Environment in the News

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Air and Air Pollution

Chapter 8

Long-Distance Transport of Air Pollution

  • Global Distillation Effect:
  • Chemicals enter the atmosphere in warm regions and are moved to cooler areas.
  • Yukon, Northern Canada
  • Chemicals concentrate (bioaccumulate) in the body fat of animals at the top of the food chain
  • A single bite of whale skin contains more PCBs than what is safe to consume in one week
  • Breast milk of Inuit women (where whale is part of the diet) has 5 times more PCB than in women in Southern Canada

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Long-Distance Transport of Air Pollution

  • Atmospheric conditions blow pollution from Asia to America across the Pacific Ocean
  • Many countries have policies and regulations to limit pollution from being transported

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Long-Distance Transport of Air Pollution

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  • Learning Objectives:

Define atmosphere and list the major gases comprising the atmosphere

Briefly describe the four major concentric layers of the atmosphere

Define Coriolis effect

The Atmosphere

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The Atmosphere

  • Atmosphere
  • Gaseous envelope surrounding the Earth
  • Oxygen and Nitrogen = 99% of dry air
  • Other gases = 1%
  • Water and traces of air pollutants
  • Four concentric layers:

Troposphere

Stratosphere

Mesosphere

Thermosphere

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The Atmosphere

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The Atmosphere

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Environmental InSight

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The Atmosphere

  • Atmosphere
  • Ecosystem Services:
  • Protects Earth from UV radiation, x-rays, cosmic rays
  • Keeps Earth’s temperature within living range
  • Organisms depend on the atmosphere
  • Organism modify and balance the atmosphere
  • Photosynthesis
  • Respiration

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The Atmosphere

  • Atmospheric Circulation
  • Global Circulation Patterns
  • Differences in air temperatures drive circulation
  • Hot air near Equator expands and rises
  • As it rises, it cools and sinks again
  • Convection process causes air currents that mix warmer and cooler parts of the atmosphere
  • moderates temperatures over Earth’s surface
  • Winds
  • Smaller-scale horizontal movements
  • Fluctuations in atmospheric pressures
  • Planet’s rotation

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The Atmosphere

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The Atmosphere

  • Wind
  • Smaller-scale horizontal movements
  • Fluctuations in atmospheric pressures
  • Air pressure is variable depending on altitude, temperature, and humidity
  • Winds blow from areas of high pressure to areas of low pressure
  • The bigger the difference between the high and low pressures, the stronger the winds
  • Planet’s rotation
  • Coriolis effect
  • Prevailing Winds
  • Polar Easterlies
  • Westerlies
  • Trade Winds

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The Atmosphere

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Global Climate Change

What gases make up the atmosphere?

What two layers of the atmosphere are closest to Earth’s surface? How do they differ from one another?

What is the Coriolis effect, and how does it influence atmospheric circulation?

Types and Sources of Air Pollution

  • Learning Objectives

Define air pollution and distinguish between primary and secondary air pollutants

List the seven major classes of air pollutants and describe their characteristics and sources

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  • Air Pollution:
  • Various chemicals (gases, liquids, solids) present in the atmosphere in high enough levels to be harmful to humans, other organisms, or materials
  • Primary Air Pollutants:
  • Harmful chemicals that enter directly into the atmosphere due to either human activities or natural processes
  • Secondary Air Pollutants:
  • Harmful chemicals that form in the atmosphere when primary air pollutants react chemically with one another or with natural components on the atmosphere

Types and Sources of Air Pollution

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Types and Sources of Air Pollution

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  • Major Classes of Air Pollutants:
  • Particulate Matter:
  • dusts (solids) and mists (liquids) suspended in the atmosphere - some are toxic or carcinogenic
  • Soil particles, soot, lead, asbestos, sea salt, sulfuric acid
  • Scatters and absorbs light, reducing visibility
  • Can corrode metals, erode buildings and sculptures
  • Eventually settles out, but can remain suspended for many years
  • Inhaling the particles introduces the chemicals into the body
  • Smaller particles are worse because they get deeper into the lungs

