HL1115 Influences on Health at Work

HL1115 Influences on Health at WorkHL1115 Influences on Health at Work

Occupational lung disorders: Occupational lung disorders: asthma, byssinosis, asthma, byssinosis, pneumoconiosis, asbestosis, pneumoconiosis, asbestosis, mesothelioma, farmers lung, mesothelioma, farmers lung, acute and chronic effects of acute and chronic effects of exposure to toxic fumes. exposure to toxic fumes.

Routes of Entry:Routes of Entry:


Mechanism vs. PathwayMechanism vs. Pathway

• Mechanism is actionMechanism is action

• Pathway is route of entryPathway is route of entry

We use both terms!We use both terms!


NasalNasal

InhalationInhalation


OralOralIngestionIngestion


Dermal (Skin)Dermal (Skin)AbsorptionAbsorptionInjectionInjection


• Inhalation Inhalation • Ingestion Ingestion • SkinSkin

– AbsorptionAbsorption– InjectionInjection


Target Organ vs. PathwayTarget 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!They don’t have to be the same!


Inhalation is particularly Inhalation is particularly important exposure portalimportant exposure portal


Inhalation:Inhalation:

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

IInhalationnhalation



AAbsorptionbsorption Factors Factors

• High surface area High surface area • Small Small air/blood air/blood distancedistance• PParticle sizearticle size

• SolubilitySolubility



• ConcentrationConcentration• DurationDuration• Respiration RateRespiration Rate

IInngestiongestion

MethodsMethods

• IncidentalIncidental • AccidentalAccidental

• DeliberateDeliberate

IInngestiongestion

AAbsorptionbsorption Factors Factors• Emotional stateEmotional state• Digestive acidsDigestive acids//enzymesenzymes• DiahhreaDiahhrea//constipationconstipation• Gastrointestinal contentGastrointestinal content

IInngestiongestion

AAbsorptionbsorption Factors Factors• Micro-flora in gutMicro-flora in gut• Metabolite formation Metabolite formation • AgeAge

• Predisposing factorsPredisposing factors

Skin AbsorptionSkin Absorption

Primary layers:Primary layers:

• EpidermisEpidermis

• DermisDermis

• Subcutaneous Subcutaneous layerlayer

Skin AbsorptionSkin Absorption


• DiseaseDisease/injury/injury state state• Blood flow, sweat & heatBlood flow, sweat & heat• Skin ageSkin age

• Skin thicknessSkin thickness

Skin InjectionSkin Injection

• IntraperitonealIntraperitoneal• SubcutaneousSubcutaneous• IntramuscularIntramuscular• IntravenousIntravenous

Respiratory SystemRespiratory System

• Nasopharynx RegionNasopharynx Region

• Tracheobronchial RegionTracheobronchial Region

• Pulmonary (Alveolar) RegionPulmonary (Alveolar) Region


• Nasopharynx Region: Nasopharynx Region: the head region, the head region, including the nose, mouth, pharynx, and including the nose, mouth, pharynx, and larynx larynx


• Tracheobronchial Region: Tracheobronchial Region: includes includes the trachea, bronchi, and bronchioles the trachea, bronchi, and bronchioles


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


Particle depositionParticle deposition

• SedimentationSedimentation


• DiffusionDiffusion


• InterceptionInterception


• ImpactionImpaction

Deposition of particlesDeposition of particles

4-5 4-5 m in respiratory tract m in respiratory tract 2.5-3 2.5-3 m in upper respiratory m in upper respiratory tract tract 2 2 m in URT and lung spaces m in URT and lung spaces 1 1 m in alveolar spacesm in alveolar spaces

Particulate SizingParticulate Sizing

Inhalable Particle MassInhalable Particle Mass

Thoracic Particle MassThoracic Particle Mass

Respirable Particle MassRespirable Particle Mass

Inhalable Particle Mass - Inhalable Particle Mass - hazardous when deposited hazardous when deposited

anywhere in the respiratory tract, anywhere in the respiratory tract, 50% cut point 100 50% cut point 100 mm

