Air pollution in Athens: existing status and abatement ...



Air pollution in Athens: existing status and abatement practices

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From 1995 traffic of all types of motor vehicles (including taxis and motorcycles, but excluding public buses) was banned from the commercial centre of Athens.

Employees were divided into four major categories with different start and completion times.

|Contribution (%) of various pollution sources to the photochemical pollution of Athens |

|  |Motor Vehicles |Domestic Heating |Industry |

|Smoke |68 |18 |14 |

|Nitrogen oxides |15 |40 |45 |

|Hydrocarbons |77 |6 |17 |

|Carbon monoxide |100 |- |- |

|Sulphur dioxide |75 |- |25 |

As a result of the abatement practices, the level of sulphur dioxide, smoke, nitrogen dioxide and ozone exhibit a gradual decrease in later years. However, the exceeding of the levels of the World Health Organization are still recognized in a higher frequency in the city centre, with the exception of zone which exhibits its higher values in the northern suburbs of Athens. It is anticipated that the completion of the major infrastructural works in Athens (e.g. Metro, peripheral roads, introduction of natural gas, replacement of buses, etc.) will decrease to a considerable extent current atmospheric pollution levels.

In recent years Athens experienced severe air quality problems, which are mostly attributed to motor vehicles and central heating. In addition to these pollution sources, forest fires taking place near urban areas may have a significant impact on the air quality of the city. We investigated this perspective by examining measurements of smoke and ozone taken in several sites within the Athens area for a time period during which a forest fire took place relatively close to Athens. The prevailing meteorological conditions supported the transfer of air masses from the burning forest area to the city. We find strong indications that the products of the forest fire influence significantly the levels of air pollution of the urban area, at least in terms of ozone and smoke.

Athens had some of the worst traffic congestion and air pollution in the world. This posed a new threat to the ancient monuments of Athens, as traffic vibration weakened foundations and air pollution corroded marble. The city's environmental and infrastructure problems were the main reason Athens failed to secure the 1996 centenary Olympic Games.

Athens Today

After this, both the city of Athens and the Greek government, aided by European Union funds, undertook major infrastructure projects such as the new Athens Airport and a new metro system. The city also tackled air pollution by restricting the use of cars in the centre of the city. As a result, Athens was awarded the 2004 Olympic Games. Despite the scepticism of many observers, the games were a great success and brought renewed international prestige (and tourism revenue) to Athens.

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Photochemical smog

In the 1950s a new type of smog, known as photochemical smog, was first described.

This forms when sunlight hits various pollutants in the air and forms a mix of inimical chemicals that can be very dangerous. A photochemical smog is the chemical reaction of sunlight, nitrogen oxides (NOx) and volatile organic compounds (VOCs) in the atmosphere, which leaves airborne particles (called particulate matter) and ground-level ozone.

Athens, city in south-east Greece, capital and largest city of the country. Situated on the Attic plain on the Greek mainland, it is surrounded by mountains on three sides, the most important of which are Párnis, Pendéli, and Hymettus (Imittós).

ATHENS (AFP) - The latest fires to ravage woodland around Athens are an ecological disaster which will affect the quality of life of the capital's 4.5 million residents for years, environmental experts said Monday.

"It's not really the first time that Attica (the prefecture including Athens) has been affected, but we have never seen a fire on such a scale before in the region," said Dimitris Karavellas, the Greek head of the environmental pressure group WWF.

Athens has long suffered from poor air quality and a lack of open spaces so the loss of yet more large swathes of forestry will be acutely felt.

"We have lost a precious filter to freshen up our air. The climate is going to get worse again, the temperature will rise and the quality of life of all Athenians is going to be affected," added Karavellas.

In Athens, two types of air pollution are recognized: the first is characterized by high concentrations of particles. The second type - photochemical smog - is linked to an excess of nitrogen oxides, hydrocarbons, carbon monoxide (primary pollutants), ozone, and organic nitrates (secondary pollutant) and results from a series of chemical reactions driven by sunlight.

Description of the Problem

Athens is an urban area with 4 million inhabitants and suffers the same significant air pollution problems shared by all the large cities of the world. These problems are becoming worse because of bad city planning and Athens’ topographical features.

Athens is located along a basin of approximately 400 km² oriented SW-NE, surrounded by high mountains and open to the sea only towards the south. Emissions are due to transport (1.7 million vehicles), scattered industry, and domestic heating. The main pollution burden is confined to the basin, with higher pollution levels usually above and around the city centre and to the west of it, where the majority of the factories are located. The pollution cloud expands according to the wind conditions and the topography. A major influence on certain pollutant concentrations is the strong solar radiation during spring and summer. This is the reason why significant ozone and NOx concentrations are often recorded in the periphery of the city during the warm season.

