CORE CLINICAL CONCEPTS OCCUPATIONAL

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CORE CLINICAL CONCEPTSOCCUPATIONAL
ENVIRONMENTAL MEDICINE

• Session Two

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LECTURE AGENDA

• Cardiopulmonary Assessment
• Pulmonary Assessment
• Common toxidromes
• cardiac
• pulmonary
• renal
• neurotoxins

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Cardiopulmonary Assessment

• Thorough history and physical
• Static electrocardiography
• Dynamic electrocardiography
• Pulmonary function testing

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Cardiopulmonary Assessment

• Important components of selected pre-placement
  and medical surveillance exams
• Individuals with routine use of air purifying
  respirators if no increased cardiac workload is
  expected
• thorough H P
• static ECG and PFTs

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Cardiopulmonary Assessment

• Workers in fully encapsulated clothing and SCBA
  exert additional CV effort with severe heat
  stress
• haz mat workers, fire fighters, asbestos removal
  crews etc.
• Pre-placement and periodic dynamic
  electrocardiography and PFTs are required
• For baseline RTW evaluations when excellent CV
  fitness is required to ensure optimal worker
  safety and protection in the workplace
• Follow standards for assessment
  criteria

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Cardiopulmonary Assessment

• Risk Factors for Morbidity and Mortality
• age
• prior infarction
• non-q wave infarction
• congestive heart failure
• persistent angina
• LV ejection fraction lt40
• complex ventricular ectopy

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Cardiotoxins

• Coronary Heart Disease
• Arrhythmias
• Cardiomyopathies
• Hypertension
• Cor pulmonale

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Cardiovascular Toxins I. CHD

• Carbon Monoxide
• Accounts for greatest of intoxications and
  deaths in industry
• Also most frequent occupational cardiotoxin
• CO has stronger affinity for Hgb than does O2
• Cigarette smoking additive to occupational
  exposures

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Carbon Monoxide

• Occupations at risk
• firefighters
• police officers
• toll collectors
• parking garage attendants
• bridge and tunnel workers
• foundry and blast furnace workers

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Carbon Monoxide

• Measure by carboxyhgb
• 10-20 headache
• 30 coma
• 50 death
• nl levels nonsmoker 4
• smokers 8
• Chronic exposure promotes atherosclerosis
• People with CAD are very sensitive

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Cardiovascular Toxins I. CHD

• Nitroglycerin and other nitrates
• Occupations at risk
• manufacturers of explosives, users (road
  builders, construction and military) and
  pharmaceutical industry
• Monday morning angina long-term exposure,
  cessation of exposure, re-exposure---gt rebound
  vasospasm and sudden V fib

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Cardiovascular Toxins I. CHD

• Noise
• gt85dBA assoc with heart disease, htn,
  arteriosclerosis
• Carbon disulfide
• 5 fold increase risk of death from CHD

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Cardiovascular Toxins II. Arrhythmias

• Hydrocarbons
• low level
• palpatations, myocardial irritability
• high levels
• SA blocks, AV blocks
• all levels
• PAT, V tach, SVT

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Cardiovascular Toxins III. Cardiomyopathy

• Cobalt
• cardiomyopathy in Canadian beer drinkers
• lead in moonshine, arsenic in beer

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Cardiovascular ToxinsIV. Hypertension

• Cadmium
• direct toxic effects , nephropathy
• Lead
• nephropathy, hyperuricemia, gout
• Psychosocial stress
• Thermal stress, noise, vibration

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Cardiovascular ToxinsV. Cor Pulmonale

• Due to advances stages of pneumonconioses

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Peripheral Vascular disease

• Vinyl chloride --- Raynauds syndrome
• Vibration--- vasospastic disease in small
  arteries of the hand -VWF

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Pulmonary Function Assessment

• Critical parameter in cardio-respiratory
  assessment
• Valuable clinical parameter in assessment of
  exposures effects, monitoring, and impairment
  severity

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Pulmonary Function Assessment

• Mandatory requirement of occupational assessment
  is some cases
• Asbestos (CFR 1910.1001)
• Cotton dust (CFR1910.10430 standards)

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Pulmonary Assessment

• FEV1/FVC ratios of 70 or less require further
  assessment before respiratory clearance can be
  given

