Transcript factores de riesgo biológico

SAMPLING FOR
CONTAMINANTS
OF BIOLOGICAL ORIGIN
PRESENTED BY
TOXIC MOLD! OH MY!
BIOLOGICAL
CONTAMINANTS
DEFINING THE ISSUE
BIOLOGICAL CONTAMINATION
As defined by ACGIH

Aerosols, gases and vapors of biological
origin of a type and concentration likely to
cause disease or predispose persons to
adverse health effects.
 Inappropriate levels indoors of bioaerosols
typically found outdoors.
 Biological growth indoors of particles that
may become airborne and have an adverse
effect on exposed individuals.
BIOLOGICAL CONTAMINANTS
AEROSOLS
Airborne particles of biological origin
bacteria, fungi, pollen, viruses
 and their by-products
endotoxins and mycotoxins
 and other fragments
insect parts and excreta, skin scales,
hair

BIOLOGICAL CONTAMINANTS
VAPORS



Fungi and bacteria in indoor environments produce
microbial volatile organic compounds or MVOCs as a
by-product of their metabolism.
The odors of MVOCs are good indicators of
microbial growth even when growth is not visible.
Knowledge is limited. MVOC research will attempt to
answer the questions:
What role do MVOCs play in health effects?
Do certain microorganisms produce a typical
MVOC fingerprint?
BACTERIA
FOUND IN THE WORKPLACE

Legionella bacteria can grow in water
systems including cooling towers and air
conditioners.
 Pseudomonas bacteria can grow in waterbased metal working fluids.
 Staphylococcus aureus including the
methicillin-resistant superbug (MRSA) can be
transmitted by direct skin-to-skin contact with
infected individuals.
BACTERIA BY-PRODUCTS



Gram-negative bacteria may contain harmful
substances in their outer membranes called
endotoxins.
Endotoxins are referred to as pyrogens as they will
induce fever. They will also cause respiratory distress
and even death at high levels.
In the workplace, the most common route of
endotoxin exposure is through inhalation of
aerosolized bacteria including Pseudomonas in
metalworking fluids.
ENDOTOXIN EXPOSURES

WORKPLACE
Can be found in
sewage treatment
plants, cotton textile
mills, fiberglass
production plants,
poultry/swine facilities,
and in industries using
metal-working fluids.

OTHER
Have been found in air
conditioning units, spa
water, and swimming
pools. They can also be
found on water damaged
material following a water
intrusion event.
FUNGI
THE USUAL SUSPECT IN IAQ

Primary biological contaminant implicated in
indoor air complaints.
 Fungi found most often in the indoor
environment include Penicillium, Aspergillus,
and Cladosporium.
 Described as saprophytic in that they can
grow on any nonliving organic material if
adequate moisture is present.
PRODUCES MYCOTOXINS

Mycotoxins are natural by-products of fungal
metabolism.
 They are produced by some species of
Aspergillus (versicolor), Fusarium
(moniliforme), and Stachybotrys (chartarum).
 Chemical structures and health effects of
mycotoxins are quite diverse.
MYCOTOXIN EXPOSURES
WORKPLACE
OTHER


Inhalation of
aerosolized fungal
spores or other fungal
structures in waterdamaged building
materials.
Ingestion of moldy
food products by
animals and people.
 Aflatoxin and
trichothecenes have
been found in moldcontaminated animal
feed and cereal grains.
BIOLOGICAL
CONTAMINANTS
WHO’S EXPOSED
WORKERS POTENTIALLY
EXPOSED TO BIOAEROSOLS
Agricultural Workers
 Grain Handlers
 Tobacco and Cotton
Handlers
 Farmers
 Livestock Producers
Food handlers and
processors
 Meat packing plants
 Poultry processors
WORKERS POTENTIALLY
EXPOSED TO BIOAEROSOLS
Industrial workers
 Pulp and Paper Mills
 Textile Mills
 Wastewater and
Sewage Treatment
Plants
 Machinists
 Industries with
cooling towers
WORKERS POTENTIALLY
EXPOSED TO BIOAERSOLS

