Environmental Protection Agency - regulates exposure to pesticides, toxic chemicals, water and air pollutants, and hazardous wastes
Food and Drug Administration - drugs, medical devices, food additives, cosmetics
Occupational Safety and Health Administration - safe environment for workers
Consumer Product Safety Commision - regulates all other products sold
Tobacco use is a risk factor for what?
chronic respiratory disease, peptic ulcers, osteoporosis, early menopause
What is tobacco use in synergy with?
smoking interacts with other enviornmental and occupational exposures in an additive or synergist fashion
What is the charac of carbon monoxide?
How is carbon monoxide made?
incomplete combustion of hydrocarbons
What makes carbon monoxide so dangerous?
it has 200-fold higher affinity for hemoglobin than oxygen
less oxygen delivered to tissue
What are the % saturation by CO for non-smoker, smoker, toxic, coma/death?
non smoker - 0-2%
smoker - 5-6%
toxic - 15-40%
coma,death - more than 40-50%
Describe the symptoms of acute carbon monoxide poisoning.
cherry-red coloring of skin and mucus membranes caused by carboxy-hemoglobin
they are incapable of carrying oxygen
interferes with release of oxygen from oxyhemoglobin
Describe the symptoms for chronic poinsoning.
persistent low levels of CO cause chronic hypoxia resulting in irreversible CNS changes
What is pneumoconioses?
non-neoplastic lung rxn to inhalation of mineral dust, organic, and inorganic particulates, chemical vapors and fumes
Development of a pneumoconiosis depends on what 4 things?
1. the maount of dust retained in the lung and airways
2. the size, shape, and therefore buoyancy of particles
3. particle solubility and physiochemical reactivity
4. the possible additional effects of other irritants
What is the most dangerous size of particles and why?
most dangerous particles = 1-5 micrometer in diameter
because they may reach the terminal small airways and air sacs and settle in their linings
Which type of particles is more likely to appear in pulmonary fluids and reach toxic levels rapidly?
What does smaller particles cause?
tend to cause acute lung inury
What does larger particles tend to cause and why?
resist dissolution and so may persist w/in the lung parenchym for years
leads to fibrosing collagenous penumoconioses (charac of silicosis)
larger particles -> fibrosis/collagenous
what are some examples of mineral dusts?
coal -> focal dust emphysema
silica -> silicotic nodule
asbestos -> abestosis
what is anthracosis?
most innocuous coalinduced pulmonary lesion in cola miners
can be seen in all urban dwellers and tobacco smokers
inahled carbon pigment is enfulfed by alveolar or interstitial macrophages, which then accumulate in the CT along lymphatics, including the pleural lymphatics, or in organized lymphoid tissue along the bronchi or in lung hilus
What are the four types of Coal Worker's pneumonconiosis?
1. asymptomatic anthracosis
2. Simple coal worker's pneumoconiosis (CWP)
3. Complicated CWP or Progressive Massive Fibrosis(PMF)
4. Caplan's Syndrome
Describe the Coal Worker's Pneumoconiosis (CWP).
benign disease that causes little decrement in lung function
in mild forms of complicated CWP fail to show abnormalities of lung function
minority of cases, PMF (progressive massive fibrosis) develops, leading to increasing pulmonary dysufnction, pulmonary hypertension, and cor pulmonale (right sided heart failure)
once PMF develops, can be progressie even if further exposure to dust is prevented
some evidence show that exposure to coal dust increases the incidence of chronic bronchitis and emphysema
What is the characterisit of simple CWP? What is it made out of? Where in the lungs would it mostly be affected?
charac - coal macules (1-2 millimeter in diameter)
macules consists of carbon-laden macrophages and small network of collagen fibers
mostly involve the upper lobes and upper zones of lower lobes
located pirmarily adjacent to respiratory bronchioles, site of initial dust accumulation
-> dilation of adjacent alveoli = centrilobular emphysema
What is complicated CWP (PMF)? How does it develop? Characterization? Composition of lesion?
many years to develop from CWP
charac - intensely blackened scars larger than 2cm-10cm, multiple
composition of lesion - desnse collagen and pigment, center is necrotic
What is Caplan's syndrome?
characterized by coexistence of rheumatoid arthritis with pneumoconiosis
What is silicosis?
lung disease caused by inhalation of crystalline silicon dioxide (silica)
is the nost prevalent chronic occupational disease in the world
presents after decades of exposure as a slowly progressing, nodular, fibrosing pneumoconiosis
What are the 2 forms that silica come in? which one is more fibrogenic?
crystalline form - quartz, crystobalite = most active form and most fibrogenic
amorphous form - talc, vermiculate, mica
What is the detection method of silicosis and what is seen?
Detected when routine chest radiography
show fine nodularity in upper zones of the lung with normal pulmonary functions
slow to kill
Silicosis is aossicated with an increased susceptibility to _____.
Characterization of silicosis.
tiny, barely palpable, discrete pale to blakened nodules in the upper zones of the lungs
nodules may coalesce into hard, ollagenous scars
some undergo central softening and cavitation
calcification occur in lymph nodes seen radiographically as eggshell calcification
histologicaly, nodular lesions consist of concentric layers of hyalinized collagen surrounded by a dense capsule of more condensed collagen
what is the pathophysiology of disease for silicosis?
silica particles causes activation and release of mediators by macrophages