Types and Sources of Air Pollution

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  • Types of Particulate Matter:
  • Nitrogen Oxides (NOx)
  • Sulfur Oxide
  • Carbon Oxides
  • Hydrocarbons
  • Ozone
  • Hazardous Air Pollutants (HAPs)

Types and Sources of Air Pollution

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Types and Sources of Air Pollution

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Types and Sources of Air Pollution

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  • Sources of Outdoor Air Pollutants
  • Not all is human generated
  • Volcanoes release particulate matter and sulfur oxides
  • Plants can contribute to air pollution in response to heat, producing compounds to protect themselves
  • Human generated pollution
  • Transportation (mobile sources)
  • Nitrogen oxides, carbon oxides, particulate matter, hydrocarbons
  • Industry (stationary sources)
  • Particulate matter, sulfur oxides, nitrogen oxides, carbon oxides
  • Combustion of fossil fuels is responsible for most emissions

Types and Sources of Air Pollution

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What A Scientist Sees

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Types and Sources of Air Pollution

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Global Climate Change

What is the difference between primary and secondary air pollutants?

What are the seven main classes of air pollutants, and what are some of their effects?

Effects of Air Pollution

  • Learning Objectives:

Relate, in general terms, the adverse health effects of air pollutants

Describe industrial smog, photochemical smog, temperature inversions, urban heat islands, and dust domes

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Effects of Air Pollution

  • Air pollution
  • Injures organisms
  • Reduces visibility
  • Attacks and corrodes materials
  • (metals, rubber, plastic, fabrics)
  • Harm the respiratory tracts of animals
  • Can worsen existing conditions
  • Lung disease, cardiovascular disease
  • Reduces productivity of crops
  • Involved in acid deposition, global warming and ozone depletion

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Effects of Air Pollution

  • Air Pollution and Human Health
  • Irritation of the eyes and inflammation of respiratory tract
  • Suppression of immune system
  • Chronic emphysema and bronchitis
  • Emphysema: alveoli become irreversibly distended
  • Breathlessness and wheezing
  • Bronchitis: bronchi become permanently inflamed
  • Breathlessness and coughing

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Effects of Air Pollution

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Effects of Air Pollution

  • Urban Air Pollution
  • Smog/Industrial Smog
  • Smoke pollution
  • Related to coal combustion
  • Sulfur oxides and particulate matter
  • Worse in winter, due to combustion of fossil fuels for heating
  • Laws have made it better in developed countries.
  • Photochemical Smog
  • Los Angeles, 1940s
  • Involves nitrogen oxides, hydrocarbons and sunlight to produce secondary pollutants
  • Worse in summer, due to higher sunlight
  • Sources: automobiles, dry-cleaners, bakeries

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Effects of Air Pollution

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Effects of Air Pollution

  • Effects of Weather and Topography
  • Changes in temperature produce air circulation patterns that help disperse air pollution
  • Temperature inversion: pollutants get trapped in a cold layer of air close to the ground, by an upper layer of warm air
  • Can last several days
  • Certain topographies increase the likelihood:
  • Cities in valleys, coastal areas, leeward side of mountains.

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Effects of Air Pollution

  • Air Pollution in Los Angeles
  • Some of the worst smog in the world
  • Topography and climate are conducive to temperature inversions
  • 1969, CA became the first state to enforce emissions standards on motor vehicles
  • Stringent smog control laws
  • LA now has the cleanest air since the 1950s, but still exceeds federal air quality standards on more days than any other city in US

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Effects of Air Pollution

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EnviroDiscovery

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Effects of Air Pollution

  • Urban Heat Islands
  • Local heat buildup in an area of high population
  • Streets, rooftops, parking lots absorb lots of heat during the day and radiate it back during the night
  • Heat from human activities, such as combustion
  • Affect local weather conditions
  • Increase the number of thunderstorms in the summer

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Effects of Air Pollution

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Effects of Air Pollution

  • Urban Dust Domes:
  • A dome of heated air that surrounds an urban area and contains a lot of air pollution
  • If wind speed increases, the particulate matter moves downwind from the city and the polluted air spreads to rural areas

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Effects of Air Pollution

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Global Climate Change

What are some of the health effects of exposure to air pollution?

