1 / 89

The ABCs of Medical Surveillance

The ABCs of Medical Surveillance. The Role of Surveillance in Occupational Health. Systematic monitoring of health events and exposures in working populations to prevent and control occupational hazards and their associated diseases and injuries Essential Functions

kelly-barnett
Télécharger la présentation

The ABCs of Medical Surveillance

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The ABCs of Medical Surveillance

  2. The Role of Surveillance in Occupational Health • Systematic monitoring of health events and exposures in working populations to prevent and control occupational hazards and their associated diseases and injuries • Essential Functions • To gather information on cases of occupational diseases/injuries and on workplace exposures • To distill and analyze data • To intervene on the basis of data to alter the factors that produced health events and hazards • To disseminate organized data to necessary parties: workers, unions, employers, government agencies, the public

  3. Role of Medical Surveillance in Occupational Health • Public Health Surveillance: • Population-based • Undertaken by government agencies • Medical Surveillance: • Ongoing application of medical tests and procedures to individual workers who may be at risk for occupational morbidity to determine whether a disorder may be present • Can detect patterns of occupational illness in program participants • Medical screening: If an individual/population is exposed to a toxin with known effects and the tests and procedures are highly targeted to detect the likely presence of one or more effects in these persons • Hazard Surveillance: monitoring of exposure to chemical agents, physical hazards or radiation in the workplace

  4. The Occupational and Environmental History and Physical Examination • Examinations: • Preplacement • Periodic medical surveillance/medical screening • Return to work assessments • Exit examinations • Evaluation for specific occupational exposures • Occupational History: • List all jobs held and approximate dates of employment • Significant changes in job duties; second jobs • “Have you ever worked with or been exposed to any of the following…?” • Environmental history: home environs, water source, heating source, indoor combustion sources, pets, hobbies, work of family members

  5. Preplacement Examinations • Evolved from a “preemployment:” or exclusionary exam to Preplacement/Postoffer • Targeted examination, job focus, business necessity • Americans with Disability Act 1990 • “Otherwise qualified” individuals with disabilities cannot be excluded from employment if they can perform the essential functions of the job, with or without reasonable accommodations. • “Physical disability”: an impairment that substantially limits a major life activity • “Disability” is defined after mitigating factors are addressed, i.e. medications, prosthetics • “Essential Job Functions”: • Fundamental – not performed as needed , or occasional; employer decision • Job description – physical tasks as determined by a job analysis specialist • If leaving out a certain function changes the job in a significant manner, than it is an essential function. • “Reasonable accommodations: • If a candidate is unable to perform the essential functions of the job • Employers responsibility to determine undue hardship

  6. Preplacement Examinations • Fitness for duty evaluation: • Determines whether a previously hired employee who was able to perform the essential functions of the job is still able to safety perform these essential functions. • Evaluation post clearance from PCP for non-occup issue • Examining physician should have access to the employees pertinent medical and personnel records in order to conduct evaluation • If employee will not sign for release of records, may proceed with examination • If disabled or unfit for duty, document the restrictions/limitations • Employer decides if accommodation exists

  7. The Medical Surveillance Examination • >30% of the US workforce receives periodic occupational health examinations • Screening: 2o prevention which focuses on the individual for the early diagnosis and treatment • Surveillance: 1o prevention focusing on identification and elimination of the causes of disease; aggregates info from individuals to examine patterns within a population. • In accordance with OSHA standard • Many employers conduct programs for hazards without standards. • The potential toxicity of ~80% of the chemicals used in the workplace has not been evaluated in humans or in vivo or in vitro test systems.

