Seasonal variation of low molecular weight carbonyls at the Ispra air monitoring station - Correlation with O-3 measurements

The seasonal variation in ambient air concentrations of low molecular weigh t carbonyls (C less than or equal to 6) measured in Ispra showed maximum co ncentrations up to 7 mu g/m(3) for formaldehyde, while monthly average valu es up to 4.3, 3.0, and 3.5 mu g/m were recorded for formaldehyde, acetaldeh yde and acetone, respectively. Considerable amounts (up to 4.5 mu g/m(3)) o f methacrolein were found in ambient air during summer and autumn. prelimin ary evidence indicated that for formaldehyde during summer sources other th an local traffic should be taken into account.