Lecture 2 – Airborne Hazards and Human Health: January, 18, 2012
Case Study 1: London smog, 1952:
Since the industrial revolution, the amount of smog has increased but not until 1952 did
people realize that something must be done
At that time everyone relied on burning coal. Soft coal was used and when this coal was
burned sulfur dioxide is released as a by product.
People got chocked because of sulfur dioxide
It was very difficult to drive because there would be smog everywhere
About 4000 people died
The relationship between smoke and sulfur dioxide pollution and deaths:
British government realized that something has to be done so government introduced
British Clean Air Act and others followed.
Even with the act, cities are still polluted and new pollutants are created.
What the British government did first was replace coal with something more efficient.
Case Study 2: Indonesian Fires, 1997:
Very common practice is Slash and Burn where trees are burned to clear the land.
In 1997, this year was different, the year was dry and rain arrived later than usual,
therefore the fire was uncontrolled and a tremendous amount of gases were released into
Mesus (rain) arrived and extinguished the fires.
Sources of Outdoor air pollution:
Nature could be a source such as volcanoes
Human sources can be divided into two categories: Stationary like industry, homes and
mobile like cars.
Primary air pollutants react in the atmosphere to become other products (secondary air
Health effects of outdoor air pollution:
The effects depend on how long someone will get exposed and dose or concentration.
Asthma is a difficulty in breathing
Tremendous cases of asthma increasing
Chronic bronchitis – excessive amount of mucus cause strong cough
Pulmonary emphysema – person has shortness of breath
Lung cancer and heart disease have also increased because of air pollution
Toxic poisoning – carbon monoxide can cause toxic poisoning because people can die
from it Eye irritation – smoke can irritate the eyes.
Air pollution can cause birth defects – more research
Seven common outdoor air pollution:
Liquids as well as salts
Two big groups of particulate matter: PM10 and PM2.5
Research has been focused on PM2.5 because these small particulates are more
dangerous because they can travel farther into our system.
These small particulates are released from internal combustion (in vehicles)
Chemical composition of particles also matters because of different toxicology per
If your exposed to high levels of CO, you will not know, when your exposed to it you
If someone is exposed to high levels of CO, the person will lose coordination and have
CO are outside
Belongs to group called photo chemical smoke
They are not product of burning of coal, mostly from internal combustion
Not very much soluble in water therefore when it comes into contact with our body
they will not dissolve in water and will travel into our airways and damaged our
lungs. They may also damage upper airways when we exercise
Air pollution is not a localized problem, it’s a global problem
12% of soft coal come from China
Very well soluble in water
Easily dissolve and mostly affect upper airways
VOC (Volatile Organic Compounds):
Volatile, as soon as you open the “can” you smell them
All hydrocarbons are volatile organic compounds. Lead:
Gasoline use to have