  8. OSHA Medical Surveillance Requirements • Acrylonitrile 29 CFR 1910.1045 • Arsenic (inorganic) 29 CFR 1918 • Asbestos 29 CFR 1910.1001 • Benzene 29 CFR 1910.10288 • Beryllium Federal Register 64:253:68853-68914 • Bloodborne Pathogens 29 CFR 1910.1030 • 1,3 Butadiene 29 CFR 1910.1051 • Cadmium 29 CFR 1910.1027 • Cotton Dust 29 CFR 1910.1027 • Diesel Exhaust 30 CFR 72 • EEOC/ADA • Ethylene oxide 29 CFR 1910.1047 • Formaldehyde 29 CFR 1910.1048 • Lead 29 CFR 1910.1025 • Methylene Chloride 29 CFR 1910.1052 • Noise 29 CFR 1910.95 • Record Keeping 29 CFR 1904 • Respirator Protection 29 CFR 1910.134 • Vinyl Chloride 29 CFR 1910.1017

  9. Acetic Acid Acrolein Asphalt/Asphalt Fume Carbon Disulfide Carbon Monoxide Ceramic Fibers Chlorine Cholinesterase-Inhibiting Substances (Pesticides) Cyanides Cytotoxic Drugs Fluoride Gasoline Glutaraldehyde Hydrogen Fluoride Hydrogen Chloride Hydrogen Peroxide Isocyanates Malathion Manganese/Manganese Fumes Mercury (inorganic) Metal working fluids Nickel Nitrogen dioxide Ozone Peracetic acid Phenol and phenolic compounds Proteolytic enzymes Psyllium Silica (Crystalline) Silver Sodium Hydroxide Soldering Solvents Sulfur dioxide Toluene/Xylene Triethylamine Trimellitic anhydride Zinc Oxide Fumes (Metal Fume Fever) Other Chemicals and Substances

  10. Respirator Protection Standard • Components of the program • All employees required to wear respirators must take part in the company’s training program prior to use, annually and with changes in workplace or type or respirator • Program administrator: • Oversees hazard assessment, respirator selection, respirator care and maintenance, medical evaluation, fit testing, employee training, respirator use, program assessment, record keeping • Nine components: • Respirator selection, medical evaluation, fit testing, emergency activities, maintenance procedures and schedules, adequacy of air quality, quantity/flow for respirators, training regarding respiratory hazards, and limitation of respirator fit/use/maintenance, evaluation of effectiveness of the program

  11. Respirator Protection Standard • Prior to respiratory selection, employer reviews worker exposures, job demands and potential adverse effects of interactions; focus on engineering and administrative controls • Qualitative vs quantitative testing: • Qualitative: negative pressure air-purifying respirators (fit factor of 100 or less) and all positive pressure respirators • Quantitative: used for all respirators • Isoamyl acetate (banana oil), saccharin or Bitrex solution, irritant smoke ( not recommended by NIOSH) • Procedures for IDLH (Immediately Dangerous to Life and Health) environment: standby personnel must be equipped with respirators and rescue equipment • consider all oxygen deficient atmospheres as IDLH • SCBA required for interior structural firefighting

  12. Respirator Protection Standard: Medical Evaluation • Recommend inclusion of questionnaire, single view chest x-ray and PFT. • Periodic examinations: • usually annual questionnaire +/- PFT • CXR: every 5 years or as medically indicated • For workers with lesser exposures: OSHA questionnaire only and examinations every 2 years • The employer must ensure that a follow-up medical examination is provided for an employee who gives a positive response to any question contained in Part A, Section 2, questions 1-8 • Tobacco, seizures, diabetes, allergic reactions, claustrophobia, trouble smelling odors, lung disease, CAD, Medications, Problems with respirator use. (eye irritation, skin allergies/rashes, anxiety, weakness/fatigue)

  13. Respirator Protection Standard: Medical Evaluation • The American National Standards Institute (ANSI), The National Institute for Occupational Safety and Health (NIOSH) and ACOEM suggest medical evaluations at time-based intervals based on worker age and the type of respirator used. • The American Thoracic Society (ATS) recommends that workers with respiratory symptoms, workers > 45 years wearing SCBA and workers > 55 years old have PFTs. • Exercise stress testing (EST): • > 10 METS without EKG changes unlikely to have clinically significant CAD • American College of Sports Medicine: Prior to vigorous exercise, EST for healthy men >40, healthy women >50, persons with 2 or more cardiac risk factors, or persons with known disease

  14. Respirator Protection Standard: Medical Evaluation • American Academy of Family Practice recommend exercise ECGs for jobs linked to police safety and require high cardiovascular performance. • DOT, NRC, FAA recommend screening certain classes of workers for asymptomatic heart disease. • ANSI recommends those who use SCBA or a re-breather respiratory in strenuous work conditions for EST

  15. Age-based Recommended Medical Evaluation Frequency McClellan, Schusler: Guide to the Medical Evaluation for Respirator Use. Table 3-4, p 59, 2000.

