These maps were created using AirBase version4 as data source:
http://www.eea.europa.eu/data-and-maps/data/airbase-the-european-air-quality-database-2

Two tables have been used: Airbase_v4_station, and Airbase_v4_statistic, both are available for download from the data set page.

- Location maps: location of stations for which 2008 air quality data for components O3, PM10, NO2, SO2, C6H6, PM2.5, Pb, CO have been reported. 
Distinction is shown if stations report a component for the first time or not.

Query used: 
select Airbase_v4_station.station_european_code, component_code,component_caption,component_name,station_longitude_deg,station_latitude_deg,station_legend from Airbase_v4_station
inner join
--Station report component for the first time in 2008
(select station_european_code,component_code,component_caption,component_name,'Station reporting this component for the first time in 2008' as station_legend,count(distinct statistics_year) as CountDistinctYear from Airbase_v4_statistic
where component_code in (/*SO2*/'1',/*NO2*/'8',/*PM10*/'5',/*PM2.5*/'6001',/*Pb*/'12',/*CO*/'10',/*C6H6*/'20',/*O3*/'7')
group by station_european_code,component_code,component_caption,component_name
having count(distinct statistics_year)=1 and max(statistics_year)=2008
union
--Station reported component in 2008 but also before.
select station_european_code,component_code,component_caption,component_name,'Station reporting this component for 2008 but not for the first time',count(distinct statistics_year) from Airbase_v4_statistic
where component_code in (/*SO2*/'1',/*NO2*/'8',/*PM10*/'5',/*PM2.5*/'6001',/*Pb*/'12',/*CO*/'10',/*C6H6*/'20',/*O3*/'7')
group by station_european_code,component_code,component_caption,component_name
having count(distinct statistics_year)<>1 and max(statistics_year)=2008
) as TableA
on Airbase_v4_station.station_european_code=TableA.station_european_code
order by Airbase_v4_station.station_european_code,component_code,station_legend



- Concentration maps: observed concentration maps for which 2008 air quality data for components O3, PM10, NO2, SO2, C6H6, PM2.5, CO have been reported.
Distinction is shown by specific relevant thresholds for each components.

Query used:
/*NO2*/
select Airbase_v4_station.station_european_code, component_code,component_caption,component_name,station_longitude_deg,station_latitude_deg,'<=20' as station_legend, statistics_average_group, statistics_year, statistic_shortname,statistic_value, measurement_unit, statistics_percentage_valid
from Airbase_v4_station
inner join dbo.Airbase_v4_statistic
on Airbase_v4_station.station_european_code=Airbase_v4_statistic.station_european_code
where statistics_average_group='day' and statistics_percentage_valid>=75 and component_code='8' and statistics_year=2008 and statistic_shortname='mean' and statistic_value<=20
union
select Airbase_v4_station.station_european_code, component_code,component_caption,component_name,station_longitude_deg,station_latitude_deg,'20 - <=40' as station_legend, statistics_average_group, statistics_year, statistic_shortname,statistic_value, measurement_unit, statistics_percentage_valid
from Airbase_v4_station
inner join dbo.Airbase_v4_statistic
on Airbase_v4_station.station_european_code=Airbase_v4_statistic.station_european_code
where statistics_average_group='day' and statistics_percentage_valid>=75 and component_code='8' and statistics_year=2008 and statistic_shortname='mean' and (statistic_value>20 and statistic_value<=40)
union
select Airbase_v4_station.station_european_code, component_code,component_caption,component_name,station_longitude_deg,station_latitude_deg,'40 - <=44' as station_legend, statistics_average_group, statistics_year, statistic_shortname,statistic_value, measurement_unit, statistics_percentage_valid
from Airbase_v4_station
inner join dbo.Airbase_v4_statistic
on Airbase_v4_station.station_european_code=Airbase_v4_statistic.station_european_code
where statistics_average_group='day' and statistics_percentage_valid>=75 and component_code='8' and statistics_year=2008 and statistic_shortname='mean' and (statistic_value>40 and statistic_value<=44)
union
select Airbase_v4_station.station_european_code, component_code,component_caption,component_name,station_longitude_deg,station_latitude_deg,'>44' as station_legend, statistics_average_group, statistics_year, statistic_shortname,statistic_value, measurement_unit, statistics_percentage_valid
from Airbase_v4_station
inner join dbo.Airbase_v4_statistic
