Transcript Biological agents - EU-OSHA

Biological agents:
Need for
Occupational Exposure Limits (OELs)
and feasibility of OEL setting
Rafal Górny
Department of Biohazards
Institute of Occupational Medicine and Environmental Health
WHO Collaborating Centre
Sosnowiec
Poland
Biological agents (BA) – is it a problem?
 Epidemiological studies: in world scale a few hundred
million people are exposed to BA
 Putting non-occupational indoor environment aside,
exposure to BA is registered for 148 specialist work
professional groups in 22 main branches of industry
 Important issue for occupational medicine and public health
 Adverse health effects: allergic reactions, infections, toxic
reactions, and nonspecific symptoms
Biological agents at work
 bioaerosols - airborne transport of biological particles
 penetration of biological agents through the skin, mucous
membrane or with a bite of bloodsucker arthropoda
 less frequently through the alimentary tract (such way is
rather atypical for occupational infections)
Conditio sine qua non of proper hygienic regime of
occupational settings and health comfort is correct control
of worker exposure and control of crucial parameters
determining contamination of work environment by BA
Necessary needs
Elaboration of widely accepted guidelines, standards or
limit values enabling proper interpretation of environmental
situations or measurement results, at least
Evaluation criteria
Chemical/physical hazards
The higher concentration/intensity,
the longer time of exposure
  
the more severe health outcome
(body damage, occupational disease)

