Environmental effects of polyhalogen compounds
(Methylene chloride CH2Cl2)
Dichloro methane is very harmful
It affects the human central
Direct contact with eye damages
Lower level exposure of dichloro
methane in air causes slight impairment of vision and heavi
Higher level exposure of dichloro
methane in air causes dizziness, nausea, numbness in fingers and toes
Chloroform when exposed to air
and light forms a poisonous compound phosgene.
Inhaling chloroform vapous
depress central nervous system causes dizziness, fatigue and head ache.
Chronic exposure of chloroform
may cause damage to kidneys and liver.
Tri iodo methane
Tri iodo methane has strong
It causes nausea and vomiting
It may cause eye irritation and
Tetra chloro methane
Carbon tetrachloride has severe
adverse health effects.
On exposure it causes eye
irritation vomiting sensation, dizziness, unconsciousness or some time death.
When carbon tetra chloride is
released to air, it rises to the atmosphere and depletes ozone layer
Depletion of ozone layer,
increase the human exposure to uv rays, which leads to skin cancer and
suppresses the immune system.
Freons chloro fluoro
Freons are highly volatile and
stable in nature (life time is more than 100 years)
Due to this they easily more up into
the stratosphere and reacts with ozone causing ozone depletion
(discussed in detail
in unit – 15)
Dichloro diphenyl tri chloro ethane
DDT is toxic, persistent and bio
accumulative and store in fatty tissues.
Highly persistent toxic DDT are
transferred from lower trophic level to higher trophic level through food
chain over the time, the concentration of toxins in higher animals causes
serious metabolic and physiological disorders.