Key Terms for Environmental Science Unit 8

Algal Bloom

rapid increase in the population of algae in aquatic environments, often resulting in vibrant green, red, or brown colors in the water.

Bioaccumulation

the process by which toxins or pollutants build up in the tissues of an organism over time, often at a rate faster than they can be eliminated.

Biomagnification

the increasing concentration of toxic substances as they move up through different trophic levels in a food chain.

Composting

the natural process of decomposing organic materials, such as food scraps and yard waste, into nutrient-rich soil.

DDT

a synthetic pesticide that was widely used for insect control during the mid-20th century. It has been banned or restricted in many countries due to its harmful effects on wildlife and potential risks to human health.

Dead zones

areas in bodies of water where oxygen levels are extremely low or completely depleted, leading to a lack of aquatic life.

Dose response curve

shows the relationship between the dosage or concentration of a substance and its effect on an organism. It helps determine the optimal dosage for desired effects and identifies potential risks associated with higher doses.

Dysentery

a gastrointestinal infection that causes inflammation of the intestines, resulting in severe diarrhea with blood and mucus. It is usually caused by bacteria or parasites.

Endocrine disruptor

substances that can interfere with the hormonal system in living organisms, causing adverse effects on growth, development, reproduction, and behavior.

Eutrophication

the excessive growth of algae and other plants due to an increase in nutrients (such as nitrogen and phosphorus) in a body of water, leading to harmful effects on aquatic ecosystems.

E-waste

discarded electrical or electronic devices, including items like computers, televisions, and smartphones.

Hypoxic

an environment or condition that has low levels of dissolved oxygen, which can be harmful to aquatic organisms. It occurs when there is insufficient oxygen to support normal life functions.

Incinerator

waste management method that involves burning solid waste at high temperatures until it turns into ash. This process reduces the volume of waste and generates heat or electricity in some cases.

Landfill

designated areas where solid waste is disposed of in a controlled manner. They involve burying waste materials in layers with soil coverings to minimize environmental impacts.

Leachate

a liquid that forms when water percolates through solid waste, dissolving various substances and creating a potentially harmful solution. This process occurs in landfills where organic and inorganic materials decompose, and it can contain toxic compounds that pose risks to the environment and human health if not managed properly.

Mercury

a heavy metal that is naturally occurring but can also be released into the environment through human activities such as burning fossil fuels, mining, and waste incineration. It is highly toxic and can accumulate in organisms, leading to serious health effects.

Mesothelioma

a rare form of cancer that develops in the lining of certain organs, most commonly the lungs or abdomen. It is primarily caused by exposure to asbestos.

Nonpoint source of pollution

contaminants that enter the environment from diffuse sources, such as runoff from agricultural fields or urban areas. They cannot be traced back to a single point of origin.

Oxygen sag curve

represents the decrease in dissolved oxygen levels downstream from a pollution source. It shows how organic pollutants consume oxygen as they decompose, leading to hypoxia or anoxia if not properly managed.

Pathogens

microorganisms, such as viruses and bacteria, that can cause disease in living organisms. They invade the body and disrupt normal bodily functions, leading to illness.

PCB

a group of synthetic chemicals that were widely used in electrical equipment, such as transformers and capacitors, until they were banned due to their toxicity. They are persistent pollutants that can contaminate air, water, soil, and food sources.

Point source of Pollution

any single identifiable source of pollution that can be traced back to a specific location or facility. Examples include industrial discharge pipes or smokestacks from power plants.

Persistent organic pollutants

organic compounds that are resistant to environmental degradation and can remain in the environment for long periods. These substances accumulate in the fatty tissues of living organisms and can be toxic, posing significant risks to human health and the environment.

Range of Tolerance

range of environmental conditions in which a species can survive and thrive. This concept highlights how various factors such as temperature, moisture, and food availability affect the health and reproduction of organisms.

Sanitary landfill

engineered waste disposal sites where solid waste is carefully placed in layers and compacted to reduce volume. They are designed to minimize environmental impacts by using liners, leachate collection systems, and daily soil cover.

Primary sewage treatment

the initial stage of wastewater treatment that involves physical processes to remove large solids and floating debris from the wastewater.

Secondary sewage treatment

where microorganisms break down organic matter in sewage treatment.

Tertiary sewage treatment

an advanced stage of wastewater treatment that goes beyond primary and secondary treatments. It involves additional processes to further remove nutrients, pathogens, and other contaminants from treated water before it is discharged into the environment.

Thermal pollution

occurs when there is an increase in temperature in natural bodies of water due to human activities. It can negatively impact aquatic ecosystems by reducing oxygen levels and disrupting the balance of species living in the water.

Toxicity

refers to the degree to which a substance can harm living organisms. It measures the potential of a substance to cause adverse effects on health, ranging from mild irritation to severe illness or death.

Wetlands

ecosystems characterized by the presence of water, either permanently or seasonally, that support aquatic plants and wildlife.