Healthcare workers
 Military personnel
 Construction and
maintenance
personnel including
remediation workers
 Office workers in
humidified indoor air
BIOLOGICAL
CONTAMINANTS
HEALTH EFFECTS
SKIN INFECTIONS
Staph bacteria,
including MRSA, can
cause skin infections
that look like a pimple
or boil. Serious
cases can lead to
bloodstream infections
or pneumonia. Mold may
also induce skin infections
like ringworm or rashes.
EYE, NOSE, THROAT
IRRITATION
ACGIH reports that
most health
complaints in indoor
environments are due
to eye, nose and
throat irritation,
headache and fatigue
from unknown
causes.
Sick Building Syndrome
INHALATION FEVERS

HUMIDIFIER
FEVER
Flu-like symptoms that
arise 4-8 hours after
exposure and subside
within 24 hours. Possibly
related to endotoxins.

PONTIAC FEVER
A self-limited, flu-like
illness caused by
contamination of water
systems with
Legionella bacteria.
HYPERSENSITIVITY
DISEASES
Result from exposure
to specific antigens in
the environment that
trigger an
immunological
response.
Dust-mite and animal
allergens are common
causes in residences.
HYPERSENSITIVITY
DISEASES IN WORKPLACE

Hypersensitivity
pneumonitis
characterized by
acute, recurrent
pneumonia with
fever, cough, chest
tightness with
progression of
symptoms.

Building-related
asthma
characterized by
chest tightness,
wheezing, cough,
and shortness of
breath that is worse
on work days and
improves on
weekends.
INFECTIOUS DISEASES

Influenza (H1N1) and SARS-viral illnesses
 Legionnaires’ Disease-pneumonia caused by
Legionella pneumophila bacteria
contaminated water sources.
 Tuberculosis-lung disease caused by
Mycobacterium tuberculosis and spread from
person to person.
HEALTH EFFECTS
FROM MYCOTOXINS

Mycotoxins will
reduce the
effectiveness of the
immune system by
interfering with or
killing macrophages.

This results in
increased
susceptibility to
infectious diseases
and a reduction in
defense against
other contaminants.
WIDE-RANGING EFFECTS
FROM MYCOTOXINS

VASCULAR SYSTEM-increased vascular
fragility; hemorrhage
 DIGESTIVE SYSTEM-vomiting; intestinal
hemorrhage; liver effects
 RESPIRATORY SYSTEM-respiratory
distress; bleeding from lungs
 NERVOUS SYSTEM-tremors; lack of
coordination; depression, headache.
BIOLOGICAL
CONTAMINANTS
CONDUCTING AN
INVESTIGATION
ACGIH RECOMMENDS
A STEPWISE APPROACH
1.
2.
3.
4.
Gather information through occupant
interviews, surveys, and building
inspections.
Formulate a hypothesis on the cause of
the complaints/illness by using the
information gathered.
Test the hypothesis by collecting samples.
Make recommendations for controls by
using sampling data & professional
judgment.
INFORMATION GATHERING
OCCUPANT INTERVIEWS



Before embarking on
a program of air
measurements,
survey both the area
and the people
involved in the
complaint.
Use this time for
information gathering.
Look around. Listen.




Complaint vs noncomplaint areas.
Date when problem
was first noted.
Days or times when
problem is noted more
and less.
Seek input so you can
formulate a hypothesis
on the root cause of the
complaints.
INFORMATION GATHERING
BUILDING INSPECTION
Examine the physical
structure, maintenance
activities, and occupancy
patterns.
2.
Look for potential
sources of biological
contaminants and
evidence of water damage.
1.
BUILDING INSPECTION:
MOISTURE INDICATORS

Water marks on ceiling tiles and other
surfaces
 Visual presence of mold
 Musty smell of microbial VOCs
 White, powdery or crystalline substance on
the surface of concrete, plaster and masonry
which are soluble salts dissolved from the
building materials
BUILDING INSPECTION:
MOISTURE METERS

Used to survey
moisture in any nonconductive porous
material to which the
probes can be
applied.






