Ozoneweb is an EEA website on near real-time

ozone Ozone (), or trioxygen, is an inorganic molecule with the chemical formula . It is a pale blue gas with a distinctively pungent smell. It is an allotrope of oxygen that is much less stable than the diatomic allotrope , breaking down in the lo ...

. The website allows the general public to track

air quality Air pollution is the contamination of air due to the presence of substances in the atmosphere that are harmful to the health of humans and other living beings, or cause damage to the climate or to materials. There are many different types ...

in a specific region and on a European level. The website displays

levels via a map of Europe. Background information on

and its health impacts are also provided. Users can monitor ozone levels in a neighbouring country or a holiday destination, check recent trends and track the spread of ozone across Europe. The website now includes a module to display exceedances in countries.

Features of the site

Key features of the site are: * Live status data on ozone * Most measurement stations in Europe (over 700) * Advanced Internet mapping tool * Interpolated maps * Comparisons views * Support factual text

About the data

Data from more than 700

measurement stations across Europe are transmitted to the EEA in Copenhagen on an hourly basis. Since the data must be as 'real-time' as possible, the data are displayed as soon as practical after the end of each hour. In the map, the

level is illustrated by colours. The colour scheme is linked to threshold values in EU legislation. To provide an estimate of the

status in areas between measurement stations, a statistical calculation ( interpolation) is carried out on the

data received by the EEA. Before the result of the calculation is shown on the map, a number of conditions have to be satisfied by the input data and the resulting calculation. URLs to data providers’ websites are available to users looking for more detailed localised information.

The ozone directive

The directive on 'ozone in ambient air' came into force in 2002. The long-term objective is to limit the number of days with average

concentrations above 120 µg/m³ to less than 25 days a year (see table below). The objectives of the directive are in line with the

World Health Organization The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health. The WHO Constitution states its main objective as "the attainment by all peoples of the highest possible level of ...

's guidelines for ozone. The directive requires national authorities to inform the public – hourly or daily – about any incidence of ozone pollution above 180 µg/m³ (information threshold). Also, Member States should report monthly to the European Commission on all exceedances of the information and alert thresholds (see table below). Each year they must provide additional information on ozone pollution, especially concerning exceedances of the long-term objective. {, class="wikitable" , - ! Objective ! Value ! Measured ! Target/action , - , Information threshold , 180 µg/m³ , Hourly average , National authorities should inform the public and give advice immediately after an exceedance. Countries should report monthly on all exceedances , - , Alert threshold , 240 µg/m³ , Hourly average , National authorities should inform the public and give advice immediately after an exceedance. Countries should report monthly on all exceedances , - , Protect human health , 120 µg/m³ , 8 hour average , Not to be exceeded on more than 25 days per year (to be met by 2010). µg/m³: The concentration of an air pollutant (e.g. ozone) is given in micrograms (one-millionth of a gram) per cubic meter air or µg/m³.

Ozone and health

Ozone Ozone (), or trioxygen, is an inorganic molecule with the chemical formula . It is a pale blue gas with a distinctively pungent smell. It is an allotrope of oxygen that is much less stable than the diatomic allotrope , breaking down in the lo ...

at high concentrations is a health hazard because it can irritate airways, cause breathing difficulties and damage lungs. It can cause lung inflammation (irritation) even after only a few hours of exposure. Ozone exposure has been linked to a number o
health effects
and is thought to be the cause of the premature deaths of thousands of people in Europe each year. Some people are more vulnerable than others. Children and people with

asthma Asthma is a long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and easily triggered bronchospasms. Symptoms include episodes of wheezing, co ...

or other respiratory illnesses are particularly high-risk groups.

Ozone and environmental impacts

Ground-level

can damage all types of green vegetation, including the foliage of trees. Ozone is absorbed by leaves and impedes plant growth. Ozone is recognised as the most serious regional air pollution problem for the agricultural sector in Europe. It reduces crop yields by hindering plant growth. In 2000, it was estimated that the overall ozone damage to crops corresponded to an economic loss to farmers across EU-25 of about EUR 2.8 billion. There are marked differences in damage to crops across Europe, depending on agricultural activity, soil moisture and ozone concentration. Most affected by elevated ozone concentrations are countries that are growing

wheat Wheat is a grass widely cultivated for its seed, a cereal grain that is a worldwide staple food. The many species of wheat together make up the genus ''Triticum'' ; the most widely grown is common wheat (''T. aestivum''). The archaeologi ...

. The economic or ecological cost of ozone damage to wild vegetation has not been estimated.

External links