Transcript Document
ENVIRONMENTAL PATHOLOGY
Diseases related to Occupation Drug reactions Poisoning Life style Drugs of abuse
RESPONSE OF THE RESPIRATORY SYSTEM TO PHYSICAL AND CHEMICAL AGENTS Physical agents: (Aerodynamics)
Particles bigger than
10
m
Particles of
2 to 10
m
in diameter are
trapped by
in diameter are
disposed by
the
nose
the
muco ciliary blanket
Smaller particles
that
land in air-spaces
are
removed by alveolar
macrophages
.
Very small particles (2
m) are exhaled
Chemical agents:
Ozone, Nitrogen dioxide, Sulfur dioxide cause airway inflammation. Further, these gases potentiate the adverse effects of tobacco smoke
Occupational diseases
Pneumoconioses:
Fibrosing pulmonary disease
reaction to inhalation of an aerosol (mineral dusts, particles, vapors, or fumes) which is non-neoplastic lung Key factors: Type of aerosol and its ability to stimulate fibrosis Dose and duration of exposure Size of the particle Pneumoconioses are diseases caused by
inorganic dusts.
Lesions produced depend on the
dose
,
size
nature
of the inhaled particles.
and
chemical Tobacco smoking
worsens the effects of inhaled dusts.
Coal – worker’s Pneumoconiosis
Occupation: coal mining (smokers). Types: Anthracosis Simple coal worker’s pneumoconiosis Complicated coal worker’s pneumoconiosis Caplan Syndrome
Anthracosis:
Carbon pigment
(anthracotic pigment) accumulates
in macrophages
pleural lymphatics, bronchial lymphatics, lung hila
along the Asymptomatic
Simple coal worker’s pneumoconiosis:
Also called
Black lung disease
Coal-dust macules and nodules
in the
upper lobes Little
pulmonary dysfunction
Complicated coal workers pneumoconiosis:
Progressive
massive fibrosis
Increasing respiratory distress
Pulmonary hypertension and cor pulmonale Caplan syndrome: Pneumoconiosis plus rheumatoid arthritis
& Intrapulmonary nodules
Asbestosis
Occupations: shipyard workers, insulation and construction industries, brake-lining.
Lung pathology
Localized or Diffuse interstitial fibrosis
which is most severe in the
lower lobes
Asbestos bodies that may become
coated with iron
(
ferruginous bodies
) Dyspnea Pulmonary hypertension and cor pulmonale
Bronchogenic carcinoma
Most common tumor
in
asbestos-exposed
individuals.
Synergistic effect
of
smoking
and asbestos exposure
Malignant Mesothelioma: Rare
highly malignant
neoplasm Occupation exposure to
asbestos
in 90% of cases Presents with
recurrent pleural effusions , dyspnea, chest pain
Gross:- encases and compresses the lung EM:- long thin
microvilli
Poor prognosis
Increased risk of laryngeal, stomach and colon cancers is also seen in persons having asbestosis.
Silicosis
Occupation: Sandblasters, metal grinders, miners Exposure to
Silicon dioxide
(
silica
) Pathology:
Dense nodular fibroses of the upper lobes
Birefringent
silica particles polarized light
can be seen with May develop
progressive massive fibrosis
Clinical course X-ray shows fibrotic nodules in the upper zones Insidious onset of dyspnea
Slowly progressive although exposure
is stopped Increased risk of
tuberculosis Caplan syndrome
Other important industrial toxins
Vinyl chloride
– plastic industry – causes
angiosarcoma of the liver
Naphthylamine
–
dye makers
and
rubber workers
– causes
bladder cancer
Carbon tetrachloride
( CCl 4 ) – Dry cleaners – causes
Liver
( centri- lobular necrosis and fatty acid change) and
Kidney toxicity
.
Poisoning
Carbon monoxide (CO):
Sources: auto emissions, home heaters, byproduct of fires, cigarette smoking Should be less than 9ppm in atmosphere.