on Airbase_v4_station.station_european_code=Airbase_v4_statistic.station_european_code
where statistics_average_group='day' and statistics_percentage_valid>=75 and component_code='8' and statistics_year=2008 and statistic_shortname='mean' and statistic_value>44
union
/*SO2*/
select Airbase_v4_station.station_european_code, component_code,component_caption,component_name,station_longitude_deg,station_latitude_deg,'<=5' as station_legend, statistics_average_group, statistics_year, statistic_shortname,statistic_value, measurement_unit, statistics_percentage_valid
from Airbase_v4_station
inner join dbo.Airbase_v4_statistic
on Airbase_v4_station.station_european_code=Airbase_v4_statistic.station_european_code
where statistics_average_group='day' and statistics_percentage_valid>=75 and component_code='1' and statistics_year=2008 and statistic_shortname='mean' and statistic_value<=5
union
select Airbase_v4_station.station_european_code, component_code,component_caption,component_name,station_longitude_deg,station_latitude_deg,'5 - <=10' as station_legend, statistics_average_group, statistics_year, statistic_shortname,statistic_value, measurement_unit, statistics_percentage_valid
from Airbase_v4_station
inner join dbo.Airbase_v4_statistic
on Airbase_v4_station.station_european_code=Airbase_v4_statistic.station_european_code
where statistics_average_group='day' and statistics_percentage_valid>=75 and component_code='1' and statistics_year=2008 and statistic_shortname='mean' and (statistic_value>5 and statistic_value<=10)
union
select Airbase_v4_station.station_european_code, component_code,component_caption,component_name,station_longitude_deg,station_latitude_deg,'10 - <=20' as station_legend, statistics_average_group, statistics_year, statistic_shortname,statistic_value, measurement_unit, statistics_percentage_valid
from Airbase_v4_station
inner join dbo.Airbase_v4_statistic
on Airbase_v4_station.station_european_code=Airbase_v4_statistic.station_european_code
where statistics_average_group='day' and statistics_percentage_valid>=75 and component_code='1' and statistics_year=2008 and statistic_shortname='mean' and (statistic_value>10 and statistic_value<=20)
union
select Airbase_v4_station.station_european_code, component_code,component_caption,component_name,station_longitude_deg,station_latitude_deg,'>20' as station_legend, statistics_average_group, statistics_year, statistic_shortname,statistic_value, measurement_unit, statistics_percentage_valid
from Airbase_v4_station
inner join dbo.Airbase_v4_statistic
on Airbase_v4_station.station_european_code=Airbase_v4_statistic.station_european_code
where statistics_average_group='day' and statistics_percentage_valid>=75 and component_code='1' and statistics_year=2008 and statistic_shortname='mean' and statistic_value>20
union
/*PM10*/
select Airbase_v4_station.station_european_code, component_code,component_caption,component_name,station_longitude_deg,station_latitude_deg,'<=20' as station_legend, statistics_average_group, statistics_year, statistic_shortname,statistic_value, measurement_unit, statistics_percentage_valid
from Airbase_v4_station
inner join dbo.Airbase_v4_statistic
on Airbase_v4_station.station_european_code=Airbase_v4_statistic.station_european_code
where statistics_average_group='day' and statistics_percentage_valid>=75 and component_code='5' and statistics_year=2008 and statistic_shortname='mean' and statistic_value<=20
union
select Airbase_v4_station.station_european_code, component_code,component_caption,component_name,station_longitude_deg,station_latitude_deg,'20 - <=31' as station_legend, statistics_average_group, statistics_year, statistic_shortname,statistic_value, measurement_unit, statistics_percentage_valid
from Airbase_v4_station
inner join dbo.Airbase_v4_statistic
on Airbase_v4_station.station_european_code=Airbase_v4_statistic.station_european_code
where statistics_average_group='day' and statistics_percentage_valid>=75 and component_code='5' and statistics_year=2008 and statistic_shortname='mean' and (statistic_value>20 and statistic_value<=31)
union
select Airbase_v4_station.station_european_code, component_code,component_caption,component_name,station_longitude_deg,station_latitude_deg,'31 - <=40' as station_legend, statistics_average_group, statistics_year, statistic_shortname,statistic_value, measurement_unit, statistics_percentage_valid
from Airbase_v4_station
inner join dbo.Airbase_v4_statistic
on Airbase_v4_station.station_european_code=Airbase_v4_statistic.station_european_code