The air pollution phenomena in Athens is known as "the nefos," which means "the cloud," a name that underscores its visible character. Visibility impairment during pollution episodes is due to high burdens of aerosol particles, and the yellowish-brown colour of the cloud is due to nitrogen dioxide. The aerosol particles are either emanated from primary emissions (soot or organic compounds) or formed by in-situ processes (most often ammonium sulphates or nitrates). In the case of Athens, the observed particles include those generated by both stationary and mobile sources, but mainly the particles are formed rapidly by gas-to-particle conversion processes.

One way of classifying the health effects of pollutants is to make a distinction between two broad categories: acute (i.e. short-term) and chronic (i.e. long-term) effects. For each of these categories, the effects can range in severity from death to minor illness or discomfort. For example, dust and other polluting particles in air can have acute effects, such as immediate irritations to eyes and throat, or hospitalisation and even deaths from respiratory failure or heart attacks, caused by severe episodes of air pollution. For some pollutants there may be a threshold level of exposure, below which no health effect is evident, e.g. SO2. For others, there may be no threshold, and some effect may occur whatever the level of exposure is, e.g. benzene.

Each episode of illness caused by or made worse by air has direct and indirect economic consequences for individuals and society. They range from the costs of medical care through costs due to absence from work, to the loss of healthy years of life.

An immediate problem facing the Parthenon is the environmental impact of the growth of Athens since the 1960s. Corrosion of its marble by acid rain and car pollutants has already caused irreparable damage to some sculptures and threatens the remaining sculptures and the temple itself. Over the past 20 years, the Greek government and the city of Athens have made some progress on these issues, but the future survival of the Parthenon does not seem to be assured.

Air pollution is a major problem for Athens today, caused by the large number of factories in the city, the dense population, and a lack of green spaces. The situation is made worse by the fact that the city is surrounded by hills, which trap the polluted air and prevent it from moving away. The high level of pollution not only affects the health of the people living there, but also causes damage to the city's ancient monuments. Environmental protection schemes, such as traffic bans, are in place in certain parts of Athens to try to prevent any further damage.

Several measures have been taken or are in the process of implementation, in an effort to improve the existing air quality conditions in the city:

• A retirement plan for old vehicles was introduced in 1991 in an effort to renew the motor vehicles fleet with new cars equipped with catalytic converters. [The measure was of nationwide coverage, lasted for two years (1991-1992) and resulted in 260,000 old cars to be retired in Greece, of which 150,000 cars in Athens].

• The national inspection programme for the control of emissions from motor vehicles was initiated in 1994, consisting of regular inspections of all private vehicles once per year and taxis and light trucks twice per year.

• Expansion of the subway system. At present two new lines of a total length of 18 km are constructed. The project is expected to conclude in the year 2000. It is anticipated that daily automobile trips in the centre of the city will be reduced by 250,000 trips.

• A project for the full replacement of the old buses with new ones equipped with anti-pollution devices.

• In addition to the replacement of buses, several other measures are taken in an effort to make public transport attractive to Athenians.

2. Rescheduling of bus routes to accommodate distant neighbourhoods or to link neighbourhoods by means of efficient routing.

3. Dedicated bus lanes to improve running conditions. According to relevant measurements, the introduction of bus lanes has resulted in the increase of the average hourly speed of a bus from 16 km/h to 30 km/h.

• The odd-even traffic regulation system. According to the system, cars with plates ending in odd numbers can circulate in the centre of Athens on odd days, whereas cars with plates ending in even numbers can circulate on even days.

• In the event that meteorological conditions for the following day may lead to pollution concentration, full banning of traffic is applied in the centre of Athens.

• In an effort to reduce traffic, the working schedule of public and private employees was modified during the summer months of 1994-1996.

A number of significant measures for the improvement of air quality were introduced in 1994 and 1995, in particular:

1. The content of sulphur in heavy fuels was reduced from 0.3% per weight to 0.2% per weight.

2. From 1/1/1995, the content of sulphur in unleaded gas was reduced from 0.10% per weight to 0.05% per weight.

3. The content of benzene in gasoline was reduced from 5% per volume to 4% per volume.

4. Introduction of natural gas at around 15% of the energy balance in Athens.(households and industrial units).

CAUSES OF POOR QUALITY OF ENVIRONMENT

CONSEQUENCES OF POOR QUALITY OF ENVIRONMENT

STRATEGIES TO OVERCOME OF POOR QUALITY OF ENVIRONMENT

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