Heavy metals like lead, mercury, cadmium and arsenic are toxic to human health. They are produced by industrial activities and deposited in water and soil. Heavy metals occur near the bottom of the periodic table, have high densities, are toxic and non-degradable. They can be transported through water, food, air or adsorption onto materials. Common health effects include skin burns, kidney damage, vision problems, brain damage and death. Sources include pesticides, mining, coal combustion, wood preservatives and tobacco smoke. Methods to determine heavy metal concentration include atomic absorption spectrophotometry and X-ray fluorescence. Control methods involve vacuuming, replacing wood-burning appliances, removing old paints and

1. HEAVY METALS
Prepared by:
Srijan Kumar
M Tech In Environmental Engineering
Jharkhand University of Technology

2. 1.Introduction
• Heavy metals are toxic to human health.
• Most common heavy metals are lead(Pb),
mercury(Hg), cadmium (Cd) and arsenic(As)
• Indoor concentration of heavy metals is
generally less than their outdoor
concentration.
• They are mainly produced by industrial
activities, and deposit slowly in the
surrounding water and soil.

3. 2.Properties of heavy metals
• They occur near the bottom of the periodic
table.
• Have high densities.
• Toxic in nature.
• Non degradable.

4. 3.Transport phenomenon
• Water
• Food
• Air
• Adsorption or absorption onto various
materials
• Example: Over half of the heavy metal input
into Great Lakes is due to deposition from air.

5. 4.Mercury
• Most volatile of all metals.
• Highly toxic in vapor form.
• Liquid mercury itself is not highly toxic, and
most of that ingested is excreted

6. 5. Arsenic
• Arsenic oxides were the common poisons
used for murder and suicide from roman
times through to the middle ages.
• Arsenic compounds were used widely as
pesticides before the organic chemicals era.
• Arsenic is very much similar to phosphorous.

7. 5.Health effects
• Skin burns
• Irritation of nose and skin
• Rashes-
• Excessive perspiration
• Damage to the kidneys
• Damage to vision
• Minimata disease
• Dysfunctions of the central nervous system
• Loss of hearing and muscle coordination
• Severe brain damage
• Death

8. 7.Sources of HM
• Pesticides
• Mining, smelting of gold, lead, copper and nickel
• Production of iron and steel
• Combustion of coal
• Leachate from abandoned gold mines
• Used as a wood preservative
• Herbicides
• Tobacco smoke
• Wallpaper paste and pigments in wallpaper

9. 8. Determining of Heavy Metals
• Most common method of collecting particulate
matter is through filters.
• Identification and concentration of individual
trace metals like lead,cadmium, arsenic, mercury
and chromium is determined by
• 1: Atomic absorption spectrophotometry is a
destructive method and requires at least 1 to 2
ml of solution
• 2: X-ray fluorescence is a nondestructive method
and works independent of the chemical state of
the sample.

10. 9. Control methods
• Periodic vacuuming of the house can be effective
in removal of these pollutants
• Replacement of wood-burning by an equivalent
gas or electrical appliance
• Removal of old lead and mercury-based paints
• The effective method for removal of mercury
vapors is by the use of packed bed of absorbents.
• Gold-coated denuder can also be used for the
removal of mercury from air.

11. THANK
YOU