Ceiling Tiles
Gypsum Board
Carpeting
Wood
Plaster
Concrete
MOISTURE METER
FROM SKC


Operates by measuring the
electrical conductance
between two probes
inserted into the material to
be tested.
Useful for construction or
renovation projects or other
situations when the test
surface can be punctured
by the probes.
SKC 753-006
DATA INTERPRETATION
MOISTURE METERS

Moisture levels can be compared from wall to
wall to determine where moisture intrusion is
occurring.
 Once the location of the moisture is found, an
investigation can be made as to the cause
and a control strategy can be developed.
DATA INTERPRETATION
MOISTURE


The Western Wood Products Association
(WWPA) has prepared a technical guide
on preventing and controlling mold in
lumber. See www.wwpa.org.
WWPA recommends that the moisture
content of the wood be kept below 20%.
DATA INTERPRETATION
MOISTURE


Greenguard Environmental Institute (GEI)
has received ANSI approval for a standard
covering the management of moisture
(and mold growth) during building
construction.
See www.greenguard.org
BUILDING INSPECTION:
HVAC SYSTEM CHECKS
OUTDOOR AIR SUPPLY

Inadequate amounts of outdoor air often
leads to building-related complaints and
health-related symptoms.
 Ensure outdoor air supply meets ASHRAE or
other appropriate standards.
BUILDING INSPECTION:
HVAC SYSTEM CHECKS
LOCATION OF AIR INTAKES

Air intakes on rooftops can draw in
bioaerosols from cooling towers, sanitary
vents, building exhausts and animal waste.
 Air intakes at street level can draw in
moisture, vehicle emissions, and odors.
BUILDING INSPECTION:
HVAC SYSTEM CHECKS
CONDITION OF AIR
FILTERS

HVAC filters are not
designed to protect
equipment or occupants
from heavily contaminated
air.
 Filters may themselves
promote the growth of
microorganisms if they
become damp.
BUILDING INSPECTION:
HVAC SYSTEM CHECKS
SUPPLY AIR

Ductwork should not be coated with
excessive debris. Dirt mixed with moisture
can support microbial growth.
 Ensure that cold air leaving a diffuser does
not produce condensation and the potential
for microbial growth.
CHOOSING A SAMPLING
METHOD TO TEST THE
HYPOTHESES
Data Interpretation
Tips
SAMPLING FOR BIOLOGICAL
CONTAMINANTS
WHY:




To test your
hypothesis on the
cause of the problem
To positively confirm
the absence/presence
of contaminant
To identify the type of
microbe
(genus/species)
To confirm the
effectiveness of
decontamination.
HOW:
 Bulk samples
 Surface samples
 Air samples
Followed by analysis
at a qualified
environmental
microbiology laboratory.
BULK SAMPLING

Portions of materials in the building can be
tested for mold or other biological
contaminants.
 Typical test materials include sections of
wallboard/wallpaper, carpet pieces, return-air
filters, duct lining, and settled dust.
 These are very useful as air sampling may
miss some contaminants due to temporal
variations.
BULK SAMPLING

Portions of the test material are typically
placed in a sealable plastic bag for transport
to the lab.
 In some cases, sterile jars for dry items or
sterile bottles for water or metalworking fluid
samples may be required.
 Settled dust can be collected using
conventional vacuum cleaners and a new
vacuum cleaner bag for each sample.
SURFACE SAMPLING
MICROVACUUM CASSETTES

Carpeting is an effective reservoir for fungal spores
and sampling this surface can reveal the history of
mold in the building.
 To sample fungal spores in carpeting, a vacuumstyle cassette is available with a 0.45 um
polycarbonate filter loaded into a 3-piece styrene
cassette with 2-inch tubing nozzle. Sample at
flows up to 16 L/min to vacuum a defined area.
 Work the inlet tube as deep as possible into the
carpeting to collect a good sample of the dust.
CARPET SAMPLING KIT
SKC 225-9540
DATA INTERPRETATION
CARPET SAMPLES
An 2003 AIHCE paper by MidWest
Microbiology gave some numerical guidelines
for fungal spores on surfaces like carpet using
microvacuum cassettes:
Normal- <5,000/1000 cm2
 Borderline- 25,000/1000 cm2
 Elevated- >75,000/1000 cm2

