WHAT
WHAT IS
IS A
A HAZARDOUS
HAZARDOUS BIOLOGICAL
BIOLOGICAL
AGENT
AGENT (HBA)?
(HBA)?
OVERVIEW
OVERVIEW OF
OF HAZARDOUS
HAZARDOUS BIOLOGICAL
BIOLOGICAL
AGENTS
AGENTS IN
IN THE
THE WORKPLACE
WORKPLACE –– LEGAL
LEGAL AND
AND
PRACTICAL
PRACTICAL ISSUES
ISSUES
Any cell (plant, animal, human),
micromicro-organism or cell culture of natural origin
or genetically engineered that
constitutes a risk to human health
Prof Mohamed Fareed Jeebhay
Occupational and Environmental Health Research Unit
School of Public Health and Family Medicine
University of Cape Town, South Africa
MAIN
MAIN PRINCIPLES
PRINCIPLES OF
OF THE
THE PREVENTIVE
PREVENTIVE
LEGISLATION
LEGISLATION
HBA-RELATED
HBA-RELATED LEGISLATION
LEGISLATION
MAJOR LAWS RELATING TO HAZARDOUS BIOLOGICAL AGENTS
Preventive
Compensation
1. OHSA
- Hazardous Chemical Substances Regs.
- Regs. Hazardous Biological Agents
2. MHSA
HCS Regs
- grain, cotton, wood
- rubber (?latex)
Regs HBA
- micro-organisms, cells,
- pathogens, cell cultures
- human endoparasites
1. Compensation for Occupational Injuries
and Diseases Act
2. Occupational Diseases in Mines
and Works Act
COIDA
- Infectious/parasitic disease - high risk work
- Toxic/inflammatory syndromes - exposure
to endotoxins,mycotoxins,glucans, VOCs
- Upper airways disorders, byssinosis, occupational
asthma, extrinsic allergic alveolitis (organic dust,
moulds, proteins/enzymes, animals/insects)
- Allergic/irritant contact dermatitis
•
Identify sources of high-risk exposure/risk assessment (inspections,
record keeping)
•
Control the hazard: substitution, isolation, engineering controls
(eg. exhaust ventilation), administrative controls (eg. universal
infection control procedures), personal protective equipment
•
Exposure monitoring: industrial hygiene surveillance and
evaluation of bioaerosols and allergens (approved inspection
authority: AIA)
•
Medical surveillance programmes
(skin prick testing, serum antibodies, target organ tests)
•
Information, education and training, and counseling programmes
(reporting, hazard awareness, safe procedures for handling/
decontamination)
PARADIGM
PARADIGM FOR
FOR EVALUATING
EVALUATING BIOLOGICAL
BIOLOGICAL
HEALTH
HEALTH RISKS:
RISKS: A
A REQUIREMENT
REQUIREMENT UNDER
UNDER
HBA/HCS
HBA/HCS REGULATIONS
REGULATIONS
HOST
(worker,
occupant)
- immunity
- atopy
- genetic (HLA)
- smoking
HEALTH
EFFECTS
Route (air/skin)
Dose (level/duration)
AGENT
(biological agent)
- name
- physical state
- properties
(virulence, allergenic
potency)
- particle size
AGENT
AGENT
ENVIRONMENT
(workplace, building)
- work process
- control measures
1
MAJOR
MAJOR CATEGORIES
CATEGORIES OF
OF BIOLOGICAL
BIOLOGICAL
AGENTS
AGENTS OF
OF NATURAL
NATURAL ORIGIN
ORIGIN
CATEGORY
Microorganisms
• Viruses
• Bacteria
• Fungi
Plants
• Lower plants
• Higher plants
Animals
• Invertebrates
• Arthropods
• Vertebrates
COMMON
COMMONOCCUPATIONAL
OCCUPATIONALSETTINGS
SETTINGS
WITH
WITH EXPOSURE
EXPOSURE TO
TO HBA
HBA
EXAMPLES
SECTOR
Agriculture
EXAMPLES
Cultivating, harvesting, forestry
•
Breeding and tending animals, fishing
•
Abattoirs, food processing plants
Agricultural products
•
Storage facilities: grain silos, tobacco
•
Processing animal hair, leather, silk
•
Textile plants, sawmills, paperpaper-mills
•
Veterinary facilities, pet shops
Animal care
Biotechnology/research labs • Production, microbiology, animal units
•
Metal working, soldering
Metal
•
Gold and coal mining
Mining
•
Hospitals, clinics, nursing homes
