Surface ozone levels in the south west of the Iberian Peninsula usually exceed the protection threshold established by EU regulations for people and plants in spring and summer, according to data gathered between 2000 and 2005 by four measuring stations in Huelva, one of them next to the Doana National Park.
The limits established to protect human and plant health by the European Directive on ozone are usually exceeded from April onwards, especially during the summer, in the south west of the Iberian Peninsula, according to a study carried out by researchers at the National Institute of Aerospace Technology (INTA) and the University of Huelva (UHU).
Understanding this situation, which is common in many developed countries, will help public authorities to take measures to prevent health and environmental risks associated with increased levels of this contaminant gas.
The new study, published in the journal Environmental Science and Pollution Research, shows the levels of seasonal surface ozone variation measurements between 2000 and 2005 for the first time at the stations in the autonomous region of Huelva in El Arenosillo (very close to the Doana National Park), Cartaya, Valverde and Huelva city.
The threshold established for human health by the European Directive is exceeded during the spring and summer months, particularly at El Arenosillo and Valverde. The level for plant protection is also exceeded at a rate ranging from 131 days per year at Cartaya to 266 at Valverde, on average.
The scientists identified "a clear daily cycle", with minimum levels recorded at about 7am, shortly after dawn, while the highest levels were recorded at about 3pm. Average concentrations varied from 57.8 micrograms/m3 at the station in Huelva to 78.5 micrograms/m3 in Valverde.
The journey of ozone
Surface or tropospheric ozone (as distinct from the stratospheric ozone of the ozone layer) is considered one of th
FECYT - Spanish Foundation for Science and Technology