where statistics_average_group='day' and statistics_percentage_valid>=75 and component_code='5' and statistics_year=2008 and statistic_shortname='mean' and (statistic_value>31 and statistic_value<=40)
union
select Airbase_v4_station.station_european_code, component_code,component_caption,component_name,station_longitude_deg,station_latitude_deg,'>40' as station_legend, statistics_average_group, statistics_year, statistic_shortname,statistic_value, measurement_unit, statistics_percentage_valid
from Airbase_v4_station
inner join dbo.Airbase_v4_statistic
on Airbase_v4_station.station_european_code=Airbase_v4_statistic.station_european_code
where statistics_average_group='day' and statistics_percentage_valid>=75 and component_code='5' and statistics_year=2008 and statistic_shortname='mean' and statistic_value>40
union
/*PM2.5*/
select Airbase_v4_station.station_european_code, component_code,component_caption,component_name,station_longitude_deg,station_latitude_deg,'<=15' as station_legend, statistics_average_group, statistics_year, statistic_shortname,statistic_value, measurement_unit, statistics_percentage_valid
from Airbase_v4_station
inner join dbo.Airbase_v4_statistic
on Airbase_v4_station.station_european_code=Airbase_v4_statistic.station_european_code
where statistics_average_group='day' and statistics_percentage_valid>=75 and component_code='6001' and statistics_year=2008 and statistic_shortname='mean' and statistic_value<=15
union
select Airbase_v4_station.station_european_code, component_code,component_caption,component_name,station_longitude_deg,station_latitude_deg,'15 - <=25' as station_legend, statistics_average_group, statistics_year, statistic_shortname,statistic_value, measurement_unit, statistics_percentage_valid
from Airbase_v4_station
inner join dbo.Airbase_v4_statistic
on Airbase_v4_station.station_european_code=Airbase_v4_statistic.station_european_code
where statistics_average_group='day' and statistics_percentage_valid>=75 and component_code='6001' and statistics_year=2008 and statistic_shortname='mean' and (statistic_value>15 and statistic_value<=25)
union
select Airbase_v4_station.station_european_code, component_code,component_caption,component_name,station_longitude_deg,station_latitude_deg,'25 - <=30' as station_legend, statistics_average_group, statistics_year, statistic_shortname,statistic_value, measurement_unit, statistics_percentage_valid
from Airbase_v4_station
inner join dbo.Airbase_v4_statistic
on Airbase_v4_station.station_european_code=Airbase_v4_statistic.station_european_code
where statistics_average_group='day' and statistics_percentage_valid>=75 and component_code='6001' and statistics_year=2008 and statistic_shortname='mean' and (statistic_value>25 and statistic_value<=30)
union
select Airbase_v4_station.station_european_code, component_code,component_caption,component_name,station_longitude_deg,station_latitude_deg,'>30' as station_legend, statistics_average_group, statistics_year, statistic_shortname,statistic_value, measurement_unit, statistics_percentage_valid
from Airbase_v4_station
inner join dbo.Airbase_v4_statistic
on Airbase_v4_station.station_european_code=Airbase_v4_statistic.station_european_code
where statistics_average_group='day' and statistics_percentage_valid>=75 and component_code='6001' and statistics_year=2008 and statistic_shortname='mean' and statistic_value>30
union
/*CO*/
select Airbase_v4_station.station_european_code, component_code,component_caption,component_name,station_longitude_deg,station_latitude_deg,'<=1' as station_legend, statistics_average_group, statistics_year, statistic_shortname,statistic_value, measurement_unit, statistics_percentage_valid
from Airbase_v4_station
inner join dbo.Airbase_v4_statistic
on Airbase_v4_station.station_european_code=Airbase_v4_statistic.station_european_code
where statistics_average_group='dymax' and statistics_percentage_valid>=75 and component_code='10' and statistics_year=2008 and statistic_shortname='mean' and statistic_value<=1
union
select Airbase_v4_station.station_european_code, component_code,component_caption,component_name,station_longitude_deg,station_latitude_deg,'1 - <=2' as station_legend, statistics_average_group, statistics_year, statistic_shortname,statistic_value, measurement_unit, statistics_percentage_valid
from Airbase_v4_station
inner join dbo.Airbase_v4_statistic
on Airbase_v4_station.station_european_code=Airbase_v4_statistic.station_european_code