Health care
•
Production of drugs, herbal products
Pharmaceutical
Sewage and waste disposal • Waste removal, treatment plants
Influenza, Rabies, Hepatitis A, HIV
Brucella, Anthrax, Leptospira, Thermophilic bacteria,
Tetanus, Mycobacteria (TB)
Aspergillus, Alternaria
Lichens, liverwarts, ferns
Grain, cotton, wood, coffee, tobacco, spices
Shistosoma (bilharzia), Anisakis, Plasmodium (malaria)
Arachnids (spiders, storage mites, ticks), Insects
(cockroaches, beetles, moths, bees), Crustaceans
Fish, Amphibians, Reptiles, Birds, Mammals (cattle,
sheep)
REGULATIONS
REGULATIONS FOR
FOR HAZARDOUS
HAZARDOUS
BIOLOGICAL
BIOLOGICAL AGENTS
AGENTS (HBA):
(HBA): SCOPE
SCOPE
HBA
HBA REGULATIONS
REGULATIONS ––
Risk
Risk Group
Group Categories
Categories for
for HBA
HBA
Scope: Every employer and self-employed person where:
z
z
•
CATEGORY DEFINITION
- unlikely to cause human disease
Group 1
Group 2
- can cause severe human disease
- might be a hazard to workers
- unlikely to spread to community
- effective prophylaxis/treatment
HBA is deliberately produced, processed, used, handled,
stored or transported
Incident or high risk exposure to a HBA in the following
work situations:
- food production plants
- contact with animals and/or products of animal origin
- health care, including isolation and post mortem units
- clinical, veterinary and diagnostic laboratories
- sewage purification installations
- general workplace
Group 3
Group 4
EXAMPLE
E Coli K10, yeast
Legionella pneum.
Leptospira
Influenza A/B (V)
Hepatitis A (V)
Ascaris (A)
- can cause severe human disease Mycobacterium TB (V)
- serious hazard to workers
Bacillus anthracis (V)
- may spread to community
Hepatitis B (V)
- effective prophylaxis/treatment
HIV, Shigella (T)
- causes severe human disease
Congo haem. fever
- serious hazard to workers
Ebola pox
- high risk of spread to community
- no effective prophylaxis/treatment
Symbols: A-allergenic, T-toxic effects, V-vaccine available
PARTICLE
PARTICLE DEPOSITION
DEPOSITION IN
IN RELATION
RELATION
TO
TO AERODYNAMIC
AERODYNAMIC DIAMETER
DIAMETER
DETERMINES
DETERMINES HEALTH
HEALTH EFFECTS
EFFECTS
Particles (MMAD 5 -10 microns)
deposited in tracheotracheo-bronchial
region as airway defences become
less efficient (thoracic
(thoracic fraction)
z
Maximal lung deposition occurs
with particles MMAD < 5 microns
(respirable fraction)
1000
z
Spearman r = 0.74
(p<0.001)
500
Particles (MMAD >10 microns)
trapped in nose or mucomuco-ciliary
escalator in tracheotracheo-bronchial tree
not retained (inhalable
(inhalable fraction)
0
z
Pilchard antigen concentration
1500
Cross-reactive
Cross-reactive allergens:
allergens: Pilchard
Pilchard and
and anchovy
anchovy
environmental
environmental antigen
antigen concentrations
concentrations in
in seafood
seafood
processing
processing workplaces
workplaces (n=198)
(n=198)
0
2000
4000
Anchovy antigen concentration
Fitted values
6000
8000
ng/m3
Jeebhay et al, Annals Occup Hyg, 49(5):423-37, 2005
2
MECHANISMS
MECHANISMS BY
BY WHICH
WHICH HBA
HBA
CAUSE
HEALTH
EFFECTS
CAUSE HEALTH EFFECTS
HAZARDOUS BIOLOGICAL AGENT
HEALTH
HEALTH EFFECTS
EFFECTS
OCCUPATIONAL
OCCUPATIONAL DISEASES
DISEASES DUE
DUE TO
TO
HBA
HBA
Microbial infection
1. Infectious material
2. Opportunist pathogens
3. Zoonoses
Allergic response
1. Micro-organisms
2. Proteinaceous material
3. Chemical compounds
Toxic response
1. Endotoxins (gram neg. bacteria)
2. Mycotoxins (fungi)
Carcinogenic
1. Wood dust
