exam274 quiz 10-13

excess nutrients in waterways

come from human activities and sources

algal blooms

can release toxins

nutrients

chemical elements found in the food that plants and animals need to grow and survive

nitrous oxide

not a primary form of N found in natural waters

solubility of phosphates

less soluble in water than nitrates

phosphates

not very mobile in soils and groundwater and tend to remain attatched to soil particles

eutrophication

natural process that results from accumulation of nutrients in lakes or other bodies of water

human activities

tend to speed up eutrophication by increasing the rate at which nutrients enter the water

algal growth

usually limited by the available supply of carbon

bacteria

organisms that are primarily responsible for the formation of hypoxic water

sources of N and P related to agriculture

human waste and chemical fertilizer

fossil fuels

use in power generation, industry, and transportation produces nutrient pollution

household sources of nutrient pollution

pet waste, certain soaps, fertilizers

algal toxins

does not only effect human health if they are ingested

organizations involved in distributing water to homes and businesses

US EPA, state govs, water utilities

public water systems

where approx 90% of US population gets drinking water

ground water

not classified as surface water

water systems

most don’t utilize ground water sources such as aquifers

safe drinking water act

recquires EPA to establish and enforce safety standards and all water systems must flow

activated sludge treatment

not a common component of drinking water treatmenrt

screening

removes large materials like wood and rocks from wastewater entering wastewater treatment plants

aeration

exposes sewage to air to remove dissolved gasses and encourage microbial breakdown of organic matter

sedimentation

settle-able debris is removed from wastewater

removed when solid waste is treated in digesters

waste volume, odors, and microorganisms

bacteria

not all harmful in water

Escherichia coli bacteria

found in digestive tract of animals and cause health problems and sickness in people

indicators of E. coli in water

sewage and animal waste contamination

watersheds that Chicago sits on

Great Lakes and Mississippi

Mississippi Watershed

water from Chicago flows into after the Chicago River was reversed

Lake Michigan

source of drinking water for Chicago

Gulf of Mexico

where water in Chicago eventually makes its way to

insecticides

chemicals used to protect crops, combat insect-borne diseases, control household pessts

resistance to insecticides

insects are capable of developing

enzymes

not many in nature are able to easily break down carbon-chlorine bonds

DDT

more toxic to insects than to animals

chemicals that bioaccumulate

not quickly broken down and excreted by organisms

organochlorine molecules

bioaccumulate because they are poorly water soluble

less persistent insecticides

less potent than more persistent insecticides because they breakdown quicker in the environment

dioxin

not a common herbicide

glyphosphate

some crops have been genetically engineered to be resistant to

chronic effect

one in which the dose is relatively low but prolonged and a time lag occurs between the initial exposure and the full manifestation of the effect

concentration

unit of LD50

cancer

involves mutation of DNA by toxicants

development of cancer

slowly after exposure to a carcinogen

steriod hormones

not water soluble peptides and proteins that bind to receptor proteins embedded in the target cell membrane and induce activation of enzymes inside the cell

BPA

not a strongly estrogenic substance that binds the estrogen receptor 10k times more tightly than estradiol

PFOA and PFOS

degrade slowly in the environment because they contain strong C-F bonds

fish consumption

most environmental toxicity associated with mercury

lead

a potent neurotoxin