HL1115 Influences on Health at Work Occupational lung disorders: asthma, byssinosis, pneumoconiosis, asbestosis, mesothelioma, farmers lung, acute and chronic effects of exposure to toxic fumes.

Routes of Entry:

Mechanism vs. Pathway Mechanism is actionMechanism is action Pathway is route of entryPathway is route of entry We use both terms!

Routes of Entry: NasalInhalation

OralIngestion

Dermal (Skin) AbsorptionInjection

Routes of Entry: InhalationInhalation IngestionIngestion SkinSkin –Absorption –Injection

Routes of Entry: Target Organ vs. Pathway Target organ is system affectedTarget organ is system affected Pathway is route of entryPathway is route of entry They don’t have to be the same!

Routes of Entry:  Inhalation is particularly important exposure portal

Routes of Entry:

Inhalation: Air exchange region of lungs is around 300 square ft at rest and about 1000 square ft at full inspiration

Inhalation

Absorption Factors High surface areaHigh surface area Small air/blood distanceSmall air/blood distance Particle sizeParticle size SolubilitySolubility

Inhalation Absorption Factors ConcentrationConcentration DurationDuration Respiration RateRespiration Rate

Ingestion Methods IncidentalIncidental AccidentalAccidental DeliberateDeliberate

Ingestion Absorption Factors Emotional stateEmotional state Digestive acids/enzymesDigestive acids/enzymes Diahhrea/constipationDiahhrea/constipation Gastrointestinal contentGastrointestinal content

Ingestion Absorption Factors Micro-flora in gutMicro-flora in gut Metabolite formationMetabolite formation AgeAge Predisposing factorsPredisposing factors

Skin Absorption Primary layers: EpidermisEpidermis DermisDermis Subcutaneous layerSubcutaneous layer

Skin Absorption Absorption Factors Disease/injury stateDisease/injury state Blood flow, sweat & heatBlood flow, sweat & heat Skin ageSkin age Skin thicknessSkin thickness

Skin Injection IntraperitonealIntraperitoneal SubcutaneousSubcutaneous IntramuscularIntramuscular IntravenousIntravenous

Respiratory System Nasopharynx RegionNasopharynx Region Tracheobronchial RegionTracheobronchial Region Pulmonary (Alveolar) RegionPulmonary (Alveolar) Region

Respiratory System Nasopharynx Region: the head region, including the nose, mouth, pharynx, and larynxNasopharynx Region: the head region, including the nose, mouth, pharynx, and larynx

Respiratory System Tracheobronchial Region: includes the trachea, bronchi, and bronchiolesTracheobronchial Region: includes the trachea, bronchi, and bronchioles

Respiratory System Pulmonary (Alveolar) Region: comprised of the alveoli; the exchange of oxygen and carbon dioxide through the process of respiration occurs in the alveolar region.Pulmonary (Alveolar) Region: comprised of the alveoli; the exchange of oxygen and carbon dioxide through the process of respiration occurs in the alveolar region.

Respiratory System

Particle deposition SedimentationSedimentation

Particle deposition DiffusionDiffusion

Particle deposition InterceptionInterception

Particle deposition ImpactionImpaction

Deposition of particles 4-5  m in respiratory tract  m in upper respiratory tract 2  m in URT and lung spaces 1  m in alveolar spaces

Particulate Sizing Inhalable Particle Mass Thoracic Particle Mass Respirable Particle Mass

Inhalable Particle Mass - hazardous when deposited anywhere in the respiratory tract, 50% cut point 100  m

Thoracic Particle Mass - hazardous when deposited anywhere in the lung airways or gas exchange region, 50% cut point 10  m

Respirable Particle Mass - hazardous when deposited in the gas exchange region, 50% cut point 4  m

Stokes Law An equation relating the terminal settling velocity of a smooth, rigid sphere in a viscous fluid of known density and viscosity to the diameter of the sphere when subjected to a known force field.

Stokes Law

v = settling velocity g = gravitational acceleration, 9.80 m/s 2  s = density of object d = diameter of object  F = density of fluid  = viscosity of fluid

Stokes Law

Reynolds Number laminar flow if R e <500 turbulent flow if R e > 500

Stokes Law settling velocity relates to diametersettling velocity relates to diameter

Pulmonary function testing (Spirometry) Pulmonary function tests are sensitive indicators of lung disease and are commonly used in the workplace environment HL1115 Influences on Health at Work

Common tests Forced Vital Capacity (FVC)Forced Vital Capacity (FVC) One Second Forced Expiratory Volume (FEV1)One Second Forced Expiratory Volume (FEV1) Ratio of FVC to FEV1Ratio of FVC to FEV1 Peak flowPeak flow HL1115 Influences on Health at Work

The most common measurements used however are those of FEV1, FVC, and the ratio of these two variables, tests which are highly reproducible within individuals and are easy to administer. HL1115 Influences on Health at Work

Pulmonary function abnormalities are generally categorized into two patterns: obstructive or restrictive. HL1115 Influences on Health at Work

