| Term | Definition |
|---|---|
| air pollutants | Harmful substances released into the atmosphere that can negatively affect air quality and human health. |
| nonpoint source | A diffused source of pollution that is difficult to identify, such as pesticide spraying or urban runoff. |
| point source | A single, identifiable source of pollution, such as a smokestack or waste discharge pipe. |
| urban runoff | Water from precipitation that flows over urban surfaces such as pavement and roofs, carrying pollutants into water systems rather than infiltrating into the ground. |
| Term | Definition |
|---|---|
| composting | The process of organic matter such as food scraps, paper, and yard waste decomposing into a product that can be used as fertilizer. |
| electronic waste | Electronic waste from discarded electronic devices that may contain hazardous chemicals including heavy metals such as lead and mercury. |
| heavy metals | Dense metallic elements such as mercury, lead, and cadmium that are toxic to organisms and can accumulate in ecosystems. |
| landfill gas combustion | The burning of gases produced from decomposition of organic material in landfills to generate electricity and reduce landfill volume. |
| landfill mitigation strategies | Methods used to reduce the negative impacts of landfills, ranging from burning waste for energy to restoring habitat on former landfills. |
| leaching | The process by which hazardous chemicals and heavy metals from landfills seep into groundwater. |
| organic matter | Biodegradable material in sewage that bacteria break down during secondary treatment. |
| recycling | A process by which certain solid waste materials are processed and converted into new products to reduce demand on natural resources. |
| Term | Definition |
|---|---|
| aeration | The process of introducing air into sewage treatment tanks to increase the rate at which bacteria break down organic matter. |
| disinfection | The process of exposing treated water to disinfectants such as chlorine, ozone, or UV light to kill bacteria before discharge. |
| inorganic sludge | Solid waste produced when bacteria break down organic matter during secondary treatment, which settles at the bottom of a tank. |
| organic matter | Biodegradable material in sewage that bacteria break down during secondary treatment. |
| primary treatment | The first stage of sewage treatment involving physical removal of large objects through screens and grates, followed by settling of solid waste in a tank. |
| secondary treatment | A biological process in sewage treatment where bacteria break down organic matter into carbon dioxide and inorganic sludge, with aeration to increase the rate of decomposition. |
| tertiary treatment | The use of ecological or chemical processes to remove remaining pollutants from water after primary and secondary treatment. |
| Term | Definition |
|---|---|
| chemical | A substance with a definite molecular composition that can cause toxic effects in organisms. |
| dose | The amount of a toxin or drug administered to or received by an organism. |
| lethal dose 50% (LD50) | The dose of a chemical that is lethal to 50% of the population of a particular species. |
| Term | Definition |
|---|---|
| dose | The amount of a toxin or drug administered to or received by an organism. |
| dose response curve | A graph that describes the relationship between the dose of a toxin or drug and its effect on an organism or mortality rate in a population. |
| mortality rate | The proportion or number of deaths in a population resulting from exposure to a particular substance or condition. |
| toxin | A poisonous substance that can cause harmful effects or death in an organism. |
| Term | Definition |
|---|---|
| asbestos | A mineral substance that causes mesothelioma and other health problems when inhaled. |
| dysentery | A disease caused by untreated sewage in streams and rivers that affects the digestive system. |
| mesothelioma | A type of cancer caused mainly by exposure to asbestos. |
| respiratory problems | Health issues affecting the lungs and breathing system that can be caused by air pollutants such as tropospheric ozone. |
| tropospheric ozone | Ground-level ozone in the lower atmosphere that can impair respiratory function and lung health when present at elevated levels. |
| Term | Definition |
|---|---|
| cholera | A bacterial disease contracted from infected water supplies. |
| climate zones | Geographic regions characterized by distinct temperature and precipitation patterns that influence the distribution of pathogens and diseases. |
| contaminated drinking water | Water supplies that contain harmful pathogens or pollutants and pose a risk to human health. |
| infectious diseases | Diseases caused by pathogens that can be transmitted from one organism to another. |
| malaria | A parasitic disease transmitted to humans through bites from infected mosquitoes. |
| MERS | Middle East Respiratory Syndrome, a viral respiratory illness transmitted from animals to humans. |