Thoracic Particle Mass - Thoracic Particle Mass - hazardous when deposited hazardous when deposited

anywhere in the lung airways or anywhere in the lung airways or gas exchange region, 50% cut gas exchange region, 50% cut

point 10 point 10 m m

Respirable Particle Mass - Respirable Particle Mass - hazardous when deposited in the hazardous when deposited in the

gas exchange region, 50% cut gas exchange region, 50% cut point 4 point 4 mm

Stokes LawStokes Law

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


2

18

1 gdv Fs


vv = = settling velocitysettling velocitygg = = gravitational acceleration, 9.80 m/sgravitational acceleration, 9.80 m/s22

ss = = density of objectdensity of object

d d == diameter of objectdiameter of objectFF = = density of fluiddensity of fluid

== viscosity of fluidviscosity of fluid


2

18

1 gdv Fs

Reynolds NumberReynolds Number

F

e

dvR

laminar flow if laminar flow if RRe e <500<500turbulent flow if turbulent flow if RRe >e >500500


• settling velocity settling velocity relates to relates to diameterdiameter

Pulmonary function testingPulmonary function testing(Spirometry)(Spirometry)

Pulmonary function tests are sensitive Pulmonary function tests are sensitive indicators of lung disease and are indicators of lung disease and are commonly used in the workplace commonly used in the workplace environmentenvironment



Common testsCommon tests

• Forced Vital Capacity (FVC)Forced Vital Capacity (FVC)

• One Second Forced Expiratory Volume One Second Forced Expiratory Volume (FEV1)(FEV1)

• Ratio of FVC to FEV1Ratio of FVC to FEV1

• Peak flowPeak flow


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


Pulmonary function abnormalities Pulmonary function abnormalities are generally categorized into two are generally categorized into two patterns: patterns:

obstructive or restrictiveobstructive or restrictive..


Obstructive flow impairment,Obstructive flow impairment, such as observed in asthma bronchitis such as observed in asthma bronchitis

and emphysema is indicated by a and emphysema is indicated by a decrease in flow (often indicated by decrease in flow (often indicated by

decreased FEV1/FVC ratio).decreased FEV1/FVC ratio).



Restrictive flow impairment,Restrictive flow impairment, such as observed in interstitial lung such as observed in interstitial lung

disease is indicated by a decrease in disease is indicated by a decrease in volumevolume..



Pulmonary function tests can be given Pulmonary function tests can be given before and after the workshift to before and after the workshift to

observe changes in the workers lung observe changes in the workers lung function during the workday. function during the workday.


Technical Requirements for Technical Requirements for Spirometry of Good QualitySpirometry of Good Quality

At least 3 acceptable tests are At least 3 acceptable tests are made with:made with:


• 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 No cough or glottal closure during the first secondfirst second


Spirometry Requirements Spirometry Requirements

• Satisfactory duration of testSatisfactory duration of test

• At least 6 secondsAt least 6 seconds– Up to 15 seconds in patients with airflow Up to 15 seconds in patients with airflow

restrictionsrestrictions

• No evidence of leak in the system No evidence of leak in the system

• No evidence of obstruction of the No evidence of obstruction of the mouthpiecemouthpiece


Spirometry RequirementsSpirometry Requirements


Reproducible resultsReproducible resultsFor FVC and FEV1, the 2 largest values For FVC and FEV1, the 2 largest values should be within 5 percent or 0.1 liter should be within 5 percent or 0.1 liter (whichever is larger) of each other.(whichever is larger) of each other.If these criteria are not met testing is If these criteria are not met testing is continued.continued.



If the criteria are not met after 8 trials, If the criteria are not met after 8 trials, testing is stopped and the interpretation testing is stopped and the interpretation is made using only the 3 best is made using only the 3 best acceptable tests.acceptable tests.


Selection of test values for Selection of test values for interpretationinterpretation

Tests of acceptable quality are used with Tests of acceptable quality are used with the largest values for FVC and FEV1 the largest values for FVC and FEV1 used, regardless of test.used, regardless of test.. .