Biohazards
Unproportionality of human body
answer to risk factor
Lack of standards/limit values
 dose-response relationship is still indeterminate and
controversial in many aspects
 it is not possible to identify individual species of microorganisms
or other specific BA responsible for health effects (except some
common allergies attributed to specific agents or exposure)
 susceptibility as an individual feature of each organism
 source data regarding environmental/occupational
concentrations of biological agents are still insufficient
 lack of standardization of sampling methods (lack of standard
samplers) and experimental procedures (lack of commonly
approved criteria for assessing exposure to biological agents)
Status quo ante
Standards or limit values, if established, base on clinical
picture of disease caused by biological agent, taking into
account only presence of the reliable factor in some element
of the studied environment (qualitative approach)
Status praesens
Nevertheless, quantitative standards, reference or limit values
do exist to facilitate interpretation of measurement data
Strategy of hygienic standard elaboration
1.
ENVIRONMENT
INDOOR
DWELLINGS
OCCUPATIONAL ENVIRONMENT
INDUSTRIAL
2.
OUTDOOR
AIR
NONINDUSTRIAL
SURFACES
Quantitative standards/limit values
ARBITRARY
Concentration of biological agent,
which is acceptable or non-acceptable
Usually for total microbial flora, their
groups or certain species
Proposed by individual investigators,
expert groups or as a result of crosssectional/large-scale research study
Not related to the specific health
outcome (do not precise doseresponse relationship)
Often equal or close to the detection
level of particular analytical method
RELATIVE/COMPARATIVE
Usually based on simultaneously
measured concentration of
biological agent in indoor and
outdoor environments
If indoor/outdoor relationship is
below 1, it shows that hygienic
conditions of indoor environment
is good or acceptable
Identification of indoor sources of
biological agent(s)
Suitable for qualitative or
frequency of appearance
comparisons
Sampling method as immanent component
of proposed standard/limit value
To ensure the reliability of bioaerosol measurement methods and
their proper interpretation, in the first place, it is necessary to
unify the methodology, i.e., to recommend the use of proper
methods.
The active air sampling (e.g., volumetric methods) should allow
the measurement of a concentration of microorganisms and
describe their taxonomical origin.
Various technological and lifestyle recommendations and
guidance allow to control the work environment contaminated
with biological agents using a few different methods (e.g.,
„Recommended limits for microbiological monitoring of clean
areas for sterile processing” according to the EU’s Good
Manufacturing Practice (GMP) guideline)
History of standards for BA
Type of premises,
biological agent
Limit value proposal, author(s), year of
publication
Dwellings
Bacteria and fungi (CFU/l)
Bacteria (#/liter)
Total microorganisms (CFU/m3)
600
50
1,8103
- Carnelley et al.
- Bujwid
- Bourdillon et al.
(1887)
(1894)
(1941)
Occupational premises
4,3105
5104
5103-1104
- Donham et al.
- Erman et al.
- Malmros et al.
(1988)
(1989)
(1992)
1103
Gram-negative bacteria (CFU/m3) 2104
1103
- Clark
- Buyanov et al.
- Malmros et al.
(1985)
(1990)
(1992)
Fungi (CFU/m3)
1107
- Clark
(1985)
Endotoxins (µg/m3)
0,1
0,1-0,2
0,1-0,2
0,005
0,025
- Clark
- Rylander
- Malmros et al.
- DECOS
- Laitinen et al.
(1985)
(1987)
(1992)
(1998)
(1999)
Total microorganisms (CFU/m3)
Quantitative standard/limit value examples
CULTURABLE OR VIABLE EVALUATION STANDARDS FOR HOME & COMMERICAL BUIDLINGS
Governmental Bodies
1. Brazil
2. Canadian Mortgage and Housing Company (CMHC)
3. Commission of European Communities
4. Czech Republic
5. Finland
6. Netherlands and Research Institute
7. New York City Department of Health (NYCDH)
8. Nordic Council
9. Poland
10. World Health Organization (WHO) Trade Associations Indoor Air Quality Standard
11. American Conference of Governmental Industrial Hygienists
Trade Associations
12. American Industrial Hygiene Association
13. Indoor Air Quality Association (AIHA)
14. International Society of Indoor Air Quality and Climate (IAQA)
TOTAL SPORE EVALUATION STANDARDS GOVERNMENTAL BODIES
15. Russian Federation Standard
16. Texas Department of Health Trade Associations (TDH)
17. American Academy of Allergy, Asthma & Immunology
18. American College of Occupational and Environmental Medicine
CULTURABLE OR VIABLE SPORE LIMITS FOR MEDICAL DEVICE & PHARMACEUTICAL CLEAM ROOMS
Governmental Bodies
19. European Union Clean Room Standard
20. U. S. Pharmacopoeia clean room standard
Quantitative standard/limit value examples
Functional Grouping of Mold and Bacteria Standards
A. Permissible or Acceptable Exposure Levels
B. Action Levels (Warranting Investigation)
C. Ceiling Limit or IDLH Levels (Immediately dangerous to life and health)
D. Clearance Levels Exposure Guidelines (Post Remediation)
E. The Inside Versus Outside Concentration Rank Order Guidelines
F. Ceiling Limits for Hospitals & Other Susceptible Occupant Environments
G. Bacteria Standards
H. Application of the Standards - The Issue of Open Windows
Quantitative standard/limit value examples
Total bacteria: 1,0103 ÷ 7,0103 CFU/m3 for dwellings and nonoccupational indoor environment as well as ≤7,5102 ÷ 1,0107 CFU/m3
for occupational environment (in all these indoor spaces no safe level for
pathogens (0 CFU/m3)
Gram-neg. bacteria: 1,0103 ÷ 2,0104 CFU/m3 for occupational environment
Endotoxins: 0,005 ÷ 0,2 µg/m3 for occupational environment
Total fungi: 1,0101 ÷ 1,0104 CFU/m3 for dwellings and non-occupational
indoor environment as well as <1,0102 ÷ 1,0107 CFU/m3 for
occupational environment (in all these indoor spaces no safe level for
pathogens (0 CFU/m3)
Subtilisins: 0,06 µg/m3 for occupational environment
House dust allergens:
mite Der p I: 2,0 ÷ <15,0 µg/g
cat Fel d I: <1,0104 ng/g
dog Can f I: <1,0105 ng/g
Quantitative standard/limit value examples
Special environments, i.e., hospital premises and clean areas for
sterile processing: 1,0100 ÷ 4,0103 CFU/m3 and
<1,0100 ÷ 1,0103 CFU/m3
Clean areas for sterile processing: the microbial quality of the air is
accompanied by the control of a quality of the surfaces. The
proposed limits are as follows:
<1,0100 ÷ 4,0102 CFU/24 cm2, if concentration is related to
the surface (usually equal to the surface of Petri dish),
<1,0100 ÷ 2,0101 CFU/glow, if the certain quality of the
worker hands is required, or
3,23105 CFU/m2, if microorganisms sediment on the surface
within 1 week or
up to 106 CFU/g of dust, if the concentration is related to the
amount of settled dust
2000
Directive 2000/54/EC of the European Parliament and of the
Council of 18 September 2000 on the protection of workers
from risks related to exposure to biological agents at work.
Defines employers’ obligations in terms of the protection of
workers against risks to their health and safety, including the
prevention of such risks, arising or likely to arise from
exposure to biological agents at work
Annex III – Community classification (the list of classified BA)
Qualitative approach
„Life after... Directive 2000/54/EC”
European standards (EN) – Workplace atmospheres:
13098: Guidelines for measurement of airborne micro-organisms and endotoxin
14031: Determination of airborne endotoxins
14042: Guide for the application and use of procedures for the assessment of exposure to
chemical and biological agents
14583: Volumetric bioaerosol sampling devices – requirements and test methods
German standards (VDI) – Measurements of airborne microorganisms and
viruses in ambient air
4252: Active sampling of bioaerosols
4253: Culture based method for the determination of the concentrations of moulds in the air
4255: Bioaerosols and biological agents - Source of emissions and control measures - Overview
No way of interpretation of quantitative
results is given
2004
Establishment of
Biological Agents Expert Group
as a part of the Interdepartmental Commission
for Maximum Admissible Concentrations and
Intensities for Agents Harmful to Health in the
Working Environment
Central Institute for Labor Protection - NRI
Warsaw, Poland
Biological Agents Expert Group
Scientific approach
If a solid link between the concentration of
investigated parameters and resulting adverse
health effect cannot be effectively established,
then, based on the biological agent concentration
measurements, the reference values should
enable evaluation of the quality of the
environment, as well as determination of “what is
typical and acceptable” and “what is atypical or
not acceptable” for a specific type of setting
Polish proposals for OEL and PSLV/RLV
for bioaerosols (volumetric methods)
Limit value
Microbial agent
Industrial settings
polluted with organic dust
Public service and
residential buildings
100.000 CFU/m3 *
5.000 CFU/m3
Gram-negative bacteria
20.000 CFU/m3 *
200 CFU/m3
Thermophilic actinomycetes
20.000 CFU/m3 *
200 CFU/m3
Mesophilic bacteria
Fungi
BA from the risk group 3 & 4
Bacterial endotoxin
50.000 CFU/m3 *
0 CFU/m3
200 ng/m3 (2.000 EU/m3) *
5.000 CFU/m3
0 CFU/m3
5 ng/m3 (50 EU/m3 )
*) For respirable fraction the proposed limits should be twice as low, i.e.,
50000 CFU/m3 for total mesophilic bacteria, 10000 CFU/m3 for both Gramnegative bacteria and thermophilic actinomycetes, and 25000 CFU/m3 for fungi
Decision making when standards/limit
values are not available
 Understanding of the nature of phenomenon
and adequate measurement of biological agent
(usually in the air)
 Understanding and defining of health effects as
a result of such exposure
 Elaboration of the real hypothesis, which
should be tested