final Flashcards
What is the pH of acid rain?
> 5.6
What is acid rain caused by?
fossil fuel sulfur and nitrogen oxides mixed with water
LD50
Definition
what does it measure
median lethal dose
◦ LD50 is the amount of material given all at once, which causes the death of 50% of a test group
way to measure short-term acute poisoning
What does a low Ld50 mean?
The LOWER the LD50, the MORE TOXIC the substance
What are the 5 mechanisms of toxicity in regards to heavy metals?
¥ Enzyme/cofactor inhibition or potentiation
¥ Disruption of membrane and other transport processes
¥ Disrupt mitochondrial functionfatigue
¥ Decreased neuronal function and nerve conduction
¥ Bind sulfhydryl groups on proteins and amino acids
What is Smog and what can it do?
Main component is from ground level ozone made from NO+VOC+Sunlight
Air pollutants impact nerve and brain development and function
What are the 6 main types of pollutants:
Lead Carbon Dioxide ground level 03 n specicies, particle water matter, so2,
How is ground level ozone made?
Not emitted directly into the air but created by chemical reactions between oxides (NOx) and Volatile Organic Compounds (VOCs) in the presence of sunlight (i.e. ozone is a secondary pollutant)secondary pollutant and main component of smog
o Primary component of smog and is a secondary pollutant
What are health problems associated with ozone?
- Eye irritation
- Throat irritation
- Worsen asthma, emphysema and bronchitis
What is the main health effect of benzene
Causes cells to not work effectively, bone marrow suppression and anemia
Do RBC’s pick up CO or Oxygen quicker
RBCs can pick up COquicker than oxygen
How are people exposed to lead?
Home
Dust, paint, soil
Pre-1978 homes with deteriorated leaded paint
Children at greatest risk
Lead dust levels have been directly correlated with children’s blood lead levels
What is a VOC?
Volatile Organic Compound
What does Benzene do to the body?
causes leukemia, cells to not work
3 ways of exposure to voc -
inhalation, ingestion, dermal
3 systems effected by voc-
Neuro, immune, hematologic
What VOC is found in non-stick pans?
Polytetrafluoroethylene (PTFE)
What is unique about the way formaldehyde affects the body?
prevents absorption intestinal tract
It is a Water soluble toxin that inhibits its ability to go low in resp
Which VOC is commonly Huffed?
toluene
Does boiling water get rid of lead?
No, running cold water before use may reduce exposure
List the products where Lead is still found.
- Computers
- Solder
- Pewter
- Ceramic glazes
- Jewelry
- Automotive batteries
- Imported or older pre-regulation products
What VOC is commonly found in dry cleaning?
Perchloroethylene (PERCS)
Which VOC are histology workers commonly exposed to?
xylene
What VOC is commonly found in carmex and chloroseptics?
phenol
Who is Most At risk for lead poisoning?
- Children living in older housing
- Pregnant women and the developing fetus
What disease is pathoneumonic for asbestos exposure:
mesothelioma
Where is lead exchanged between?
Lead is exchanged between blood, soft tissues, and mineralizing tissues(bones)
Why are developmental neurological effects of greatest concern regarding led exposure and children?
- Crosses the placental barrier: affects fetal viability
- Neurologic effects on children documented below 10mcg/dL
What is the Primary metabolite of nicotine that we can use to measure tobacco exposure?
Contanine
Major source of new car smell:
vinylflouride
What does PAH stand for ?
What are the two types?
PAH: poly cyclic aromatic hydrocarbon
low molecular weight
high molecular weight
Where are Low Molecular Weight PAH’s found?
low molecular weight found in moth balls as napthaline
Where are High Molecular Weight PAH’s Found?
high molecular weightbenzoapyrine, comes from charred and grilled food
What is the name of the Specicies of black mold?
stachiboytris charcharum
Which VOC is 25x more reactive than benzene
Toluene
Xylene Main effect is?
CNS depression
What are the main health effects of lead poisoning?
- microcytic hypochromic anemia with basophilic stippling
- And then can see D-ALA accumulation in urine
What are the main health effects of formaldehyde?
NOT Lower Respiratory Tract
Bronchitis, pulmonary edema, asthma
Anticipated to be a human carcinogen: sinonasal, nasopharyngeal carcinoma and leukemia
Vinyl Chloride and PVC is what?
a. Highly hepatotoxic- hepatic angiosarcoma
b. Portal hypertension and cirrhosis
High Molecular Weight PAH is what molecule?
benzo(a)pyrene
Low Molecular Weight PAH is what molecule?
naphthalene
What is the Definition of Environmental Medicine?
the study of the effects of external physical, chemical, biological and emotional factors on human beings
What is Multiple Chemical Sensitivity?
Environmental Illness = Toxicant-Induced Loss of Tolerance = “Idiopathic Environmental Intolerance” Can not figure out what is causing them to be sick, may be allergic to multiple things
- The EPA states:
“A condition in which a person reports sensitivity or intolerance (as distinct from “allergic”) to a number of chemicals and other irritants at very low concentrations.. There are different views among medical professionals about the existence, causes, diagnosis, and treatment of this condition.”
Often no detectable triggers
What is the Criteria to dx Multiple Chemical Sensitivity?
- Sx are reproducible with repeated chemical exposures.
2. Condition has persisted for significant period of time.
3. Low levels of exposure result in manifestations of the syndrome (i.e. increased sensitivity).
4. Sx improve when the triggering chemicals are removed.
5. Responses often occur to multiple chemically unrelated substances.
6. Symptoms involve multiple-organ symptoms
What is Sick Building Syndrome(SBS)?
describes a situation where people experience sxs of ill health that seem to be linked to spending time in a building but where no specific cause can be identified
What is building related illness?
recognized diseases caused by being in a building
What are the signs and symptoms of lead toxicity in children?
- Decreased learning and memory
- Lowered IQ
- Decreased verbal ability
- Impaired speech and hearing functions
- Early signs of hyperactivity or ADHD
What do labs show for lead poisoning ?
Basophilic stifling
What is a humans most common source of mercury toxicity?
Dental Amalgams
Where does methyl mercury accumulate
aquatic and terrestrial food chains
Large amounts of fish eaten over weeks and months can cause what?
Why?
Damage to the nervous system
Infant born with cerebral palsy
95% of what is absorbed from our food?
Methylmercury
What heavy metal crosses the blood brain barrier and placental barriers?
Mercury
What is the half life of mercury in adults
50-70 days
What is the half life of mercury in children
90 days
What heavy metal has a high uptake in the brain making it a potent neurotoxin and teratogen?
Mercury
What is the reference range for mercury in the body?
Whole Blood <5.0 ug/L
Which heavy metal is used in the predominant commercial use for battery manufacturing
cadmium
What is the main source of airborne cadmium
Cigarette smoke
How does cadmium affect the body?
Accumulates in the liver and kidneys where its bound to metallothionein
What does cadmium do to the kidneys?
It causes renal tubular and glomerular damaging leading to irreversible proteinuria and progressive reduction in GFR
How does cadmium affect the bones?
Results in painful osteomalacia or osteoporosis
How does cadmium affect the lungs?
Emphysema and lung CA
What lab test is best for short-term acute exposure
Blood
Hair Lab testing must be what?
confirmed by a blood or urine test if positive.
it is only a screen
Hair testing is good for evaluating what metal?
methylmercury
What do you want to always do when testing the urine for acute exposure to metals
use a chelating agent
What are the 3 provocative chelators
DMSA
DMPS
EDTA
