Pollution: A major problem in environment, its causes and effects...

Pollution 

Any detrimental change in the environment

Pollutant 

Any agent that triggering pollution 

Sources of Pollutants

• Mobile Sources
• Stationary Sources
• Point Sources
• Non-point Sources
• Area Sources

Effect of pollution

• Irritation and aesthetic 
•  insultProperty destruction
• Loss to Plants
• Mutilation to Animals
• Damage to Humans
• Disruption of Natural life system

Nature of Pollutants

Three factors determine the severity of effects of pollutants

It’s Chemical Nature: How active and dangerous it is to living being

 It’s Concentration: quantity / volume of air, soil, or water body being polluted

It’s Persistence: How long it stays in the air, soil or water body etc.

Air pollution

The term "air pollution" is used to describe elements that are artificially introduced into the air. Air pollution stanches from gases and airborne particles that are harmful to human health, buildings and ecosystems.

Presence of polluted materials in the air in certain conc. Prove dangerous to man and his environment

2 billion metric tons of pollutants/year

90% natural sources

10% anthropogenic

Types of air pollutants

They are mainly two types of air pollutants such as 

Primary pollutants 

These pollutants are openly emitted into the air, some of these:

• Particulate matter
• CO2
• SO2
• NOx
• Hydrocarbons

Secondary pollutants

These pollutants are formed by reaction between primary pollutants and atmospheric components.

• Ozone
• PAN-Peroxy acetyl Nitrate

Effects of air pollution

On vegetation:

• Destruct the leaf tissue, needles and fruits
• Lessening in growth rates/suppression
• Increased vulnerability to diseases, pests etc.
• Disruption of reproductive developments

On Humans:

• Toxic poisoning
• Cancer
• Birth blemishes
• Eye irritation
• Irritation of respiratory system
• Increased susceptibility to viral septicity, causing pneumonia, bronchitis
• Increased susceptibility to heart diseases
• Worsening for chronic diseases such as asthma and emphysema

On Animals:

• Impairment of respiratory system
• Damage to eyes, teeth, bones
• Increased susceptibility to diseases, parasites, and other stress-related environmental threats
• Decreased availability of food sources

Reduced capacity for successful reproduction

On soil and water resources

• Become toxic from deposition of pollutants
• Leakage of nutrients by acidic pollutants

On human-made structures:

• Discoloration, corrosion, and disintegration of building material
• 200 compounds of air pollutants are identified by US-EPA
• Mainly six standard are air toxics

        E.g. H2S, HF, VOCs, Benzene

• 150 million people are exposed by air pollution
•  Pollutants cause 300 000 deaths per year
• Annual health budget is US$50 billion

Particulate matter

Aerosols:

Aerosols are suspended particles of solid, liquid, or gaseous origin that do not obey the normal laws of gravity.

Particulate matter:

• These are solid or liquid particles that up in the air. Some features of particulate matter are:
• Most important size fractions are PM10, PM2.5, PM1

• Diameter of human hair is 60µm - 150µm
• Fine particulate matter can enter deeper into lungs and get absorbed into the blood stream
• Ultrafine particles are less than 0.18 mm in diameter
• Rich in organic compounds and other reactive chemicals
• Cannot be easily strained and can easily enter the blood stream
• Can contribute to infection (cell and tissue damage by oxidation) Leads to obstruction in the arteries that can result in heart attack and stroke. 
• The processes is involved in reduce the protecting quality of good cholesterol

Lead (Pb)

• Lead enters into environment by natural or anthropogenic sources and causes adverse effects on environment.  
•  Important components are automobile batteries and many other industrial products
• Added to gasoline to help protect engines and uphold more even fuel consumption

Sox (Oxides of sulphur)

• Toxic poisoning
• Cancer
• Birth blemishes
• Eye irritation
• Irritation of respiratory system
• Increased susceptibility to viral septicity, causing pneumonia, bronchitis
• Increased susceptibility to heart diseases
• Worsening for chronic diseases such as asthma and emphysema

Sources:

• Scorching of fossil fuels
• Industrial procedures like (petroleum refining to production of paper, cement, aluminum)

Adverse effects:

• These pollutants causes the acid rain
• Damage or even cause death to animals and plants
• Rusting the paint and metals
• Drastically harmful to human lungs and other animals

NOx (Oxides of Nitrogen)

• These are generally released as NO and NO2 into environment. 
• NO2 is a yellow-brown gas that turn into reddish-brown gas by oxidation
• It Can be altered into NO3-² ion, which lessens visibility

Sources:

• Vehicles, power plants and burning of fossil fuels

   Adverse effects:

• NO2 and NO combines to form Smog
• NO2 causes  Acid rain
• The smog and acid rain cause adverse effects on environment.
• Annoyance for eyes, nose, throat and lungs
• Increased vulnerability to viral infections – can cause respiratory tract infection, pneumonia, bronchitis
• Weaken the visibility in the form of nitrate that
• Suppresses plant growth.
• Nitrate, deposited on soil, can stimulate plant growth through nitrogen fertilization.

Carbon monoxide (CO)

• It is colourless and odourless gas
•  It is extremely toxic at even low concentrations
• It has high toxicity due to a physiological effect
• The Hemoglobin of blood takes up CO 250 times more rapidly than CO2 from the environment

 Sources:

• 90% natural, 10% from fires, vehicles and other sources of partial burning of fossil fuel

Adverse effects:

• Prolonged contact causes dizziness and headaches and even death
• May cause birth defects including mental retardation and diminishing the growth of foetus

Ozone (O3)

• It is a gas has no color but it is a faintly sweet odour
• Relatively unstable, releases 3rd O atom readily which oxidizes or burns things more rapidly
• Is also used to sterilize water – toxic and kills bacteria
• A photochemical oxidant results from the atmospheric exchanges of NO2 and sunlight.

Adverse effects:

• When breathe in, ozone can damage the lungs.
•  Its low volumes can cause (chest throbbing, coughing, quickness of breath and throat irritation).
•  It also cause deteriorates chronic respiratory diseases (asthma), compromise the ability of the body to contest respiratory infections.

                 Written by:  sumayya latif