where statistics_average_group='dymax' and statistics_percentage_valid>=75 and component_code='10' and statistics_year=2008 and statistic_shortname='mean' and (statistic_value>1 and statistic_value<=2)
union
select Airbase_v4_station.station_european_code, component_code,component_caption,component_name,station_longitude_deg,station_latitude_deg,'2 - <=10' as station_legend, statistics_average_group, statistics_year, statistic_shortname,statistic_value, measurement_unit, statistics_percentage_valid
from Airbase_v4_station
inner join dbo.Airbase_v4_statistic
on Airbase_v4_station.station_european_code=Airbase_v4_statistic.station_european_code
where statistics_average_group='dymax' and statistics_percentage_valid>=75 and component_code='10' and statistics_year=2008 and statistic_shortname='mean' and (statistic_value>2 and statistic_value<=10)
union
select Airbase_v4_station.station_european_code, component_code,component_caption,component_name,station_longitude_deg,station_latitude_deg,'>10' as station_legend, statistics_average_group, statistics_year, statistic_shortname,statistic_value, measurement_unit, statistics_percentage_valid
from Airbase_v4_station
inner join dbo.Airbase_v4_statistic
on Airbase_v4_station.station_european_code=Airbase_v4_statistic.station_european_code
where statistics_average_group='dymax' and statistics_percentage_valid>=75 and component_code='10' and statistics_year=2008 and statistic_shortname='mean' and statistic_value>10
union
/*C6H6*/
select Airbase_v4_station.station_european_code, component_code,component_caption,component_name,station_longitude_deg,station_latitude_deg,'<=2' as station_legend, statistics_average_group, statistics_year, statistic_shortname,statistic_value, measurement_unit, statistics_percentage_valid
from Airbase_v4_station
inner join dbo.Airbase_v4_statistic
on Airbase_v4_station.station_european_code=Airbase_v4_statistic.station_european_code
where statistics_percentage_valid>=50 and component_code='20' and statistics_year=2008 and statistic_shortname='mean' and statistic_value<=2
union
select Airbase_v4_station.station_european_code, component_code,component_caption,component_name,station_longitude_deg,station_latitude_deg,'2 - <=5' as station_legend, statistics_average_group, statistics_year, statistic_shortname,statistic_value, measurement_unit, statistics_percentage_valid
from Airbase_v4_station
inner join dbo.Airbase_v4_statistic
on Airbase_v4_station.station_european_code=Airbase_v4_statistic.station_european_code
where statistics_percentage_valid>=50 and component_code='20' and statistics_year=2008 and statistic_shortname='mean' and (statistic_value>2 and statistic_value<=5)
union
select Airbase_v4_station.station_european_code, component_code,component_caption,component_name,station_longitude_deg,station_latitude_deg,'5 - <=7' as station_legend, statistics_average_group, statistics_year, statistic_shortname,statistic_value, measurement_unit, statistics_percentage_valid
from Airbase_v4_station
inner join dbo.Airbase_v4_statistic
on Airbase_v4_station.station_european_code=Airbase_v4_statistic.station_european_code
where statistics_percentage_valid>=50 and component_code='20' and statistics_year=2008 and statistic_shortname='mean' and (statistic_value>5 and statistic_value<=7)
union
select Airbase_v4_station.station_european_code, component_code,component_caption,component_name,station_longitude_deg,station_latitude_deg,'>7' as station_legend, statistics_average_group, statistics_year, statistic_shortname,statistic_value, measurement_unit, statistics_percentage_valid
from Airbase_v4_station
inner join dbo.Airbase_v4_statistic
on Airbase_v4_station.station_european_code=Airbase_v4_statistic.station_european_code
where statistics_percentage_valid>=50 and component_code='20' and statistics_year=2008 and statistic_shortname='mean' and statistic_value>7
union
/*O3*/
select Airbase_v4_station.station_european_code, component_code,component_caption,component_name,station_longitude_deg,station_latitude_deg,'<=60' as station_legend, statistics_average_group, statistics_year, statistic_shortname,statistic_value, measurement_unit, statistics_percentage_valid
from Airbase_v4_station
inner join dbo.Airbase_v4_statistic
on Airbase_v4_station.station_european_code=Airbase_v4_statistic.station_european_code
where statistics_average_group='dymax' and statistics_percentage_valid>=75 and component_code='7' and statistics_year=2008 and statistic_shortname='mean' and statistic_value<=60
union