SURFACE SAMPLING
STERILE WIPES



A swab or filter wetted with
sterile water or wash
solution is used to wipe a
specified area.
Typically, the swab is then
used to inoculate an agar
plate for growth culture.
This technique is often
used for MRSA testing.
SKC 225-2402
DATA INTERPRETATION
SWAB SAMPLES
The November 2001 AIHA Synergist
guidelines for fungal spores in swab
samples:
Normal: <1,500 cfu/cm2
 Probable Contamination: >1,500 cfu/cm2

SURFACE SAMPLING
LIFT TAPE

Collected by placing clear adhesive or packing tape
or commercially available sampling strips onto a
surface and removing it with slow, steady force
 Following collection, the tape is attached to glass
slides and examined using light microscopy to view
mold spores.
SURFACE SAMPLING
LIFT TAPE ON A
SLIDE
 Flexible plastic
microscopic slides with
a sticky adhesive
sample area can be
used like lift tape.
 Press on the test
surface, place the slide
in the provided mailer
and send to a qualified
laboratory.
Stick-to-It Slides
SKC 225-9808/9
DATA INTERPRETATION
LIFT TAPE SAMPLES
The November 2001 AIHA Synergist
guidelines for fungal spores in tape
samples:

Normal: No significant fungal material or
biomass; 1-5% spores
 Probable Contamination: 25-100% spores
AIR SAMPLING:
WHY AND HOW
Air Sampling for
Like with chemical
sampling, air sampling Bioaerosols
for biological
contaminants is done
for the purpose of
evaluating actual
human exposures.
involves the use of:
 Impactors
 Filters or
 Liquid-based
(impinger-type)
devices
AIR SAMPLING
SPORETRAP CASSETTES

Easy, inexpensive screening device.
 Use with a pump at 15-30 L/min for up to 10
minutes.
 Spores impact onto a microscopic slide with a
sticky surface.
 Slide is stained and analyzed microscopically.
VERSATRAP CASSETTES
SKC 225-9820/1
AIR SAMPLING PUMPS
FOR USE WITH SPORETRAPS





Constant flows from
10-30 L/min
User selectable
sampling times
Lithium-ion battery
powered up to 4 hrs
Indefinite run time from
AC adapter
Optional sampling wand
SKC 228-9530
DATA INTERPRETATION
SPORE TRAPS

Spore trap analysis will
provide the total
number of spores and
the genus of the spores
found.

This information can

be used to compare the
complaint area to noncomplaint areas of the
building and to the
outdoors.
The genus of the spores
should be similar inside
and out.
The numbers should be
lower inside.

DATA INTERPRETATION
SPORE TRAPS
November 2001 AIHA Synergist guidelines for
Air samples:
Residential Buildings:
Normal: <5,000 spores/m3
Probable Contamination: >10,000 spores/m3
Commercial Buildings:
Normal: <2,500 spores/m3
Probable Contamination: >10,000 spores/m3
AIR SAMPLING
VIABLE CASCADE IMPACTOR




Specified in NIOSH
Methods 0800 and 0801
Used with a pump at 28.3
L/min for typical sample
times of 2-5 minutes
Bioaerosols impact onto
growth medium (agar).
Agar plates are shipped
to a microbiology laboratory
for growth culture.
SKC Biostage
225-9610/11
SKC BIOSTAGE
SAMPLER PREPARATION
SKC BIOSTAGE
WITH QUICKTAKE 30 PUMP
Sample Assurance Tip:
Impactor must be
cleaned with isopropyl
alcohol before each
use.
Evaluate blank
samples of agar plates.
AIR SAMPLING
FILTERS

Collection of bioaerosols is
achieved by passage of air through a
porous medium, typically a membrane
filter.
 Polycarbonate, mixed cellulose ester,
or polyvinyl chloride filters may be
used depending upon the application.
 Gelatin filters will help to maintain
viability by minimizing dehydration of
the microbes.
GELATIN FILTERS
WITH SKC BUTTON SAMPLER


