4 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 experience adverse health effectsInappropriate indoor levels of bioaerosols typically found outdoorsBiological indoor growth of particles that may become airborne and have an adverse effect on exposed individuals
5 BIOLOGICAL CONTAMINANTS AEROSOLS Airborne particles of biological originbacteria, fungi, pollen, virusesBy-productsendotoxins and mycotoxinsOther fragmentsinsect parts and excreta, skin scales, hair
6 BIOLOGICAL CONTAMINANTS VAPORS Fungi and bacteria in indoor environments produce microbial volatile organic compounds (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?
7 BACTERIA FOUND IN THE WORKPLACE Legionella bacteria can grow in water systems including cooling towers and air conditioners.Pseudomonas bacteria can grow in water-based metal working fluids.Staphylococcus aureus, bacteria including the methicillin-resistant superbug (MRSA), can be transmitted by direct skin-to-skin contact with infected individuals.
8 BACTERIA BY-PRODUCTSGram-negative bacteria may contain harmful substances in their outer membranes called endotoxins.Endotoxins are referred to as pyrogens because 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 found in metalworking fluids.
9 ENDOTOXIN EXPOSURES WORKPLACE OTHER Can be found in sewage treatment plants, cotton textilemills, fiberglassproduction plants,poultry/swine facilities,and in industries usingmetal-working fluidsOTHERHave been found in airconditioning units, spawater, and swimmingpools. They can alsobe found on waterdamaged materialfollowing a waterintrusion event
10 FUNGI THE USUAL SUSPECT IN IAQ Primary biological contaminant implicated in indoor air complaintsFungi found most often in the indoor environment include Penicillium, Aspergillus, and Cladosporium.Described as saprophytic because they can grow on any nonliving organic material if adequate moisture is present.
11 TOXIC MOLD 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.
12 MYCOTOXIN EXPOSURES WORKPLACE OTHER Inhalation of aerosolized fungal spores or other fungalstructures in water-damaged buildingmaterialsOTHERIngestion of moldyfood products byanimals and peopleAflatoxin andtrichothecenes havebeen found in mold-contaminated animalfeed and cereal grains.
18 SKIN INFECTIONS Staph bacteria, including MRSA, can cause skin infectionsthat look like a pimpleor boil. Seriouscases can lead tobloodstream infectionsor pneumonia. Mold mayalso induce skin infectionslike ringworm or rashes..
19 EYE, NOSE, AND THROAT IRRITATION ACGIH reports thatmost healthcomplaints in indoorenvironments are dueto eye, nose, andthroat irritation,headache, and fatiguefrom unknowncauses.Sick Building Syndrome
20 INHALATION FEVERS HUMIDIFIER FEVER PONTIAC FEVER Flu-like symptoms thatarise 4 to 8 hours afterexposure and subsidewithin 24 hours. Possiblyrelated to endotoxinsPONTIAC FEVERA self-limited, flu-likeillness caused bycontamination of watersystems withLegionella bacteria
21 HYPERSENSITIVITY DISEASES Result from exposureto specific antigens inthe environment thattrigger animmunologicalresponseDust-mite and animalallergens are common causes in residences.
22 HYPERSENSITIVITY DISEASES IN THE WORKPLACE Hypersensitivity pneumonitis characterized by acute, recurrent pneumonia with fever, cough, chest tightness, and a progression of symptomsBuilding-related asthma characterized by chest tightness, wheezing, coughing, and shortness of breath that is worse on work days and improves on weekends
23 INFECTIOUS DISEASES Influenza (H1N1) and SARS - viral illnesses Legionnaires’ Disease - pneumonia caused by Legionella pneumophila bacteria contaminated water sourcesTuberculosis - lung disease caused by Mycobacterium tuberculosis and spread from person to person
24 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.
25 WIDE-RANGING EFFECTS FROM MYCOTOXINS VASCULAR SYSTEMIncreased vascular fragilityHemorrhageDIGESTIVE SYSTEMVomitingIntestinal hemorrhageLiver effectsRESPIRATORY SYSTEMRespiratory distressBleeding from lungsNERVOUS SYSTEMTremorsLack of coordinationDepressionHeadache
26 BIOLOGICAL CONTAMINANTS CONDUCTING AN INVESTIGATION
27 ACGIH RECOMMENDS A STEPWISE APPROACH 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 and professional judgment.
28 INFORMATION GATHERING OCCUPANT INTERVIEWS Before embarking on a program of air measurements, survey the area and the people involved in the complaint.Use this time for information gathering.Look around and listen.Complaint vs non-complaint areasDate when problem was first notedDays or times when problem is noted more and lessSeek input to formulate a hypothesis on the root cause of the complaints.