2. Mycotoxins (aflatoxin)
Examples
1. C. Tetanus, Leptospira
2. Legionella Pneumophilia
3. B. Anthracis, Brucella
Examples
1. Mould e.g. Aspergillus
2. Pollen, dust, animal secretions
3. Plicatic acid, gums, resins
Examples
1. Stored grain, hay, cotton, swine
and poultry confinement units
2. Stored fodder, grain, nuts
Examples
1. Hardwood (Beech, oak), Softwood
2. Stored nuts
INFECTIONS/ZOONOSIS
INFECTIONS/ZOONOSIS
OCCUPATIONAL DISEASES
Inhalation fever
(fever, myalgia, fatigue)
- Toxic pneumonitis
- Organic toxic dust syndrome
(fever, myalgia, headache, respiratory symptoms)
Infections (including zoonosis)
- Rhinitis, conjunctivitis, urticaria
- Asthma
- Asthma-like syndrome (acute functional respose)
- Contact irritant dermatitis
- Contact allergic dermatitis
- Protein contact dermatitis
Hypersensitivity pneumonitis
(extrinsic allergic alveolitis)
Carcinoma (eg. nasopharynx, liver, lung)
- Chronic bronchitis
- Chronic obstructive lung disease
Anthrax:
Anthrax:skin
skin“eschar”
“eschar”
Malaria
Malaria--mosquitoe
mosquitoebite
bite
EXTRINSIC
EXTRINSIC ALLERGIC
ALLERGIC ALVEOLITIS/
ALVEOLITIS/
HYPERSENSITIVITY
HYPERSENSITIVITY PNEUMONITIS
PNEUMONITIS
OCCUPATIONAL
ASTHMA
Allergy
Allergyto
toflour
flourdust:
dust:wheat,
wheat,rye,
rye,
corn
cornflour
flourallergens
allergensin
inaabaker
baker
3
SKIN
SKIN ALLERGY
ALLERGY
ENVIRONMENT:
ENVIRONMENT:
Dermatitis/eczema
Dermatitis/eczema
Urticaria/”bommels”/wheals
Urticaria/”bommels”/wheals
-- high
high risk
risk populations:
populations: multiple
multiple
exposures
exposures
-- route
route of
of exposure:
exposure: inhalation,
inhalation, direct
direct
skin
skin contact,
contact, (ingestion)
(ingestion)
-- dose
dose and
and duration
duration of
of exposure
exposure
Latex allergy prevalence studies in teaching
hospitals in the Western Cape
__________________________________________________________
Hospital
Overall latex
allergy (%)
prevalence
__________________________________________________________
Sheep
Sheepworkers:
workers:bacteria
bacteria
Health
Healthcare
careworkers:
workers:
--viruses/bacteria:
viruses/bacteria:
hepatitis,
HIV,
hepatitis, HIV,TB;
TB;
--allergens:
allergens:latex,
latex,drugs
drugs
Sewer
Sewerworkers:
workers:bacteria
bacteria
Number
surveyed
No. with
WRS
Groote Schuur,
Schuur, 2001
2300
712 (31%)
9%*
Red Cross, 2001
302
142 (47%)
5%
Tygerberg,
Tygerberg, 1999
250
180 (72%)
21%
________________________________________________________________________________________________________________________________
___________________________________________
___________________________________________________________________________________________________________________________________________________________________________
* 25% = latex +, 7% = asthma, 15% urticaria,
urticaria, 17% conjunctivitis
Potter, ACI, 2002
EPIDEMIOLOGICAL
EPIDEMIOLOGICAL STUDIES
STUDIES OF
OF
OCCUPATIONAL
OCCUPATIONAL ALLERGY
ALLERGY AND
AND ASTHMA
ASTHMA IN
IN
SOUTH
SOUTH AFRICAN
AFRICAN FOOD
FOOD INDUSTRIES
INDUSTRIES
Exposure group
SPT/
WRS Asthma
Specific agents
RAST +
Prevalence
Grain mill (n=111)
26%
23%
24%
17%
16%
11%
(Jeebhay et al, 2004)
15%
29%
7%
Vineyards (n=207)
23%
26%
7%
spider mite: Tetranychus
species
8-11%
47%
-
fungi: Alternaria sp. Mucor
sp., pollen (Dactylis sp.)
4%
32%
-
chicken feed, serum,
feathers, faeces
Fish processing (n=594) 7%
(Jeebhay et al, 2001)
9%
16%
3%
fish: pilchard, anchovy
fish parasite: Anisakis sp.