What are urban heat islands? What are dust domes?

Controlling Air Pollutants

  • Learning Objectives:

Summarize the Effects of the Clean Air Act on US air pollution

Contrast air pollution in highly developed countries and in developing countries

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Controlling Air Pollutants

  • Technology exists to deal with Air Pollution
  • smokestacks with precipitators, fabric filters, scrubbers reduce particulates
  • Careful excavation, sprinkling water over soil being moved also reduce particulates
  • Measures that increase fuel efficiency also reduce pollution
  • Using low sulfur fuels, or removing sulfur before combustion
  • Modification of furnaces and engines to provide fuller combustion
  • Catalytic afterburners
  • Reduction of spills and evaporation of petroleum and benzene

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Controlling Air Pollutants

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Controlling Air Pollutants

  • The Clean Air Act (CAA)
  • Air quality has improved since 1970s, thanks to CAA
  • Updated and amended in 1977, 1990
  • Authorizes EPA to apply and enforce CAA by establishing limits on the amounts of specific air pollutants permitted in the US
  • Lead, particulates, carbon monoxide, nitrogen oxides, ozone
  • Lead showed a 98% decrease between 1970 and 1990
  • Since 2008, EPA can also regulate CO2

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Controlling Air Pollutants

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Controlling Air Pollutants

  • Air Pollution in Developing Countries
  • Environmental quality is a low priority in economic development
  • Old technology is less expensive
  • Air pollution laws are non-existent or not enforced
  • Air quality is deteriorating rapidly in many developing nations
  • Growing number of automobiles
  • No pollution control devices, 10+ yrs old
  • Lead pollution form leaded gasoline
  • Respiratory disease is the leading cause of death for children worldwide
  • More than 80% of deaths is for children under 5 who live in cities in developing countries

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Controlling Air Pollutants

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Global Climate Change

What is the U.S. Clean Air Act, and how has it reduced air pollution?

Where is air pollution worse: in highly developed nations or in developing countries? Why?

Indoor Air Pollution

  • Learning Objectives:

Summarize at least four sources of indoor air pollution and explain their role in sick building syndrome

Describe the effects of indoor air pollution in developing countries

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Indoor Air Pollution

  • Developed Countries
  • Most common indoor air pollutants-
  • Radon, cigarette smoke, carbon monoxide, nitrogen dioxide, formaldehyde, household pesticides, cleaning solvents, ozone, asbestos
  • Viruses, bacteria, fungi, dust mites, pollen
  • Sick Building Syndrome
  • Eye irritations, nausea, headaches, respiratory infections, depression, and fatigue caused by indoor pollution
  • 20 million employees are exposed to health risks from indoor air pollution
  • EPA estimates $50 billion cost in loss of work, productivity, health costs to the economy

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Indoor Air Pollution

  • Developing Countries:
  • Most common air pollutants
  • Smoke form indoor cooking with firewood or animal dung contains
  • Carbon monoxide, particulates, hydrocarbons, formaldehyde and benzene
  • Women and children are most exposed and harmed
  • Lower respiratory infections, eye infections, lung cancer
  • WHO estimates 1.6 million people die each year from the health hazards of smoke from indoor cooking

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Indoor Air Pollution

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Indoor Air Pollution

  • Radon
  • Colorless, odorless, tasteless radioactive gas
  • Important indoor air pollutant in US
  • Seeps through ground and enters buildings, where it concentrates
  • Causes 12% of lung cancers
  • Cigarette smoking makes it worse
  • EPA: 6% of US homes have too much Radon
  • Southeastern PA, northern NJ and NY

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Indoor Air Pollution

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Indoor Air Pollution

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Global Climate Change

What are some common indoor air contaminants?

Why is indoor air pollution such a serious health hazard in developing countries?

Case Study

  • Curbing Air Pollution in Chattanooga
  • Worst air pollution in the US in 1960s
  • Headlights were necessary during the day
  • Today, air is clean
  • CAA allowed the city to apply and enforce air quality regulations
  • In 2000s, Chattanooga continued to move toward environmental sustainability
  • Planning to renovate a brown-field and convert it into an industrial ecosystem, where people live near their places of work

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Case Study

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