29 INFORMATION GATHERING BUILDING INSPECTION Examine the physical structure, maintenance, and occupancy patterns.Look for potential sources of biological contaminant and evidence of water damage.
30 BUILDING INSPECTION MOISTURE INDICATORS Water marks on ceiling tiles and other surfacesVisual presence of moldMusty smell of microbial VOCsWhite, powdery, or crystalline substance on the surface of concrete, plaster, and masonry, which are soluble salts dissolved from the building materials
31 BUILDING INSPECTION MOISTURE METERS Used to survey moisture in any non-conductive, porous material to which the probes can be appliedCeiling TilesGypsum BoardCarpetingWoodPlasterConcrete
32 MOISTURE METERS FROM SKC ECONOMY MODELOperates by measuring the electrical conductance between two probes inserted into the test materialUseful for construction, renovation projects, or other situations when the test surface can be punctured by the probesSKC Cat. No
33 MOISTURE METERS FROM SKC PINLESS MODELMeasures resistance between two low-frequency signals transmitted from conductive pads without the need for insertion into the test material.Specialty models available for testing concreteSKC Cat. Nos /102
34 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.
35 DATA INTERPRETATION MOISTURE METERS The Western Wood Products Association (WWPA) has prepared a technical guide on preventing and controlling mold in lumber.SeeWWPA recommends that the moisture content of the wood be kept below 20%.
36 DATA INTERPRETATION MOISTURE METERS Greenguard Environmental Institute (GEI) has received ANSI approval for a standard covering the management of moisture (and mold growth) during building construction.See
37 BUILDING INSPECTION HVAC SYSTEM CHECKS OUTDOOR AIR SUPPLYInadequate amounts of outdoor air often leads to building-related complaints and health-related symptoms.Ensure outdoor air supply meets ASHRAE or other appropriate standards.
38 BUILDING INSPECTION HVAC SYSTEM CHECKS LOCATION OF AIR INTAKESAir 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.
39 BUILDING INSPECTION HVAC SYSTEM CHECKS CONDITION OF AIRFILTERSHVAC filters are not designed to protect equipment or occupants from heavily contaminated air.Filters may promote the growth of microorganisms if they become damp.
40 BUILDING INSPECTION HVAC SYSTEM CHECKS SUPPLY AIRDuctwork 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.
41 CHOOSING A SAMPLING METHOD TO TEST THE HYPOTHESES Data Interpretation Tips
42 SAMPLING FOR BIOLOGICAL CONTAMINANTS WHY:To test your hypothesis on the cause of the problemTo positively confirm the absence/presence of contaminantTo identify the type of microbeGenus/speciesTo confirm the effectiveness of decontaminationHOW:Bulk samplesSurface samplesAir samplesFollowed by analysisat a qualifiedenvironmentalmicrobiology laboratory
43 BULK SAMPLINGPortions 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 because air sampling may miss some contaminants due to temporal variations.
44 BULK SAMPLINGPortions 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.
45 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.Sample fungal spores in carpeting using a vacuum-style cassette.0.45 µm polycarbonate filter loaded into a 3-piece styrene cassette with 2-inch tubing nozzleSample 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.
47 DATA INTERPRETATION CARPET SAMPLES An 2003 AIHCE paper by MidWestMicrobiology gave some numerical guidelinesfor fungal spores on surfaces like carpet usingmicrovacuum cassettes:Normal - < 5000/1000 cm2Borderline - 25,000/1000 cm2Elevated - 75,000/1000 cm2
48 SURFACE SAMPLING STERILE WIPES A swab or filter wetted with sterile water or wash solution is used to wipe a specified area.The swab is then used to inoculate an agar plate for growth culture.This technique is often used for MRSA testing.SKC Cat. No
49 DATA INTERPRETATION SWAB SAMPLES The November 2001 AIHA Synergistguidelines for fungal spores in swabsamples:Normal: < 10,000 cfu/in2 or < 1500 cfu/cm2Probable Contamination: > 10,000 cfu/in2 or > 1500 cfu/cm2
50 SURFACE SAMPLING LIFT TAPE Collected by placing clear adhesive, packing tape, or commercially available sampling strips onto a surface and removing it with slow, steady forceFollowing collection, the tape is attached to glass slides and examined using light microscopy to view mold spores.
51 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 SlidesSKC Cat. Nos /9
52 DATA INTERPRETATION LIFT TAPE SAMPLES The November 2001 AIHA Synergistguidelines for fungal spores in tapesamples:Normal: No significant fungal material or biomass1 to 5% sporesProbable Contamination: 25 to 100% spores
53 AIR SAMPLING WHY AND HOW Air Sampling forBioaerosolsInvolves the use of:ImpactorsFiltersLiquid-based (impinger-type) devicesLike with chemicalsampling, air samplingfor biologicalcontaminants is donefor the purpose ofevaluating actualhuman exposures.