(Jeebhay et al, 1997)
Bakeries (n= 517)
(Jeebhay et al, 2002)
Maize farm (n= 101)
(van Niekerk et al, 1989)
Poultry farm (n=134)
(Rees et al, 1998)
grains: wheat and rye;
storage mites: Tyrophagus
sp; Lepidoglyphus sp.,
beetles: weevil, mealworm
cereal flours: wheat, rye,
alpha-amylase
Bird
Birdhandlers:
handlers:feathers,
feathers,droppings,
droppings,
mites,
mites,bacteria,
bacteria,volatile
volatileorganic
organic
compounds
compounds(e.g.
(e.g.ammonia)
ammonia)
4
Cotton
Cottonworkers:
workers:cotton
cottondust
dust
contaminated
contaminatedwith
withendotoxin
endotoxin
Fruit
Fruitfarm
farmworkers:
workers:spider
spidermite,
mite,
predator
predatormites,
mites,storage
storagemites,
mites,pollen
pollen
3
(Current
(CurrentOEL
OEL0.5
0.5mg/m
mg/m3))
Mites
Mites are
are major
major determinants
determinants of
of work-related
work-related
asthma
asthma symptoms
symptoms among
among table
table grape
grape farm
farm
workers
workers in
in the
the Western
Western Cape
Cape (n=207)
(n=207)
(Jeebhay
(Jeebhayet
etal,
al,Curr
CurrAllerg
AllergClin
ClinImmunoI,
ImmunoI,2003)
2003)
_________________________________________________________________________________________
Outcome
Predictor
Prevalence
Confidence
p-value
Odds Ratio
Interval
_________________________________________________________________________________________
Skin (urticaria)
Pesticide crop sprayers*
3.42
1.00 – 11.66
0.050
Ocular-nasal
Male gender
Pesticide crop sprayers*
House dust mite (SPT)*
1.93
3.49
3.17
1.01 – 3.72
1.31 – 9.31
1.37 – 7.33
0.048
0.012
0.007
Wheeze
Age
1.03
1.00 – 1.06
0.031
Spider mite (ELISA)*
5.78
1.75 – 19.05
0.004
Storage mite (RAST)*
2.39
1.02 – 5.59
0.044
_________________________________________________________________________________________
*Adjusted for age and gender
Grain
Grainharvesting
harvestingand
andmilling
milling
workers:
workers:grain
graindust,
dust,storage
storage
mites,
mites,beetles,
beetles,mealworm,
mealworm,mould
mould
3
(Current
(CurrentOEL
OEL10
10mg/m
mg/m3))
Grain
Grain mill
mill workers
workers can
can become
become sensitised
sensitised to
to aa
broad
broad spectrum
spectrum of
of allergens
allergens (n=106)
(n=106)
(Jeebhay
(Jeebhayet
etal,
al,Curr
CurrAllerg
AllergClin
ClinImmunoI,
ImmunoI,2005
2005))
45
Significant determinant of
work-related wheeze (OR:6.2)
40
35
30
25
20
15
10
High risk work processes associated with
exposure to sensitising agents in flour dust
in bakery workers
Storage mites
Grains
Cockroaches
Bread
Breaddough
doughmixing
mixing
Beetles
Mould
Dough
Doughhandling
handling
0
T. B.
Pu Tr
tr op
L. es ica
D ce lis
es nt
tr iae
uc
B
to
.G
r
P. e r m
A an
m
B e ic
. O ri a
rie can
nt a
al
S.
