Environmental impact—heavy metals

Environmental impact—heavy metals

Environmental Impact—Heavy Metals

Features and Common Sources of Heavy Metals

• Heavy metals are naturally occurring elements that have a high atomic weight and a density at least 5 times greater than that of water.
• They consist of elements such as lead, mercury, cadmium, zinc, copper, nickel, and arsenic.
• Common sources of heavy metals include industrial effluents, domestic sewage, mining, atmospheric deposition, and metallurgical industries.

Toxicity of Heavy Metals

• Unlike organic pollutants, heavy metals are not biodegradable and tend to bio-accumulate in living organisms.
• Heavy metals are known to be toxic at low concentrations to a variety of organisms and can interfere with various biochemical processes.
• Exposure to heavy metals can lead to various health hazards such as neurological and behavioural disorders, cancer, kidney damage, and developmental disorders.

Heavy Metal Contamination in Soil

• The accumulation of heavy metals in soil can lead to toxicity in plants, leading to reduced growth and productivity.
• It can also impact soil health by altering microbiological and biochemical attributes, thus affecting soil fertility.
• The mobility of heavy metals in soil can lead to groundwater contamination, affecting the quality of surface and underground water.

Heavy Metal Contamination in Water

• Heavy metals can enter water bodies via industrial discharges and can accumulate in the aquatic ecosystem, causing biological magnification.
• Aquatic life can be severely affected upon exposure to high concentrations of heavy metals, potentially leading to a decline in their population.
• Consumption of contaminated water or seafood can lead to serious health risks in humans and other terrestrial animals.

Remediation Techniques for Heavy Metal Contamination

• Remediation techniques for heavy metal contamination include phytoremediation, where plants are used to absorb and accumulate heavy metals from the environment.
• Adsorption technique involves using materials such as activated carbon, clay, and biomass to adsorb heavy metals from water.
• Chemical methods such as precipitation, ion exchange, and membrane filtration can also be used for heavy metal removal from water.

Sustainable Practices to Minimise Heavy Metal Pollution

• The use of clean technology in industries can significantly reduce the emission of heavy metals into the environment.
• Regular monitoring and regulation of industrial discharge can help keep heavy metal contamination in check.
• Public awareness and education about the sources and dangers of heavy metals can promote more responsible usage and disposal of heavy metal-containing products.

Environmental Regulations

• The control of heavy metal release rests largely on environmental regulations enforced by governments and related bodies.
• These regulations set standard limit values to major parameters related to heavy metals such as acceptable levels in soil, water, and air.
• Strict enforcement and implementation of these regulations are crucial in controlling heavy metal pollution.