HLSC 4P04 -- Air and Air Pollution

Lecture 3

Air Pollution

The presence of toxic chemicals or compounds (including those of biological origin) in the air, at levels that pose a health risk; lower the quality of the air or cause detrimental changes to QOL (e.g., damaging ozone layer or causing global warming)

Air is a mixture of what gases? What is considered clean air?

• Air is a mixture of gases - nitrogen, oxygen, carbon(IV) oxide, water vapor and noble gases

• Clean dry air is mostly (99%) nitrogen gas and oxygen gas (very little percentage of the other gases mentioned + dust particles)

What was Earth's early atmosphere like 4.5–5 billion years ago compared to now?

It was similar to the gas mixture released by volcanic eruptions, including water vapor, carbon dioxide, and nitrogen. Todays atmosphere comes from green plants through photosynthesis

What type of early organisms began producing oxygen through photosynthesis and how did it contribute to atmospheric oxygen?

Cyanobacteria (blue-green algae) uses sunlight and carbon dioxide to produce organic compounds, they released oxygen as a byproduct.

Major pollutants in outdoor air are:

– particulate matter (PM),

– ozone (O3),

– sulfur dioxide (SO2),

– nitrogen dioxide (NO2),

– carbon monoxide (CO),

– Lead (Pb)

What does the State of Global Air 2024 report highlight about air pollution?

That air pollution is a permanent global health threat, although serious recognition came only after major pollution events

What happened during the 1948 air inversion in Donora, Pennsylvania?

• Heavy smog and carbon hung in the air

• 20 people died within 36 hours

• 7,000 became sick

• Visibility was poor and air was dirty

What was the impact of the 1952 “Great Smog” in London, England?

• Lasted 5 days

• Over 4,000 deaths occurred

• The elderly and people with chronic conditions were most affected

What is an air inversion and why are they dangerous?

A weather condition where a layer of colder air is trapped beneath warmer air, preventing pollutants from rising and dispersing. They are dangerous because they trap pollutants close to the ground, allowing them to accumulate and harm human health.

Which cities besides Donora and London have experienced serious air pollution events?

New York and other major cities have gone through pollution alerts due to hazardous air conditions

Who is especially vulnerable to the effects of air pollutants?

People with asthma, people with Chronic Obstructive Pulmonary Disease (COPD), the elderly

What does the health impact of air pollution depend on?

The components and sources of pollutants, which vary by country, season, and time.

What are major outdoor sources of air pollutants in developing countries?

Combustion of solid fuels, transportation emissions, industrial production, forest fires, garbage burning, and agriculture-related burning.

What are fine particles (PM2.5)?

Particulate matter 2.5 micrometers or smaller, from combustion processes like motor vehicles, power plants, wood burning, etc.

What is the largest single source of airborne particulate matter (PM) in major cities?

Diesel exhaust particles, which may account for up to 90% of airborne PM.

How do indoor and outdoor air pollution compare?

Indoor air contains many of the same pollutants, but often at different concentrations, and may include additional indoor-specific sources.

What are major indoor air pollution sources in developing countries?

• Solid fuel combustion (biomass, coal) for cooking/heating

• Poor ventilation

• Stoves without chimneys

• Tobacco smoking

What are additional sources of indoor air pollutants?

• Construction materials (e.g., radon gas)

• Furniture chemicals (e.g., formaldehyde, benzene)

• Poorly maintained ventilation/AC systems

Why are formaldehyde and benzene concerning as indoor pollutants?

Due to their high concentration levels and hazardous health effects.

What actions can vulnerable individuals take to reduce exposure to air pollution?

• Monitor air quality

• Limit outdoor time when pollution is high

• Wear masks

• Improve indoor air quality

How can indoor air pollution be reduced in developing countries?

• Use clean fuels

• Improve stoves for more efficient burning

• Ensure emissions are vented outdoors

What are some health effects of environmental tobacco smoke (ETS)?

• Increased lung cancer, stroke, acute coronary syndromes

• Higher respiratory symptoms

• Inflammation

How does ETS affect children and infants?

• Causes acute respiratory infections

• Linked to sudden unexpected death in infancy (SUDI)

• Children made up 34% of health loss due to ETS in NZ (2006)

What did research find about ETS and pediatric pancreatitis?

• Second-hand smoke exposure may increase hospital admission rates and length of stay (LOS).

• Children with CFTR mutation are at higher risk.
  (Source: Ballengee CR, 2019)

What harmful substances are found in tobacco smoke?

• Over 5,200 components, including PAHs, heavy metals, aromatic amines, N-nitrosamines.

• PAHs are often carcinogenic, mutagenic, and cytotoxic.

What did Vanker (2018) find about indoor pollution and pregnancy?

Indoor pollution and tobacco use in pregnant mothers were linked to early respiratory infections in infants.

How can exposure to ETS be measured in children?

Through urine cotinine/creatinine ratio and household smoking history.

What sources of pollution existed in Civitavecchia, Italy?

• Three thermoelectric plants

• A cement factory

• Harbor emissions (industrial traffic and high-sulfur fuel)

What pollutants were found in Civitavecchia’s industrial emissions?

• Particulate matter (PM10)

• Nitrogen oxides (NOx)

• Sulfur dioxide (SO2)

• Dusty materials and high-sulfur fuel emissions from ferries and trucks

What health risks were associated with PM10 exposure in Civitavecchia?

• All-cause mortality (HR=1.06)

• Cancer (HR=1.11)

• Cardiac disease (HR=1.12)

What health risks were associated with NOx exposure from traffic?

• Cancer (HR=1.13)

• Neurological diseases (HR=1.50)

What risks were found for those living near the harbor?

• Higher lung cancer risk (HR=1.31)

• Higher neurological disease risk (HR=1.51)

Which cancers had elevated mortality linked to pollution in the study?

• Pancreatic cancer (HR=1.49)

• Pleural cancer (HR=3.75)

• Kidney cancer (HR=1.79)