  16. Spirometry Interpretation –Obstructive Lung Disease • Is FEV1/FVC%pred> LLN (lower limit of normal)? • YESnot obstructed; IF NO • Is FEV1%pred> LLN? • YESborderline obstruction; IF NO • Is FEV1 (60%pred - <LLN)? • YESMild obstruction; IF NO • Is FEV1%(41-59%pred)? • YESModerate obstruction; IF NO • Is FEV1< 40%pred? • YES Severe obstruction

  17. Spirometry Interpretation – Restrictive Lung Disease • If FEV1/FVC%pred WNL, with FVC < LLN mixed obstructive/restrictive pattern • Is FVC%pred> LLN? • YES Not restricted; IF NO • Is FVC (60%pred- <LLN)? • YESMild restriction; IF NO • Is FVC (51-59% pred)? • YESModerate restriction: IF NO • Is FVC < 50% pred? • YES Severe restriction

  18. Lower Limit of Normal for Spirometric Percent Predicted Values from Knudson Prediction Equation FEMALE MALE McClellan, Schusler: Guide to the Medical Evaluation for Respirator Use. Table 3-6, p 63, 2000.

  19. Respirator Protection Standard:Medical Decision Making • Seizures: • PCPs written opinion • May be approved for respirator use if seizure free for 6-12 months without impairment or symptoms, no med side effects • May approve: History of early childhood seizure due to fever, isolated seizure > 5years ago or multiple seizures > 10years ago without recurrence off medication • Controlled seizure activity (no seizure on/of med in the last year) • PCP opinion, non IDLH environment, exam for SCBA, med eval for IDLH • Poorly controlled (changing meds, Workplace exposure to triggers, side effects from meds • Medical eval, neurologist letter, accommodations or denial • DOT, NFPA 1582: epileptic conditions are disqualifying unless identifiable precipitant, normal EEG, normal neuro exam, seizure free 1 year off meds, neurologist’s statement

  20. Respirator Protection Standard:Medical Decision Making • Diabetes • Episodic, unpredictable impairment of psychomotor abilities due to hypoglycemia presents the greatest endocrinologic concern for respirator use • Majority of people with Type 1experience between 1-2 hypoglycemic episodes • Minimum of 17% of people receiving conventional insulin treatment have a least one severe hypoglycemia episode per year • Issues: shift work, irregular meals, erratic exercise and difficulty maintaining a regular medication schedule • Driving simulators: driving performance deteriorates significantly when blood glucose drops below 65mg/ml  Impairs judgment about physical capabilities • At least 50% of drivers with low BS decide to drive at least 50% of the time

  21. Plastics, Rubbers and Resins:Acrylonitrile, 1,3 Butadiene, Vinyl Chloride, Carbon Disulfide • Acrylonitrile • Manufacture of acrylic fibers, rubber-like materials, pesticides • OSHA PEL 2ppm, 10ppm ceiling (15minutes) • Health Effects • Route of exposure: inhalation and skin • Potent mucous membrane irritant; skin blistering • Metabolized to cyanide: cyanide/thiocyanate in blood/urineweakness,asphyxia, death • Suspected human colon/lung carcinogen • Medical Surveillance: at least annually • skin, respiratory tract, GI, neurolook for nausea vomiting, dizziness, weakness, CNS signs that may indicate exposure • CXR, Occult blood for workers>40yrs • Respirator program • Biological monitoring: thiocyanate levels • Mean postshift urine levels of 11.4mg/l8 hr avg exposure of 4.2ppm • Chronic human toxicity: 16-100ppm for 20-45 min nasal irritation, H/A , nausea, fatigue

