Particulate and fog- and cloud-water bromide in polluted air

Particulate water soluble bromide was determined in source regions at concentrations typically 0.1-1 hg m−3, and—distinctly less concentrated—at subalpine mountain sites downwind from urban areas. High to extremely high concentrations, 1–10 mg −1 and above, were found in urban fog water and lower values, 0.01-0.1 mg −1 in orographic clouds at the mountain sites. Bromide was predominantly concentrated in the accumulation mode of the atmospheric aerosol. In fog- and cloud water a tendency to higher concentrations in small droplets was observed. The particulate Br concentration level observed at the urban sites and a rural site is comparable to what had been measured 5–10 yr earlier at urban sites in Germany although the former major anthropogenic Br source, 1,2-dibromoethane in gasoline, had been reduced and finally phased out.