Chapter 20 Lecture Access to Health Thirteenth Edition © 2014 Pearson Education, Inc. Preserving...

Chapter 20 Lecture

Access to HealthThirteenth Edition

© 2014 Pearson Education, Inc.

Preserving andProtecting YourEnvironment


Did you PREPARE and did you LEARN?

• Explain the environmental impact associated with global population growth.

• Describe major causes of air pollution and the consequences of greenhouse gas accumulation and ozone depletion.

• Identify sources of water pollution and chemical contaminants often found in water.


Did you PREPARE and did you LEARN?

• Distinguish municipal solid waste from hazardous waste, and list strategies for reducing land pollution.

• Discuss the health concerns associated with ionizing and nonionizing radiation.

• Describe the physiological consequences of noise pollution and how to prevent or reduce its effects.


Measuring the Impact of People

• Impact on other species

• Impact on our food supply

• Land degradation and contamination of drinking water

• Energy consumption


Projected World Population Growth, 1950–2100


World Energy Consumption by Fuel,1990–2035 (Quadrillion Btu)


Factors That Affect Population Growth

• Total fertility rate is a measure of the average number of births a female in a certain population has during her reproductive years.

• In America, that rate is nearly 2 per woman, while in India, many Asian, Latin American, and African countries the rate ranges from 5 to nearly 8 per woman.


Differing Growth Rates

• India is expected to increase its population by 600 million by 2050, surpassing China.

• In developing nations, large families occur because of – High infant mortality rates– Children being the family's "social security"– Low education and economic status of

women


Differing Growth Rates

• In wealthier nations, with the exception of the United States, population sizes are either static or declining.

• The United States ranks 123rd out of 233 nations in population growth, adding 3 million people each year, or 8,000 per day.

• The United States is among the five countries of the world with the biggest "ecological footprint," exerting a greater impact on many of the planet's resources than any other nation.


Zero Population Growth

• Total zero population growth limits couples to two offspring. Once the parents die, these two children are their replacements, allowing the population to stabilize or even decrease.

• There are over 20 countries with zero or negative population growth.

• Education is the single largest contributor to zero population growth.


1. How does eating less beef help to reduce the effects of climate change?

2. What is an energy audit? How does it help to save energy?

Power of 2: Get an Energy Audit


Air Pollution

• Air pollution is either naturally occurring or anthropogenic (caused by humans).

• Components of air pollution– Sulfur dioxide, particulates, carbon monoxide,

nitrogen dioxide, ground-level ozone, and lead.

• Photochemical smog– Contains particulates and gases that form when

oxygen-containing compounds of nitrogen and hydrocarbons react with sunlight.


Air Quality Index

• Like the weather, air quality changes day to day, hour to hour.

• The Air Quality Index focuses on health effects that can occur within a few hours or days after a person breathes polluted air.

• The scale runs from 0 to 500. When it rises above 100, it is considered unhealthy.


Air Quality Index (AQI)


Acid Deposition and Acid Rain

• Acid deposition (acid rain) is precipitation that has fallen through acid air pollutants.

• Acid pollutants are deposited in two ways:– Wet deposition: acidic rain, fog, and snow– Dry deposition: chemicals that are incorporated into

dust or smoke before falling to the ground

• Sources of acid deposition are mostly processes that burn fossil fuels.

• Acid deposition damages lakes and ponds, kills trees, and causes human health effects.


Indoor Air Pollution

• Prevention of indoor air pollution– Source control– Ventilation improvements– Air cleaners

• Environmental tobacco smoke is a form of indoor air pollution.

• Home heating by woodstoves and oil- or gas-fired furnaces can emit particulates and carbon monoxide, respectively.


Indoor Air Pollution

• Asbestos, if disrupted, produces tiny fibers that become airborne.

• Formaldehyde is contained in many home materials.

• Radon seeps into homes through cracks and pipes.

• Molds and fungi live both in and outdoors.

• Lead is a metal pollutant

• "Sick building syndrome" is primarily related to poor ventilation.


