Mercury has transformed into a key concentration of concern for every country around the world, as developing countries as well as developed countries are also affected by and experiencing its effects on health and the environment.
Pollution has many structures, the air we inhale, the water we drink, the soil where we grow our food crops and even the growing noise we hear commonly add to all medical problems and lower personal satisfaction.
Various industries discharge toxic heavy metals into the environment that considerably enhanced the humiliation of our marine environment and significantly threats the ecosystem. These heavy metals are characteristic part of the earth’s crust and their continuous leaching causes the contamination of air, water, and food; due to which a minor extent of these metals indirectly enter into the human bodies. These unwanted chemicals cause severe health problems, when they exceed their tolerance limit.
Mercury (atomic weight: 200.59) is heavy and silvery colored metal liquid at room temperature. It has density of 13.53 g mL-1 with three available oxidation states (0, +1, +2). It has a frequent use in modern batteries and cells, thermometers, thermostats, switches, vacuum pumps, fluorescent and energy saving lights, tooth fillings, medicines, cosmetics and electrical components.
In recent years, as awareness about the harmfulness of mercury has increased among people, most of the medicines have become obsolete. It is now become a a toxic and non biodegradable heavy metal that can be generated by several sources, such as pharmaceuticals, textile industries, chlor-alkali, paint, pulp and paper, oil refining, electrical, rubber processing, and fertilizer resulting in contamination of eco system (including; air, water, and soil).
The toxic and carcinogenic effects of mercury on living beings are quite well known. Its bio accumulative nature increase its tendency for binding protein and to affects the endocrine and central nervous systems. The signs of mercury toxicity include severe neurological disorders particularly paralysis, blindness, liver and brain harm, chromosomal damage and many times its excess level create birth defects. ‘Minamata’ is one of the mercuric disease that originate mental disturbance, speech / sight / and hearing difficulty due to acute toxicity of mercury.
The chemical state of mercury (inorganic / organic) is also responsible for its hazardous effects; for example, inorganic mercury has a very high affinity for protein sulf – hydryl groups, which is henceforth gathered in the kidneys, whereas organic mercury has a great affinity for the brain. The capability of living organisms to convert inorganic mercury to organic mercury compounds increases the hazard of its exposure even at trace levels.
Long term exposure of mercury can result in brain damage and in extreme cases, death. Typically, mercury metal gather in living tissues and in this way, replicate the risk. The health hazards of mercury ingestion accordingly are of wide range. Only in few of the cases it cause physical distresses while in many circumstances it may bring life – threatening illness, harm to indispensable body framework, or cause different harms. Consequently, it is extremely important to control emanation of mercury heavy metal at trace and ultra-trace levels into the environment.
Conclusively, to decrease the high concentrations of mercury ions up to the permissible levels (i.e., recommended by the World Health Organization: 1 ppb (0.001 mg L-1) from aqueous solution, various physic – chemical processes such as chemical precipitation, electrode deposition, reverse osmosis and evaporation electrolysis, ion exchange, adsorption, cementation, membrane filtration, and liquid liquid extraction have been introduced and still new cost effective remediation methods are launching by many researchers.
Dr. Umer chattha