  22. Plastics, Rubbers and Resins:Acrylonitrile, 1,3 Butadiene, Vinyl Chloride, Carbon Disulfide • 1,3 Butadiene • Exposure occurs primarily through inhalation during monomer/polymer production • OSHA PEL 1ppm (TWA), 15 minute STEL of 5ppm, action level 0.5ppm • Health Effects: • Liquidskin burns, frost bite; Gas mucous membrane irritant, blurred vision, cough, drowsiness • Anesthetic at high concentrations • Human/animal carcinogens: leukemia and lymphosarcoma; male/female reproductive toxicity and embryo toxicity in animals; infertility, miscarriage, anemia • Medical Surveillance: • > PEL on 10 or > days/yr • > PEL on > 30days/yr for 10 or more years • > the action level on 60 or more days/yr for 10 or more years • Above 10ppm on 30 or more days in any past year • Any employee exposed in an emergency situation • Medical screening no later than 48 hours after the exposure • CBC within 48 hours of the exposure, repeated monthly for 3 months

  23. 1,3 Butadiene (cont) • Medical Surveillance: • Health questionnaire yearly, emphasis on blood disorders • Exam focused on lymphatic system, liver, spleen, skin • Respirator standard • CBC with diff and platelet count • Before employees assuming duties in a job with BD exposure, • Every 3 years after the initial physical exam or at the discretion of health professionals • At time of reassignment to an area where exposure is below the action level • At termination of employment if 12 months have elapsed since last physical examination

  24. Plastics, Rubbers and Resins:Acrylonitrile, 1,3 Butadiene, Vinyl Chloride, Carbon Disulfide • Vinyl Chloride • Primary use is production of Polyvinyl Chloride • OSHA PEL 1ppm (8 hr TWA); STEL 5ppm (15 minutes) • Health Effects: • Historically – narcosis, acroosteolysis (resorption of the terminal phalanges) • 1970s epidemiological studies showed link to hepatocellular injury and angiosarcoma of the liver • Pneumoconiosis: high dust exposure >10mg/m3 • Medical Surveillance: • History: alcohol use, hepatitis, exposure to hepatotoxic drugs/materials, blood transfusions • Exam: liver, spleen, kidneys, skin, connective tissues and respiratory • Examine annually; if working with VC/PVC manufacturing for 10 years or longer, must be examined every 6 months • Lab findings: • Elevated liver enzymes/alkaline phosphatase, • Fasting levels of serum bile acids/urinary coproporphyrins – indicators of early chemical industry • Alpha glutamyl transpeptidase level ~vinyl chloride exposure, greater specificity • Liver US – periportal fibrosis among highly exposed workers. • Biomarkers: p63 and DNA adducts under investigation

  25. Plastics, Rubbers and Resins:Acrylonitrile, 1,3 Butadiene, Vinyl Chloride, Carbon Disulfide • Carbon Disulfide (not federally mandated) • Intermediate for other chemical (I.e. carbon tetrachloride) and products (cellophane, rayon viscose fibers, adhesives, herbicides); manufacture of optical glass • OSHA PEL 20ppm (8 hr TWA); STEL 30ppm; 30minutes maximum allowable exposure 100ppm; IDLH (immediately dangerous to life and health) 500ppm • Health effects: • Foul odor desensitizes olfactory system • Skin and Inhalation: skin irritation, mucous membranes (esp eyes), CN deficits, peripheral neuropathy, paresthesias, unsteady gait and dysphagia; Nerve damage does not resolve with end of exposure • Extreme intoxication – parkinsonism-like syndrome, psychosis and suicide • May accelerate the development or worsen heart disease – risk decreased with removal • Eyes: microaneuryms • Ears: high frequency hearing loss/ vestibular symptoms of vertigo and nystagmus • Effects libido; women at <10ppm menstrual abnormalities, spontaneous AB, premature births • No carcinogenicity

  26. Carbon Disulfide (continued) • Medical Surveillance: • History/exam: eyes, skin, central and peripheral nervous systems, CAD, liver, kidneys • History and physical exam every 3-5 years • Biological monitoring: • Preshift urines for 2-thiothiazolidine-4-carboxylic acid (TTCA) • Spot urine of 0.95 mmol per mole of Cr proposed as a reliable indicator of recent exposure • 5mg corresponds to an 8 hr TWA

