MERCURY:
Mercury is a naturally-occurring chemical element found in rock in the earth's crust, including in deposits of coal. It exists in several forms: methyl mercury and other organic compounds, elemental (metallic) mercury, and inorganic mercury compounds. Mercury becomes a problem for the environment when it is released from rock and ends up in the atmosphere and in water.
Sources Of Mercury:
Mercury gets into the air from a number of sources, emission from power plants, wildfires and emission from volcanoes, burning of municipal waste, Burning oil that contains mercury, burning wood that contains mercury and consumer products that contain mercury, like electronic devices, batteries, light bulbs and thermometers that are thrown into garbage that is incinerated.
Major Source of Mercury in Pakistan:
In Pakistan the major source of mercury is the emission from power plant, industrial waste discharge in water bodies and the burning of solid waste and agriculture waste. Textile and glass industries are found to be major mercury effluents also solid waste disposable sites in all areas of provinces of Pakistan.
Mechanism of Mercury Toxicity:
Once in the air, mercury eventually settles into bodies of water like lakes and streams, or onto land, where it can be washed into water. Microorganisms in water bodies can change it into methyl mercury, where it builds up in fish and shellfish. At high levels of exposure, methyl mercury’s harmful effects on animals include death, reduced reproduction, slower growth and development, and abnormal behavior. The main way that people are exposed to mercury is by eating fish and shellfish that have high levels of methyl mercury. Mercury affects the nervous system, causes reproductive abnormalities, kidney failure, and emotional instability, affects lungs and immune system of all ages. High levels of methyl mercury in the bloodstream of babies developing in the womb and young children may harm their developing nervous systems, affecting their ability to think and learn.
Management Of Mercury:
1) Implementing Laws:
• The Clean Air Act regulates 188 air toxics, also known as “hazardous air pollutants.” Mercury is listed as one of these air toxics. The Act directs EPA to establish technology-based standards for certain sources that emit these air toxics. Those sources also are required to obtain Clean Air Act operating permits and to comply with all applicable emission standards
• Under the Clean Water Act, states adopt water quality standards for their rivers, streams, lakes, and wetlands. These standards identify acceptable pollution levels in water for many pollutants, including mercury. These levels must be met in order to protect human health, fish, and wildlife.
2) Treatment:
• If your mercury levels reach a certain point, your doctor will have you do chelation therapy. Chelating agents are drugs that remove the metal from your organs and help your body dispose of them. Long term, you may need continuing treatment to manage the effects of mercury poisoning, such as neurological effects.
Case (mercury intoxication):
More than 40 per cent of Pakistanis living in urban areas are exposed to mercury contamination through dust particles and bioaccumulation, says a new study. The study published last month (November) in Science of the Total Environment, amassed hair samples from 22 sites in five zones in Pakistan — Swat Valley & Gilgit-Baltistan regions, Kashmir Valley, Lower Himalaya Mountains and Indus Plains. The study which provides the first baseline data for total mercury contamination showed the heavy metal concentrated in agricultural and industrial areas in the lower Indus plains. Scalp-hair was preferred for the sampling because it readily absorbs mercury and other trace metals from the environment, explains Hussain. The researchers found industrial and hospital waste discharges as key sources of the mercury pollution in the surveyed areas. Mercury affects the nervous system, causes reproductive abnormalities, kidney failure, emotional instability, gingivitis and tremors or the shivering of body parts often initially with hands before spreading to other parts of the body.