Atmospheric alcohols and aldehydes concentrations measured in Osaka, Japanand in Sao Paulo, Brazil

The use of alcohol fuel has received much attention since 1980s. In Brazil, ethanol-fueled vehicles have been currently used on a large scale. This pa per reports the atmospheric methanol, ethanol and isopropanol concentration s which were measured from May to December 1997, in Osaka, Japan, where alc ohol fuel was not used, and from 3 to 9 February 1998, in Sao Paulo, Brazil , where ethanol fuel was used. The alcohols were determined by the alkyl ni trite formation reaction using gas chromatography (GC-ECD) analysis. The co ncentration of atmospheric alcohols, especially ethanol, measured in Sao Pa ulo were significantly higher than those in Osaka. In Osaka, the average co ncentrations of atmospheric methanol, ethanol, and isopropanol were 5.8 +/- 3.8, 8.2 +/- 4.6, and 7.2 +/- 5.9 ppbv, respectively. The average ambient levels of methanol, ethanol, and isopropanol measured in Sao Paulo were 34. 1 +/- 9.2, 176.3. +/- 38.1, and 44.2 +/- 13.7 ppbv, respectively. The ambie nt levels of aldehydes, which were expected to be high due to the use of al cohol fuel, were also measured at these sampling sites. The atmospheric for maldehyde average concentration measured in Osaka was 1.9 +/- 0.9 ppbv, and the average acetaldehyde concentration was 1.5 +/- 0.8 ppbv. The atmospher ic formaldehyde and acetaldehyde average concentrations measured in Sao Pau lo were 5.0 +/- 2.8 and 5.4 +/- 2.8 ppbv, respectively. The C2H5OH/CH3OH an d CH3CHO/HCHO were compared between the two measurement sites and elsewhere in the world, which have already been reported in the literature. Due to t he use of ethanol-fueled vehicles, these ratios, especially C2H5OH/CH3OH, a re much higher in Brazil than these measured elsewhere in the world. (C) 20 01 Elsevier Science Ltd. All rights reserved.