GLOBAL warming could release thousands of tonnes of toxic pollution trapped
in Britain鈥檚 peat bogs, poisoning rivers and threatening wildlife, say
government scientists. Badly contaminated bogs in other parts of Europe, Russia
and North America may present just as much of a threat.
Over centuries, bogs have soaked up the heavy metals that industry releases
into the atmosphere, combining them with organic materials in the peat. The
danger now, according to a forthcoming report by the Centre for Ecology and
Hydrology in Bangor, Gwynedd, and Windermere, Cumbria, is that climate change
will dry out the bogs, letting the metals escape back into the environment.
Researchers found levels of lead and cadmium in excess of Dutch and German
safety limits, which are lower than those in England, in 7 out of 10 bogs in
northern England and Scotland. Nickel levels in 8 bogs and zinc in all 10
exceeded stricter limits which the researchers believe are necessary to protect
the environment.
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Heavy metals can interfere with soil microbes, kill insects, stunt the growth
of plants and disable the gills of fish. The report, which Scottish Natural
Heritage will publish in the spring, concludes that all of the bogs are likely
to be damaged by the contamination.
Ed Tipping from the Windermere centre says that the increase in droughts
expected this century will oxidise sulphur pollution in the bogs, and as a
result sulphuric acid will leach more metals from the peat. 鈥淏ecause of their
sensitivity to climate change, bogs may stop storing pollution and start
releasing it,鈥� he says.