Abstract
Long-range transport of air pollutants occurs very frequently in summer which causes high ozone concentration in the mountainous region more than 100 km inland from the large emission sources along Tokyo Bay in the Central Japan. Behavior of lower fatty acids along with the other pollutants was investigated in the co-operative field observation from 26 July to 2 August, 1986.
The fatty acids were collected on beads which were coated by 1 wt% strontium hydroxide and packed in a sampling tube. The collected fatty acids were regenerated by formic acid and measured by GC-FID. The concentrations of acetic, propionic and n-butyric acids increased to 4-8 ppb, 0.3-0.7 ppb and 0.1-0.3 ppb, respectively in the daytime, in particular, when the transported air mass was arrived at the sampling sites, and decreased at night. These diurnal variations were very similar to that of ozone, thus having a strong correlation with the concentration of ozone, while they were not correlated with the concentration of hydrocarbon attributable to motor exhausts.
Of the fatty acids more than 60% were estimated to be produced by photochemical reaction in the daytime. Moreover, it corresponded to about 10% of hydrocarbons transformed. Thus, it was concluded that most of the fatty acids in the atmosphere were produced by the photochemical oxidation of anthropogenic compounds during the long-range transport.
