Mitigating Heavy Metal Burden
Source: Toxics Link, Date: February , 2011
At a time when the world is contemplating answers to the
global climate change demon, countless anthropogenic externalities are striking
us parallel and dearly; escalating heavy metal pollution and consequential
health impacts is one such menace. Alike the climate fight, the science has
risen to counter this threat rather late, with understanding, measures, means
and even success rate varying temporally and spatially. For example, toxicity
of lead (Pb) and mercury, both heavy metals, have been known since ages but
their far-reaching eco-health upshots became a matter of global concern only
recently while their several usages continue.
Applications where heavy metal usage are extrinsic, there are scientific
successes such as unleaded gasoline, unleaded household paints, membrane
technology in place of mercury process in chlor-alkali plants, non-mercury
alternatives to dental filling, digital thermometers etc. Similarly for
treating cut-woods copper and boron compounds have replaced arsenic compounds.
However, in segments like electronics and electrical, the alternatives are
still being experimented.
The technological advancements in sectors where heavy metals are geogenic, have
been partial and mostly remedial. For instance, growing legumes, cereals,
tomato, melons or even bio-energy crops in places known to contain heavy metals
intrinsically, substantially cut down their toxic trail in the food chain.
Inorganic methods such as lime application could reduce the heavy metal uptake
in crops by manipulating soil pH. Alternatives to coal based fuel (coal contain
natural mercury) especially in power generation and industries are still quite
There are areas where scientific management has answers to reducing heavy metal
burden. For example, growing electronic waste is now being countered with safer
components, design engineering and recycling and management of e-waste.
The new-age nano-science is claimed to have one-point solution in many fields.
However, nano has to cross numerous barriers counting that of toxicity,
ecological footprints and even ethical considerations to be finally accepted as
a wonder science.
In short, modern science might have solutions to the heavy metal menace but the
future control strategies would depend not only on the science that is logical
but also its management and enforcement. It has to be assimilative science. We
need to follow the lifecycle approach. First, build inventory to ascertain
sources of heavy metals pollution, qualify what’s essential and what’s not.
Non-essential uses can then be bracketed into something like ‘no-tolerance’
zone. Second, set priorities in ‘essential’ sphere, look for safer alternatives
and upscale. There can be immediate, intermediate and long-term priorities
based on technological advancement and economics. Remediation and the treatment
can be the final two steps. Critical would be the policy (science based and
dynamic) and its strict enforcement. The way forward is not to be trapped into
the vicious cycle and fall pray to the unknown. We need to change the way we
think about the ‘change’. We can’t accept a development model where we first
create the muck and then look for solutions to clean that up!