Unit 8 · Aquatic and Terrestrial Pollution

Point source pollution ● (core concept) — A point source refers to a single, identifiable source of a pollutant, such as a smokestack or waste discharge pipe.

Nonpoint source pollution ● (core concept) — Nonpoint sources of pollution are diffused and can therefore be difficult to identify, such as pesticide spraying or urban runoff.

Range of tolerance (pollutants) ● (core concept) — Organisms have a range of tolerance for various pollutants. They have an optimum range for each factor where they can maintain homeostasis; outside of this range, organisms may experience physiological stress, limited growth, reduced reproduction, and in extreme cases, death.

Coral reef damage ● (core concept) — Coral reefs have been suffering damage due to a variety of factors, including increasing ocean temperature, sediment runoff, and destructive fishing practices.

Oil spill impacts on marine life ● (core concept) — Oil spills in marine waters cause organisms to die from the hydrocarbons in oil. Oil that floats on the surface can coat the feathers of birds and fur of marine mammals. Some components of oil sink to the ocean floor, killing some bottom-dwelling organisms.

Oil spill economic consequences ● (core concept) — Oil that washes up on the beach can have economic consequences on the fishing and tourism industries.

Oceanic dead zones ● (core concept) — Oceanic dead zones are areas of low oxygen in the world's oceans caused by increased nutrient pollution.

Oxygen sag curve ● (core concept) — An oxygen sag curve is a plot of dissolved oxygen levels versus the distance from a source of pollution, usually excess nutrients and biological refuse.

Heavy metals in groundwater ● (core concept) — Heavy metals used for industry, especially mining and burning of fossil fuels, can reach the groundwater, impacting the drinking water supply.

Litter in aquatic ecosystems ● (core concept) — Litter that reaches aquatic ecosystems, besides being unsightly, can create intestinal blockage and choking hazards for wildlife and introduce toxic substances to the food chain.

Sediment in waterways ● (core concept) — Increased sediment in waterways can reduce light infiltration, which can affect primary producers and visual predators. Sediment can also settle, disrupting habitats.

Mercury to methylmercury ● (core concept) — When elemental sources of mercury enter aquatic environments, bacteria in the water convert it to highly toxic methylmercury.

Clean Water Act ● (core concept) — The Clean Water Act regulates the discharge of pollutants into the waters of the United States and establishes water quality standards for surface waters.

Safe Drinking Water Act (SDWA) ● (core concept) — The Safe Drinking Water Act authorizes the Environmental Protection Agency (EPA) to set standards for drinking water quality and oversee the safety of public drinking water supplies.

Endocrine disruptors ● (core concept) — Endocrine disruptors are chemicals that can interfere with the endocrine system of animals.

Effects of endocrine disruptors ● (core concept) — Endocrine disruptors can lead to birth defects, developmental disorders, and gender imbalances in fish and other species.

Wetlands ● (core concept) — Wetlands are areas where water covers the soil, either part or all of the time.

Wetland ecosystem services ● (core concept) — Wetlands provide a variety of ecological services, including water purification, flood protection, water filtration, and habitat.

Threats to wetlands and mangroves ● (core concept) — Threats to wetlands and mangroves include commercial development, dam construction, overfishing, and pollutants from agriculture and industrial waste.

Eutrophication ● (core concept) — Eutrophication occurs when a body of water is enriched in nutrients.

Algal bloom and oxygen depletion ● (core concept) — The increase in nutrients in eutrophic aquatic environments causes an algal bloom. When the algal bloom dies, microbes digest the algae, along with the oxygen in the water, leading to a decrease in dissolved oxygen levels. The lack of dissolved oxygen can result in large die-offs of fish and other aquatic organisms.

Hypoxic waterways ● (core concept) — Hypoxic waterways are those bodies of water that are low in dissolved oxygen.

Oligotrophic waterways ● (core concept) — Compared to eutrophic waterways, oligotrophic waterways have very low amounts of nutrients, stable algae populations, and high dissolved oxygen.

