Princeton Review AP Environmental Science Chapter 9

toxin

any substance that, when inhaled, ingested, or absorbed at sufficient dosages, damages a living organism

toxicity

the degree to which a toxin is biologically harmful

dose-response analysis

a process in which organisms are exposed to a toxin at different concentrations, and the dosage that causes the death of the organism is recorded

dose-response curve

the resulting curve of a dose-response analysis

LD50

the dosage of a toxin it takes to kill 50% of the test animals

poison

any substance that has an LD50 of 50 mg or less per kg of body weight.

ED50

the point at which 50% of the test organisms show a negative effect from the toxin

threshold dose

the dosage at which a negative effect occurs

acute effect

an effect caused by a short exposure to a high level of a toxin (ex. snakebite)

chronic effect

an effect caused by long-term exposure to low levels of toxin (ex. lead paint in a house)

infection

the result of a pathogen invading the body

disease

occurs when an infection causes a change in the state of health

pathogens

bacteria, viruses, or other microorganisms that can cause disease; five main categories: viruses, bacteria, fungi, protozoa, and parasitic worms

vector

a carrier organism through which pathogens can be spread

risk

the degree of likelihood that a person will become ill after exposure to toxin or pathogen

risk assessment

calculating risk

risk management

using strategies to reduce the amount of risk

primary pollutants

pollutants that are released directly into the lower atmosphere (troposphere) and are toxic (ex. carbon monoxide, carbon dioxide, nitrogen oxide, nitrogen dioxide, sulfur dioxide, unburned hydrocarbons, VOCs, etc.)

secondary pollutants

pollutants that are formed by the combination of primary pollutants in the atmosphere (ex. sulfur trioxide, nitric acid, sulfuric acid, hydrogen peroxide, ozone, PANs, aldehydes, etc.)

sulfur oxides (SOx)

source: coal burning

effects: acid deposition, respiratory irritation, damages plants

equation for acid formation: SO2 + O2 = SO3 + H2O = H2SO4

reduction: scrubbers, burn low sulfur fuel

stationary sources

non-moving sources of pollution, such as factories.

moving sources

pollution sources that are mobile, such as cars

point source pollution

describes a specific location from which pollution is released (ex. a factory or a site where wood is being burned)

non-point source pollution

pollution that does not have a specific point of release (ex. a combination of many sources, like a number of cows releasing methane gas within few square miles)

criteria pollutants

the six pollutants that were classified as doing the most harm to human health and welfare; carbon monoxide (CO), lead (Pb), ozone (O3), nitrogen dioxide (NO2), sulfur dioxide (SO2), and particulate matter

main greenhouse gases

carbon dioxide, methane, nitrous oxide, water vapor, ozone, and CFCs

stratospheric ozone

ozone occurring in the stratosphere, which absorbs UV light from the Sun and therefore protects life on our planet

tropospheric ozone

ozone occurring in the troposphere, which is a result of air pollution; it is a powerful respiratory irritant and precursor to secondary air pollutants; it results from the interaction of nitrogen oxides, heat, sunlight, and VOCs; forms smog

nitrogen oxides (NOx)

source: auto exhaust

effects: acidification of lakes, respiratory irritation, leads to smog & ozone

equation for acid formation: NO + O2 = NO2 + H2O = HNO3

reduction: catalytic converter

industrial smog (gray smog) (gray-air smog)

the smog that covered London throughout the 19th century, and well into the 20th century; results from the burning of large amounts of low-quality coal

photochemical smog (brown smog)

usually formed on hot, sunny days in urban areas, in which NOx compounds, VOCs, and ozone all combine to form smog with a brownish hue (ex. in Los Angeles, California and in Athens, Greece)

chlorofluorocarbons (CFCs)

a family of organic compounds whose properties make them ideal for use in refrigeration and air-conditioning but resulted in the thinning of the ozone layer during their time of use

ozone loss

greatest in the spring as the chlorine breaks down ozone into O2

acid precipitation

whether in the form of acid rain, hail, snow, etc., occurs as a result of pollution in the atmosphere, primarily os SO2 and nitrogen oxides; these gases combine with water to form acids (typically nitric acid and sulfuric acid) that are deposited on the Earth through precipitation

dry acid particle deposition

acid precipitation in the form of gases and particles, usually occurring two to three days after emission into the atmosphere

wet deposition

acid deposition in the form of rain or snow that is usually delayed for four to fourteen days after emission; it can travel in air currents to locations that are many miles downward of the emission source

