Tag: secondary sector : industry

When humans burn fossil fuel sulfur dioxide (SO₂) and nitrogen oxides (NOx) are released into the atmosphere. These gases when react with rain water form nitric and sulphuric acids and result in acid rains. Death of fish in lakes and rivers in some countries has been attributed to such acid rains.

A yellowish or blackish fog is called smog. Smoke and fog combines to form smog. It is mainly formed by a mixture of pollutants in the atmosphere which consists of fine particles and ground level ozone. Smog occurs mainly because of air pollution. Smog also refers to hazy air that makes breathing difficult.  It causes various respiratory problems as well as irritation in eyes.

Lead is a cumulative toxicant that affects multiple body systems. Lead in the body is distributed to the brain, liver, kidney and bones. It is stored in the teeth and bones, where it accumulates over time. There is no known level of lead exposure that is considered safe. Lead can have serious consequences for the health of children. If lead accumulation occurs for long in body, it attacks the brain and central nervous system to cause coma, convulsions and even death. Children who survive severe lead poisoning may be left with mental retardation and behavioural disorders.

The cutting down of trees and clearing off the forests is known as deforestation. Deforestation is caused due to following reasons:- 

• Requirement of more land for housing and urbanization
  
• Harvesting timber to create commercial items such as paper, furniture and homes
  
• Cattle grazing
  
• Mining activities
  
• Cultivation
• Burning trees and clear cutting

An ecosystem can be defined as a biological community with interacting organism and their physical environment. Though urbanization and industrialization may disturb the ecosystem to an extent, introduction of toxins into environment will spoil the ecosystem from its roots.

Dichloro diphenyl trichloroethane (DDT) is a colorless, crystalline, tasteless, and almost odorless organochlorine known for its insecticidal properties and environmental impacts.