OVERVIEW OF INDUSTRIAL
HYGIENE
UNIVERSITY OF HOUSTON –
DOWNTOWN CAMPUS
BIOLOGICAL SAFETY
Discipline of Biosafety grew out of research
involving biological warfare agents at Fort Detrick
in Frederick, MD. The Chemical Warfare Service
was established by the US Army in 1941 and the
National Academy of Science formed a biological
warfare committee in 1942. Microbiologists from
ASM served as advisors.
Fort Detrick Biological Defense Research
Program formed the framework for the discipline
of biosafety.
BIOLOGICAL SAFETY
The responsibility of the biosafety professional,
infection
control
practitioner,
or
hospital
epidemiologist again shifts to include the task of
assessing the need for appropriate containment
for patients.
OSHA Bloodborne Pathogens (1991) developed
as a result of HIV in the 1980s, Hepatitis B
infection, etc..
The biosafety professional uses similar practices
to define and control workplace hazards re IH.
HAZARD IDENTIFICATION
Microorganisms are a diverse group of
microscopic
organisms that includes
bacteria, fungi, algae, protozoa, viruses, and
prions. Pathogenic or disease-producing
are a small portion of total microbials. Also,
fungi produce spores and mycotoxins.
Other biological agents such as pollen,
mites, urine proteins, animal dander, and
snake venoms broaden the scope of
biological hazards to consider.
MICROORGANISMS
- Prokaryotes – organisms in which DNA is
not physically separated from the cytoplasm;
small size (around 1 um in diameter) and
absence of a nuclear membrane.
- Eukaryotes – organisms containing a
membrane-bound nucleus; larger and
contain a membrane-bound nucleus and
organelles such as mitochondria.
- Four major groups of eukaryotes are
algae, protozoa, fungi, and slime molds.
- Viruses – totally dependent on hosts for
replication; smallest infectious agents.
- Viroids and Prions
INFECTION
Infection is a general term applied to the entry
and development of multiplication of an
infectious agent.
Further defined as an invasion of the body by
pathogenic microorganisms and the reaction of
the tissues to their presence and to the toxins
generated.
Normal flora can take advantage of a lowering
of host immunity to produce an infectious
disease.
Infectious disease is not always the end result
of exposure to and colonization by an
infectious agent; depends on the virulence of
the agent, the route of infection, and the
relative immunity and health of the host.
EPIDEMIOLOGY
Potential for work-associated infection.
Epidemiology methods provide the tools to
evaluate the extent and nature of worker
exposure.
Defining
the
event
or
illness/infection, determining the population at
risk, establishing the factors affecting exposure,
and developing intervention controls are all part
of the process to prevent occurrence or
recurrence of infections.
Sulkin and Pike; 4K+ infections with 168 deaths.
10 most frequently reported agents or diseases
for lab-acquired infections: brucellosis, Q fever,
hepatitis, typhold fever, tularemia, TB, etc.;
routes – percutaneous inoculation; aerosol
inhalation;
mucous
membrane
contact;
ingestion.
WORKPLACES
- Agricultural environments and
processing facilities;
- Microbiology, public health, clinical
labs;
- Hospital and Health Care facilities;
- Biotechnology facilities;
- Animal facilities and veterinary
practices; and,
- Miscellaneous.
RISK ASSESSMENT
 Modes of
Transmission
 Routes of Entry
 Infectious Dose
 Agent Viability and
Virulence
 Host Susceptibility
 Other Factors
BIOSAFETY CONTAINMENT
- CDC/NIH Guidelines for Microbiological
and Biomedical Laboratories.
Risk management is achieved through use
of practices, facilities, and equipment
specified in defined biosafety containment
levels. Biosafety practices are an important
part of a program to manage the risk of
exposure to potentially infectious agents.
- NIH Guidelines for Research involving
Recombinant DNA Molecules.
BIOSAFETY CONTAINMENT
LEVELS
- Biosafety Level 1 (BSL-1) – work with defined
and
well-characterized
strains
of
viable
microorganisms of no known or of minimal
potential hazard to lab personnel or the
environment.
- Biosafety Level 2 (BSL-2) – work with many
moderate-risk agents present in the community
(indigenous) and associated with human disease
of varying degrees of severity.
e.g. clinical, diagnostic, teaching, and other
research facilities with individual level of
competency
BIOSAFETY CONTAINMENT
LEVELS
- Biosafety Level 3 (BSL-3) – work with indigenous
or exotic agents where the potential for infection
by aerosols is real and the disease may have
serious or lethal consequences.
e.g. clinical diagnostic microbiology work when TB
or brucellosis is suspected, etc.
- Biosafety Level 4 (BSL-4) – work with dangerous
and exotic agents that pose a high individual risk
of life-threatening disease. Agents have a low
infectious dose and poses a danger for the
community from person-to-person spread.
e.g. stringent requirements such as a Class III
BSC, etc.
HAZARD CONTROL
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Containment
Facility Design
Safety Equipment
BSCs (Class I, II, III)
Work Practices
Decontamination
BIOSAFETY PROGRAM
MANAGEMENT
 Program Support
 Biosafety Specialist
 Institutional Biosafety
Committee
 Biosafety Manual
 Occupational Health Program
 Information and Education
TOPICS IN BIOSAFETY
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Bloodborne Pathogens
Hepatitis B and C Viruses
HIV
Tuberculosis
Bioterrorism
Legionellosis
Occupational Health Program
BRI vs. SBS