can be transported long distances downwind and deposited onto natural surfaces.

• Severe problems (such as the acidification and contamination of soils and surface water) can result, which dramatically affect the diversity and conditions of ecosystems, including forests and crops.

• Fish dieback is a serious problem in regions susceptible to freshwater acidification  .

• The highest deposition levels in Europe are found in the highly populated and industrialised zones between Poland and the UK.

Global air pollution

• The build-up of long-life pollutant compounds alters the atmosphere's composition, chemistry and dynamics.

• It also leads to possible climatic changes and the depletion of the shield protecting against solar UV-radiation provided by the stratospheric ozone layer  .

• Europe's contribution to most man-made emissions of greenhouse gases and ozone-depleting compounds is disproportionately large in relation to its geographical area and population size.

• Water

Water is a unique component of our planet. It is also a commodity to manage and sell, and is the object of many controversial economic interests and complex social interrelations.

• Water properties

Water is at once simple and complex. A water molecule is made up of only three atoms — two hydrogen and one oxygen. The configuration of this building block, however, produces a molecule with almost magical properties.

• Some physical and chemical properties

Water molecules are attached to each other, creating hydrogen bonds.

• These strong bonds determine almost every physical characteristic of water and many of its chemical properties.

• Water is the only substance present in nature in three forms: solid, liquid and gaseous.

Pure water at sea level boils at 100 degrees Celsius and freezes at 0 degrees.

• At higher elevations, where atmospheric pressure is lower, water's boiling temperature is lower.

• This effect explains why it takes longer to boil an egg at higher altitudes.

• Dissolving a substance in water lowers the water's freezing point, which is why people spread salt on streets in winter to prevent ice formation.

Water is called the universal solvent. • It can dissolve more substances than any

other solvent. • There is hardly a substance known that

has not been identified as soluble in the Earth's waters.

• Water molecules, as well as binding to each other, bind to many other substances, such as glass, cotton, plant tissue and soil.

• This is called adhesion.

Importance to life

• Nearly all substances become heavier and thicker when converted from a liquid to a solid state.

• Water, however, increases in volume and becomes lighter when it turns into ice.

• This property is of vital importance for sustaining life in basins during winter.

A drop of rainwater falling through the air dissolves atmospheric gases.

• When rain reaches the Earth, it affects the quality of the land, lakes and rivers.

• Water can store huge quantities of energy, which can turn oceans, seas and lakes into giant heat reservoirs.

• This particular property influences climates in areas situated near water basins.

• It is also due to its energy-retaining quality that water is widely used for cooling and transferring heat in thermal and chemical processes.

• Water-surface tension is a measure of its surface-film strength.

• The attraction between water molecules creates a strong film, which among other liquids is surpassed only by mercury.

• This surface tension permits water to hold up substances heavier and denser than itself.

• Some aquatic insects, such as the water spider, rely on surface tension to walk on water.

• Water surface tension is essential for the transfer of energy from wind that creates waves.

• Waves are necessary for rapid oxygen diffusion in lakes and seas.

• In a thin glass capillary, for example, when molecules at the edge reach for and adhere to the molecules of glass just above them, they tow other water molecules at the same time.

• The water surface, in turn, pulls the entire body of water upward until the downward force of gravity is too great to be overcome.

• This process is called "capillary action," and it allows a sponge to be used to soak up spilled water.

• Without this property, the nutrients needed by plants and trees would remain in the soil.

• A large percentage of our blood is water. • People must exchange about two litres of

water per day in order to regulate their body temperature.

Places where water is preserved on land are called water basins.

• Water can be found in rivers, lakes, pools, animals, plant stems and under the ground.

Water in motion

• Water is constantly moving between the Earth and the atmosphere.

• The sun and wind evaporate water from soil, plant leaves and animals, and from the surfaces of rivers, lakes and oceans.

• This process changes water to a gaseous form called water vapour.

• Water vapour condenses under certain conditions and falls back to earth as rain or snow.

