Environmental Pathology 1 Flashcards
which 2 cell types does ozone affect?
free radicals cause injury to:
1) epithelial cells
2) type I pneumocytes
ozone is more dangerous for patients with which conditions?
asthma or emphysema (causes upper respiratory inflammation)
sources of sulfur dioxide?
power plants and paper mills
sulfur dioxide gives what symptoms clinically?
burning sensation in throat. rise to bronchitis over time
what size of particulate matter is most harmful?
ultra fine particles (less than 10 micrometers)
what do ultra-fine particles of particular matter result in clinically?
Myocardial Ischemia!
what is the mechanism of action of particulate matter inducing symptoms clinically (i.e. asthma, irritation, MI?)
phagocytozed by macrophages and neutrophils in ALVEOLI –> releases macrophage, inflammatory protein 1a and ENDOTHELIN
what are the 2 main sources of CO?
1) incomplete oxidation of carbon materials (car engines, heating appliances)
2) chronic poisoning in individuals working in confined environments with high exposure to fumes (i.e. tunnels, underground garages)
pathophysiological effects of CO?
CO binds to Hb with 240 greater affinity than O2 binds. –> Cb-hb does not carry oxygen.
systemic asphyxia (CO kills by inducing CNS depression)
Acute CO poisoning results in what clinically?
Cherry Red color of skin and mucous membranes
Chronic CO poisoning results in what clinically?
carboxy-hb levels rise to life-threatening levels and cause widespread CNS ischemia
6 indoor air pollutants
1) Tobacco
2) wood smoke
3) radon
4) bio-aerosols
5) formaldehyde
6) sick bldg syndrome
What can Radon pollutant cause clinically?
Lung cancer in uranium miners (indirectly)
Where is formaldehyde often found? and what population does it pose most danger to?
manufacture of building materials (cabinetry, furniture)
Refugees from environmental disasters living in poorly ventilated trailers (i.e. Katrina 2005)
what are the main environmental, occupational and recreational causes of lead poisoning?
environmental:
1) lead containing house paints & gasoline
2) flaking lead paint in older homes and soil contamination
3) Pica (childhood craving) for eating lead-based paint
occupational:
1) mining, foundries
2) pottery painter
3) automobile factory (incinerate batteries!)
recreational:
glazed pottery making, painting
clinical features of lead exposure in children and adults
children: low intellectual capacity and behavioral problems (at subclinical levels)
adults: BLUE LINE on gums “lead lines”, CNS symptoms, anemia
Effects of lead exposure in the CNS (children & adults)
children –> encephalopathy
adults –> peripheral neuropathies
effects of lead exposure in bone
impaired remodeling of calcified cartilage in epiphyses of children. “lead lines” – impairs healing of fractures
What type of anemia results from lead poisoning?
Microcytic, hypochromic anemia.
what is the mechanism of heme deficiency in lead poisoning? (i.e. inhibition of what two enzymes in heme synthesis?)
1) gamma-aminolevulinic acid (ALA) dehydratase
2) Ferrochelatase (inhibition causes rise in PROTO-PORPHYRIN LEVELS)
Diagnosis of lead poisoning in children (and definitive diagnosis)
1) neurological and behavioral changes
2) unexplained anemia with BASOPHILIC STIPPLING IN RED CELLS
Definitive diagnosis = elevated blood lead levels & free (or zinc-bound) red cell “protoporphyrin”
Microscopic changes in BM and peripheral blood from lead poisoning
BM: RINGED SIDEROBLASTS (red cell precurors with iron-laden mitochondria)
Peripheral blood: microcytic, hypochromic anemia with basophilic stippling of red cells
microscopic changes in brain from lead poisoning
in children: Brain Edema
gama-ALA damages neurons and increases vessel permeability
in adults: peripheral demyelinating neuropathy
(wrist drop & foot drop)