Obstructive flow impairment, such as observed in asthma bronchitis and emphysema is indicated by a decrease in flow (often indicated by decreased FEV1/FVC ratio). HL1115 Influences on Health at Work

Restrictive flow impairment, such as observed in interstitial lung disease is indicated by a decrease in volume. HL1115 Influences on Health at Work

Pulmonary function tests can be given before and after the workshift to observe changes in the workers lung function during the workday. HL1115 Influences on Health at Work

Technical Requirements for Spirometry of Good Quality At least 3 acceptable tests are made with: HL1115 Influences on Health at Work

Full inhalation before start of testFull inhalation before start of test Satisfactory start of exhalationSatisfactory start of exhalation Evidence of maximal effortEvidence of maximal effort No hesitationNo hesitation No cough or glottal closure during the first secondNo cough or glottal closure during the first second HL1115 Influences on Health at Work Spirometry Requirements

Satisfactory duration of testSatisfactory duration of test At least 6 secondsAt least 6 seconds –Up to 15 seconds in patients with airflow restrictions No evidence of leak in the systemNo evidence of leak in the system No evidence of obstruction of the mouthpieceNo evidence of obstruction of the mouthpiece HL1115 Influences on Health at Work Spirometry Requirements

Reproducible results For FVC and FEV1, the 2 largest values should be within 5 percent or 0.1 liter (whichever is larger) of each other. If these criteria are not met testing is continued. HL1115 Influences on Health at Work

Spirometry Requirements If the criteria are not met after 8 trials, testing is stopped and the interpretation is made using only the 3 best acceptable tests. HL1115 Influences on Health at Work

Selection of test values for interpretation Tests of acceptable quality are used with the largest values for FVC and FEV1 used, regardless of test.. HL1115 Influences on Health at Work

Selection of test values for interpretation Tests of acceptable quality are used with the largest values for FVC and FEV1 used, regardless of test. HL1115 Influences on Health at Work

For indexes of average or instantaneous flow values from the test with the largest value for FVC and FEV1 combined are used. HL1115 Influences on Health at Work

Biological Reaction to inhaled dust HL1115 Influences on Health at Work

Lung Diseases Fibrosis - scar tissue formation Bronchitis - overproduction of mucus Asthma - constriction of bronchial tubes HL1115 Influences on Health at Work

Systemic reactions toxicants adsorbed by blood and distributed to target organs e.g. - lead, manganese, cadmium, mercury HL1115 Influences on Health at Work

Metal fume fever inhalation of finely divided, freshly generated metal fumes Al, Zn, Mg, Cu and their oxides HL1115 Influences on Health at Work

Allergic and sensitization reactions inhalation of certain dusts from woods, grains & chemicals HL1115 Influences on Health at Work

Bacterial and fungal infections inhalation of contaminated dusts from grains, textiles etc. HL1115 Influences on Health at Work

Irritation of the nose and throat inhalation of acids and alkalis soluble chromates can cause nasal passage ulceration (& cancer) HL1115 Influences on Health at Work

Internal damage inhalation of radioactive materials HL1115 Influences on Health at Work

Examples

Allergic Alveolitis Also known as: Hypersensitivity Pneumonitis (HP) or Extrinsic Allergic alveolitis (EAA) Other names include: farmers lungfarmers lung bagassosisbagassosis pigeon fanciers lungpigeon fanciers lung

Allergic Alveolitis Acute symptoms include fever, chills, dyspnea, leukocytosis 4-6 hours after exposure and may recur on re- exposure. Chronic disease shows progressive dyspnea, fatigue, low-grade fever, weight loss, chronic nonproductive cough, and bibasilar crackles.

Allergic Alveolitis a restrictive type impairment type III and IV hypersensitivity reaction

Farmers Lung source: moldy crops organisms: Thermoactinomyces sacchari Thermoactinomyces vulgaris Micropolyspora faeni

Bagassosis source: moldy sugar cane organisms: Thermoactinomyces vulgaris Micropolyspora faeni Aspergillus species

Pigeon Fancier’s Lung source: pigeon dust and bloom substance: proteins

Byssinosis source: cotton dust substance: Endotoxin?

Byssinosis chest tightness, cough, wheezing, dyspnea; decreased FEV; bronchitis; malaise; fever, chills, upper respiratory symptoms after initial exposure

Byssinosis Stages: 1.only on Monday 2.persistent, greater on Monday 3.irreversible

Organic Dust Toxic Syndrome (ODTS)

ODTS Grain feverGrain fever Pulmonary mycotoxicosisPulmonary mycotoxicosis Silo unloader's syndromeSilo unloader's syndrome Inhalation feverInhalation fever Mill feverMill fever

ODTS Not a hypersensitivity reactionNot a hypersensitivity reaction Does not require repeated exposures to the same causative agentDoes not require repeated exposures to the same causative agent May occur after a single heavy exposure to dustMay occur after a single heavy exposure to dust

ODTS Fever occurs 4-12 hours after exposure followed by flulike symptoms such as general weakness, headache, chills, body aches, and cough.Fever occurs 4-12 hours after exposure followed by flulike symptoms such as general weakness, headache, chills, body aches, and cough.