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Occupational Asthma

• 5 of all asthma is occupationally related
• some occupations (flour milling, baking)
  incidence is 40

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Occupational Asthma

• NIOSH definition for occupational asthma
• dx of asthma
• assoc. between sxs and work

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Occupational Asthma

• Airflow narrowing causally related in the work
  environment to dusts, vapors or fumes
• Type 1 IgE mediated
• cotton, wood dust, Western Red Cedars
• animal, bird dusts, excreta
• chemicals--diisocyanates
• metals--nickel, chromium, platinum, steel, cobalt

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Occupational Asthma

• Byssinosis
• cotton dust, flax or hemp
• sxs occur dramatically on Monday after weekend of
  no exposure
• treatment at the the workplace -- exposure to
  steamed raw cotton eliminates the respiratory
  response

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Occupational Asthma

• Hypersensitivity pneumonitis
• if asthma is the lungs reaction to inhaled
  matter at the bronchial level, hypersensitivity
  pneumonitis is the reaction to inhaled material
  at the alveolar and terrminal bronchiole level

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Hypersensitivity Pneumonitis

• Extrinsic allergic alveolitis
• resembles pneumonia
• mostly type 3 hypersensitivity
• Farmers lung, moldy hay
• bagassosis - moldy sugar cane
• suberosis - moldy cork

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Hypersensitivity Pneumonitis

• Prototype is farmers lung
• onset fever and myalgias 4-8 hours after exp.
• cough and dyspnea
• sxs peak at 12 hours
• moderate cases x-ray--gtinfiltrate
• tx- remove from exposure
• repeated exposure --gtfibrosis

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Acute Respiratory Irritants

• Primarily caused by irritant gases and fumes
• ammonia
• chlorine
• sulfur dioxide
• nitric oxide
• ozone mercury vapor

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Asbestosis

• Dose related disease with long latent period
• Asbestos body -- protein coated fiber which
  contains iron
• Cigarette smoke asbestos ---gt DNA damage
• Causes mesothelioma, lung cancer, pleural plaques
  and benign pleural effusions
• Spirometry ---gt restrictive

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Coal Workers Pneumonconiosis

• Typical lesion is pinhead sized macules loaded
  with black coal dust near alveolar ducts
• May progress rapidly from minor lesions to
  advanced forms
• Associated with centrolobular emphysema
• Spirometry ---gt obstructive pattern

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Silicosis

• Progresses slowly through increasingly severe
  disease
• May be carcinogenic
• Spirometry ---gt restrictive

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Neurotoxins

• Most common peripheral neurotoxins
• OP pesticides
• carbamates
• CS2
• mercury
• lead
• arsenic
• antimony and acrylamide

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Neurotoxins

• Most common CNS neurotoxins
• arsenic, lead (epilepsy)
• manganese (Parkinsons)
• mercury
• CS2
• Chlorinated hydrocarbons
• CO
• benzene, toulene, xylene

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Neurotoxins

• Parkinsons
• manganese
• CO
• CS2
• MPTP n-methyl-4 phenyltetrahydropyridine

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Arsenic

• Smelting, orchard spraying, sheep-dipping,grapevin
  e growing, forestry
• Arsenic trioxide, arsenic pentoxide and arsine
  gas
• Exposure
• inhaltion
• ingestion
• skin

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Arsenic

• Inhalation--nasal, pulmonary irritation
• Dermal irritant or allergic contact dermatitis
• Teratogenic, mutagenic, and carcinogenic

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Arsenic

• Keratoses
• Keratoconjunctivits
• Myocardial damage (prolonged QT)
• Bone marrow hypoplasia
• Peripheral neuropathy
• sensory
• motor

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Beryllium

• Used in aerospace industry, many alloys
• Exposure
• inhalation

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Beryllium

• Chronic beryllium lung disease
• long latent period
• exertional dyspnea, cough
• hilar adenopathy
• rx corticosteroids

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Lead

• Plumbers,
• solderers, painters
• Batteries, glass, ceramics
• Exposure
• inhalation
• ingestion

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Lead

• Storage compartments
• blood/internal organs
• skin/muscles
• bone

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Lead

• Organ systems affected
• gi
• bone marrow/circulating RBCs
• CNS/PNS
• kidneys
• reproductive

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Lead intoxication - effects

• In children
• almost all organs affected
• permanent damage at low levels
• nervous system and kidney
• ADD, learning disabilities, decrease
  intelligence, behavioral problems
• speech and language impairment
• decrease muscle and bone growth, hearing damage

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Lead intoxication - effects

• In adults
• fetal damage/demise
• fertility problems
• hyptertension
• gi problems
• neurological disorders
• memory/concentration problems
• impotency

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Lead poisoning - at what level?

