ENVI 405 Lecture Notes - Lecture 5: Acceptable Daily Intake, Water Cycle, Reference Dose
Leading cause of Death in the US
Cardiovascular disease
Leading causes of deaths are different in
High income and low income countries
EPA's attribute system
Potency (P)
Severity (S)
Prevalence (Pr)
Magnitude (M)
Acute vs. Chronic Toxicity
immediate vs. longterm
acute - drop dead fast
chronic - long amount of exposure then death/sick
Dose Response Mortality Curve
describes the change in effect on an organism caused by differing levels of exposure (or doses) to a
stressor (usually a chemical) after a certain exposure time, or to a food. This may apply to individuals
(e.g.: a small amount has no significant effect, a large amount is fatal), or to populations (e.g.: how many
people or organisms are affected at different levels of exposure).
Mutagenicity
cause mutations (DNA, Chromosomes)
Carcinogenicty
causes cancers
Chemical testing
In Vitro
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Test on Rats
Epidemiology
Epidemiology is the study and analysis of the patterns, causes, and effects of health and disease
conditions in defined populations.
Potency factor
Potency Factor = (incremental lifetime cancer risk)/(chronic daily exposure)
Oral & Inhalation
LOEL
lowest dose with observed effect
NOEL
highest dose with no effect
RfD
Reference dose
- Formerly acceptable daily intake
Water properties
- Max density at 4 degrees C
- High heat capacity
- Universal solvent
- Hydrologic cycle
Why is the ocean salty?
because salts get evaporated and transported to the ocean in the hydrologic cycle
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Types/locations of water on Earth
Oceans
Glaciers and Ice Caps
Ground Water
Freshwater use in U.S.
Agriculture
Power plants
Municipal (what we drink)
Industry
Pathogens
- Virus ex. enteroviruses
- Bacteria ex. Salmonella, cholera
- Protozoa ex. Giardia, Crypto
- Helminth (worm) ex. Ascaris(roundworm), hookworm, whipworm
F-diagram
Fingers, flies, fields, fluids ---> food
Thermal heat
from power plants, decreases high value fish, less oxygen saturation, faster consumption of oxygen
Pollutants
- Heavy metals: Hg, Pb, Cd, As
- Volatile organic chemicals (VOC): solvents, refrigerents
- Pesticides: Atrazine (herbicide), Dicambi (herbicide), DDT (insecticide), etc
Biochemical Oxygen Demand (BOD)
consumes oxygen in natural waters receiving wastes
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Document Summary
Chronic toxicity immediate vs. longterm acute - drop dead fast chronic - long amount of exposure then death/sick. Dose response mortality curve describes the change in effect on an organism caused by differing levels of exposure (or doses) to a stressor (usually a chemical) after a certain exposure time, or to a food. Epidemiology is the study and analysis of the patterns, causes, and effects of health and disease conditions in defined populations. Potency factor = (incremental lifetime cancer risk)/(chronic daily exposure) Why is the ocean salty? because salts get evaporated and transported to the ocean in the hydrologic cycle. Thermal heat from power plants, decreases high value fish, less oxygen saturation, faster consumption of oxygen. Pesticides: atrazine (herbicide), dicambi (herbicide), ddt (insecticide), etc. Biochemical oxygen demand (bod) consumes oxygen in natural waters receiving wastes five day bod = bod_5 ** Oligotrophic young lake with low organics, low algae, etc. Eutrophic aging lake with higher organics, algae, etc.
