J Matschullat | PubMed Health

PubMed2000

Arsenic in the geosphere--a review.

An attempt is made to quantify the global element cycle for arsenic, based on an extensive literature research with special emphasis on the most recent works. Reservoirs in and fluxes within and through lithosphere, atmosphere, pedosphere, hydrosphere, biosphere, and anthrosposphere are being presented. Crucial knowledge gaps are addressed and some simple model calculations partially question currently held ideas about sources, pathways, and the fate of arsenic in the environment.

Air Pollutants↗

PubMed1992

Catchment acidification-from the top down.

Three main factors define the speed of catchment acidification: the total input of pollutants; the thickness and character of soils, including the nature of the bedrock; and the size of subcatchments. The aerial input of pollutants in the Harz is among the highest in Central Europe (e.g. SO4-S: 22-70 kg (ha year)(-1); NO3-N: 9-10 kg (ha year)(-1); NH4-N: 10-15 kg (ha year)(-1) and Cd: 2.6-8.7 g (ha year)(-1); Cu: 34-125 g (ha year)(-1); Pb: 150-380 g (ha year)(-1); Zn: 105-560 g (ha year)(-1)). Thick soil profiles (2-4 m) acidify from the top down. Whether the soils will neutralize incoming acids depends on their buffering capacity. The small headwater subcatchments acidify first and subsequently release acidic water with pH values down to < or = 40. Four brook zones can be divided by the composition of their biocoenoses. The latter depend on the degree of acidification. These zones are also characterized by different hydrochemical conditions.

Journal Article↗