| pathogen adaptation | The process by which pathogens evolve to exploit new opportunities to infect and spread through human populations. |
| pathogens | Organisms or agents that cause disease in humans and other organisms. |
| plague | A bacterial disease transmitted to humans through bites from infected organisms or contact with contaminated fluids or tissues. |
| sanitary conditions | Environmental conditions related to cleanliness and hygiene that affect disease transmission. |
| sanitary waste disposal | The safe and hygienic removal and treatment of human waste to prevent disease transmission. |
| SARS | Severe acute respiratory syndrome, a form of pneumonia transmitted by inhaling or touching infected fluids. |
| tuberculosis | A bacterial infection that typically attacks the lungs and is spread through inhalation of bacteria from an infected person's bodily fluids. |
| vectors | Organisms that transmit pathogens from one host to another, such as mosquitoes or fleas. |
| West Nile virus | A viral disease transmitted to humans through bites from infected mosquitoes. |
| Zika | A virus transmitted to humans through bites from infected mosquitoes and through sexual contact. |
| Term | Definition |
|---|---|
| aquatic ecosystems | Water-based ecosystems including oceans, rivers, lakes, and wetlands that support diverse organisms and ecological processes. |
| coral reefs | Marine ecosystems built by coral organisms that provide habitat for diverse species and are sensitive to temperature changes, sediment, and fishing practices. |
| dead zones | Areas in oceans with very low dissolved oxygen levels caused by excess nutrient pollution, making them unable to support most aquatic life. |
| destructive fishing practices | Fishing methods that damage marine ecosystems, including coral reefs and seafloor habitats. |
| dissolved oxygen | Oxygen gas dissolved in water that aquatic organisms require for respiration; levels decrease during eutrophication as microbes decompose dead algae. |
| food chain | A linear sequence showing the transfer of energy and nutrients from one organism to the next, starting with a producer and moving through consumers. |
| fossil fuels | Non-renewable energy sources formed from ancient organic matter, including coal, oil, and natural gas, that release carbon dioxide when burned. |
| groundwater | Water stored beneath Earth's surface in soil and rock layers, serving as a smaller reservoir in the hydrologic cycle. |
| heavy metals | Dense metallic elements such as mercury, lead, and cadmium that are toxic to organisms and can accumulate in ecosystems. |
| homeostasis | The ability of an organism to maintain stable internal conditions despite changes in the external environment. |
| hydrocarbons | Organic compounds containing hydrogen and carbon released during fossil fuel combustion that contribute to air pollution. |
| intestinal blockage | A condition in animals caused by ingesting litter or debris that prevents normal digestion and can be fatal. |
| light infiltration | The penetration of sunlight through water, which is necessary for photosynthesis by aquatic primary producers. |
| litter | Solid waste that enters aquatic ecosystems and can harm wildlife through ingestion or entanglement. |
| mercury | A toxic heavy metal that bioaccumulates in organisms and biomagnifies through food chains, causing neurological and reproductive harm. |
| methylmercury | A highly toxic organic form of mercury created by bacteria in aquatic environments that accumulates in organisms and food chains. |
| mining | The industrial process of extracting minerals, ores, and other valuable materials from the Earth. |
| nutrient pollution | Excess nitrogen and phosphorus in water that causes algal blooms and subsequent oxygen depletion. |
| ocean temperature | The thermal conditions of ocean water that influence atmospheric temperature, precipitation, and weather patterns. |
| oil spills | The release of crude oil or refined petroleum into marine waters, causing harm to organisms and ecosystems. |
| optimum range | The specific conditions for an environmental factor where an organism can best maintain homeostasis and function most effectively. |
| oxygen sag curve | A graph showing how dissolved oxygen levels decrease and then recover with distance from a pollution source in a waterway. |
| physiological stress | Physical strain on an organism's body systems that can result from environmental conditions outside its tolerance range. |
| primary producers | Aquatic organisms such as algae and aquatic plants that produce energy through photosynthesis and form the base of aquatic food chains. |
| range of tolerance | The limits within which an organism can survive and function for a particular environmental factor, beyond which stress or death occurs. |
| sediment runoff | Soil and rock particles that wash into waterways from land, reducing water clarity and damaging aquatic habitats. |