Selection of test values for Selection of test values for interpretationinterpretation

Tests of acceptable quality are used Tests of acceptable quality are used with the largest values for FVC and with the largest values for FVC and FEV1 used, regardless of test.FEV1 used, regardless of test.


For indexes of average or For indexes of average or instantaneous flow values from the instantaneous flow values from the test with the largest value for FVC and test with the largest value for FVC and FEV1 combined are used.FEV1 combined are used.


Biological Reaction to inhaled Biological Reaction to inhaled dust dust


Lung DiseasesLung Diseases

Fibrosis - Fibrosis - scar tissue formationscar tissue formation Bronchitis - Bronchitis - overproduction of mucusoverproduction of mucus

Asthma - Asthma - constriction of bronchial constriction of bronchial tubestubes


Systemic reactionsSystemic reactions

toxicants adsorbed by blood and toxicants adsorbed by blood and distributed to target organs distributed to target organs e.g. - lead, manganese, cadmium, e.g. - lead, manganese, cadmium, mercurymercury


Metal fume feverMetal fume fever

inhalation of finely divided, freshly inhalation of finely divided, freshly generated metal fumes generated metal fumes Al, Zn, Mg, Cu and their oxidesAl, Zn, Mg, Cu and their oxides


Allergic and sensitization Allergic and sensitization reactionsreactions

inhalation of certain dusts from woods, inhalation of certain dusts from woods, grains & chemicalsgrains & chemicals


Bacterial and fungal infectionsBacterial and fungal infections

inhalation of contaminated dusts inhalation of contaminated dusts from grains, textiles etc.from grains, textiles etc.


Irritation of the nose and throatIrritation of the nose and throat

inhalation of acids and alkalis inhalation of acids and alkalis soluble chromates can cause nasal soluble chromates can cause nasal passage ulceration (& cancer)passage ulceration (& cancer)


Internal damageInternal damage

inhalation of radioactive inhalation of radioactive materialsmaterials


ExamplesExamples


Allergic Allergic AAlveolitislveolitis

Also known as:Also known as:

Hypersensitivity PneumonitisHypersensitivity Pneumonitis (HP) (HP) oror

Extrinsic Extrinsic Allergic alveolitisAllergic alveolitis (EAA) (EAA)

Other names include:Other names include:• farmers lungfarmers lung• bagassosisbagassosis• pigeon fanciers lungpigeon fanciers lung


Acute symptoms include fever, chills, Acute symptoms include fever, chills, dyspnea, leukocytosis 4-6 hours after dyspnea, leukocytosis 4-6 hours after exposure and may recur on re-exposure and may recur on re-exposureexposure..

Chronic disease shows progressive Chronic disease shows progressive dyspnea, fatigue, low-grade fever, dyspnea, fatigue, low-grade fever, weight loss, chronic nonproductive weight loss, chronic nonproductive cough, and bibasilar crackles. cough, and bibasilar crackles.


a restrictive type impairment a restrictive type impairment

type III and IV hypersensitivity reaction type III and IV hypersensitivity reaction

FFarmers armers LLungung

source: moldy source: moldy cropscrops

organisms:organisms:

Thermoactinomyces Thermoactinomyces saccharisacchari

Thermoactinomyces Thermoactinomyces vulgarisvulgaris

Micropolyspora faeniMicropolyspora faeni

BBagassosisagassosis

source: moldy sugar source: moldy sugar cane cane

organisms:organisms:

Thermoactinomyces Thermoactinomyces vulgarisvulgaris

Micropolyspora faeniMicropolyspora faeni

AspergillusAspergillus species species

PPigeon igeon FFancierancier’’s s LLungung

source: source: pigeon dustpigeon dust and bloomand bloom

substancesubstance::

proteinsproteins

ByssinosisByssinosis

source: source: cotton dustcotton dust

substancesubstance::

Endotoxin?Endotoxin?


chest tightness, chest tightness,

cough,cough, wheezing, wheezing, dyspnea; dyspnea;

decreased decreased FEVFEV; ;

bronchitis; malaise; bronchitis; malaise; fever, chills, fever, chills,

upper respiratory upper respiratory symptoms after initial symptoms after initial exposure exposure