• Precipitation that ultimately reaches streams and rivers, often transporting other material with it, is known as runoff.

• Rain fills up rivers and lakes. • Rivers flow into the oceans. • Some precipitation penetrates the ground

and forms groundwater. • In this way water circulates constantly

from the earth to the atmosphere and back again, in what is called the hydrological cycle  .

• The hydrological cycle

TranspirationWater vapour is also emitted from plant leaves by a process called transpiration.

• Every day an actively growing plant transpires 5-10 times as much water as it can hold.

• Condensation

As water vapour rises, it cools and eventually condenses, usually on tiny particles of dust in the air. When it condenses it becomes a liquid again or turns directly into a solid (ice, hail or snow). These water particles then collect and form clouds.

• Water table

The water table is the level to which water rises in an open well.

• EvaporationAs water is heated by the sun, its surface molecules become sufficiently energised to break free of the force binding them together.

• They then evaporate and rise into the atmosphere as invisible vapour

• Percolation

Some precipitation and melted snow moves down through the soil, percolates and infiltrates through cracks and pores in soil and rocks until it reaches the water table, where it becomes groundwater.

• Groundwater

Subterranean water is held in cracks and pores.

• Depending on the geology, groundwater can flow to support streams.

• It can also be tapped by wells.

• Some groundwater is extremely old and may have been under the Earth for thousands of years

• Runoff

Excessive rain or melting snow can produce overland flow to creeks and ditches.

• Runoff is the visible flow of water into rivers, creeks and lakes as the water stored in basins drains out.

• Precipitation

Precipitation, in the form of rain, snow and hail, comes from clouds.

• Propelled by air currents, clouds move around the world.

• When rising over mountain ranges, they cool, becoming so saturated with water that it begins to fall as rain, snow or hail, depending on the temperature of the surrounding air.

• Water quality

Impact on human health and food

•The contamination of drinking water and food with microbiological agents can cause a variety of communicable diseases, such as hepatitis A, salmonellosis or shigellosis.

• In Europe, microbiological contamination of bathing water results in over two million cases of gastrointestinal diseases annually.

• Nitrate concentrations of groundwater in several areas across Europe with intensive agriculture were found to exceed guideline levels.

• These levels were established to protect infants from serious, life-threatening diseases (for example, ethaemoglobinemia).

• Concentrations of arsenic found in water can also lead to health problems such as skin cancer.

Impact on plants and animals

• The lack of sufficient oxygen (due to organic waste pollution or the presence of nitrates and phosphates in water) can cause the death of fish and other forms of aquatic life.

• Chemicals such as inorganic and organic compounds, oil, gasoline and pesticides harm fish and other aquatic life and depress crop yields.

• Sediment (insoluble particles of soil suspended in water) clouds water, inhibits photosynthesis and destroys the aquatic food chain.

Water resources

• Surface water and groundwater are important elements of the Earth's hydrological cycle.

• Surface water includes rivers, lakes and glaciers.

• Groundwater remains one of the least-studied and most difficult water resources to determine.

• Surface water

In Europe, annual runoff is greatest in western Norway.

• Considerably less is seen in parts of Spain, central Hungary, eastern Romania and the southern part of Russia.

• The differences in river flow regimes are apparent in Western Europe (where flows are at a minimum in summer and late autumn), mountain-fed catchments (where flows are greatest in summer), and Eastern and Northern Europe (where most runoff occurs during the spring-melt period).

• Many European river flow regimes are heavily affected by human activities such as water abstraction and damming

• Groundwater

Natural groundwater resources are stored in aquifers, which are permeable rock formations, or in unconsolidated deposits (sands, silts or gravels). The main characteristics of groundwater systems are:

• invisible and relatively inaccessible locations;

• low flow rates;

• long residence times; and

• slow reactions to changes on the surface.

• Groundwater plays a number of important economic and ecological roles, as well as being an essential element of human health.

• Groundwater systems are normally very stable, in both quantity and quality.

