Test 2 Flashcards
Current leading causes of death in developed countries
Cancer, cardiovascular disease, respiratory disease, chronic liver disease
Epidemiology
comparison of health and disease in different populations
human-based evidence for human health issues
epidemiology, occupational exposures, accidents, etc
lab- based evidence for human health issues
in vitro, in vivo
factors that impact toxicity
- Dose
- Exposure period
- Mixtures
- Age
- Genetic make-up
- Diet
- Others
Cancer
Unrestrained proliferation of cells, invasion, metastases
Carcinogen
substance that causes or induces neoplasia,
new or autonomous growth of tissue
Neoplasm
lesion resulting from growth
IARC category meanings.
* Group 1:
* Group 2A:
* Group 2B:
* Group 3:
* Group 4
Group 1: Carcinogenic to humans
Group 2A: Probably carcinogenic to humans
Group 2B: Possibly carcinogenic to humans
Group 3: Not classifiable as to its carcinogenicity to humans
Group 4: Probably not carcinogenic to humans
how may known carcinogens are in tobacco smoke
60
acute and chronic effects of Benzene
acute: dizziness, headaches, confusion
chronic: leukemia
Organic teratogens definition and examples
substances that cause birth defects.
ex. cigarette smoke, benzo[a]pyrene, pesticides (DDT)
Endocrine hormone system
A control system that responds to internal/external
signals to maintain the body in a chemical equilibrium
(homeostasis)
how do Mechanism of action exert their influence
– Mimicking the effects of endogenous hormones
such as estrogens and androgens
– Antagonising the effects of endogenous hormones
– Altering the pattern of synthesis and metabolism
of normal hormones
– Modifying hormone receptor levels
example of something toxic at high quantities but essential for health
Fluorine
Bioaccessable
the proportion of a
chemical that is
soluble in bodily fluids
Speciation of metal
This refers to the chemical form of the metal or inorganic element.
Speciation affects toxicity (hazard)
Speciation can also refer to the valence or oxidation
state of a metal
in-vivo
animal tests
in-vitro
lab tests
Lead effects on humans
neurological damage in young
children. Prenatal exposure is also a concern.
Organophosphate Pesticides traits
Low-to-moderate persistence - don’t bioaccumulate
- Toxicity might need to be “highly”-to-”extremely” to have effect
Specificity Problem for Organophosphate Pesticides
Mode of action is neurotoxicity through inhibiting acetylcholinesterase enzyme
- enzyme removes acetylcholine neurotransmitter after nerve signal
- if enzyme inhibited, nerve synapse can’t “reset”, get paralysis
this will happen in many non-target organisms, including humans
Herbicides
easier than other pesticides to make non-toxic to vertebrates/mammals/humans
2 types of radiation
non-ionizing, ionizing
Particulate radiation
– Alpha particles: (2 N and 2P – heavy)
collide with matter and lose their
energy quickly, barely able to
penetrate skin, concern if inhaled or
ingested
– Beta particles-: electrons (negatively
charged), very small, penetrate 1-2 cm
of water or human flesh
– Neutrons: generated from splitting
atoms in nuclear reactors, penetrate
the furthest
Electromagnetic waves
– Gamma rays: energy transmitted in a
wave, penetrate greater than alpha
and beta particles
– X-rays: similar to gamma except
artificially produced
types of ionizing radiation
particulate & electromagnetic radiation
isotopes
variants of elements which have different numbers of neutrons but same number of protons
radioisotopes
isotopes that are unstable and release energy as they decay
Radon
radioactive gas found naturally on earth. cause lung cancer.
sievert
measure of the health effects of low doses of ionizing radiation of the human body
Genotoxic
toxic to genetic material of organism
Properties of Mercury
- Metallic mercury, is liquid at room temperature
- can form inorganic and organic compounds
“mad as a hatter” origin
from the suggestion that hatters were exposed to mercury
most toxic form of mercury
Organically-bound mercury (methylmercury and
dimethylmercury)
how are most humans exposed to mercury (specifically MeHg)
fish
what is mercury transport like
Volatile nature of mercury leads to long-distance transport
and widespread contamination
what kind of mercury is in most occupational exposures
inorganic or elemental Hg
GMO benefits
- Reduced environmental impacts of spraying pesticides
- Increased agricultural yield per land mass to feed
a hungry, growing world population - Decreased frost damage
- Increased opportunity for beneficial insects
- Efficient production of life-saving medicines
GMO environmental concerns
- Invasiveness
- Resistance
- Cross-contamination
- Co-existence with traditional crops
- Potential for environmental impact
Pathogen
a bacterium, virus, or other
microorganism that can cause disease
main soures of pathogens in water
fecal from mammals or birds