Anthropogenic causes of eutrophication ● (core concept) — Anthropogenic causes of eutrophication are agricultural runoff and wastewater release.

Thermal pollution ● (core concept) — Thermal pollution occurs when heat released into the water produces negative effects to the organisms in that ecosystem.

Water temperature and dissolved oxygen ● (core concept) — Variations in water temperature affect the concentration of dissolved oxygen because warm water does not contain as much oxygen as cold water.

Persistent organic pollutants (POPs) ● (core concept) — Persistent organic pollutants (POPs) do not easily break down in the environment because they are synthetic, carbon-based molecules (such as DDT and PCBs).

POPs accumulate in fat ● (core concept) — Persistent organic pollutants (POPs) can be toxic to organisms because they are soluble in fat, which allows them to accumulate in organisms' fatty tissues.

Long-range transport of POPs ● (core concept) — Persistent organic pollutants (POPs) can travel over long distances via wind and water before being redeposited.

Bioaccumulation ● (core concept) — Bioaccumulation is the selective absorption and concentration of elements or compounds by cells in a living organism, most commonly fat-soluble compounds.

Biomagnification ● (core concept) — Biomagnification is the increase in concentration of substances per unit of body tissue that occurs in successively higher trophic levels of a food chain or in a food web.

Biomagnification effects on top carnivores ● (core concept) — Some effects that can occur in an ecosystem when a persistent substance is biomagnified in a food chain include eggshell thinning and developmental deformities in top carnivores of the higher trophic levels.

Biomagnification effects on humans ● (core concept) — Humans also experience harmful effects from biomagnification, including issues with the reproductive, nervous, and circulatory systems.

Substances that bioaccumulate ● (core concept) — DDT, mercury, and PCBs are substances that bioaccumulate and have significant environmental impacts.

Solid waste ● (core concept) — Solid waste is any discarded material that is not a liquid or gas. It is generated in domestic, industrial, business, and agricultural sectors.

Landfills ● (core concept) — Solid waste is most often disposed of in landfills. Landfills can contaminate groundwater and release harmful gases.

Electronic waste (e-waste) ● (core concept) — Electronic waste, or e-waste, is composed of discarded electronic devices including televisions, cell phones, and computers.

Sanitary landfill design ● (core concept) — A sanitary municipal landfill consists of a bottom liner (plastic or clay), a storm water collection system, a leachate collection system, a cap, and a methane collection system.

Landfill decomposition ● (core concept) — Factors in landfill decomposition include the composition of the trash and conditions needed for microbial decomposition of the waste.

Incineration ● (core concept) — Solid waste can also be disposed of through incineration, where waste is burned at high temperatures. This method significantly reduces the volume of solid waste but releases air pollutants.

Illegal waste dumping ● (core concept) — Some items are not accepted in sanitary landfills and may be disposed of illegally, leading to environmental problems. For example, used rubber tires left in piles can become breeding grounds for mosquitoes that can spread disease.

Ocean dumping of waste ● (core concept) — Some countries dispose of their waste by dumping it in the ocean. This practice, along with other sources of plastic, has led to large floating islands of trash in the oceans. Additionally, wildlife can become entangled in the waste, as well as ingest it.

CERCLA (Comprehensive Environmental Response, Compensation, and Liability Act) ● (core concept) — The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) provides for the cleanup of sites contaminated with hazardous substances and holds responsible parties liable for cleanup costs.

RCRA (Resource Conservation and Recovery Act) ● (core concept) — The Resource Conservation and Recovery Act (RCRA) governs the management of solid and hazardous waste from generation to disposal.

Recycling ● (core concept) — Recycling is a process by which certain solid waste materials are processed and converted into new products.

Recycling tradeoffs ● (core concept) — Recycling is one way to reduce the current global demand on minerals, but this process is energy-intensive and can be costly.

Composting ● (core concept) — Composting is the process of organic matter such as food scraps, paper, and yard waste decomposing. The product of this decomposition can be used as fertilizer. Drawbacks to composting include odor and rodents.