is
G
ra
na
T. ri
(m mo us
ea lit
lw or
o
W rm
he )
at
R
M
ye
ou
ld
m
ix
1
5
Cleaning/Sweeping
Cleaning/Sweeping
5
Flour
Flour dust
dust exposures
exposures among
among supermarket
supermarket
bakers:
bakers: proportion
proportion of
of inhalable
inhalable dust
dust samples
samples
3*
above
per job
job category
category (n=211)
(n=211)
above 0.5mg/m
0.5mg/m3*per
(Baatjies,
(Baatjies,Jeebhay
Jeebhayet
etal,
al,Curr
CurrAllerg
AllergClin
ClinImmunoI,
ImmunoI,2005
2005))
Prevalence
Prevalence of
of allergic
allergic sensitsation
sensitsation among
among
supermarket
supermarket bakers
bakers according
according to
to employment
employment
(Baatjies,
duration
(Baatjies,Jeebhay
Jeebhayet
etal,
al,2005
2005))
duration (n=517)
(n=517)
90
Prevalence of sensitisation by jobtitle for total population and
short and long duration of employment
80
45
40
60
50
35
40
Percentage
Percentage
70
30
20
10
0
Baker
Confectioner
Supervisor
Manager
Counterhand
Job title
30
Total
25
Less than 3 years
20
More than 3 years
15
10
5
0
Counterhand
Manager
Supervisor
Confectioner
Baker
*The American Conference of Government Industrial Hygienists (ACGIH) 8-hr TWA-OEL = 0.5mg/m3
Wheat allergen results 100% of samples above 0.2 µg/m3 (Houba R, 1998)
ROUTES
ROUTES OF
OF EXPOSURE
EXPOSURE AND
AND HIGH
HIGH RISK
RISK
WORK
WORK PROCESSES
PROCESSES IN
IN THE
THE SEAFOOD
SEAFOOD
INDUSTRY
INDUSTRY
Seafood category Sources of occupational exposure to seafood
product/s
Fishermen
Fishermenand
andfish
fishprocessing
processing
workers:
workers:fish
fishprotein
protein(blood,
(blood,guts,
guts,
muscle),
muscle),Anisakis
Anisakisparasite,
parasite,
fishmeal
fishmealdust
dust
- inhalation of wet aerosols from lobster "tailing",
crab "cracking", butchering and degilling, boiling,
prawn "blowing" (water jets, compressed air)
- dermal contact from unprotected handling of prawn;
hand immersion in water containing fish juice
Molluscs
Oysters, mussels
- inhalation of wet aerosols from oyster "shucking"
- dermal contact from unprotected handling
Finfish
Salmon, pilchard,
anchovy
- inhalation of wet aerosols from fish heading,
degutting, boiling
- inhalation of dry aerosols from fishmeal milling,
bagging
- dermal contact from unprotected handling
Jeebhay et al, Occup Env Med, 2001
Environmental exposures among fish
processors in the Western Cape (n=198)
(Jeebhay et al, Ann Occup Hyg 2005)
Work process Thoracic
particulate
conc.
GM(range)
(mg/m3)
Protein
conc.
Pilchard
antigen
conc.
GM(range) GM(range)
3
(ug/m )
(ng/m3)
Anchovy
antigen
conc.
GM(range)
(ng/m3)
Fishmeal
productn
Jetty, canning,
pick-ups,
stores
Admin, boiler,
labeling,
w/shop
0.447
(0-1.570)
0.504
(0-9.846)
0.118
(0-0.439)
0.064
(0-0.593)
220
(0-563)
132
(0-898)
456
(0-1485)
292
(0-795)
0.472
(0-7.725)
0.096
(0-1.150)
68
(0-68)
98
(0-128)
GM: geometric mean
Crustaceans
Crabs, prawns
Detection limit of antigen assay: 0.5 µg/ml
Dose-response
Dose-response relationship
relationship between
between pilchard
pilchard fish
fish
3
antigen
antigen exposures
exposures (log
(log ng/m
ng/m3)) and
and onset
onset of
of workworkrelated
related asthma
asthma symptoms
symptoms among
among fish
fish processors
processors
(n=594)
((Jeebhay
Jeebhayet
etal,
al,Ann
AnnOccup
OccupHyg
Hyg2005)
2005)
(n=594)
Pilchard antigen conc. at
time of onset of
symptoms
>30 (categ 2) vs <30 (cat 1)
>60 (categ 3) vs <30
>90 (categ 4) vs <30
Hazard
ratio
95% CI
