prevention of (occupational) disease. - institute of population
TRANSCRIPT
Prevention of (occupational) disease.
MBChB, Phase I, Year 1, Semester 230th April 2009, 11.00 a.m.
Roscoe Bldg, Lect. Theatre A
Raymond AgiusProfessor of Occupational & Environmental Medicine,
& Consultant in Occupational Medicine*
*Medical specialty dealing with the effects of work on health,and of health on work.
The effects of work on health can be positive or negative. In this session we are dealing with the latter.
www.medicine.manchester.ac.uk/oeh/undergraduate/onlineresources/
Learning Objectives:
• Understand the relevance of work to health and disease. (Knowledge)
special reference to recognition & prevention of disease
• Take an occupational history … (Skill)
• Appreciate the different perspective required by the Occupational Health approach (Attitude)
Structure of Presentation:
Introduction.
Body:1. Burden of Occupational Disease in the UK.2. Recognising Occupational Disease & its causes
- Taking an Occupational History3. Preventing Disease related to work.Conclusion.
Structure of Presentation:
Introduction.
Body:1. Burden of Occupational Disease in the UK.2. Recognising Occupational Disease & its causes
- Taking an Occupational History3. Preventing Disease related to work.Conclusion.
Estimated prevalence of self-reported work-related illness in Great Britain in 2006/7
People who believed that they were suffering from an illness caused or made worse by their current
or past work.
?
Estimated prevalence of self-reported work-related illness in Great Britain in 2006/7*
Total ~ 2 Million
(2,200,000. Confidence Interval: 2,131,000 to 2,269,000)Rate: 5110 per 100,000 ever employed
*Self-reported work-related illness in 2006/2007: Results from the Labour Force Survey. Jones et al; HSE
Estimated prevalence of self-reported work-related illness in Great Britain in 2006/7
Musculoskeletal:
?
Estimated prevalence of self-reported work-related illness in Great Britain in 2006/7
Musculoskeletal~ 1.0 Million
(1,144,000 Confidence Interval: 1,094,000 to 1,193,000)Rate per 100,000 ever employed = 2650
Estimated prevalence of self-reported work-related illness in Great Britain in 2006/7
Stress, depression or anxiety:
?
Estimated prevalence of self-reported work-related illness in Great Britain in 2006/7
Stress depression / anxiety: 530,000
(Confidence Interval: 496,000 to 565,000)Rate per 100,000 ever employed = 1230
Estimated prevalence of self-reported work-related illness in Great Britain in 2006/7
Breathing and lung problems:
?
Estimated prevalence of self-reported work-related illness in Great Britain in 2006/7
Breathing and Lung problems: 142,000
(Confidence Interval: 125,000 to 159,000)Rate per 100,000 ever employed = 330
Diseases caused by asbestos include:
Asbestosis (a form of lung fibrosis)
Bronchial cancer
Mesothelioma ( cancer of the pleura)
[still responsible for thousands of deaths per year from exposures of 3-4 decades ago]
Pneumoconioses are diseases caused by dust,
e.g. silicosis caused by silica
Occupational asthma is the commonest occupational lung disease arising from current exposures
Examples of agents causing asthma:
Number of Estimated Cases of Asthma Attributed to Glutaraldehyde Exposure Reported to SWORD
(1989-2008)
84
27
46
1712
5 37 5
2 1 0 1
18 1613
612
5 37 5
2 1 0 10
20
40
60
80
100
1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008
num
ber o
f cas
es
Estimated casesActual cases
Estimated prevalence of self-reported work-related illness in Great Britain in 2006/7
Hearing problems:
?
Estimated prevalence of self-reported work-related illness in Great Britain in 2006/7
Hearing problems: 75,000
(Confidence Interval: 63,000 to 87,000)Rate per 100,000 ever employed = 170
Audiogram showing Noise Induced Hearing Loss
Estimated prevalence of self-reported work-related illness in Great Britain in 2006/7
Heart disease/attack, other circulatory system:
?
Estimated prevalence of self-reported work-related illness in Great Britain in 2006/7
Heart disease/attack, other circulatory system: 60,000
(Confidence Interval: 49,000 to 71,000)Rate per 100,000 ever employed = 140
Estimated prevalence of self-reported work-related illness in Great Britain in 2006/7
Skin problems:
?
Estimated prevalence of self-reported work-related illness in Great Britain in 2006/7
Skin problems: 29,000
(Confidence Interval: 21,000 to 36,000)Rate per 100,000 ever employed = 67
Eczema / dermatitis
The commonest occupational skin disease
Occupational skin disease - Most frequently reported industries
Estimated cases of all skin disease reported by dermatologists in 2008 (‘Epiderm’: University of Manchester)
345
284
267
229
0 50 100 150 200 250 300 350 400
Health and social care(213)
Hairdressing andbeauty (86)
Public administration& defence (58)
Construction (75)
Estimated cases
Incidence rates of all skin disease reported to EPIDERM (2008) by most frequently reported industries per 100,000 employed per year
compared with population denominator from the Labour Force Survey 2007 data
9.77
114.08
12.84
9.79
0 20 40 60 80 100 120
Health and social care
Hairdressing andbeauty
Public administration& defence
Construction
incidence rate
But other occupational skin disease too …
•Case:
fair skinnedoutdoor exposure
3years flat mole1 month pink raiseditchy, bleeding
Melanoma (malignant)
•Case
Vet
tending cattle
Orf
Estimated prevalence of self-reported work-related illness in Great Britain in 2006/7 –
order of illness types
Estimated prevalence (thousands) Rate per 100,000 ever employedDiagnostic category
Central Lower CI Upper CI Central Lower CI Upper CI
Musculoskeletal 1144 1094 1193 2650 2540 2770
Stress, depression / anxiety
530 496 565 1230 1150 1310
Breathing / lung problems
142 125 159 330 290 370
Other complaints 147 129 165 340 300 380
Hearing problems 75 63 87 170 150 200
Circulatory system 60 49 71 140 110 160
Infectious disease 72 32 52 98 75 120
Skin problems 55 21 36 67 49 85
0% 25% 50% 75% 100%
All cases
Health & social care
Construction
Public admin & defence
Retail
Education
Catering
Other business
Food Manufacture
Metal manufacture
Financial
Land transport
Agriculture
Hair & beauty
Musculoskeletal Mental ill health Skin Respiratory Audiological Other
Industries reported by diagnostic category by GPs (THOR-GP 2006-07)
Structure of Presentation:
Introduction.