Reducing e-waste ● (core concept) — E-waste can be reduced by recycling and reuse. E-wastes may contain hazardous chemicals, including heavy metals such as lead and mercury, which can leach from landfills into groundwater if they are not disposed of properly.

Landfill mitigation ● (core concept) — Landfill mitigation strategies range from burning waste for energy to restoring habitat on former landfills for use as parks.

Landfill gas to energy ● (core concept) — The combustion of gases produced from decomposition of organic material in landfills can be used to turn turbines and generate electricity. This process reduces landfill volume.

Primary sewage treatment ● (core concept) — Primary treatment of sewage is the physical removal of large objects, often through the use of screens and grates, followed by the settling of solid waste in the bottom of a tank.

Secondary sewage treatment ● (core concept) — Secondary treatment is a biological process in which bacteria break down organic matter into carbon dioxide and inorganic sludge, which settles in the bottom of a tank. The tank is aerated to increase the rate at which the bacteria break down the organic matter.

Tertiary sewage treatment ● (core concept) — Tertiary treatment is the use of ecological or chemical processes to remove any pollutants left in the water after primary and secondary treatment.

Sewage disinfection ● (core concept) — Prior to discharge, the treated water is exposed to one or more disinfectants (usually, chlorine, ozone, or UV light) to kill bacteria.

LD50 ● (core concept) — Lethal dose 50% (LD50) is the dose of a chemical that is lethal to 50% of the population of a particular species.

Dose response curve ● (core concept) — A dose response curve describes the effect on an organism or mortality rate in a population based on the dose of a particular toxin or drug.

Pollution and health cause-effect ● (core concept) — It can be difficult to establish a cause and effect between pollutants and human health issues because humans experience exposure to a variety of chemicals and pollutants.

Dysentery ● (core concept) — Dysentery is caused by untreated sewage in streams and rivers.

Mesothelioma ● (core concept) — Mesothelioma is a type of cancer caused mainly by exposure to asbestos.

Tropospheric ozone and lung health ● (core concept) — Respiratory problems and overall lung function can be impacted by elevated levels of tropospheric ozone.

Delaney Clause ● (core concept) — The Delaney Clause of the Food, Drug, and Cosmetic Act prohibits the approval of food additives that have been found to cause cancer.

Pathogen adaptation ● (core concept) — Pathogens adapt to take advantage of new opportunities to infect and spread through human populations.

Pathogens in sanitary-looking environments ● (core concept) — Specific pathogens can occur in many environments regardless of the appearance of sanitary conditions.

Climate change and disease spread ● (core concept) — As equatorial-type climate zones spread north and south into what are currently subtropical and temperate climate zones, pathogens, infectious diseases, and any associated vectors are spreading into these areas where the disease has not previously been known to occur.

Poverty and infectious disease ● (core concept) — Poverty-stricken, low-income areas often lack sanitary waste disposal and have contaminated drinking water supplies, leading to havens and opportunities for the spread of infectious diseases.

Plague ● (core concept) — Plague is a disease carried by organisms infected with the plague bacteria. It is transferred to humans via the bite of an infected organism or through contact with contaminated fluids or tissues.

Tuberculosis ● (core concept) — Tuberculosis is a bacterial infection that typically attacks the lungs. It is spread by breathing in the bacteria from the bodily fluids of an infected person.

Malaria ● (core concept) — Malaria is a parasitic disease caused by bites from infected mosquitoes. It is most often found in sub-Saharan Africa.

West Nile virus ● (core concept) — West Nile virus is transmitted to humans via bites from infected mosquitoes.

SARS ● (core concept) — Severe acute respiratory syndrome (SARS) is a form of pneumonia. It is transferred by inhaling or touching infected fluids.

MERS ● (core concept) — Middle East Respiratory Syndrome (MERS) is a viral respiratory illness that is transferred from animals to humans.

Zika virus ● (core concept) — Zika is a virus caused by bites from infected mosquitoes. It can be transmitted through sexual contact.

Cholera ● (core concept) — Cholera is a bacterial disease that is contracted from infected water.