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Global Environmental PH Part Two

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achapss's version from 2017-02-22 16:49

Section

Question Answer
Mutationany change in genetic material with mutant cells, if it takes place in gametes this will effect other generations as well
Single Gene Mutationaka Point Mutation, deletion, addition, or substitution of a single base pair or small portion of a single gene leading to misreading of the genetic code
Chromosome Abnormality loss or addition of a sizable piece of chromosome or a change in the number of chromosomes in the nucleus
Mutagen substance capable of mutation
Dose Response Effect the concept that as the dosage of a teratogen increases so does the damage
Rubella aka german measles, pathogenic infection leading to congenital heart defect, deafness and cataracts
Syphillis and Herpes Simplex 2pathogenic infection causing microcephaly and mental retardation
Cytomegalovirus kidney and liver disorder, brain damage, pneumonia
Zikapathogenic infection that is suspected to cause microcephaly
Toxoplasmosis pathogenic infection via parasite found in cat feces that causes fatal lesions in the CNS
Thalidomideold treatment for morning sickness and sleep that causes phocomelia in the first trimester
Phocomeliahand or foot directly attached to torso, or limbs completely absent caused by thalidomide
DESinitially prescribed in the US to prevent miscarriage, increased miscarriage and caused vaginal cancer, reproductive deformity, decreased male fertility, genetic change in embryonic sex cells
Dioxinsfound in agent orange herbicide, lead to miscarriage and structural deformity
Mercuryfound from the aquatic food chain, brain damage, heart and vision problems
Anesthetic Gasused during surgery, leads to fetal alcohol syndrome
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Section 2

Question Answer
Impact Factorhow often a source is cited by others usually indicates quality
Toxicantssubstances that have the ability to cause harm to organs or other biochemical processes away from the site of exposure, not all are poisons
Poisonmore narrow classification, a toxicant that chemical that can cause illness and death with small doses of exposure
Acute Toxicityone time exposure of a large amount of a substance
Chronic Toxicityrepeated over time exposure of small doses of a substance
What are the modes of toxicant exposure?oral, dermal, respiratory
Testing for acute toxicityLD50 lethal dose, defined as amount of chemical dose required to kill 50% of a population of test animals in a 14 day period measured in mg chemical per kg body weight
Testing for chronic toxicity"a threshold exposure" involves animal feeding experiments with three test groups and a control
Chronic Toxicity Test Group 1dose expected to have significant and chronic and sublethal effects
Chronic Toxicity Test Group 2dose expected to have no effect
Chronic Toxicity Test Group 3somewhere in the middle of groups one and two with a moderate effect
Margin of Safetybuffer zone between highest level of a chemical without adverse health effects in animals and a level of exposure safe for humans
What are the steps of a health risk assessment?hazard identification, dose response assessment, exposure assessment, risk characterization
What happens in hazard identification?first step in health risk assessment, based on testing for harm in animals
What happens in dose response assessment?second step in health risk assessment, based on toxicity testing
What happens in exposure assessment?part three of risk assessment, number and type of people, magnitude, geographic extent
What happens in risk characterization?brings all of the information together, determines likely and adverse effects on a population
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Section 3

 

Question Answer
PCBsused in industrial settings for sealants, cooling liquid etc, escaping into ecosystems, prevalent in breast milk samples, toxicity at low concentrations, dermal exposure causes least risk and oral and respiratory much more, common chloracne
Dioxinschemical from herbicide agent orange spread via precipitation and accumulates in fatty tissues, leads to chloracne and thyroid/fertility issues as well as cancer, carcinogen at high levels and low levels display no effect
Asbestosold construction materials responsible for most death and disability common cancer and in men, toxic via oral and respiratory exposure through inhalation of fibers caught in the lungs
What are the three outcomes of asbestos exposure?Asbestosis, lung cancer, mesothelioma
Asbestosischronic disease scarring lung tissue, irreversible, painful, degenerative, can be deadly
Mesotheliomafatal cancer of the lungs and stomach lining ONLY caused by asbestos
What are the risk factors for asbestos?level and duration of exposure, time since exposure occurred - symptoms are not immediate, synergistic effect of smoking, short fibers cause less damage than long
Synergistic Effectinteraction of two or more substances that produce an impact greater than the sum of their independent impacts
Mercurycomes from coal combustion, ores, waste incineration and ends up in water sources, humans are most commonly exposed via fish
What are the outcomes of mercury exposure?enters the blood stream and attaches to RBCs then diffuses to the brain and causes issues with speech, walking, vision, and death at both acute and chronic exposure
Leadsingle most concerning exposure for children in the US, finally declining but still bad
What is the outcome of lead exposure?issue with blood cell formation leading to anemia, damage to the CNS leading to hyper irritability, poor memory and mental retardation, epileptic convulsions, coma and death
Continuum of Toxicityany amount of exposure exhibits some kind of harm
What are the modes of exposure for lead?Oral - ingested as a large hazard for children due to underdeveloped blood brain barrier, nutrient deficiency increases and nutritious foods can prevent adverse effects, Respiratory - lead dust and fumes into bloodstream and more permanently into bones of which it can be rereleased
Chelationtreatment for high blood lead levels, employs a drug that binds to lead and facilitates excretion in a painful process that can not reverse any damage that is already done
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