  27. Healthcare: Formaldehyde and Ethylene Oxide • Formaldehyde • Backbone of chemical industry • Tissue preservative and disinfectant; construction and insulation materials, cosmetics, fertilizer, textiles, foundries, pesticides/fumicides, ink, photography and others • OSHA PEL 0.75ppm 8-hr TWA; STEL 2ppm (15min); Action level 0.5ppm; IDLH (Immediately dangerous to life and health) 100ppm • Health Effects: • 1ppm – potent irritant of eyes, skin, mucous membranes and respiratory tract • Dermatitis, sensitization • Lungs: rapid absorption and excreted as formic acid; bronchitis, allergic/asthmatic reactions, pulmonary edema • Sensitization: occupational asthma associated with formaldehyde resin dust • Probable human carcinogen – lung, nasopharyngeal, malignant melanoma, pancreatic cancer in embalmers • Neuropsychologic issues; spontaneous abortion (cosmetologists/lab workers with use of disinfectants and formalin); delayed conception in woodworkers

  28. Formaldehyde (continued) • Medical surveillance • Focus on respiratory, skin, eyes and mucous membranes and to allergens/allergic reactions • General medical questionnaire; exam focused on eyes, skin, mucous membranes and upper respiratory tract • Baseline PFT and annually • Respirator Standard • Biological Monitoring • Urinary formate: useful with ambient concentration of >1ppm • Low level exposure during embalming associated with cytogenetic changes in epithelial cells of the mouth and in blood lymphocytes; may be useful biologic monitoring

  29. Healthcare: Formaldehyde and Ethylene Oxide • Ethylene Oxide (ETO) • Manufacture of ethylene glycol (antifreeze, polyester, film, bottle), detergents, textile chemicals, pesticide, hospital sterilant, medical products • Mostly used in closed operations (<1ppm) • Potential exposure: maintenance, repair, product sampling, loading/unloading transport tanks • ~0.02% of production used for sterilization in hospitals; NIOSH estimates that 75,000 health care workers have potential exposure to ETO. • Field surveys of hospital gas sterilizers have generally found 8 hr TWA exposures <1ppm; opening sterilizer, transfer of sterilized instruments to central supply, tank changes • OSHA PEL 1ppm TWA, 5ppm excursion limit (15min) NIOSH: REL <0.1ppm TWA; 5ppm ceiling (10min/d)

  30. Ethylene Oxide (continued) • Health Effects: • Ether-like odor, but odor threshold 700ppm • Absorbed through skin, respiratory tract • Binds to DNA; may cause cellular mutation • Irritating to eyes, respiratory tract, skin, respiratory depression at high concentrations • URI irritation between 200-400ppm • >1000ppm may cause H/A, nausea, dypsnea, vomiting, drowsiness, weakness, incoordination • Splashes can cause burns • Reproductive toxicity men and women: increase spontaneous AB and preterm birth • Human carcinogen-lymphatic/ hematopoietic, stomach • Neuropsychiatric, neuropathy • Occupational asthma

  31. Ethylene Oxide (continued) • Medical Surveillance • Exposed at or above action level for at least 30 days during the past year; upon termination of employment, reassigned to a work area with ETO exposure below the action level; emergency exposure of signs and symptoms • Pulmonary, hematologic, neurologic, reproductive systems • Initial white blood cell count and periodically if exposure >0.5ppm 8-hr TWA or of intermittent exposures exceed 5ppm • Consistent changes in CBC have not been demonstrated • Can see elevated numbers of eosinophils, RBC, HCT • Biological monitoring • Increased chomosomal aberrations

  32. Solvents/Paints • Benzene • Core of aromatic hydrocarbons; • Aromatics include benzene, toluene (methyl benzene), xylene (dimethyl benzene), ethyl benzene, cumene (isopropyl benzene) styrene ( vinyl benzene) • Half of benzene used to synthesize ethyl benzene for production of styrene. • Toluene/Xylene principally used in paints adhesives and pesticides. • OSHA PEL 1ppm 8-hr TWA STEL 5ppm over 15 minute period Action level 0.5ppm

