Flashcards in Environmental Pathology 1 Deck (58):
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?
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
2) wood smoke
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?
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
1) mining, foundries
2) pottery painter
3) automobile factory (incinerate batteries!)
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)
how are the kidneys and GIT affected from lead poisoning?
kidneys -- PCT damage with intra-nuclear lead inclusions. interstitial fibrosis which can lead to renal failure and gout.
GIT- lead colic
sources and mechanism of mercury poisoning?
contaminated fish & vapors from dental amalgams
inorganic (mercury chloride) converted to organic (methyl mercury) by bacteria (usually from industrial sources) and gets concentrated in carnivorous fish.
from mercury poisoning.
cerebral palsy, deafness, blindness, mental retardation and major CNS defects in children exposed in utero
acute mercury exposure
bread made from grain with "methyl mercury based fungicide" (iraq 1971)
2 main effects of mercury toxicity?
1) Nephrotoicity - Kidney = main target.
Acute = PCT necrosis
chronic = nephrotic syndrome with proteinuria
clinical findings: constriction of visual fields, paresthesia, ataxia, dysarthria, hearing loss.
cerebellum- atrophy of granular layer. spongy softening in visual cortex
common sources of arsenic poisoning?
wood preservers, herbicides
ground water used for drinking (bangladesh, chile, china)
acute arsenic poisoning
sensorimotor neuropathy (parasthesia, numbness and pain) 2-8 weeks post exposure
GIT, CVS, CNS disturbances (interference with mitochondrial ox phos since trivalent arsenic can replace phosphates in adenosine triphosphate. causes vomiting, abd pain, and diarrhea)
chronic arsenic poisoning (4 things)
1) increased risk of cancers (lung, liver-angiosarcoma, skin, GI)
2) skin changes:
i- hyperpigmentation & hyperkeratinosis
ii- basal and squamous cell carcinoma
3) nail changes "mees' lines"
4) non-malignant resp. disease
sources of cadmium poisoning
production of nickel-cadmium batteries, food, cigarette smokers (through inhalation), soil and plants via fertilizers
toxic effects of excess cadmium (4 things)
1)obstructive lung disease (necrosis of alveolar macrophages)
2) kidney damage
3) skeletal abnormalities related to calcium loss "Itai Itai"(post-menopausal women, japan, osteoporosis and osteomalacia)
4) *increased risk of lung cancer!
which 3 toxicants can cause lung cancer?
health risks and uses of chloroform and carbon tetrachloride
found in dry cleaning agents and paint removers
liver and kidney toxicity
health risks and uses of Benzene
widely used in industrial processes
marrow aplasia (aplastic anemia) and acute myeloid leukemia
(oxidized by hepatic CYP2E1 to toxic metabolites)
Health risk and uses of Ethylene glycol
used as anti-freeze and substitute for ethanol by alcoholics (+ adulterate wines)
toxicity = toxic within minutes due to "oxalic acid" metabolite. Results in metabolic acidosis, CNS depression, nausea, vomiting, hypocalcemia-related cardiotoxicity, renal failure
health risks and uses of polycyclic hydrocarbons
uses: potent carcinogen (released during combustion of fossil fuels, etc)
LUNG AND BLADDER CANCER
health risks and uses of methanol
used as substitute for ethanol
poisoning due to metabolism of formaldehyde and formic acid
health risks and uses of organo-chlorines
anti-estrogenic or anti-androgenic activity
health risks of Dioxins and Polychlorinated biphenyls (PCBs)
1) skin disorders (folliculitis and chloracne-dermatosis). around face and behind ears
2)Liver and CNS abnormalities
health risks of mineral dusts
pneumoconiosis (from inhalation)-- chronic, non-neoplastic lung disease.
(mineral dusts = coal, silica, asbestos, beryllium)
Occupational exposure to asbestos linked to (4)
1) localized fibrous plaques
2) parenchymal interstial fibrosis (asbestosis)
3) lung carcinoma
What are the 2 forms of asbestos?
what are the differences between amphibole and serpentine asbestos?
Amphibole is less prevlanet and more pathogenic. Contains straight, stiff fibers that are delivered deep into lung tissues
serpentine is more flexible and less likely to be impacted in upper airways. More prevalent in industry but less carcinogenic
What is the oncogenic effect of asbestos?
tumor initiator and promoter.
Increases LUNG carcinoma 5 fold (more common in smokers)
Increases Mesothelioma 1000 fold
Gross characteristics of asbestos (3)
1) diffuse pulmonary interstitial fibrosis
2) pleural plaques
Microscopic characteristics of asbestos (3)
1) spindle cells or plump rounded cells
2) asbestos bodies -- golden brown fusiform or beaded rods
3) ferruginous bodies-- inorganic particles coated with iron-protein complexes
leads to angiosarcoma of liver
what are the 3 major toxicants that lead to lung cancer?
what are the 2 major toxicants that lead to fibrosis in lung?
what are the 2 major toxicants that lead to hypersensitivity and irritation of lung?
what are the 2 major toxicants that lead to Bladder cancer?
2) rubber products
what toxicant leads to leukemia?
what toxican leads to liver angiosarcoma?