An AIHA Journal article
reported that 25-mm
filters used with the
SKC Button Sampler
provided collection
efficiencies close to
100% for enumeration
of airborne spores.
SKC offers sterile
gelatin filters in 25 or
37-mm diameters.
(Cat. No. 225-9551/2).
SKC 225-360
INHALABLE SAMPLING
@ 4 L/min
VIABLE AIR SAMPLING
FILTERS



Filters, support pads
and cassettes should
be sterile.
Samples are collected
with a portable pump at
1-4 L/min for 5-30
minutes.
After sampling, the
material collected on
the filters is inoculated
onto agar plates.
AIR SAMPLING
COLLECTION INTO LIQUID


Bioaerosols are often
collected into a liquid
medium, typically a
dilute buffer solution or
mineral oil.
Portions of the
collection liquid can be
placed onto nutrient
agar and incubated or
analyzed using other
methods.
Biosampler
SKC 225-9595
ADVANTAGE: 8-hr sampling
OPERATION OF THE
BIOSAMPLER

Particle collection is achieved
by drawing the bioaerosols through
3 nozzles directed at an angle toward
the inner sampler wall.

The collection liquid swirls upward
on the inner surface and removes the
collected particles.
ANALYSIS OPTIONS





Growth culture
Microscopic
Bioassay
Immunoassay
PCR (using water
as collection media)
2 COMMON QUESTIONS
1.
Why is the Sonic Flow Pump required
for the Biosampler? Can we use the
QT30 instead?
2.
Can the Biosampler be used for PCR
(DNA based) analysis?
DATA INTERPRETATION
VIABLE AIR SAMPLES
November 2001 AIHA Synergist guidelines:
Residential Buildings:
Normal: <500 cfu/m3
Probable Contamination: >1,000 cfu/m3
Commercial Buildings:
Normal: <250 cfu/m3
Probable Contamination: >1,000 cfu/m3
AIR SAMPLING FOR MVOCs

Sorbent
Tubes/Pumps

Stainless Steel
Canisters
AIR SAMPLING FOR MVOCs

Photoionization
Detectors (ppb
RAE)

Man’s best friend
See
www.Mold-dog.com
DATA
INTERPRETATION
GENERAL GUIDELINES
WHAT ABOUT OELs?

Few established guidelines/standards for
biological contaminants except for wood dust,
cotton dust, etc.
 ACGIH indicates that a “general exposure
limit for concentrations or countable biological
agents is not scientifically supportable”.
1.
2.
3.
4.
Biological contamination typically is a complex
mixture of many types of microorganisms.
The health effects for various microorganisms vary
greatly between individuals.
There is no single sampling method that is
appropriate for all types of biological contamination.
There is insufficient scientific evidence to support a
dose-response relationship from which an exposure
standard could be derived.
ACGIH RECOMMENDS
“Gather the best data possible and use
knowledge, experience, expert opinion,
logic, and common sense to interpret
information, design control and
remediation strategies.”
GENERAL GUIDELINES
FOR DATA INTERPRETATION
1.
2.
Fungi found in indoor air should be the
same species as that found in outdoor air,
but the levels should be lower.
If there is a dominant fungal species in
indoor air that is not present in outdoor air, it
is probably growing from biological
contamination within the building and is
reducing air quality.
GENERAL GUIDELINES
FOR DATA INTERPRETATION
3.
4.
Comparisons of indoor/outdoor air or
problem/non-problem areas should be
made at the species level, not just at the
genus level.
Some species may be considered indicator
organisms indicating specific problems such
as E. Coli as an indicator of sewage
contamination.
GENERAL GUIDELINES
FOR DATA INTERPRETATION
5. In order to compare sampling results from
indoor/outdoor areas or from different zones,
an identical sampling protocol for each zone
including the sample media, sampling
duration, sampler type and laboratory
analysis is required.
HOW DO YOU KNOW WHEN YOU
HAVE FINISHED REMEDIATION?
1.
2.
3.
4.
5.
Water problem is fixed.
Moldy materials removed.
Mold similar in type/number inside and
outside.
No new growth or water damage.
No health problems on reentry.
THANK YOU FOR YOUR
ATTENTION!
YOU ARE NOW AN
OFFICIAL SKC
MOLDBUSTER!
SKC