| visual predators | Predators that rely on sight to locate and capture prey, which are hindered by reduced water clarity from sediment. |
| Term | Definition |
|---|---|
| birth defects | Structural or functional abnormalities present at birth that result from developmental problems during pregnancy. |
| developmental disorders | Conditions that impair the normal physical, cognitive, or behavioral development of an organism. |
| endocrine disruptors | Chemical substances that interfere with the normal functioning of the endocrine system, disrupting hormone production and regulation in organisms. |
| endocrine system | The body system composed of glands and hormones that regulates growth, metabolism, reproduction, and other physiological processes in animals. |
| gender imbalances | Abnormal ratios of males to females in a population, often caused by disruption of sex determination or reproductive processes. |
| Term | Definition |
|---|---|
| commercial development | A human activity that threatens wetlands and mangroves through land conversion for business and urban expansion. |
| dam construction | A human activity that threatens wetlands by altering water flow and hydrology. |
| ecosystem services | The benefits that humans receive from natural ecosystems, including resources, regulation of environmental processes, and cultural values. |
| flood protection | An ecosystem service provided by wetlands that reduces the impact of flooding events. |
| mangroves | Coastal ecosystems that provide ecosystem services and are threatened by human activities such as commercial development and overfishing. |
| overfishing | The removal of fish from aquatic systems at rates faster than populations can reproduce, leading to depletion of fish stocks. |
| pollutants | Harmful substances in the environment that are absorbed and filtered by forest trees. |
| water filtration | An ecosystem service provided by wetlands that removes particles and pollutants from water. |
| water purification | An ecosystem service provided by wetlands that removes contaminants and improves water quality. |
| wetlands | Areas where water covers the soil for at least part of the year, providing ecosystem services such as water purification and habitat. |
| Term | Definition |
|---|---|
| agricultural runoff | Water flowing from agricultural land that carries fertilizers, pesticides, and other pollutants into aquatic ecosystems, contributing to eutrophication. |
| algal bloom | A rapid increase in algae population in a water body, typically caused by excess nutrients, which can deplete oxygen when the algae die and decompose. |
| anthropogenic causes | Environmental changes or substances caused by human activities, such as the release of CFCs into the atmosphere. |
| aquatic ecosystems | Water-based ecosystems including oceans, rivers, lakes, and wetlands that support diverse organisms and ecological processes. |
| detergents | Cleaning agents that contain phosphorus and other nutrients and can contribute to nutrient pollution in aquatic ecosystems when released into waterways. |
| dissolved oxygen | Oxygen gas dissolved in water that aquatic organisms require for respiration; levels decrease during eutrophication as microbes decompose dead algae. |
| eutrophication | The process by which a body of water becomes enriched with excessive nutrients, leading to algal blooms and oxygen depletion. |
| fertilizers | Substances added to soil to increase nutrient content for plant growth, which can cause water pollution and eutrophication when they run off into waterways. |
| hypoxic waterways | Bodies of water with low dissolved oxygen levels, often resulting from eutrophication and unable to support most aquatic life. |
| nutrients | Chemical elements or compounds, such as nitrogen and phosphorus, that promote the growth of plants and algae in aquatic environments. |
| oligotrophic waterways | Bodies of water with very low nutrient levels, stable algae populations, and high dissolved oxygen, representing the opposite condition of eutrophic waterways. |
| wastewater release | The discharge of treated or untreated water from human activities containing nutrients and other pollutants into aquatic environments. |
| Term | Definition |
|---|---|
| aquatic ecosystems | Water-based ecosystems including oceans, rivers, lakes, and wetlands that support diverse organisms and ecological processes. |
| dissolved oxygen | Oxygen gas dissolved in water that aquatic organisms require for respiration; levels decrease during eutrophication as microbes decompose dead algae. |
| thermal pollution | The release of excess heat into the environment from nuclear power plants, which can harm aquatic ecosystems. |
| water temperature | The measure of thermal energy in water, which affects the solubility of oxygen and metabolic rates of aquatic organisms. |
| Term | Definition |
|---|---|