select Airbase_v4_station.station_european_code, component_code,component_caption,component_name,station_longitude_deg,station_latitude_deg,'60 - <=80' as station_legend, statistics_average_group, statistics_year, statistic_shortname,statistic_value, measurement_unit, statistics_percentage_valid
from Airbase_v4_station
inner join dbo.Airbase_v4_statistic
on Airbase_v4_station.station_european_code=Airbase_v4_statistic.station_european_code
where statistics_average_group='dymax' and statistics_percentage_valid>=75 and component_code='7' and statistics_year=2008 and statistic_shortname='mean' and (statistic_value>60 and statistic_value<=80)
union
select Airbase_v4_station.station_european_code, component_code,component_caption,component_name,station_longitude_deg,station_latitude_deg,'80 - <=100' as station_legend, statistics_average_group, statistics_year, statistic_shortname,statistic_value, measurement_unit, statistics_percentage_valid
from Airbase_v4_station
inner join dbo.Airbase_v4_statistic
on Airbase_v4_station.station_european_code=Airbase_v4_statistic.station_european_code
where statistics_average_group='dymax' and statistics_percentage_valid>=75 and component_code='7' and statistics_year=2008 and statistic_shortname='mean' and (statistic_value>80 and statistic_value<=100)
union
select Airbase_v4_station.station_european_code, component_code,component_caption,component_name,station_longitude_deg,station_latitude_deg,'>100' as station_legend, statistics_average_group, statistics_year, statistic_shortname,statistic_value, measurement_unit, statistics_percentage_valid
from Airbase_v4_station
inner join dbo.Airbase_v4_statistic
on Airbase_v4_station.station_european_code=Airbase_v4_statistic.station_european_code
where statistics_average_group='dymax' and statistics_percentage_valid>=75 and component_code='7' and statistics_year=2008 and statistic_shortname='mean' and statistic_value>100
union
/*BAP*/
select Airbase_v4_station.station_european_code, component_code,component_caption,component_name,station_longitude_deg,station_latitude_deg,'<=0.4' as station_legend, statistics_average_group, statistics_year, statistic_shortname,statistic_value, measurement_unit, statistics_percentage_valid
from Airbase_v4_station
inner join dbo.Airbase_v4_statistic
on Airbase_v4_station.station_european_code=Airbase_v4_statistic.station_european_code
where statistics_percentage_valid>=14 and component_code in ('6015','5029','5129','1029') and statistics_year=2008 and statistic_shortname='mean' and statistic_value<=0.4
union
select Airbase_v4_station.station_european_code, component_code,component_caption,component_name,station_longitude_deg,station_latitude_deg,'0.4 - <=0.6' as station_legend, statistics_average_group, statistics_year, statistic_shortname,statistic_value, measurement_unit, statistics_percentage_valid
from Airbase_v4_station
inner join dbo.Airbase_v4_statistic
on Airbase_v4_station.station_european_code=Airbase_v4_statistic.station_european_code
where statistics_percentage_valid>=14  and component_code in ('6015','5029','5129','1029') and statistics_year=2008 and statistic_shortname='mean' and (statistic_value>0.4 and statistic_value<=0.6)
union
select Airbase_v4_station.station_european_code, component_code,component_caption,component_name,station_longitude_deg,station_latitude_deg,'0.6 - <=1' as station_legend, statistics_average_group, statistics_year, statistic_shortname,statistic_value, measurement_unit, statistics_percentage_valid
from Airbase_v4_station
inner join dbo.Airbase_v4_statistic
on Airbase_v4_station.station_european_code=Airbase_v4_statistic.station_european_code
where statistics_percentage_valid>=14  and component_code in ('6015','5029','5129','1029') and statistics_year=2008 and statistic_shortname='mean' and (statistic_value>0.6 and statistic_value<=1)
union
select Airbase_v4_station.station_european_code, component_code,component_caption,component_name,station_longitude_deg,station_latitude_deg,'>1' as station_legend, statistics_average_group, statistics_year, statistic_shortname,statistic_value, measurement_unit, statistics_percentage_valid
from Airbase_v4_station
inner join dbo.Airbase_v4_statistic
on Airbase_v4_station.station_european_code=Airbase_v4_statistic.station_european_code
where statistics_percentage_valid>=14  and component_code in ('6015','5029','5129','1029') and statistics_year=2008 and statistic_shortname='mean' and statistic_value>1
order by component_code, Airbase_v4_station.station_european_code