Lecture 2: Air Pollution Overview

Today’s 6 air pollution problems

1. ozone smog

2. fine particulate matter

3. hazardous air pollutants

4. occupational exposures

5. indoor air quality

6. exposure to multiple pollutants

what are the human sources of air pollution

1. stationary

2. mobile

what are the natural sources of air pollution

1. tree

2. wildfire

3. wind-blown dust

4. volcanoes

definition of sattionary sources

an immobile source of pollution, such as a power plant or industrial facility

definition of mobile sources

vehicles, engines, and equipment that move or can be moved from place to place and emit air pollution

what is an on-road source

type of mobile source, these are vehicles that use public roads to transport passengers or freight

ex. passanger cars or motorcycles

ex. buses and trucks

what is a non-road (off-road) source

type of mobile source, inclues wide range of quipment and vehicles not used on public roads

ex. construction and agricultural equipment

ex. air crafts

ex. lawn and garden equipment

definition of natural sources

air pollution not caused directly by human activies

how are volcanoes an example of natural sources of pollution

they release SO2, volvanic ash can be inhaled, causing respiratory problems, and can travel long distances, damaging crops and contaminating water supplies

explain dust as an air pollutant (what is it, what makes it worse, what is a concern)

• wind picks up and transports soil particles releasing them into the atmosphere

• dust emissions are exasterbated by factors like lack of vegitation and loose, dry soil.

• agriculture and land disturbance increase dust storm freq.

• increasing concern due to climate change

explain pollen as an air pollutant (what is it, what is a concern)

• trees and other vegetation release pollen, a type of particulate matter that acts as an allergen to many

• climate change is extending the pollen season, introducing pollen problems in new geographies

explain wildfire smoke as an air pollutant (what is it)

produces a complex micture of pollutants like PM, NOx, CO, VOCs) that significiantly degrade air quality and pose health risks to nearby populations and beyond

What are local examples of air pollutants (short atmospheric lifetime)

• PM (primary)

• Sulfure dioxide

• nitrogen dioxide

• Lead

• Carbon monoxide

what are regional air pollutants (moderate atmospheric lifetime)

• PM (Secondary)

• Ozone

• wildfire smoke

what are global air pollutants (long atmospheric lifetime)

• greenhouse gases (ex. CO2 and methane)

four air pollution categories

1. criteria air pollutants

2. Hazardous air pollutants

3. Primary air pollutants

4. Secondary air pollutants

what are primary air pollutants

emitted directly from a source into the atmosphere

ex. CO, SO2, and PM

What are secondary air pollutants

form in the atmosphere through chemical reactions between primary pollutants or with other atmospheric substances

ex. ground-level ozone, secondary PM

What is the clean air act

federal law that regulates air emissions from stationary and mobile sources.

• law authorizes EPA to establish National Ambient Air Quality Standards (NAAQS) to protect public health and to regulate emissions of hazardous air pollutants

what is National Ambient Air Quality Standards (NAAQS)

federal air quality limits set by EPA under the clean air act

what are the Clean Air Act Criteria Air Pollutants(6) for NAAQS?

CO, Lead, NO2, Ozone(O3), PM, SO2

What is particulate matter (PM)

a complex mixture of extremely small particles and liquid droplets suspended in the air

difference between PM2.5 and PM10

PM10: fine particles smaller than 10 micrometers that can be inhaled into the lungs

PM2.5: fine particles smaller than 2.5 micrometers, more dangerous because they can travel deeper into the respiratory tract and even enter the bloodstream

main health effects of PM

• can cause premature death in people with heart or lung disease

• nonfatal heart attacks

• aggravated asthma

• decrease lung function

key sources of PM

• vehicle exhaust, power plants, wildfires, industrial processes, and construction sites

• can be emitted directly or form through building blocks in the atmosphere

what is Ozone (O3, Smog)

a harmful air pollutants that forms near the ground (troposphere) when nitrogen oxides (NOx) and volatile organic compounds (VOCs) react chemically in the presence of sunlight

• different than the protective ozone layer in the stratosphere

main health effects of Ozone (O3, smog)

• can cause coughing, chest pain, throat irritation, and shortness of breath

• trigger or worsen asthma attacks

• permanently damage lung tissue with repeated exposure

key sources of Ozone

• emissions from motor vehicles, industrial facilities, and electric utilities

• only formed chemical reactions amongst primary pollutants (NOx and VOCs) in the atmosphere

What is the “formula” for Ozone (O3) formation

NOx + sunlight +VOCs = O3

what are volatile organic compounds (VOCs)

any organic compound that participates in atmospheric photochemical reactions

ex. Formaldehyde, Benzene, Acetone

What is nitrogen dioxide (NO2)?

a reddish-brown, highly reactive gas that is part a group gases called nitrogen oxides (NOx)

health effects of NO2

• irritate airways

• aggravate respiratory diseases

• can contribute to the development of asthma (and other disease)

key sources of NO2

• fuel combustion in cars, trucks, buses, power plnts, and off-road equipment

• key ingredient in ground level ozone formation

what is sulfuer dioxide (SO2)

highly reactive gas, part of sulfur oxides

health effects of SO2

• short termexposure can harm respitory system, making breathing difficult

• contributes to secondary formation of PM

key sources of SO2

• primarily emitted from burning of fossil fules (coal and oil) at power plants and industrial facilities

• other sources include locomotives, ships, metal extraction from ore

what is lead

a toxic metal found naturally in he environment and in manufactured products

main health effects

• lead can harm the nervous syste, kidneys, and immune system

• children especially vulnerable- slowed growth, behavioral problems, etc.

key sources of Pb

• the phase out of leaded gasoline has reduced emissions

• primary sources today are industrial processes like metal precessing

• waste incineration

• piston engine aircraft operating on leaded aviation gasoline

what is carbon monoxide (CO)

a colorless, odorless, and poisonous gas that is formed when carbon in fuel doesnt burn completely

main health effects of CO

• when inhaled it enters the bloodstream and reduces oxygen delivery to organs and tissues

• can cause headaches, dizziness, impaired vision, and coordination problems

• can be patal to people with heart disease

key sources for CO

• motor vehicle exhaust is a major source

• industrial processes and inefficiently burning furnaces and appliances

what are Hazardous Air Pollutants (HAPs)

also known as toxic air pollutants, are air pollutants not covered by ambient air quality standards (NAAQS) but which as defined int he Clean Air Act, may present a threat to human and environmental health

where does radon gas come from

from the natrual decay of uranium found in nearly all soils and rocks

explain radon in Wi issue

Seaps into houses from the ground of old houses build on radon covered soils and rocks, can accumulate to dangerous levels and cause lung cancer