National Ambient Air Quality Standards (NAAQS)

amendment of the EPA's Clean Air Act which specifies concentration limits for pollutants and requires localities to improve air qualities to meet these limits

catalytic converter

a platinum-coated device that oxidizes most of the VOCs and some of the CO that would otherwise be emitted in exhaust, converting them to CO2

Corporate Average Fuel Economy (CAFE)

requires vehicle manufacturers to comply with the gas mileage, or fuel economy, standards set by the Department of Transportation (DOT); CAFE values are obtained using the city and highway fuel economy test results and a weighted average of vehicle sales

grassroots organizations

locally based groups that work to develop and improve the community

material used for fuel (ex. dung, wood, and crop waste)

main indoor air pollutants in developing countries

VOCs, CO, tobacco smoke, and radon

main indoor pollutants in developed countries

volatile organic compounds (VOCs)

organic compounds that become vapors at typical atmospheric temperatures; found in carpet, furniture, plastic, oils, paints, adhesives, pesticides, and cleaning fluid

sick building syndrome (SBS)

a term that is used when the majority of a building's occupants experience certain symptoms that vary with the amount of time spent in the building and for which no other cause can be identified

building-related illness

condition in which the signs and symptoms of a human sickness can be attributed to a specific infectious organism that resides in the building (ex. Legionella pneumophila)

anthropogenic greenhouse gas

a greenhouse gas produced by human activity- main sources include burning of fossil fuels, deforestation, enteric fermentation, rice farming, use of fertilizers, and use of chlorofluorocarbons and halons (three main anthropogenic greenhouse gases are carbon dioxide, methane, and nitrous oxide)

carbon sequestration

the process of capturing and storing atmospheric carbon dioxide

Kyoto Protocol

controlling global warming by setting greenhouse gas emissions targets for developed countries

heat islands

urban areas that heat up more quickly and retain heat more than do nonurban areas

2 ways to reduce thermal difference between urban and rural areas for urban populations

1.) replacing dark, heat-absorbing surfaces (such as roofs) with light-colored, heat-reflecting surfaces

2.) planting trees and adding to green spaces, which cool areas via transpiration process, shade areas, and decrease urban runoff

thermal pollution

a temperature increase in a body of water that is caused by human activity and that has a harmful effect on water quality and on the ability of that body of water to support life

thermal expansion

an increase in the size of a substance in response to an increase in the temperature of the substance

green roof

roof covered in vegetation - helps combat heat-island effect

temperature inversion

a phenomenon in which air pollutants become trapped over cities because they are not able to rise into the atmosphere

normal atmosphere: warm, polluted air over a city rises into the cooler atmosphere

inversion: the air above the city is warm and blocks the polluted air from rising

excess nutrients

runoff from land that can create eutrophication in a body of water and dead zones

dead zones

areas with little oxygen and little life; can be self-perpetuating with the dying organisms subsequently decomposing and causing continued oxygen demand by microbes

eutrophication

a process by which nutrients, particularly phosphorus and nitrogen, become highly concentrated in a body of water, leading to increased growth of organisms such as algae or cyanobacteria

hypoxic zone

an area in which the water contains low or no dissolved oxygen causing a condition known as hypoxia; nothing that depends on oxygen can survive there

pH

a measure of acidity or alkalinity (normal for water is 6-8)

hardness

a measure of the concentration of calcium and magnesium

dissolved oxygen

oxygen dissolved in water, dissolved oxygen is important for fish and other aquatic animals; low levels of dissolved oxygen indicate am inability to sustain life- warm water holds less dissolved oxygen than cool water

turbidity

cloudiness of water; the density of suspended particles in the water

biological oxygen demand (BOD)

a measure of the rate at which bacteria absorb oxygen from the water

wastewater

refers to any water that has been used by humans

physical treatment

in a sewage treatment plant, the initial filtration that is done to remove debris that were flushed down toilets, which is then sent to a landfill

primary treatment

in a sewage treatment plant, after physical treatment, the remaining water slows so that suspended soils settle out as sludge; chemically treated polymers may be added to help the suspended solids separate and settle out; removes about 60% of the suspended solids and 30% of the organic waste that requires oxygen in order to decompose

secondary treatment

in a sewage treatment plant, it refers to the biological treatment of wastewater in order to continue to remove biological waste; done by using trickling filters, or sludge processors- both include the use of anaerobic bacteria digesting waste

sludge processor

a tank filled with anaerobic bacteria that is used to treat sewage during secondary treatment

sludge

solid waste material from wastewater

gray water

wastewater from baths, showers, bathrooms, and washing machines

tertiary treatment

in a sewage treatment plant, it involves passing of the secondary treated water through a series of sand and carbon filters and then further chlorination in order to be used for groundwater recharge