2.25
2.20
2.47
1.06 – 4.75 0.034
1.03 – 4.69 0.042
1.15 – 5.31 0.021
Exposure entered as a time varying covariate (months)
Models adjusted for age (at start of employment), gender, atopy,
smoking status
pvalue
Probability: absence of work-related asthma
1.00
concat 1
concat 2
concat 3
0.75
concat 4
0.50
0.25
0.00
0
200
Time: months
400
600
6
MEASURING
MEASURING AND
AND INTERPRETING
INTERPRETING
EXPOSURE
EXPOSURE DATA
DATA FROM
FROM BIOLOGICALLY
BIOLOGICALLY
DERIVED
DERIVED AIRBORNE
AIRBORNE CONTAMINANTS
CONTAMINANTS
CATEGORY
Total culturable/countable bioaerosols
EXPOSURE
EXPOSURE ASSESSMENT
ASSESSMENT
Specific bioaerosols
Infectious agents
EXAMPLE
total bacteria, fungi,
pollen
Aspergillus fumigatus
Legionella Pneumophilia
Mycobacterium
tuberculosis
endotoxin, mycotoxin,
allergens, volatile
organic compounds
(ammonia, SO2, CO2,
ethanol)
Assayable biological contaminants
INTERPRETING
INTERPRETING EXPOSURE
EXPOSURE
MEASUREMENTS
MEASUREMENTS –– HCS
HCS STANDARDS
STANDARDS
ARE
ARE NOT
NOT PROTECTIVE
PROTECTIVE
AGENT
Cellulose
Cotton
Flour
Grain (oat, wheat, barley)
ACGIH TWA
10 mg/m3
0.2 mg/m3
0.5 mg/m3 (Inhal)
4 mg/m3
HCS OELS
0.5 mg/m3
10 mg/m3
Natural rubber latex (total protein)
0.001 mg/m3 (Inhal)
8 mg/m3CL
Nicotine
0.5 mg/m3
-
Pyrethrum
5 mg/m3
-
Rosin core solder (colophony)
Low as possible
-
Subtilisins (proteolytic enzymes)
0.00006 mg/m3STEL -
Starch/sucrose
10 mg/m3
-
Vegetable oil mists (metal working) 0.2 mg/m3
-
HOST
HOST FACTORS
FACTORS
-- atopy
atopy
-- smoking
smoking
-- genetic
genetic (e.g.
(e.g. HLA-type)
HLA-type)
Wood
0.5-1 mg/m3 (Inhal)
10 mg/m3
Endotoxins, (1-3)B,D-glucans
Under study
-
3
Relationship
Relationshipbetween
betweeninhalable
inhalabledust
dust(log
(logmg/m
mg/m3)/wheat
)/wheat
3
allergens
allergens(log
(logµgEQ/m
µgEQ/m3)) and
andallergic
allergicsensitization
sensitizationamong
among
Dutch
bakers
and
flour
mill
workers
according
to
Dutch bakers and flour mill workers according toatopic
atopicstatus
status
(Peretz
(Peretzet
etal,
al,Sc
ScJJWork
WorkEnv
EnvHealth,
Health,2005)
2005)
Table 3: The effect of smoking on sensitisation:
prevalence ratios and population attributable fractions
in 4 factories for all workers and for atopic workers
separately
PR
0.4
1.0
1.7
1.7
2.3
0.7
Total
1.1
95%CI
AFp
0.5-2.2
1.0-3.0
1.0-2.8
1.0-4.9
1.3%
15%
21%
42%
0.8-1.6
5.3%
0.6
Probability
Probability
0.3
0.8
Pine sawmill
Maize mill
Soybean plant
Fish plant
0.2
0.1
Atopic workers
0.5
0.4
0.2
0.1
0
-4
-3
-2
-1
0
1
2
3
4
Exposure levels to inhalable dust(logged)
Non-atopic
(n=193)
5
PR
95%CI
AFp
Pine sawmill
Maize mill
Soybean plant
Fish plant
1.2
1.3
2.4
1.8
0.4-3.6
0.8-2.1
1.3-4.4
0.6-4.8
6.5%
9.8%
75%
31%
Total
1.3
0.9-2.0
15%
0.3
0
-5
-4
-3
-2
-1
0
1
2
3
4
Exposure to inhalable dust (logged )
5
6
Atopic (n=77)
Rees D, Bartie D, Fox F, Jeebhay M, Mansoor N, Occ H SA, 2005
7
ACKNOWLEDGEMENTS
University of Cape
Town, South Africa
Andreas Lopata
Roslynn Baatjies
THANK YOU
Univ. of Washington, USA
Noah Sexias
Cape Peninisula Univ.
Technology, South
Africa
Raymond Beukes
Dashwill George
Emmanuel Rusford
BGFA, Ruhr Univ.
Bochum,
Bochum, Germany
Monika Raulf-Heimsoth
Ingrid Sander
Univ. of Michigan, USA
Thomas Robins
Xihong Lin
Tulane Univ., USA
Samuel Lehrer
Joshua Fernandez
Funded by:
- NIOSH R01 Grant
- MRC (South Africa)
- Fogarty
- ALLSA
IRAS, Univ. Utrecht, Neth.
Neth.
Dick Heederik
Gert Doekes
Hans Kromhout
Tim Meijster
8