Pathogenesis: Odorless, colorless gas High affinity for hemoglobin Forms carboxyhemoglobin, which shifts the oxygen dissociation curve Causes
systemic hypoxia
Symptoms depend on the
concentration
: 10% → asymptomatic 30% → headache and shortness of breath on exertion 50% → loss of consciousness, convulsions and coma 60% → death
Bright
“
Cherry-red
"
color of the skin
,
mucosal membranes and the blood
.
Treatment : high concentration Oxygen
Cyanide poisoning • Clinical finding: “
Bitter Almond
” scented
breath
• M/A:
blocks cellular respiration
by binding to
mitochondrial cytochrome oxidase
• Systemic asphyxiant
Treatment
• supportive care with administration of oxygen
• • •
Antidotes or Drugs
poisoning
Sodium Sodium
nitrite thiosulfate used for cyanide
Hydroxocobalamin
/ B12 • • Dicobalt EDTA
Sodium
bicarbonate • Epinephrine
Carcinogenic metals • Arsenic.
• Nickel.
• Cadmium.
• Chromium.
Arsenic poisoning
used extensively in
paints (Paris green), wall papers, pesticides
, and even medicinal.
Can be
detected in hair
and
nails long after exposure
Acute poisoning : * Hemorrhagic gastroenteritis
* CNS toxicity
coma and seizures
* "
Garlic - scented " breath
Chronic Arsenic poisoning
* Malaise and abdominal pain * Peripheral neuropathy and muscular weakness * Skin changes (hyper pigmentation and dermatitis)
* Mees lines :
transverse bands on the fingernails
Complication : Squamous cell carcinoma
of the
skin and lung
CHROMIUM
• • Chromium (III) is an essential nutrient that can be toxic in large doses. • The toxicity of chromium compounds depends on the oxidation state of the metal. • Occupational exposure to
chromium (VI)
has been associated with increased incidence of
lung cancer
.
•
CADMIUM
Part 1. Sources of cadmium exposure
– Occupational exposures – Non-occupational exposures • Affects – Kidney – liver
• Significant exposures to cadmium dusts appear to be generated at all stages in the manufacture of both industrial and household nickel-cadmium batteries, including plate-making, impregnation, plate preparation and assembly. Cadmium health effects may be confounded by associated exposures to nickel in this environment •
Overexposure
to
cadmium
fume (usually from welding or cutting materials containing cadmium)
can cause tracheo-bronchitis, pneumonitis
(inflammation of the lungs) and
pulmonary edema
•
LEAD Poisoning (Plumbism)
• Effects Immunity – – – – – – – T lymphocytes B lymphocyte Cytokine production Neutrophil Immunogenicity of normal cellular proteins Macrophages Natural killer cells Reproductive systems
Epidemiology Sources : lead paint, lead plumbing and leaded gasoline * Most common type of chronic metal poisoning in the US * Primarily affects children in poor urban areas CNS toxicity * Lethargy * Cognitive impairment and behavioral problems.
• The Mental retardation • Cerebral edema – encephalopathy
inhibition of heme synthesis
leads to anemia and the characteristic
Basophillic stippling
seen on a peripheral smear.
Diagnosis
– Blood lead levels –
Increased free erythrocyte protoporphyrin Treatment
: Chelating drugs (dimercaprol, pencillamine)
• • • • • • Wrist and foot drop occur in adults due to peripheral motor nerve demyelination Abdominal pain (lead colic) Renal tubular acidosis and renal failure
Microcytic anemia
with
basophilic stippling
– caused by precipitated ribosomes in reticulocytes Deposition of lead at the
gingivodental line
(“
Lead line
”) X-ray long bones have lead lines
increased bone density at the epiphyseal growth plates
Lead Lines
Basophilic Stippling
MERCURY
• Although all mercury compounds are toxic, the
small-chain alkyl compounds
vary in toxicity are the
most hazardous
. Mercury compounds •
Health Effects
According to Agency for Toxic Substances and Disease Registry (ATSDR), mercury is not classifiable as a human carcinogen, although
mercury chloride and methyl mercury are possible human carcinogens
.
Mercury poisoning: Neurotoxicity
– Intention tremors – Dementia and delirium
Nephrotoxicity
(acute tubular necrosis)