Clean Water Act (1972)

used regulatory and non-regulatory tools to protect all surface waters in the United States

Ocean Dumping Act (1972)

made it unlawful for any person to dump, or transport or the purpose of dumping, sewage, sludge, or industrial waste into ocean waters

Safe Drinking Water Act (1974)

established a federal program to monitor and increase the safety of the drinking water supply; it does not apply to wells that supply fewer than 25 people; amendments in recent years have led to more stringent regulation of lead and algal toxins in drinking water

solid waste

can consist of hazardous waste, industrial solid material, or municipal solid waste (MSW)

primary recycling (closed-loop recycling)

materials such as plastic or aluminum are used to rebuild the same product (ex. recycling aluminum cans to produce more aluminum cans)

secondary recycling (open-loop recycling)

materials are reused to form new products that are usually lower quality goods (ex. old tires being recycled to form carpet and plastic bottles being recycled to create decking material)

composting

allows the organic material in solid waste be decomposed and reintroduced to the soil

Pay-As-You-Throw (PAYT) programs

programs that charge municipal customers for the amount of household garbage they throw away; provide a strong incentive for people practice good waste production habits

Not In My Backyard (NIMBY)

it was widely agreed that landfills were needed, but no one wanted a landfill close to their home

sanitary landfills

disposal sites for non-hazardous solid waste that is spread in layers and compacted to the smallest practical volume; the sites are typically designed with floors made of materials to treat seeping liquids (like clay and plastic liners) and are covered by soil as the wastes are compacted and deposited into the landfill to prevent the presence of pests and rodents/insects

leachate

polluted liquid produced by water passing through buried wastes in a landfill

Waste-to-Energy (WTE) program

when the energy released from waste incineration is used to generate electricity

the Resource Conservation and Recovery Act (RCRA) (1976)

controls hazardous waste with a cradle to grave system

corrosive waste

waste that corrodes metal (ex. batteries)

ignitable waste

substances that can easily catch fire (ex. alcohol and gasoline)

reactive waste

substances that are chemically unstable or react readily with other compounds, resulting in explosions or causing other problems (ex. lithium-sulfur batteries)

toxic waste

waste that creates health risks when inhaled or ingested, or when it comes into contact with skin (ex. batteries for electronic devices, pesticides, cell phones, and computers)

surface impoundment

type of hazardous waste storage that is typically used for liquid waste; it involves the creation of shallow, lined pools from which the hazardous liquid evaporates

deep well injection

type of hazardous waste storage that involves drilling a hole in the ground that is below the water table; these wells must be below the impervious soil layer into porous rock, and waste is injected into the well

nuclear waste burial

long-term storage method for spent fuel rods

transuranic waste

waste that is left over from the construction of nuclear weapons

low-level radioactive waste

radioactive wastes that produce low levels of ionizing radiation

high-level radioactive waste

radioactive wastes that produce high levels of ionizing radiation

its place of origin

how the EPA categorizes radioactive waste

brownfield sites

sites that were already contaminated by hazardous waste or pollutants

Love Canal

a neighborhood in Niagara Falls, New York, which became the subject of national and international attention, controversy, and eventual environmental notoriety following the discovery of 21,000 tons of toxic waste buried beneath the neighborhood; it was built upon a closed landfill

Hazardous Materials Transportation Act (1975)

governed the transportation of hazardous material and wastes in commerce

Toxic Substances Control Act (TOSCA) (1976)

gave the EPA the ability to track the 75,000 industrial chemicals currently produced in or imported to the United States; EPA repeatedly screens those chemicals and can require reporting or testing of those that may pose an environmental or human health hazard; allows the EPA to ban the manufacture and import of those chemicals that pose an unreasonable risk

the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) (the Superfund Act) (1980)

-created a tax on the chemical and petroleum industries and provided broad federal authority to respond directly to releases or threatened releases of hazardous substances that may endanger public health or the environment

-established prohibitions and requirements concerning closed and abandoned hazardous waste sites

-provided for liability of persons responsible for releases of hazardous waste at these sites

-established a trust fund to provide for cleanup when no responsible party could be identified