Good job bringing this to light. People won't realise how huge the problem is and municipalities are woefully ill equipped to...
Agreed; mining can never be sustainable, but then how do you get the metals to make all the things you need in the course of...
Very good piece.
AS A result of industrial and mining
operations, extensive acres of agricultural
land are poisoned worldwide due to toxic
effluents. Scientists at Oxford Universitv
LJK, have found a possible solution to this
growing menace by producing genetically
engineered cabbages, cauliflowers arid
Brussels sprouts, that would soak up
toxic metals and consequently cleanse
polluted soils at a much lower cost than
that engendered by chemical treatment.
Then, these nictal-rich crops can be harvested arid burnt to reclaim metals for
recycling (Spectrum, No 254).
Alyssum, a small common plant with
white flowers widely grown along garden borders, was investigated by
Andrew Smith of the department of
plant sciences at Oxford and was found
to be a hyper-accumulator of metals.
The absorbed metals acted as a protective shield, too, on the plant as this gave
the plant a bad taste, thus preventing
birds and insects from feeding on it.
The mechanism by which plants are
able to accumulate these metals without
letting them interfere in their biochemistry is still unknown. The potentiality of plants in being able to do this is
making them important in transforming
wastelands into agricultural land.
Scientists have been able to discover a
particular molecule - histicline - that
does this metal binding. Histidine
accumulates in large quantities in plants
that are able to store nickel.
To experiment on this, Smith
sprayed histidine solution around
Alyssum species which cannot tolerate
toxic metals. As histidine was absorbed,
the plants were temporarily able to
tolerate metals effectively, but this
lasted until histiclinc broke down and
disappeared. However, such a wav
of spraying histiclinc is not practically
possible on a large scale. Therefore, an
alternative and effective way was to alter
the genetic constitution of the plants, so
that they can themselves produce large
quantities of histiclinc. For doing this
the genes which produce histicline need
to be identified and isolated. This will
then make it possible to modify a large
number of plants genetically so that they
can - in situ - produce histidine and
consequently, get transformed into
Smith hopes to be doing all this
on his selected brassicas (a family of
plants which includes Brussels sprouts,
cauliflowers and broccoli) which have
extensive root systems. After transformation into metal-accumulating plants,
they will prove to be very effective in
decontaminating polluted soils.
Unfortunately, such vegetable grown
on industrial wasteland will surely not
be edible in the first few years. But they
will help in cleaning Lip the soil at a
much lower cost.