  33. Benzene (continued) • Health Effects • Acute anesthetic, respiratory tract irritation, dermatitis, neurobehavioral dysfunction • Benzene: bone marrow, aplastic anemialeukemia (acute neuro behavior • No evidence that substituted benzenes have any of the myelotoxic effects. • Toluene: renal tubular acidosis, cerebellar ataxia • Toluene/xylene: raise auditory thresholds in animal at low level • Benzene: human carcinogenicity

  34. Benzene • Medical Surveillance: • All employees who are or may be exposed to benzene at or above the action level for 30 days or more per year and employees engaged in certain manufacturing must have surveillance • Past exposure to benzene and other heme toxins, blood dyscrasias (hematologic neoplasms, genetic heme abnormalities), renal or liver dysfunction, medicines, previous exposure to ionizing radiation and marrow toxins. • Annual physical examination for signs related to blood disorders; • CBC, WBC with differential, quantitative thrombocyte count, indices (MCV, MCH, MCHC) • Emergency exposure: provide end of shift urinary phenol within 72 hours; urine specific gravity is to be corrected to 1.024. • If urinary phenol = to or > than 75mg/l, CBC, RBC count, WBC with diff and thrombocyte count monthly for 3 months.

  35. Solvents/Paints • Methylene chloride: • Paint remover, manufacture of urethrane film • OSHA 8-hr TWA PEL of 25 ppm and STEL of 125 ppm • Health effects – Inhalation hazard • CNS depression: coordination/alertness • Cardiac toxicity: Metabolized to CO – susceptible individuals include persons with heart disease and those with risk factors for hear disease • Liver toxicity • Medical surveillance • At or above the action level (1/2 PEL) on 30 or more days per year or above the 8-hr TWA PEL or the STEL 10 or more days per week. • Neuro, skin, hematologic, liver disease, heart disease, risk factors for cardiac disease.

  36. Methylene Chloride (continued) • Medical surveillance (continued) • Annual updates of the medical/work histories for each affected employee • Physical examinations, including lab surveillance • 45 yrs or older within 12 months of initial surveillance or any subsequent surveillance • <45 years within 36 months of initial surveillance or subsequent surveillance • If employee leaves the employers workplace to is reassigned to an area where exposure to MC is consistently at or below the action level and STEL, medical surveillance must be made available at that time if 6 months or more have elapsed since the last medical surveillance. • Must provide opinion concerning whether exposure to MC may contribute to or aggravate the employees existing cardiac, hepatic, neurology, dermal disease and whether employee has any other medical condition that would place him at increased risk of material impairment from exposure to MC

  37. Metals – Arsenic, Beryllium, Cadmium, Lead, Mercury (inorganic) • Arsenic • Elemental, trivalent, pentavalent – most common inorganic forms • Most reports of acute/chronic toxicity – arsenic trioxide • Pentavalent  trivalent • Arsine gas- extremely potent/acute poison; used in microelectronics and in the manufacture of gallium arsenide substrates • Arsenic trioxide/pentoxide used in pesticides • Metallic arsenic – alloy for hardening lead in battery grids, bearing, and cable sheaths • Exposure: maintenance, manufacture, flu dust (smelting) • Environment: average daily intake: 10-50ug/d; drinking water standard 10ppb, organic arsenic compounds present in seafood – not metabolized, excreted unchanged

  38. Arsenic (continued) • Ingestion and inhalation; limited skin absorption • Taken up by RBCliver, kidney, muscle, bone, skin, hair • As: OSHA PEL and ACGIH TLV 0.01mg/m3 TWA • Arsine: OSHA PEL and ACGIH TLV 0.05ppm • Health Effects: • Irritation to skin, eyes, mucous membranes • GI (fluid loss, bleeding) • Nervous system: Neuropathies, weakness, paralysis • Cardiomyopathy, peripheral vascular disease • Lung Cancer, leukemia, lymphoma, angiosarcoma of the liver • Medical Surveillance: • Absorbed trivalent arsenic is metabolized to dimethlarsinic acid (DMA) and monomethylarsonic (MMA) and excreted in the urine with a half-life of 10 hrs • Organic arsenic cpds excreted unchanged in the urine

