APES Unit 8

point pollution

Pollutants discharged from a single identifiable location (e.g., pipes, ditches, channels, sewers, tunnels, containers of various types).

non-point pollution

pollution that comes from many sources, not easily to identify where the exact sources come from (EX: water, air)

oxygen sag curve

Oxygen depletion from pollution in rivers and lakes (Less DO, less animals can survive)*

range of tolerance

the limits to the abiotic conditions that a species can tolerate (Amount of DO, food, space, etc)

What can nutrient pollution lead to?

Eutrophication and then dead zones

Dead zones

In a body of water, an area with extremely low oxygen concentration and very little life. Often caused by eutrophication

How does warm temperatures effect dissolved oxygen (DO)?

Lessens the amount of DO

Sediment Pollution

It reduces light infiltration, lower the amount of photosynthesis that can occur under water.

Endocrine disruptors

Chemicals that disrupt normal hormone functions. Can cause birth defects, developmental disorders, etc)

Endocrine system

Glands secrete hormones that regulate processes such as growth, reproduction, and nutrient use (metabolism) by body cells. Can be disrupted by pollution.

What is an example of an endocrine disruptor?

DDT

Ecological services of wetlands

water purification, flood protection, water filtration, and habitat

Wetland threats

commercial development, dam construction, overfishing, and pollutants from agriculture and industrial waste

Oligotrophic lakes

Lake with high DO, low BOD, low nutrients, low algae content, Usually high in the mountains.

Eutrophic lakes

Lakes with low DO, high BOD, high nutrients, high algae content

Biological demand of oxygen (BOD)

How much oxygen a species needs to survive

process of eutrophication

Nutrients added to water -\> algae bloom -\> algae die -\> algae decompose (consumes O2, BOD increases) -\> DO decreases -\> dead zone

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

Solutions to thermal pollution

Cooling towers (cools water being put in) and closed systems (keeps water out of watershed)

Thermal pollution graph

As the water temperature increases, the DO concentration decreases.

persistant organic pollutants (POPs)

compound with carbon in it that resists photochemical, biological and chemical degradation

Carcinogen

A cancer-causing substance, often found in POPs (EX: asbestos)

What do POPs cause?

Carcinogens, endocrine disruptors, nervous/immune system damage, Wildlife decline and reproductive impairment

How can POPs travel long distance?

Through wind, water, and bioaccumulation

Biomagnification

An increased concentration of substances per unit of body tissue. Gets worse the higher up the food chain

Bioaccumulation

The absorption of elements/compound by cells. Do not go away and can be passed on to next organism if current one is eaten.

Biomagnification/Bioaccumulation impacts of humans

Reproductive issues, nervous system issues, cardiovascular impacts

Biomagnification/Bioaccumulation impacts of top carnivores

egg shell thinning, developmental issue, reproductive problems

sanitary landfill

A place to deposit solid waste, where a layer of earth is dug up, lined with plastics or clay, storm water collection leachate collection and methane collection implanted, filled with waste, covered over by land

Landfill

Most common type of solid waste disposal, decomposition depends on trash and conditions, can contaminate groundwater and release harmful gases

Incinerators

Trash is burned, gets rid of trash volume, releases air pollutants

Illegal dumping

Happens if waste collection is too expensive, leads to environmental problems

ocean dumping

leads to trash islands, marine life killed by entangling or ingesting waste

3 Rs

reduce, reuse, recycle

Landfill mitigation

lowers the amount of landfills, done by incineration and habitat restoration

waste-to-energy

A system in which heat generated by incineration is used as an energy source rather than released into the atmosphere

Three stages of sewage treatment

Primary (physical, Secondary (biological), and tertiary (chemical)

Primary (physical) sewage treatment

screen or grate removes large objects from waste

Secondary (biological) sewage treatment

Solid waste settles to the bottom, waste water aerated to allow good bacteria to break down bad bacteria

Tertiary (chemical) sewage treatment

Water treated with CL, O3, or UV light to kill remaining bacteria

LD50

lethal dose (of a toxin) for 50% of the test population. Smaller the dose, the more toxic the substance is.

Pathogens

Microbes that cause disease

How do pathogens spread

Areas lack sanitary waste disposal/ have contaminated water supply -\> spread of infectious disease (tropical ones heading more north/south with climate change)

Resource Conservation and Recovery Act (RCRA)

controls hazardous waste with a cradle to grave system

Neurotoxins

toxic substances, such as lead or mercury, that specifically poison nerve cells

Teratogens

agents, such as chemicals and viruses, that can reach the embryo or fetus during prenatal development and cause harm

How do you find the safe human dose of LD50?

The divide the dose by 1000