Occupational Asthma (OA)

Common Asthmagens IsocyanatesIsocyanates Solder fumeSolder fume MetalsMetals LatexLatex Vegetable dustsVegetable dusts Animal proteinsAnimal proteins EnzymesEnzymes

Occupational Asthma Variable airflow limitation and/or bronchial hyperresponsiveness from work-related exposureVariable airflow limitation and/or bronchial hyperresponsiveness from work-related exposure Obstuctive type impairmentObstuctive type impairment

Asthma Characterized by episodes of airflow obstruction in the bronchial tubes. Symptoms caused by this obstruction include coughing, chest tightness, wheezing and shortness of breath. Although problems are often separated by symptom-free periods, asthma is a chronic illness.

Rhinitis A reaction that occurs in the eyes, nose and throat when airborne irritants or allergens trigger the release of histamine. Histamine causes inflammation and fluid production in the fragile linings of nasal passages, sinuses, and eyelids.

Rhinitis sneezingsneezing congestioncongestion runny noserunny nose itchy nose, throat, eyes, and earsitchy nose, throat, eyes, and ears

Rhinitis Allergic rhinitis pollenpollen dust mitesdust mites moldmold animal danderanimal dander

Rhinitis Nonallergic rhinitis fumesfumes odorsodors temperaturetemperature smokesmoke other irritantsother irritants

Pneumoconiosis HL1115 Influences on Health at Work

Silicosis seen in any industry using quartz containing dusts such as stonework, foundries, glassmaking, pottery, etc. HL1115 Influences on Health at Work

Several forms of free silica: quartz, cristobalite, tridymite, fused silica dust, tripoli & silica flour inhalation of crystalline silica (silicon dioxide) causes fibrotic changes in the lungs HL1115 Influences on Health at Work

Bentonite Uses: foundry sand bond, drilling mud, clays for dams etc. Disease: silicosis Cause: quartz HL1115 Influences on Health at Work

Fuller's earth Uses: adsorbent clay Disease: silicosis like pneumoconiosis Cause: montmorillonite, quartz HL1115 Influences on Health at Work

Mica Uses: drilling mud, decorative finishes Disease: radiographic changes and fibrotic changes Cause: mica and silica HL1115 Influences on Health at Work

Berylliosis Uses - Be/Cu alloys, Be/Ni alloys, Be ceramics spark proof tools, aircraft brakes, electronics HL1115 Influences on Health at Work

Two diseases : acute pneumonitis and chronic berylliosis HL1115 Influences on Health at Work

Acute syndrome less than a year during exposure includes any or all of the following: nasopharyngitis, tracheitis, bronchitis, pneumonitis, dermatitis, conjunctivitis HL1115 Influences on Health at Work

Chronic longer than a year with both systemic and pulmonary abnormalities HL1115 Influences on Health at Work

A separate disease is subcutaneous granulomas secondary to direct implantation of Be compounds under the skin HL1115 Influences on Health at Work

CWP Coal workers pneumoconiosis, "Black Lung" HL1115 Influences on Health at Work

Hard metal disease Tungsten Carbide tungsten carbide used in abrasive tools can result in an asthma syndrome or a diffuse interstitial fibrosis HL1115 Influences on Health at Work

Mica pneumoconiosis HL1115 Influences on Health at Work

Kaolinosis

Bauxite pneumoconiosis HL1115 Influences on Health at Work

Siderosis Inhalation of iron fume relatively benign pneumoconiosis, by itself, with fibrogenic mineral dusts, pulmonary fibrosis termed mixed dust pneumoconiosis or siderosilcosis HL1115 Influences on Health at Work

Factors that influence the development of pneumoconiosis HL1115 Influences on Health at Work

1.Amount and kind of dust inhaled. 2.% of mineral compound in the dust (concentration) 3.the crystalline structure of the mineral 4.the size of the particles inhaled HL1115 Influences on Health at Work

5.duration of the exposure 6.Individual susceptibility resistance 7.Presence of other pre-disposing factors HL1115 Influences on Health at Work

Asbestos Asbestos Uses - insulation, fireproofing HL1115 Influences on Health at Work

Where asbestos is found

Asbestos cement

Sprayed asbestos 125

Sprayed asbestos

Lagging

Asbestos insulating board

Asbestos textiles

Several types in two main forms: HL1115 Influences on Health at Work

Serpentine – chrysotile (white A), Amphibole - crocidolite (blue A), amosite (brown A), anthophyllite, tremolite and actinolite HL1115 Influences on Health at Work

Asbestosis - diffuse interstitial scarring Bronchogenic carcinoma Mesothelioma (pleural or peritoneal) Cancer of stomach, colon, rectum HL1115 Influences on Health at Work

Questions? Questions?