Activity Break

• Do you believe that if we do not change our current rate of population growth and our consumption of natural resources, we may face a situation where:

– Electricity is available for only a few hours each day, so that you have to choose between using a refrigerator, TV, computer, or electric light?

– Only limited amounts of gasoline are available for your car and there are shortages of grocery supplies?


Ozone Layer Depletion

• The ozone layer forms a protective layer in Earth's stratosphere.

• It protects the planet from ultraviolet B (UVB) radiation.

• In the 1970s, it was discovered that chlorofluorocarbons (CFCs) contribute to the rapid depletion of the ozone layer.

• Aerosol sprays containing CFCs were banned in the 1970s.


Global Warming

• Greenhouse gases– Carbon dioxide, CFCs, ground-level ozone, nitrous

oxide, hydrocarbons, and methane form a gaseous layer that allows solar heat to pass through the atmosphere to Earth, but it also traps the heat and prevents it from escaping.

• Kyoto Protocol– This is an international plan to reduce the human-made

emissions responsible for climate change. It has been signed by more than 160 countries, including more than 30 industrialized nations.

– This document, unsigned by the United States, would require us to reduce emissions by 33%.


The Enhanced Greenhouse Effect


Reducing Air Pollution and the Threat of Global Warming

• Changes must occur in energy, transportation, and industrial practices.

• Reducing consumption of fossil fuels in cars and shifting to alternate fuels, improving gas mileage, and using mass transportation are crucial to the reduction of air pollution.

• In what ways can you reduce your carbon footprint?


Water Pollution and Shortages

• About 75% percent of Earth's surface is covered with water; only 1% of this water is available for human use.

• Water contamination– Point source pollutants enter a waterway at a

specific location.

– Nonpoint source pollutants consist of runoff and sedimentation.


Water Pollution

– Septic systems.– Landfills.– Gasoline and petroleum products.– Chemical contaminants designed to dissolve grease

and oil.– Although polychlorinated biphenyls are now banned in

the United States, some 500 million pounds have already been dumped into landfills and waterways.

– Dioxins, commonly found in herbicides.– Pesticides.– Lead.


Potential Sources of Groundwater Contamination


Land Pollution

• Solid waste– Every day, 4.4 pounds of municipal solid waste per

person is generated in the United States.

– Although 90% of our trash is recyclable, only a little more than 1/3 is actually recycled.

• Hazardous waste– The Superfund law was enacted in 1980 to provide

money for the cleanup of hazardous chemical sites.


What's in Our Trash?


Land Pollution

• The number of landfills has decreased in the past decade, but their mass has increased.

• As communities run out of disposal space, it is becoming more common to take garbage out to sea and dump it there, thus contaminating the ocean ecosystem.


Land Pollution

• Strategies to control waste:– Source reduction (waste prevention)– Recycling– Composting– Combustion with energy recovery


How Much Do We Recycle?


1. Can you recycle on campus? Do you?

2. Were you aware of the Great Pacific Garbage Patch? In what way do you think it affects the environment? What should be done about it?

Crack Those Recycling Codes


Radiation

• Nonionizing radiation: radio waves, TV signals, microwaves

• Ionizing radiation: the sun, uranium• Radiation absorbed doses (RADs)• Electromagnetic fields (EMFs)• Nuclear power plants

– Nuclear meltdown occurs when a nuclear reactor's core temperature increases to melt both the nuclear fuel and the containment vessel that holds it.

– At the nuclear power plant in Chernobyl, there was a reactor core fire and explosion.


Assessing Yourself–A Personal Inventory

• Go online to the Live It! section of www.pearsonhighered.com/donatelle to take the "Are You Doing All You Can to Protect the Environment?" assessment.

• Have you limited or will you limit your reproductive activity to two children?

• What are you doing personally to reduce air pollution?• When you shop, do you consider buying products with

less packaging or recycled packaging?• Do you recycle everything that you can and minimize

your driving?

Chapter 20 Lecture Access to Health Thirteenth Edition © 2014 Pearson Education, Inc. Preserving...

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