Naturally produced adsorbable organic halogens (AOX) in humic substances from soil and water

• Published in: The Science of the total environment 1989, Vol.81, p.239-248
• Main Authors: Asplund, G., Grimvall, A., Pettersson, C.
• Format: Article
• Language: English
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/0048-9697(89)90130-7

The present study has shown that surface water, groundwater and soil, even in areas far from industrial activities, contain measurable amounts of adsorbable organic halogens (AOX). Although the concentrations are relatively low, the pools of AOX in the environment are considerable. In surface water, the ratio between AOX and total organic carbon (TOC) varied between 730 and 8600 μg/g. In soil, the AOX content ranged from 210 to 1400 μg AOX per g organic matter. The fact that organohalogens (230–370 μg/g) could be detected in fulvic acids isolated from old groundwaters (1300, 4600 and 5200 yrs) indicates a large natural production of organohalogens. This hypothesis was further strengthened by mass balance calculations for a raised bog in Sweden. The pool of AOX in this bog is at least 300 times larger than the present annual deposition. The total pool of AOX in peat in Sweden was estimated to be at least 300,000 metric tons. Potential artefacts in the analytical procedures used are discussed.