air pollution. mexico city clear day not so clear day

Air Pollution

Mexico City

Clear Day

Not soclear day

Smokey Mountains

Smog – US, global

Denver Houston

BeijingTokyo

Smog

When air pollution hangs over urban areas and reduces visibility.

Atmosphere – the gaseous envelope surrounding the earth

Air pollution• The presence of chemicals in the air in high

enough quantities to cause harm

Sources of Air pollution

Mobile

Stationary

Vehicles Forest Fires

Power plants Volcanoes

Man Made Natural

Primary Pollutants

• CO• CO2

• SO2

• NO• Volatile organic compounds• Particulate matter – “stuff” floating in the air

– Ex: soot from smoke, fine cement particles

Pollutants emitted directly into the air by human activity

Secondary Air Pollutants

• SO3

• H2O2

• O3 – ground level ozone

When primary pollutants react with one another or the air to form another pollutant

Motor Vehicles

• Produce the most air pollution by burning gas

Clean Air Act 1970• Gave the EPA the authority to regulate car emissions

– Unleaded gasoline– Catalytic converters – clean exhaust – makes water

ZEV’s

• Zero-emissions vehicle– No tailpipe emissions– No gas emissions– No emission control system

• Electric cars – only true ZEV• Partial ZEV’s

– Hybrids– Methanol fuel cells

Temperature inversion• What is it?

Why is it bad?

© 2003 John Wiley and Sons Publishers

Fig 23.16 Two causes for the development of atmospheric inversion, which may aggravate air pollution problems.

LA or LimaLA or Lima

LondonLondon

• How does Temperature inversion affect Knoxville?

Donora, PADonora Death Fog

Donora, PA

October 1948 air pollution event killed at least 20 and hospitalized close to half of the town. Public outcry helped set in motion early air pollution regulations.

Alcoa??

“Pea Soup”London smog

12000 people died prematurely

What do you thinkcaused all the smog?

Factors that help reduce air pollution

• Precipitation (rain, snow)• Sea spray• Wind

Factors that increase air pollution

• Urban buildings• Hills/mountains• High temperatures

Acid rain – Precipitation that contains high concentrations of acid

• 3.5 – 5.0 on the pH scale (about as acidic as tomato juice)

• Normal is about 5.8 – 6.0• Causes acidification – a rise in the acidity

of soil and water– Some nutrient are dissolved– Some toxic chemicals are released

Smokey Mountains

Acid Shock

• When acid snow melts and large amounts of acid rush into water.

• Kills many aquatic species

Forests of Vermont – dyingCoal burning in Ohio Valley

What harmful effects does it cause to humans?

• Resperatory disease– Bronchitis– Asthma

Other ways acid rain can cause damage

• Can leach toxic metals in to water source• Damages metals, statues, buildings etc.• Water and soil pollution

What can we do?

• Reduce emissions• Limestone in lakes

– Expensive– Temporary– Kills some aquatic life

• Fertilizers?

Indoor Air Pollution• Usually 2-5 times higher than outdoors• Can be 100 times greater

As much as 18 timeshigher in a car

• On average people spend 70-98% of their time indoors or in their cars.

Sick building syndrome • Bad pollution - causes dizziness, headaches,

coughing, sneezing, etc.• New buildings worse than old ones

– B/c there is less air exchange to save energy– Chemicals from new furniture and carpet

=

Most dangerous indoor air pollutants

• Cigarette smoke• Formaldehyde (fabrics)• Radioactive radon (in rocks)• Fine and ultrafine particles

Other Indoor Pollutants

• Radon – colorless, tasteless, odorless gas– Radioactive and causes lung cancer– Found in rocks below your home– Second leading cause of lung cancer in US

• Asbestos – used as a heat insulator– US banned its use in the early 1970’s– Causes asbestosis

How your body helps you

• Nose hairs• Mucus• Coughing/sneezing

Too much exposure

• Asthma• Chronic bronchitis• Lung cancer• Emphysema 

Good News

• The Laws are working• Between 1970-2001 

• there was a 25% decrease even though – population 32%

– energy consumption 42% – vehicle travel 150%

Bad News

• Nitrogen Oxide levels have 15%• Surface ozone has increased• 133 Million people still live in unhealthy

areas

Improvement

• We need to prevent not just clean• Better fuel efficiency• Better regulation of small motors• More CO2 reduction

Noise Pollution

• Unwanted sound• 12 of teens have permanent hearing loss

– Caused by headphones• Headphones are not regulated in the US• In Europe they cannot be louder than 100dB

Light Pollution

• No health effect• Diminishes views of the sky• Wastes energy

– Lights that shine into the sky• Billboards• Poor street lights