| bioaccumulation | The process by which a persistent substance accumulates in the tissues of an organism over time, increasing in concentration as the organism is exposed to the substance. |
| DDT | A persistent pesticide that bioaccumulates in organisms and biomagnifies through food chains, causing significant environmental damage. |
| fat solubility | The ability of persistent organic pollutants to dissolve in and accumulate within fatty tissues of organisms. |
| long-distance transport | The movement of persistent organic pollutants over great distances through wind and water, allowing them to spread globally. |
| persistent organic pollutants (POPs) | Synthetic, carbon-based molecules that do not easily break down in the environment and can accumulate in organisms' fatty tissues, causing toxic effects. |
| polychlorinated biphenyls | Polychlorinated biphenyls; persistent industrial chemicals that bioaccumulate and biomagnify, causing reproductive, nervous, and circulatory system damage. |
| synthetic molecules | Human-made chemical compounds, such as DDT and PCBs, that are resistant to natural breakdown in the environment. |
| Term | Definition |
|---|---|
| bioaccumulation | The process by which a persistent substance accumulates in the tissues of an organism over time, increasing in concentration as the organism is exposed to the substance. |
| biomagnification | The process by which the concentration of a persistent substance increases at each successive trophic level in a food chain. |
| DDT | A persistent pesticide that bioaccumulates in organisms and biomagnifies through food chains, causing significant environmental damage. |
| developmental deformities | Abnormal physical or physiological development in organisms caused by exposure to biomagnified toxic substances. |
| eggshell thinning | A condition in birds where persistent substances in the environment cause eggshells to become thinner and more fragile, reducing reproductive success. |
| fat-soluble compounds | Chemical substances that dissolve in fats or lipids and are commonly subject to bioaccumulation in living organisms. |
| food chain | A linear sequence showing the transfer of energy and nutrients from one organism to the next, starting with a producer and moving through consumers. |
| food web | A model depicting interlocking patterns of multiple food chains that shows the complex flow of energy and nutrients among organisms in an ecosystem. |
| mercury | A toxic heavy metal that bioaccumulates in organisms and biomagnifies through food chains, causing neurological and reproductive harm. |
| persistent substance | A chemical that resists breakdown in the environment and accumulates in organisms over time. |
| polychlorinated biphenyls | Polychlorinated biphenyls; persistent industrial chemicals that bioaccumulate and biomagnify, causing reproductive, nervous, and circulatory system damage. |
| top carnivores | Predators at the highest trophic level of a food chain that accumulate the highest concentrations of biomagnified substances. |
| trophic level | The position an organism occupies in a food chain or food web, determined by the number of energy transfer steps from the primary producer. |
| Term | Definition |
|---|---|
| air pollutants | Harmful substances released into the atmosphere that can negatively affect air quality and human health. |
| electronic waste | Electronic waste from discarded electronic devices that may contain hazardous chemicals including heavy metals such as lead and mercury. |
| groundwater contamination | The pollution of water found beneath the Earth's surface, often resulting from mining operations. |
| incineration | A waste disposal method in which solid waste is burned at high temperatures, significantly reducing its volume while releasing air pollutants. |
| landfill decomposition | The breakdown of waste materials in a landfill through microbial activity, influenced by trash composition and environmental conditions. |
| landfills | Designated areas where solid waste is disposed of and buried, which can release methane and carbon dioxide as organic matter decomposes. |
| leachate | Liquid that percolates through solid waste in a landfill and can carry contaminants into groundwater. |
| methane | A greenhouse gas with global warming potential lower than nitrous oxide but higher than carbon dioxide, contributing to climate change. |
| microbial decomposition | The process by which microorganisms break down organic waste materials. |
| ocean dumping | The practice of disposing of waste by depositing it into the ocean. |
| plastic pollution | The accumulation of plastic waste in the environment, including large floating islands of trash in oceans. |
| sanitary landfills | A engineered landfill designed with a bottom liner, storm water collection system, leachate collection system, cap, and methane collection system to minimize environmental impact. |
| solid waste | Any discarded material that is not a liquid or gas, generated from domestic, industrial, business, and agricultural sectors. |