Body:1. Burden of Occupational Disease in the UK.2. Recognising Occupational Disease & its
causes - Taking an Occupational History3. Preventing Disease related to work.Conclusion.
The Occupational History.Bernardino Ramazzini:
“What is your job?…Tell me about it”
Work can be: • The ‘unique’ cause of a disease, or• A contributory factor amongst others, or• It can make a disease worse
Determining Cause
The Occupational History
What pattern of enquiry would you follow to determine whether there was a causal relationship between a particular exposure and a worker’s health concerns?
NB: For this purpose, and at this stage DO NOT address specific exposures nor specific symptoms/signs.
Enquiry:When in relation to exposure do / did the symptoms start?
Temporality
Enquiry:Do the symptoms improve when no longer exposed?
Reversibility
Enquiry:Are the symptoms especially worse when undertaking high exposure tasks or in areas with high exposures?
Exposure-response
Enquiry:Do other workers / patients suffer from similar symptoms associated with the same exposures?
Strength of association
Enquiry:What other exposures / causal factors could be responsible for the same symptoms?
Specificity
Enquiry:Are there other reports of the same symptoms associated with or caused by the same exposure?
Consistency
Enquiry:Have similar agents/ chemicals of similar structure been implicated in the same ill health.
H2N NH2
P-Phenylenediamine
HN NH
Piperazine
CH3
NCO
NCO
2,4-Toluene diisocyanate
N
CONH-NH2
Isonicotinic acid hydrazide
HydralazineNH-NH2
N
N
CH3CH2NH2Ethylamine
NH2
Aniline
NH
Piperidine
H2NCH2CH2NH2Ethylenediamine
H2NCN:NCNH2Azodicarbonamide
O ONot-asthmagens vs Asthmagens
Enquiry:Have similar agents/ chemicals of similar structure been implicated in the same ill health.
Analogy
Enquiry:Do the symptoms 'add up' in terms of what is known about the mechanisms of disease?
Biological plausibility
Austin Bradford Hill’s ‘criteria’ for causal association•Temporality•Reversibility•Exposure-response•Strength of Association•Specificity•Consistency•Analogy•Biological Plausibility
Clinical (individual) approach Epidemiologic (group) approach
Individuals Groups of people
Symptomatic/ill/worried Ill or at risk
Aims for Diagnosis Aims for Causal relationships
Individual risk factors Contributory factors Or workplace hazards Exposure-response relationships
Treatment / local control Population intervention
Education Attitudes in society
Review Evaluation of intervention
Structure of Presentation:
Introduction.
Body:1. Burden of Occupational Disease in the UK.2. Recognising Occupational Disease & its causes
- Taking an Occupational History3. Preventing Disease related to work.Conclusion.
Steps to prevent occupational disease:
1. Eliminate the hazard or 2. Substitute it by something ‘safer’.
Cases of occupational asthma attributed to latex: 1991-2008(SWORD: Surveillance of Work related & Occupational Respiratory Disease
– The University of Manchester)
31
4
10
16
20
5148
17
30
1012
16
42 2 3
0
31
4
10
16
9
18
1517
810
12
5 42 2 3
00
10
20
30
40
50
60
1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008
num
ber o
f cas
es
EstimatedActual
Steps to prevent occupational disease:
3. Contain / segregate the hazard or 4. Draw the hazard awayor5. Wear personal protection(last resort since it does not work as well as expected, and can be awkward to wear or be a hazard in itself)
Some examples in the health service
Manufacturing Industry
6. Most important steps to prevent work related ill health (can apply to all jobs):
Improve the organisation of work, and work practices, addressing issues such as:
- Proper communication between employers and employees - Workload (overload or underload)- Matching workers’ skills to the jobs- Having clear lines of accountability and responsibilities- Appropriate work patterns e.g. shiftwork- Job security- Ensuring a ‘happy’ workplace and worker – free from bullying etc- ‘Safe’ working practices- Training and educating workers
… but not like this!
However absence of work is also associated with increased ill-health!
“Employment is nature’s physician and is essential for human happiness”
Galen, ca 180 AD
Structure of Presentation:
Introduction.
Body:1. Burden of Occupational Disease in the UK.2. Recognising Occupational Disease & its causes
- Taking an Occupational History3. Preventing Disease related to work.Conclusion.
• There remains a large burden of work related ill health in the UK.
• Appropriate history taking is essential to recognise this.
• A hierarchy of control can prevent it:– Elimination or substitution of hazards– Enclosure/Segregation so as to reduce exposure– Local exhaust and/or dilution ventilation if relevant– Appropriate education, work organisation and practice– Personal protection
• (But most work is probably good for you)
Thank you.