• However, the effects of pollution and overexploitation could lead to drastic changes, with the period of recovery lasting centuries.

• Surface water is the main source for water abstraction in Europe — about 70 percent of the total abstraction on average.

• However, there is significant variation among European countries  .

• European water resources

Overall, there is no water shortage problem in Europe.

• However, the amount of water available for sustained consumption is very unevenly distributed across the continent.

• There are extreme variations that range from less than 100 cubic metres per capita per year in Malta to more than 630,000 cubic meters per capita per year in Iceland.

• Many European countries are heavily dependent on external contributions of water through transboundary rivers to meet their demands.

• Countries located downstream of large rivers (Moldova, Romania, Hungary, Luxembourg and The Netherlands) receive more than 75 percent of their flows from other countries, which could result in a dispute over transboundary water pollution or the disposal of water resources.

Impacto humano

• Human impact on water

Water is used for agricultural purposes (irrigation), by industry (production of goods, and as a cooling and heating agent) and for domestic purposes (drinking, personal hygiene, washing, recreation, etc.).

• In Europe as a whole, 53 percent of transported surface water and groundwater is used by industry.

• Twenty-six percent of it is used for agriculture and only 19 percent for domestic purposes.

• There is large variability in water abstraction among various economic sectors of European countries  .

• Water pollution

There are several classes of common water pollutants.

Disease-causing agents (pathogens)

• These include bacteria, viruses, protozoa, and parasitic worms that enter water from domestic sewage and untreated human and animal wastes.

• Every day about 14,000 people, half of them children, die due to this type of water pollution worldwide.

• Oxygen-demanding waste•

This term refers to organic waste matter requiring aerobic decomposition by bacteria.

• Large populations of bacteria supported by the presence of these wastes degrade water quality by depleting it of dissolved oxygen.

• This process can cause the death of fish and other forms of oxygen-consuming aquatic life.

• Water-soluble inorganic chemicals•

These are acids, salts and compounds of toxic metals such as mercury and lead.

• High levels of these chemicals can make water unfit to drink, harm fish and other aquatic life, depress crop yields and accelerate the corrosion of machinery that uses water.

Industry is the main source of water-soluble inorganic chemicals.

• Inorganic plant nutrientsThese are water-soluble nitrates and phosphates that can cause excessive growth of algae and other aquatic plants.

• As these plants decay they deplete the water of dissolved oxygen, which fish need to survive.

People who drink water with excessive levels of nitrates suffer a reduction in the oxygen-carrying capacity of their blood.

• Agriculture is the main source of such pollution.

• Organic chemicalsOrganic chemicals include oil, gasoline, plastics, pesticides, cleaning solvents, detergents and many other chemicals.

• They threaten human health and harm fish and other aquatic life.

The main sources of such water pollution are transport, industry, urban activities and household cleaning.

• Sediment (suspended matter)

• Insoluble particles of soil and other solids become suspended in water, mostly when soil is eroded from the land.

• By weight, this is by far the biggest water pollutant.

• Sediment clouds water, inhibits photosynthesis and destroys the aquatic food chain.

• Water can be the subject of

• radioactive pollution (caused by water-soluble, radioactive isotopes),

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• thermal pollution (after using water to cool down industrial and power plants) or

• genetic pollution (caused by accidental introduction of non-native species such as mussels and phytoplankton).

• Sources of water pollution

Wastewater treatment facilities themselves, if operating incorrectly, can cause water pollution.

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• Sources of water pollution

Agricultural activities such as the dispersion of pesticides, fertilisers and other chemical products cause significant air and water pollution

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• Sources of water pollution

Bridge construction and riverbank corrections can cause changes in river flows and groundwater levels.

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• Sources of water pollution

Petroleum-product and chemical spills destroy aquatic ecosystems.

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• Sources of water pollution

Many towns do not posses wastewater treatment facilities.

• Direct wastewater discharges into rivers destroy aquatic ecosystems.