• Childhood lead poisoning was redefined in 1990 by
  CDC
• blood lead level of 10 micrograms per deciliter
  or above

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Lead

• Medical surveillance requirements
• Medical removal protection
• Role of chelation therapy

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Lead intoxication -- action at what level?

• Blood lead level
• 0-9
• 10-14
• 15-19
• 20-44
• 45-69
• gt69

• Action taken
• Routine testing
• Env/nutritional education, home lead check.
  Retest 3 months
• As above, referral, possible chelation
• chelation therapy
• emergency, chelation therapy and support

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Cadmium

• Electroplating, fabrication,welding
• Colored pigments, batteries
• Exposure
• inhalation

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Cadmium

• Storage sites
• liver
• kidney
• Acute toxicity
• metal fume fever
• bronchial, pulmonary irritation
• rare, pulmonary edema

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Cadmium

• Chronic toxicity
• renal proximal tubule damage
• impaired low MW protein absorption
• bone changes secondary to renal tubular
  dysfunction
• latent period of 10-20 years

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Nickel

• Electroplating, production of catalysts, mining,
  smelting, refining
• Route of exposure
• inhalation
• dermal

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Nickel

• Allergic contact dermatitis
• Respiratory tract irritant/asthma
• Carcinoma of lung and nasal sinus
• soluble nickel compounds--greatest risk
• metallic nickel--no increased risk

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Nickel Carbonyl

• Acute Inhalation
• headache, fatigue, weakness, nausea
• influenza-like illness
• initial sxs clear--12-36 hour latent period,
  followed by severe SOB,CP

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Vanadium

• Found in nature as insoluble salt, not metal
• Used in production of steel, alloys, catalysts,
  and dye manufacture
• Vanadium oxides--welding, brazing,cutting of steel

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Vanadium

• Exposure
• inhalation
• eye
• Acute/chronic toxicity
• rhinorrhea, sneezing
• eye watering, sore throat
• cough, wheezing
• green tongue

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Metal Fume Fever

• Associated with inhalation of metallo-oxides
• Zinc, copper, cadmium, magnesium
• Onset 4-6 hours after exposure

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Metal Fume Fever

• Upper respiratory tract irritation
• Chest tightness, cough
• Headache, myalgias
• Fever, tachycardia
• Elevated WBC with shift

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Reproductive Toxicity

• REPRODUCTIVE FUNCTION
• Women Who Are Pregnant
• Women of Child Bearing Age
• Men
• Teratogenicity

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Reproductive Toxicity

• First occupational reproductive hazard Percival
  Pott but not taken seriously until
• 1975 lead exposed male workers in Romania 1977
  DBCP in exposed male workers in California

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Reproductive Toxicity

• Difficulty in studying repro toxicity in women
• nature of the female cycle
• relative frequency spontaneous abortions
• common occurrence of birth defects in general
  population

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Male Reproductive Function

• Normal
• 70-80 days for spermatogenesis
• 20-350 million sperm/day
• 50-100 million sperm/ml
• Fertility Criteria
• gt20 million sperm/ml
• gt40 motile
• gt70 normal morphology

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Reproductive Function Norms

• Azospermai 1/100
• Low Birthweight (2.5kg) 7/100
• Failure to conceive 10-15/100
• Spontaneous ab 10-20/100
• Chromosomal abnormalities 30-40/100

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Reproductive Function Norms

• Stillbirths 2-4/100
• Birth Defects 2-3/100
• Chromosomal abnormalities 0.2/100
• Severe retardation 0.4/100

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Regulated Agents in the Workplace

• Lead - seen at BLL of 40 mg/dl
• Ethylene oxide
• DCBP (dichlorobromopropane)
• banned by EPA

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Summary of Repro Tox Studies

• Challenge arises due to
• wide ranges of normal reproductive variations
• correlating exposure observed effect
• normal variation in critical outcome and
  birth-related factors