SStages: tages:

1.1. only on Monday only on Monday

2.2. persistent, greater persistent, greater on Monday on Monday

3.3. irreversible irreversible

Organic Dust Toxic Syndrome Organic Dust Toxic Syndrome (ODTS)(ODTS)

ODTSODTS

• Grain feverGrain fever

• PulmonaryPulmonarymycotoxicosismycotoxicosis

• Silo unloader's Silo unloader's syndromesyndrome

• Inhalation feverInhalation fever

• Mill feverMill fever

ODTSODTS

• Not a hypersensitivity reaction Not a hypersensitivity reaction

• Does not require repeated exposures Does not require repeated exposures to the same causative agentto the same causative agent

• May occur after a single heavy May occur after a single heavy exposure to dustexposure to dust

ODTSODTS

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

Occupational AsthmaOccupational Asthma(OA)(OA)

Common ACommon Asthmasthmagensgens

• IsocyanatesIsocyanates• SSolder fumeolder fume• MetalsMetals• LatexLatex• VVegetable dustsegetable dusts• AAnimal proteinsnimal proteins• EEnzymesnzymes

Occupational Occupational AAsthmasthma

• Variable airflow limitation and/or Variable airflow limitation and/or bronchial hyperresponsiveness from bronchial hyperresponsiveness from work-related exposurework-related exposure

• Obstuctive type impairmentObstuctive type impairment

AAsthmasthma

CCharacterized by episodes of airflow haracterized by episodes of airflow obstruction in the bronchial tubes.obstruction in the bronchial tubes.

Symptoms caused by this obstruction Symptoms caused by this obstruction include coughing, chest tightness, include coughing, chest tightness, wheezing and shortness of breath.wheezing and shortness of breath.

Although problems are often separated Although problems are often separated by symptom-free periods, asthma is a by symptom-free periods, asthma is a chronic illness.chronic illness.

RhinitisRhinitis

AA reaction that occurs in the eyes, reaction that occurs in the eyes, nose and throat when airborne nose and throat when airborne irritants irritants or or allergens trigger the allergens trigger the release of histamine. release of histamine.

Histamine causes inflammation and Histamine causes inflammation and fluid production in the fragile linings fluid production in the fragile linings of nasal passages, sinuses, and of nasal passages, sinuses, and eyelidseyelids..

RhinitisRhinitis

• sneezing sneezing • congestion congestion • runny nose runny nose • itchy nose, itchy nose,

throat, eyes, throat, eyes, and earsand ears

RhinitisRhinitis

AAllergic rhinitis llergic rhinitis • pollen pollen • dust mites dust mites • mold mold • animal danderanimal dander

RhinitisRhinitis

NNonallergic rhinitis onallergic rhinitis • ffumesumes• odors odors • temperature temperature • smoke smoke • other irritantsother irritants

PneumoconiosisPneumoconiosis


SilicosisSilicosis

seen in any industry using quartz seen in any industry using quartz containing dusts such as stonework, containing dusts such as stonework, foundries, glassmaking, pottery, etc.foundries, glassmaking, pottery, etc.


Several forms of free silica: quartz, Several forms of free silica: quartz, cristobalite, tridymite, fused silica cristobalite, tridymite, fused silica dust, tripoli & silica flour dust, tripoli & silica flour

inhalation of crystalline silica inhalation of crystalline silica (silicon dioxide) causes fibrotic (silicon dioxide) causes fibrotic changes in the lungs changes in the lungs


BentoniteBentonite

Uses: foundry sand bond, drilling Uses: foundry sand bond, drilling mud, clays for dams etc.mud, clays for dams etc.Disease: silicosisDisease: silicosisCause: quartzCause: quartz


Fuller's earthFuller's earth

Uses: adsorbent clayUses: adsorbent clayDisease: silicosis like Disease: silicosis like pneumoconiosispneumoconiosisCause: montmorillonite, quartzCause: montmorillonite, quartz


