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Airborne Contaminants Lab. Topics. Overview of workplace health and its regulation Particulates and microscopy Gases and vapors Monitoring Real time Noise. Format. Lecture with break Break Hands-on, with Sheila M Simmons Environmental Health, Safety, and Risk Management
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Topics • Overview of workplace health and its regulation • Particulates and microscopy • Gases and vapors • Monitoring • Real time • Noise
Format • Lecture with break • Break • Hands-on, with Sheila M Simmons • Environmental Health, Safety, and Risk Management • http://www.uaf.edu/safety/
Practical Application • The terms • “Environmental Engineering” • “Environmental work • Often extend to analyzing the workplace environment for contaminants • hence offering opinions on human health • firms often practice in this area.
Alphabet Soup • EPA • OSHA • NIOSH • AIHA • ACGIH
Alphabet Soup • OSHA, Occupational Safety and Health Administration • NIOSH, National Institute of Occupational Safety and Health • AIHA, American Industrial Hygiene Association • ACGIH, American Conference of Governmental Industrial Hygienists.
OSHA and NIOSH • Created in 1970’s by same act of congress • MSHA was earlier, • OSHA • Law enforcement • Department of Labor • NIOSH • Science • Center for Disease Control in PHS.
AIHA and ACGIH • Industrial hygiene = science of workplace health • AIHA accredits laboratories • ACGIH produces TLV’s • “safe values”
Occupational Standards • OSHA, PELs • (CFR, code of federal regulations, on line) • PELs • ACGIH, TLVs • NIOSH, RELs • DFK, MAKs
TLVs • Of the approximately 450 standards • 15% have human or otherwise well tested • 25% have some animal testing • 60% Based on “analogy,” “supposed,” or “traditional.”
OSHA • OSHA main site OSHA • 1910 Subpart Z • 1910.1000 • History of Tables • ANSI list • lawsuits
Contaminant Particulates • Asbestos • Quartz • Dust
Asbestos is useful • Asbestos used since ancient times • Fireproof • WW II ship building • Insulation • 1950’s Schools • Sound proofing, • Many materials • Strength of fibers, chemical resistant
Asbestos kills • About 10,000 persons die each year from asbestos related disease • 1,000 from mesothelioma • 4,000 from asbestosis • 5,000 from lung cancer • (correlated with cigarette smoking) • 20 to 40 year latency period • Airborne fibers, not parent material
Asbestos is regulated • OSHA regulates workplace exposures • EPA regulates schools • EPA regulates disposal process
Insert SiO4: Asbestos Minerals • Asbestos is a commercial term • Polysilicate minerals
lisa m applebee: structure Amphiboles • Amosite (Mg, Fe) • Actinolite (Ca, Mg, Fe) • Anthophyllite (Mg, Fe) • Crocidolite (Na, Fe+++, Fe++) • Tremolite (Ca, Mg)
Serpentine • Chrysotile (Mg)
Respiratory Tract • Anatomy • Physiology • Notes on the asbestos diseases
Asbestosis • Fibrotic lung disease • Lungs fill with scar tissue • restrictive lung disease, stiff • oxygen transport reduced • breathing labored
Gallery • Boston University School of Public Health • Breath Taken: The Landscape & Biography of asbestos • http://www/busph.bu.edu/Gallery
Mesothelioma • Cancer of the lining of the abdominal cavity • Or thoracic cavity • Fatal
childhood exposure father worked in plant and died of asbestosis note tumor on right side, fills with fluid
Mesothelioma is a rare cancer • 2 deaths per million populations • But in a study of asbestos insulation workers there were 175 deaths from mesothelioma.
Lung Cancer • 32 of 41 studies indicated statistically significant increase in lung cancer of asbestos workers • Non-smokers were 5-fold higher than non-exposed • Smoking asbestos workers were much higher 50- to 90-fold
Toxicology, Fiber type • Some studies indicate chrysotile can cause mesothelioma • Most indicate amphiboles, especially crocidolite • Some authors have concluded amphiboles are 100 times more potent than chrysotile in inducing mesothelioma.
particle fiber
Clearance and fiber size • Residents of cities breath several hundred grams of particles over a lifetime • Only a few grams at autopsy • Most are cleared from lung • Sorting in the airways by aerodynamic diameter • Thin fibers penetrate much deeper than round particles of similar diameter
Clearance mechanism by location of deposition • Nasal clearance: • in from of ciliated, by sneezing or blowing • further back swept down and swallowed • Tracheobronchial: cleared via cilia • mucociliary escalator • Alveolar • macrophage
Robins pg. 757 Macrophages • Digest particles • Carry towards ciliated airway • Can wind up in lymph nodes and elsewhere • especially is “surface” route is overwhelmed
Clearance • Fibers less than 1 micron cleared half-life of 10 days • Fibers longer than 16 micron, half-life over 100 days • Maximum fiber length of one macrophage about 16-17 microns
Disease vs. fiber length • Animal studies • Dust rich in f < 5 less lung cancer • Dust rich in f > 5 more lung cancer • Asbestosis associated f > 2 • Lung cancer f > 5 • Mesothelioma f > 10