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• Sources of water pollution

Rivers are often polluted by sewage and land runoffs

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• Sources of water pollution

Dumping garbage into a body of water decreases its quality and destroys aquatic ecosystems.

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• Sources of water pollution

Large animal concentrations in intensive pig and poultry farms release a great deal of waste.

• Discharging this waste into a river without proper treatment can cause death to aquatic flora and fauna and affect human health.

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• Wastewater management

In rural and suburban areas, sewage from homes is usually discharged into a septic tank.

• To avoid groundwater pollution, septic tanks must be cleaned out every three to four years by a specialised company.

• In urban areas, most waterborne wastes from homes, businesses, factories and storm runoff flow through a network of sewer pipes to wastewater treatment plants.

• Some cities have separate lines for storm water runoff.

When sewage reaches a treatment plant  it may undergo as many as three levels of purification.

• Treatment plant

Secondary sewage treatmentSecondary sewage treatment is a biological process in which aerobic bacteria are used to remove up to 90 percent of biodegradable, oxygen-demanding organic waste.

• Sewage is usually pumped into a large tank and mixed for several hours with bacteria-rich sludge and oxygenating air bubbles to facilitate the degradation of microorganisms.

• The water then goes to a sedimentation tank, where most of the suspended solids and microorganisms settle out as sludge.

• The sludge produced from primary and secondary treatment is broken down by anaerobic digestion and then incinerated, dumped in a landfill or applied to land as fertiliser.

Even after secondary treatment, however, wastewater still contains some oxygen-demanding wastes, suspended solids, 70 percent of its phosphorus (mostly as phosphates), some nitrates and a number of toxic metal compounds.

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• Water: a conflict of interests

It is said that in the 19th century wars were waged over metals, in the 20th century over petrol, and if there is a war in the 21st century, it will definitely be over sources of drinking water.

There are 214 rivers and lakes on the planet that belong to two or more countries - 66 of these are shared by four or more nations. Conflicts often result:

• The NileAn Egyptian leader once threatened that abuse of the Nile River was a declaration of war. The waters of the longest river in the world run through Tanzania, Rwanda, Zaire, Uganda, Ethiopia, Sudan and Egypt.

When Ethiopia declared in 1990 that it intended to build a huge reservoir on the river, the Egyptian government reacted negatively.

• At Egypt's request, Ethiopia was not granted a loan to construct the dam, and the project failed.

• The Ganges RiverA water conflict over the Ganges River has transpired between India and Bangladesh for 25 years.

• A huge amount of its water is being diverted by India's government to meet the needs of giant cities such as Calcutta.

• In October 1995 more than 40 million people in Bangladesh were dying of hunger and thirst because India had diverted this water to irrigate its agricultural lands.

• The Danube River The Danube River passes through nine European countries.

• Water pollution caused by one country often affects neighbouring environments as much as its own.

• In February 2000 a large quantity of cyanide was released from a gold mine in Romania, causing the mass death of fish in two Hungarian rivers flowing into the Danube.

• Experts declared the five-kilometre carpet of dead fish floating on the river the greatest ecological disaster in the area since the Chernobyl nuclear accident in 1986.

• Images of the river's casualties being hauled away by train drew international attention.

• The pollution also affected countries downriver from the spill.

• Water crisis hits home

In Central and Eastern Europe (CEE), the need to address water problems is as urgent as anywhere else in the world.

• Broadly speaking, the region's problems include pollution and water quality deterioration, water resource issues and institutional and financial concerns.

• Water problems in CEEEcosystems in CEE are at risk due to land conversion, changes in hydrological regimes, pollution by inadequately controlled agricultural discharges and the low level of wastewater collection and treatment.

• Water quality improvement and pollution control, including protection of surface and groundwater and the marine environment of the Baltic and Black seas, are urgent tasks for the region.

• Rehabilitation of degraded areas, such as old military camps and industrial sites, is also essential for preserving the region's water resources.

• Another group of problems for the region involves coping with floods and droughts and satisfying water demands.