  39. Arsenic (continued) • Medical Surveillance • Preplacement surveillance • For workers exposed to inorganic arsenic for at least 30 days per year • Focus on history of smoking history and evidence of respiratory disease • CXR – PA view • Nasal and skin exams • Respiratory standard: exposed above action level (5ug/m3) • Periodic surveillance • For covered employees <45 years old with < 10 years employment in areas exceeding the action level; annual interim history • For other covered employees, interim history, physical exam and lab studies every 6 months • Lab studies: • Measure DMA, MMA eliminate confusion over dietary sources or organic arsenic compounds • Nonexposed workers<10ug/g Cr • Workers exposed to 0.01mg/mwill have level of 50ug/g Cr

  40. Metals – Arsenic, Beryllium, Cadmium, Lead, Mercury (inorganic) • Beryllium • Production of hard, corrosion-resistant alloys for use in the aerospace industry; nuclear reactors, ceramics, semiconductors • Mining of beryllium ore is not associated with adverse health effects; use of beryllium compounds, especiallly beryllium oxide carries substantial risk of disease • Exposure to minute ultrafine particles, rather than total mass/dose is key factor in sensitization • OSHA PEL 2.0ug/m3;NIOSH REL not to exceed 0.5ug/m3; ACGIH TLV 0.2ug/m3 • Poorly absorbed after inhalation, ingestion or skin • Retained in lung, deposited in bone, liver and spleenNoncaseating granulomas • Slow renal excretion; confirms exposure, levels usually undetectable in nonexposed individuals.

  41. Beryllium (continued) • Health effects: • Acute exposure: irritant effects on eyes, mucous membranes, respiratory tract; tracheobronchitis, chemical pneumonitis, pulmonary edema; after skin contact irritant/allergic dermatitis, granuloma • Chronic exposure: exertional dypsnea, fatigue, wt loss, rales, lymphadenopathy, clubbing, pulmonary HTN • Lung cancer in humans; lung cancer, osteogenic sarcoma in animals • Medical Surveillance • Preplacement: • Medical/occupational histories: previous or anticipated exposure • Respiratory standard as appropriate • Physical exam: skin, eyes, respiratory tract • CXR – B reader, PFT • Be-induced lymphocyte proliferation (Be-LPT): confirms sensitization • Periodic: • Annually for beryllium workers, every 3 years for beryllium associated workers • Hx, PE, Respiratory Questionnaire • Be-LPT • CXR every 5 years

  42. Metals – Arsenic, Beryllium, Cadmium, Lead, Mercury (inorganic) • Cadmium • Metal plating, solder, smelting (cadmium oxide), battery alloys, pigments, printing, semiconductors • Present in the diet (liver, shellfish, meat by-products, vegetables), environmental exposure – exposure to cigarette smoke @ 2ug/day • Absorbed primarily through ingestion; inhalation 10-40%; GI 5% • Renal excretion with t1/2 of 8-30yrs cadmium nephrotoxicity • OSHA PEL – 5ug/m3 at 8 hr TWA; Action level – 2.5ug/m3 • Health effects: • Acute inhalation: sore throat, H/A/, myalgia, nausia, fever, metallic taste  SOB, chemical pneumonitis, respiratory failure; hepatic/renal injuty • Chronic exposure: proteinuria with excretion of LMW proteins (B1, B2 microglobulins) renal stones, bone pain, pulmonary fibrosis, emphysema, central/peripheral nervous system, human carcinogen (lung, GU,Prostate), reproductive effects (testicular)

  43. Cadmium (continued) • Medical Surveillance • Preplacement:: • Medical/Occupational hx: cardiovascular, respiratory, renal,reproductive, musculoskeletal, hematopoietic • Physical exam: including prostate exam for male >40 • CXR/PFT – pulmonary toxicity/respirator use • Kidney, liver, Hb • Annual exam for employees with exposure > 30 days

