Chapter 15: Promoting Environmental Health © 2017 Pearson Education, Inc.

Learning Outcomes Explain the environmental impact associated with global population growth and our global ecological footprint. Discuss major causes of air pollution and the consequences of ozone depletion. Explain climate change and global warming, the underlying causes of each, impacts on health, and key actions for reducing risks. Identify sources of pollution and chemical contaminants often found in water. © 2017 Pearson Education, Inc.

Learning Outcomes (cont.) Distinguish between municipal solid waste and 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. © 2017 Pearson Education, Inc.

The Threat of Overpopulation Bursting with people: measuring the impact Impact on other species Impact on our food supply Land degradation and contamination of drinking water Energy consumption © 2017 Pearson Education, Inc.

Estimated and Projected World Population Growth, 1950–2100 © 2017 Pearson Education, Inc.

The Threat of Overpopulation (cont.) Factors that affect population growth Fertility rate refers to the number of births a woman has by the end of her reproductive period. Global fertility rate is an average of 2.5 births per woman. The U.S. rate is just over 2 births per woman. Zero population growth (ZPG) This is the idea that each couple should produce only two offspring. Differing growth gates India is expected to have the largest growth by adding another 600 million people by 2050. © 2017 Pearson Education, Inc.

Global Fertility Rates, by Region © 2017 Pearson Education, Inc.

Air Pollution Pollutants are either naturally occurring or anthropogenic (caused by humans). Natural air pollutants include particulate matter, such as ash from volcanic eruptions. Anthropogenic sources include stationary sources such as power plants, factories, and refineries; and mobile sources, such as vehicles. © 2017 Pearson Education, Inc.

Components of Air Pollution Concern about air quality resulted in the Clean Air Act. It sets standards for six of the most widespread air pollutants that seriously affect health: Sulfur dioxide Particulates Carbon monoxide Nitrogen dioxide Ground level ozone Lead © 2017 Pearson Education, Inc.

Photochemical Smog Smog is a brownish haze produced by the photochemical reaction of sunlight with hydrocarbons, nitrogen compounds, and other gases in vehicle exhaust. It tends to occur in areas that experience a temperature inversion. © 2017 Pearson Education, Inc.

Air Quality Index (AQI) The AQI is a measure of how clean or polluted the air is on any given day. The AQI focuses on health effects that can happen within a few hours or days after breathing polluted air. The index runs from 0 to 500, with higher values having a greater level of air pollution and health risk. © 2017 Pearson Education, Inc.

Sources, Health Effects, and Environmental Impacts of Six Major Air Pollutants © 2017 Pearson Education, Inc.

Air Quality Index (AQI) © 2017 Pearson Education, Inc.

Acid Deposition Acid deposition refers to the deposition of wet and dry acidic components that fall to the earth in dust or smoke. Acid deposition gradually acidifies ponds, lakes, and other bodies of water. It aggravates and may even cause bronchitis, asthma, and other respiratory conditions. © 2017 Pearson Education, Inc.

Indoor Air Pollution Indoor air pollution levels may be two to five times higher than outdoor pollution levels. Indoor air pollution comes primarily from cooking stoves and furnaces, woodstoves, space heaters, household cleaners and solvents, pesticides, asbestos, formaldehyde, radon, mold and lead. Prevention should focus on three areas: Source control (eliminating or reducing contaminants) Ventilation improvements (increasing the amount of outdoor air coming indoors) Air cleaners (removing particulates from the air) © 2017 Pearson Education, Inc.

Ozone Layer Depletion The ozone layer protects the planet and its inhabitants from ultraviolet B (UVB) radiation. Chlorofluorocarbons (CFCs) contribute to ozone depletion. The United States and other nations have banned CFCs CFC replacements may cause the greenhouse effect © 2017 Pearson Education, Inc.

Climate Change Climate change refers to a shift in typical weather patterns across the world, including global warming where seasonal temperatures increase. An enhanced greenhouse effect is a warming of Earth's surface which is driven largely by human activities that release greenhouse gases into the atmosphere, trapping more of the sun's radiation than is normal. In the last 100 years, average temperature of the earth has increased by 1.5ºF, with projections of another 2º to 11.5ºF rise in the next 100 years. © 2017 Pearson Education, Inc.

Climate Change (cont.) Most scientists believe that the planet is warming. Greenhouse gases in the atmosphere went up dramatically around the time of the industrial revolution. © 2017 Pearson Education, Inc.

The Enhanced Greenhouse Effect © 2017 Pearson Education, Inc.

Reducing the Threat of Global Warming Climate change problems are rooted in our energy, transportation, and industrial practices. Toward sustainable development Development that meets the needs of the present without compromising the needs of future generations Possible carbon tax: incentivizing individuals to invest in non-carbon power generation and reducing their carbon footprint Cap and trade: sets limits on how much carbon large industrial polluters can emit, and taxes those who exceed the limit © 2017 Pearson Education, Inc.

Water Pollution and Shortages Point source pollutants enter a waterway at a specific location through a pipe, ditch, culvert, or other conduit. Major sources are sewage treatment plants and industrial facilities. Nonpoint source pollutants seep into waterways from broad areas of land. Major sources are the result of land use practices. © 2017 Pearson Education, Inc.

Water Pollutants Among the pollutants causing the greatest potential harm are the following: Gasoline and petroleum products Organic solvents Fracking by-products Polychlorinated biphenyls (PCBs) Dioxins Pesticides © 2017 Pearson Education, Inc.

Solid Waste Per day, each person generates more than 4.4 pounds of municipal solid waste (MSW), totaling about 254 million tons each year. About 90 percent of waste is recyclable, but only 34.3 percent of MSW is recycled or composted. Strategies to reduce MSW include source reduction, recycling, composting, and combustion with energy recovery. © 2017 Pearson Education, Inc.

How Much Do We Recycle? © 2017 Pearson Education, Inc.

Hazardous Waste Hazardous waste is toxic waste that poses a hazard to humans or to the environment. The Comprehensive Environmental Response and Liability Act (the Superfund) was enacted to provide funds for cleaning up hazardous waste. Many types of waste are now banned from land disposal or are being treated to reduce toxicity before disposal. © 2017 Pearson Education, Inc.

Radiation Nonionizing radiation Electromagnetic waves having a relatively long wavelength and enough energy to move atoms around or cause them to vibrate. Ionizing radiation Electromagnetic waves and particles having a short wavelength and energy high enough to ionize atoms. Radiation exposure is measured in radiation absorbed doses, or rads. The maximum "safe" exposure ranges from 0.05 to 5 rads per year. © 2017 Pearson Education, Inc.

Nuclear Power Plants Proponents believe it is a safe and efficient way to generate electricity. Disposal of nuclear waste is extremely problematic. A nuclear meltdown can occur when the temperature in the core of a nuclear reactor increases enough to melt both the nuclear fuel and its containment vessel. © 2017 Pearson Education, Inc.

Noise Pollution A sound with a decibel (dB) level of 110 is 10 times louder than one at 100 dB. The human voice measures about 60 dB; a jet takeoff from 200 feet measures 140 dB. Short-term exposure to loud noise reduces concentration and productivity and may affect mental and emotional health. Prolonged exposure can lead to hearing loss. © 2017 Pearson Education, Inc.

Noise Levels of Various Sounds (in Decibels) © 2017 Pearson Education, Inc.

Noise Pollution To protect your hearing: Use headphones that go over, rather than inside your ears, and don't crank up the volume. Always use ear protection when using power equipment or firearms. Close windows to establish a barrier between yourself and outside noise. Wear earplugs when attending loud concerts and clubs. © 2017 Pearson Education, Inc.