• Flood management is a constant concern in Poland, Lithuania and all countries located in the Danube River basin. But high water is a problem all over the region.

• Ironically, long-term droughts are a problem in the same areas that are plagued by flooding.

• The total loss of water from plant transpiration and evaporation from the ground, known as "evapotranspiration," is high in several parts of the Danube Basin, and may exceed the total volume of precipitation.

• One example of a drought caused by evapotranspiration in CEE can be observed along the Tisza River, where the streams in the catchment area are low.

• In the Baltics, the annual runoff from the Vistula and Odra basins in dry years may be about 50 percent less than the mean annual value.

• Water management in CEEThe institutional arrangements for managing water in CEE are too complicated, not transparent and not financially self-supporting, according to Janusz Kindler and Laszlo Somlyody, who contributed to the 2000 series of reports entitled Water for the 21st Century: Vision to Action.

• The principles of river basin management are well known across the region, and some countries even have river basin agencies.

• But those agencies are often not well incorporated into the overall government structure, according to Kindler and Somlyody.

• The situation is expected to improve as the countries of the region seek to align themselves with the European Union's Water Framework Directive.

• The directive offers a clear mechanism for reform of institutions dealing with water management.

• Because rivers in the region pass through many countries, flood control along them requires international solutions.

• In August 2002, Hungarian Prime Minister Peter Medgyessy took steps toward achieving such a solution.

• He launched an initiative for regional cooperation in addressing floods among countries located in the Danube, Odra and Elbe river basins.

• Paying for better managementAchieving alignment with EU regulations on water will be costly. Investment needs in the area of water supply and water sanitation are enormous in both the rural and urban areas of CEE.

• Kindler and Somlyody estimate that the investment required to meet EU directives ranges between USD 500 and 1,000 per capita in the countries of the region.

• This is obviously a huge sum when compared to the average, per-capita, gross domestic product of CEE countries.

• Finding means for financing the work that is needed, and using subsidies efficiently, are therefore essential for countries seeking to accede to the EU.

• Developing the economies in this region could also make it easier for these countries to pay for improvements in their water infrastructure.

• And CEE countries will have to build their capacity to handle certain types of work, including integrated water resources management, environmental economics and wastewater management.

• One important international effort that affects CEE directly is the EU Water Initiative, a strategic partnership between the EU, Africa and 12 countries from Eastern Europe, the Caucasus and Central Asia.

• The aim of this initiative is to create a higher efficiency of water-related development by providing a platform to coordinate and streamline activities.

• The EU, which says it is the largest donor in the field of water with an average of EUR 1.4 billion a year, has announced that it wants to serve as a major driving force to meet goals set at the World Summit on Sustainable Development in Johannesburg in relation to water.

• CEE countries are increasingly playing a role in international water initiatives.

• Along with these various international efforts, these countries are addressing water issues as they work toward compliance with the EU Water Framework Directive, which will reshape water protection and water management in the region.

— The Bulletin, December 2002

Agua y la gente

• Water and people

The Earth is called the Blue Planet because of the proliferation of water, yet only 0.6 percent of it is fit for drinking.

Only 3 percent of the water we use serves an essential human need. The remainder could be controlled and decreased.

• People are now realising that excessive and unnecessary water use and increased pollution of drinking water sources will lead to catastrophe.

Since we all use water, we are all responsible for saving it. The two basic principles behind maintaining water resources are: conserve and protect

• Conserve and protect

Scientists claim that when modern technologies are applied, household water consumption is reduced by one-third, agricultural by one-half and industrial by 90 percent!

• Click on the pictures to find out what needs to be done.

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• Conserve and protect

Repair water pipes to minimise water lost in transport.

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• Conserve and protect

Implement the drop-method of agricultural irrigation to increase water-use efficiency by minimising evaporation losses.

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• Conserve and protect

Introduce the circular mode of industrial water supply.

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• Conserve and protect

Impose an environmental taxation on water that would cover all delivery, management and purification costs.

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• Conserve and protect

Build purification systems for wastewater everywhere.