54 AIR SAMPLING SPORE TRAP CASSETTES Easy, inexpensive screening deviceUse with a pump at 15 to 30 L/min for up to 10 minutes.Spores impact onto a microscopic slide with a sticky surface.Slide is stained and analyzed microscopically.
56 AIR SAMPLING PUMPS FOR USE WITH SPORE TRAPS Constant flows from10 to 30 L/minUser selectable sampling timesLithium-ion battery powered up to 4 hoursIndefinite run time from AC adapterOptional sampling wandSKC Cat. No
57 DATA INTERPRETATION SPORE TRAPS Spore trap analysis will provide the total number of spores and the genus of the spores found.Information can be used to compare the complaint area to non-complaint areas of the building and outdoors.Genus of the spores should be similar inside and outside.Numbers should be lower inside.
59 AIR SAMPLING VIABLE CASCADE IMPACTOR Specified in NIOSH Methods 0800 and 0801Used with a pump at 28.3 L/min for typical sample times of 2 to 5 minutesMold impacts onto growth medium (agar)Agar plates are shippedto a microbiology laboratory for growth cultureSKC BiostageCat. Nos /11
61 SKC BIOSTAGE WITH QUICKTAKE 30 PUMP Sample Assurance Tip:Impactor must be cleaned with isopropyl alcohol before each useEvaluate blank samples of agar plates
62 AIR SAMPLING FILTERSCollection of microorganisms 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 spores.
63 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. Nos /2)SKC Cat. NoINHALABLE SAMPLING at 4 L/min
64 VIABLE AIR SAMPLING FILTERS Filters, support pads and cassettes should be sterile.Samples are collected with a portable pump at 1 to 4 L/min for 5 to 30 minutes.After sampling, the material collected on the filters is inoculated onto agar plates.
65 AIR SAMPLING COLLECTION INTO LIQUID Pumps are used to pull mold spores into glass impingers filled with a liquid collection 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.BioSamplerSKC Cat. NoADVANTAGE: 8-hour sampling
66 OPERATION OF THE BIOSAMPLER Particle collection is achievedby drawing the aerosol through3 nozzles directed at an angletoward the inner sampler wall.The collection liquid swirls upwardon the inner surface and removesthe collected particles.
72 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.”
73 WHY??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 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.
74 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.”
75 GENERAL GUIDELINES FOR DATA INTERPRETATION 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.
76 GENERAL GUIDELINES FOR DATA INTERPRETATION 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.
77 GENERAL GUIDELINES FOR DATA INTERPRETATION 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.
78 CONTROL AND REMEDIATION OF MICROBIAL CONTAMINATION
79 GENERAL CONTROL RECOMMENDATIONS Within 24 to 48 hours after floods or leaks, dry materials and discard sewage-contaminated materials.Have an effective drainage plan to prevent penetration of rain, snow, and groundwater through materials.The relative humidity of an air-conditioned building should not exceed 60%.
80 GENERAL CONTROL RECOMMENDATIONS Install appropriate insulation to prevent large temperature differences between air and surfaces.Maintain and inspect HVAC components such as filters and drain pans to avoid accumulation of water or debris.Pay close attention to the location of the outside air intake. Air intakes should be as far as possible from cooling towers, standing water, bird droppings, and vehicle emissions.
81 MOST IMPORTANT ISSUES IN REMEDIATION Identify the conditions that contributed to microbial growth in the building.Determine if mold is an allergen or a toxin for appropriate remediation steps.
82 TO REMOVE EXISTING CONTAMINATION Vacuum with high-efficiency filters.Discard materials with “extensive” microbial growth.Surface areas greater than 3 m2Wash with a dilute biocide (such as a 1:10 dilution of bleach) and with detergent followed by thorough drying.
83 TO REMOVE EXISTING CONTAMINATION Soda BlastingSimilar to sandblasting, but the sodamaterial will notdamage buildingmaterials
84 HOW DO YOU KNOW WHEN YOU HAVE FINISHED REMEDIATION? Water problem is fixedMoldy materials removedMold similar in type/number inside and outsideNo new growth or water damageNo health problems on re-entry
85 ESSENTIAL REFERENCESField Guide for the Determination of Biological Contaminants in Environmental SamplesBy AIHABioaerosols: Assessment and ControlBy ACGIH
86 THANK YOU FOR YOUR ATTENTION! YOU ARE NOW ANOFFICIAL SKCMOLDBUSTER!SKC
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