MicaMica

Uses: drilling mud, decorative Uses: drilling mud, decorative finishesfinishesDisease: radiographic changes and Disease: radiographic changes and fibrotic changesfibrotic changesCause: mica and silica Cause: mica and silica


BerylliosisBerylliosis

Uses - Be/Cu alloys, Be/Ni alloys, Be Uses - Be/Cu alloys, Be/Ni alloys, Be ceramicsceramicsspark proof tools, aircraft brakes, spark proof tools, aircraft brakes, electronicselectronics


Two diseasesTwo diseases: acute pneumonitis : acute pneumonitis and chronic berylliosisand chronic berylliosis


Acute syndrome less than a year Acute syndrome less than a year during exposure includes any or all of during exposure includes any or all of the following: the following: nasopharyngitis, tracheitis, bronchitis, nasopharyngitis, tracheitis, bronchitis, pneumonitis, dermatitis, conjunctivitis pneumonitis, dermatitis, conjunctivitis


Chronic longer than a year Chronic longer than a year with with both systemic and pulmonary both systemic and pulmonary abnormalitiesabnormalities


A separate disease is subcutaneous A separate disease is subcutaneous granulomas secondary to direct granulomas secondary to direct implantation of Be compounds under implantation of Be compounds under the skinthe skin


CWPCWP

Coal workers pneumoconiosis, Coal workers pneumoconiosis, "Black Lung""Black Lung"











Hard metal diseaseHard metal disease

Tungsten CarbideTungsten Carbidetungsten carbide used in abrasive tungsten carbide used in abrasive tools can result in an asthma tools can result in an asthma syndrome or a diffuse interstitial syndrome or a diffuse interstitial fibrosisfibrosis


Mica pneumoconiosisMica pneumoconiosis


KaolinosisKaolinosis


Bauxite pneumoconiosisBauxite pneumoconiosis


Siderosis Siderosis Inhalation of iron fumeInhalation of iron fumerelatively benign pneumoconiosis, by relatively benign pneumoconiosis, by itself, with fibrogenic mineral dusts, itself, with fibrogenic mineral dusts, pulmonary fibrosis termed mixed dust pulmonary fibrosis termed mixed dust pneumoconiosis or siderosilcosis pneumoconiosis or siderosilcosis


Factors that influence the Factors that influence the development of development of pneumoconiosispneumoconiosis


1.1. Amount and kind of dust inhaled.Amount and kind of dust inhaled.

2.2. % of mineral compound in the dust % of mineral compound in the dust (concentration)(concentration)

3.3. the crystalline structure of the the crystalline structure of the mineralmineral

4.4. tthe size of the particles inhaledhe size of the particles inhaled


5.5. duration of the exposureduration of the exposure

6.6. Individual susceptibility resistanceIndividual susceptibility resistance

7.7. Presence of other pre-disposing Presence of other pre-disposing factors factors


AsbestosAsbestos

AsbestosAsbestosUses - insulation, fireproofingUses - insulation, fireproofing


Where asbestos is foundWhere asbestos is found

Asbestos cementAsbestos cement

Sprayed asbestosSprayed asbestos

125

Sprayed asbestosSprayed asbestos

LaggingLagging

Asbestos insulating boardAsbestos insulating board

Asbestos insulating Asbestos insulating boardboard

Asbestos textilesAsbestos textiles

Several types in two main Several types in two main forms:forms:


Serpentine – Serpentine – chrysotile (white A), chrysotile (white A),

AmphiboleAmphibole - crocidolite (blue A), - crocidolite (blue A), amosite (brown A), anthophyllite, amosite (brown A), anthophyllite, tremolite and actinolitetremolite and actinolite


Asbestosis - Asbestosis - diffuse interstitial diffuse interstitial scarringscarring

Bronchogenic carcinomaBronchogenic carcinoma

MesotheliomaMesothelioma (pleural or peritoneal) (pleural or peritoneal)

Cancer of stomach, colon, rectumCancer of stomach, colon, rectum




Questions?Questions?

HL1115 Influences on Health at Work

Documents

oralingestion routes

gas exchange region

head region

air exchange region

upper respiratory tract

farmers lung

lung spaces

lung airways