Climate impact on air quality and health in the city of Rijeka area, Croatia

Meteorological parameters in the period 1977-2010 indicate annual mean temperature increase of approx 1.5oC, as well as maximum temperature increase of 10o C. In the same time period, the number of rainy days increased by 40 up to 2007, while the precipitation depth showed a decline. This trend is somewhat smoothed in the last three years (2007-2010). High pollution by SO2 and NO2 and moderate pollution by NH3, TSP, PAH and metals during the eighties is observed. Due to reduced emission primarily of SO2, NOx and other combustion products from industrial sources since beginning of nineties, the airborne concentrations of these pollutants showed a decreasing trend, less pronounced for NO2 as traffic emissions are still slowly going on. Ozone levels since 1999 also follow the same declining trend, contrary to the expected increase due to increase in temperatures. Diminishing of ozone seems to be the regional pattern, since data on ozone concentration from the only long term station at high elevation Puntjarka (above capital Zagreb, at 900 m a.s.l) show the same declining trend since 1990. One of the possible reasons for lower ozone pollution could be the lower emission of NOx in the Rijeka Bay, but also generally in Croatia, that led to lower production of ozone, considered also as a greenhouse gas. Obviously, in spite of air quality improvement within the Rijeka Bay Area the global warming is still overwhelming. Such a condition may represent threat to human health, either by introducing some insects- vectors of infectious disease (like Tiger mosquito) or suffering from exposures to higher ambient air temperatures and/or pollutants (ozone and PM). Except the estimation for the 2003 heat wave, there is no clear evidence of harmful effects on human health (asthma caused by allergy and gastrointestinal diseases) due to increased air temperature and/or pollution in the last decade. For such a purpose more precisely statistic records and longer periods are needed.