  44. Cadmium (continued)

  45. Metals – Arsenic, Beryllium, Cadmium, Lead, Mercury (inorganic) • Productions of electrical equipment, instruments, medicinal/skin care products, lubrication oils • Exposure via inhalation of mercury vapor, ingestion, skin contact with liquids or salts • ACGIH TLV 0.025mg/m3 • Health effects: • CNS, blood, kidneys, liver, respiratory • Mercury vapors: Micromercurialism – weakness, fatigue, weight loss, mercurial “facies” (tremors), “Mad as a hatter”. • Medical Surveillance • Focus medical/occupational hx: CNS, respiratory, kidneys, skin • Urine Hg history of exposure • Workplace monitoring – urine is first choice • Normal concentrations: nonexposed <0.01mg/L whole blood; <10ug/g Cr urine; substantial seafood consumption – high blood levels with low urine levels

  46. Mercury (inorganic)Medical Surveillance

  47. Metals – Arsenic, Beryllium, Cadmium, Lead, Mercury (inorganic) • Lead: • Storage batteries, alloys, pipes, cable sheathing solder, paints/plastics, cosmetics, munitions, glassware, jewelry • Occupational exposure is a result of a combination of inhalation and ingestion • Environmental exposure: auto exhaust, near lead smelters, moonshine, acidic foods/beverages in ceramics, herbal remedies • Approximately 40% of inhaled lead oxide fume absorbed through the respiratory tract; GI absorption 5% • Greater GI absorption in infants/children • Iron, Ca deficiencies and high fat diets increase GI absorption • Metabolism: • Bound to RBC’s free fraction in plasma distributed to brain, kidney, liver, skin, muscle • Crosses the placenta (fetal level ~maternal levels), pregnancy mobilizes lead • Bone is major site of deposition of absorbed lead • Binds to sulfhydryl groups (found in hair and nails) • Excreted primarily via kidney; t1/2 5-10 years

  48. Lead • Water soluble alkyl lead compounds are readily absorbed through skin contact, inhalation or ingestion • Tetraethyl/methyl lead tri alkyl metabolites toxicity • Accumulates in CNS – fat soluble • Ultimately converted to inorganic lead and excreted in urine • Health Effects • Acute: GI (abdominal pain, constipation, N/V tarry stools); Neurologic manifestations of lead encephalopathy (H/A, confusion, stupor, coma, seizures); Renal failure/oliguria • Chronic: • Early: Fatigue, irritability, vague GI symptoms, arthralgia/ myalgias • Later: confusion, memory, distal motor neuropathy (wrist/.foot drop); encephalopathy/seizures/coma; infertility (spermatogenesis, spontaneous AB); HTN, cardiac conduction, gouty arthritis, nephropathy

  49. Lead • Medical Surveillance • Focus on lead exposure history, hygiene, GI, heme, renal, repro, neuro, pulmonary status (respiratory use), BP • Labs: • BLL (blood lead level), ZPP, HB/HCT, Cr/UA • BLL – recent exposure (days/weeks); nonexposed: 1-5ug/dl; subtle effect on central/peripheral nervous system 30-50ug/dl • ZPP – alters heme synthesis increase ZPP • Recent studies: at BLL of 17ug/dl see increase ZPP • Abnormal for @120 days • Represents average lead exposure for past 3 months • Limited usefulness since health effects occur at much lower levels (CDC recommends <10ug/dl for children) • Chronic exposure: • K-band xray fluorescence of bone is best • EDTA lead mobilization test (>350ug/L) confirms past exposure, but not lead toxicity

  50. Lead • Medical surveillance (continued) • Medical examinations: • Yearly for BLL > 40ug/dl • Prior to assignment • Signs/symptoms of toxicity • Medical surveillance: • Required for exposure to air level > 30ug/m3 for at least one day in 12 months • BLL every 6 months if <40ug/dl • BLL every 2 months if > 40ug/dl until (2) consecutive determinations are < 40 ug/dl • Monthly during medical removal • For >60ug/dl • Average levels >50ug/dl • Risk of health impairment • May return if (2) consecutive BLL <40ug/dl

More Related