APES 8.1-8.5

Point source pollution

Pollution that comes from one clear, traceable location

Key traits of point source pollution

Comes from a specific location, easier to monitor and regulate, often concentrated in a plume

Example of point source pollution

Smoke from a smokestack or sewage discharge pipe

Legislation targeting point source pollution

Clean Water Act (CWA)

Nonpoint source pollution

Pollution from many small, spread-out sources that is difficult to trace

Key traits of nonpoint source pollution

Pollutants come from large areas, transported via runoff, often after rainfall

Example of nonpoint source pollution

Fertilizers washing off farmland during storms

Why nonpoint source pollution is difficult to regulate

No single identifiable polluter to find or track

Types of environmental hazards

Physical, chemical, biological, cultural

Range of tolerance

The range of environmental conditions an organism can survive within

Indicator species

Species sensitive to environmental stress used to monitor ecosystem health

Dissolved oxygen (DO)

Amount of oxygen in water; essential for aquatic life, low levels can cause fish kills and hypoxia

Biological Oxygen Demand (BOD)

Amount of oxygen required to decompose organic waste

Eutrophication

Excess nutrients lead to algal blooms and oxygen depletion

Consequence of nutrient pollution

Hypoxia and formation of dead zones (e.g., Gulf of Mexico Dead Zone)

Sediment pollution

Soil erosion and construction runoff that blocks sunlight and harms aquatic life

Thermal pollution

Discharge of heated water that lowers dissolved oxygen levels

Heavy metals

Toxic pollutants like mercury and lead from mining and industrial discharge

Biomagnification

Increasing concentration of toxins up the food chain

Oil spill impacts

Coats wildlife, kills fish, harms tourism and fisheries

Microplastics

Tiny plastic particles that accumulate in organisms and food chains

Bioaccumulation

Build-up of chemicals in a single organism over time

Endocrine disruptors

Chemicals that interfere with hormone systems

Sensitivity of early life stages to endocrine disruptors

Low doses can cause major effects during development

Pollution and biodiversity

Pollution reduces biodiversity and can collapse ecosystems

Oxygen Sag Curve

Graph showing dissolved oxygen decreasing downstream of pollution

Water quality monitoring importance

Assesses ecosystem health using indicators like DO and BOD

Sediment pollution impact

Reduces photosynthesis and clogs fish gills

Types of endocrine disruptors

Synthetic chemicals, byproducts, natural compounds

Function of endocrine system

Regulates hormones controlling growth, metabolism, development, reproduction

Key endocrine glands

Pituitary, adrenal, ovaries/testes, pancreas, thyroid

Stress hormone

Adrenaline

Sources of endocrine disruptors

Plastics, personal care products, pesticides, industrial waste, pharmaceuticals

Primary contamination pathway of endocrine disruptors

Leaching from plastics and packaging

Effects of endocrine disruptors on wildlife

Intersex traits, reproductive issues, developmental delays, altered behavior

Effects of endocrine disruptors on humans

Birth defects, reduced sperm count, early puberty, hormone-related cancers

BPA

Commonly found in plastics, bottles, and canned food linings

Wetlands

Areas where water covers soil part or all of the time

Types of wetlands

Coastal/tidal and inland/non-tidal

Role of mangroves

Trap sediment, prevent erosion, provide nursery habitats

Wetlands and water purification

Filter pollutants like fertilizers, pesticides, sediment

Wetlands and flood protection

Store and slow runoff from storms

Human impacts on wetlands

Urban development, dams, overfishing, pollution

Climate change impact on wetlands

Sea level rise and saltwater intrusion disrupt habitats

Overfishing impact in wetlands

Disrupts food webs and ecosystem balance

PBDEs

Flame retardants used in furniture and electronics

Challenge studying endocrine disruptors

Exposure to multiple chemicals at once

Neurological links of endocrine disruptors

Potential links to ADHD and autism

Phytoestrogens

Natural plant estrogens found in foods like soy

Wetlands and groundwater recharge

Help refill aquifers