The group said the threshold was exceeded on 92 occasions last summer but that this year the figure had been surpassed 244 times - 163 times in July alone through to Tuesday.

With Madrid sweltering under its traditional summer heatwave ecologists are forecasting a 300 percent increase in cases rising above the threshold for

Ecologistas en Accion slammed the quality of the capital's air as "deplorable" - something borne out by the Madrid authorities' own internet log of day-to-day ozone levels, which showed a peak value of 243 mg/m3 on June 18 and values surpassing 200 mg/m3 on an almost daily basis.

An intergovernmental panel studying climate change earlier this year warned that global ozone pollution was set to rise by some 25 percent by 2030.

TERRA.WIRE