BioAerosols: Living or Dead, These Biological Pollutants Are Nothing to Sneeze At

flu virus, bacteria, mold spores, pollen, dander, and dust mites are common bioaerosols



List of Airborn Pathogens and BioAerosols

Many components of bioaerosols such as biological allergens and toxins are being inhaled by you every day. Can your immune system take it?

Airborne Pathogen

Group

Disease

Status

Source

Size microns

Parvovirus B19

VIRUS

fifth disease, anemia

Contagious

Humans

0.022

Rhinovirus

VIRUS

colds

Contagious

Humans

0.023

Coxsackievirus

VIRUS

colds

Contagious

Humans

0.027

Echovirus

VIRUS

colds

Contagious

Humans

0.028

Hantavirus

VIRUS

Hantavirus

Non Contagious

rodents

0.06

Togavirus

VIRUS

rubella (German measles)

Contagious

Humans

0.063

Reovirus

VIRUS

colds

Contagious

Humans

0.075

Adenovirus

VIRUS

colds

Contagious

Humans

0.08

Orthomyxovirus - Influenza

VIRUS

flu

Contagious

Humans, birds

0.1

Coronavirus

VIRUS

colds

Contagious

Humans

0.11

Morbillivirus

VIRUS

measles (rubeola)

Contagious

Humans

0.12

Varicella-zoster

VIRUS

chickenpox

Contagious

Humans

0.16

Arenavirus - Junin

VIRUS

hemmorhagic fever

Contagious

rodents

0.18

Arenavirus - Machupo

VIRUS

hemmorhagic fever

Contagious

rodents

0.18

Arenavirus - Lassa

VIRUS

Lassa fever

Contagious

rodents

0.18

Filovirus - Marburg

VIRUS

hemmorhagic fever

Contagious

rodents

0.18

Parainfluenza

VIRUS

flu

Contagious

Humans

0.22

Respiratory Syncytial Virus

VIRUS

pneumonia

Contagious

Humans

0.22

Poxvirus - Variola

VIRUS

smallpox (extinct)

Contagious

Humans

0.23

Poxvirus - Vaccinia

VIRUS

cowpox

Non Contagious

Agricultural

0.23

Monkeypox

VIRUS

monkeypox

Contagious

Monkeys

0.23

Paramyxovirus

VIRUS

mumps

Contagious

Humans

0.23

Francisella tularensis

BACTERIA

tularemia

Non Contagious

wild animals

0.2

Bordetella pertussis

BACTERIA

whooping cough

Contagious

Humans

0.25

Mycoplasma pneumoniae

BACTERIA

pneumonia

Contagious

Humans

0.25

Chlamydia pneumoniae

BACTERIA

pneumonia, bronchitis

Contagious

Humans

0.3

Chlamydia psittaci

BACTERIA

psittacosis

Non Contagious

Birds

0.3

Klebsiella pneumoniae

BACTERIA

opportunistic infections

Endogenous

Environmental

0.4

Haemophilus influenzae

BACTERIA

meningitis

Contagious

Humans

0.43

Coxiella burnetii

BACTERIA

Q Fever

Non Contagious

Cattle, sheep

0.5

Pseudomonas aeruginosa

BACTERIA

opportunistic infections

Contagious

Environmental

0.57

Pseudomonas pseudomallei

BACTERIA

opportunistic infections

Non Contagious

Environmental

0.57

Actinomyces israelii

BACTERIA

actinomycosis

Endogenous

Humans

0.6

Legionella parisiensis

BACTERIA

pneumonia(?)

Non Contagious

Environmental

0.6

Legionella pneumophila

BACTERIA

LD, Pontiac fever

Non Contagious

Environmental

0.6

Cardiobacterium

BACTERIA

opportunistic infections

Endogenous

Humans

0.63

Alkaligenes

BACTERIA

opportunistic infections

Endogenous

Humans

0.75

Yersinia pestis

BACTERIA

pneumonic plague

Contagious

Rodents

0.75

Pseudomonas cepacia

BACTERIA

nonrespiratory airborne(?)

Non Contagious

Environmental

0.77

Pseudomonas mallei

BACTERIA

opportunistic infections

Non Contagious

Environmental

0.77

Enterobacter cloacae

BACTERIA

nonrespiratory airborne(?)

Contagious

Humans

0.8

Enterococcus

BACTERIA

nonrespiratory airborne(?)

Contagious

Humans

0.8

Neisseria meningitidis

BACTERIA

meningitis

Endogenous

Humans

0.8

Streptococcus faecalis

BACTERIA

nonrespiratory airborne(?)

Contagious

Humans

0.8

Streptococcus pyogenes

BACTERIA

scarlet fever, pharyngitis

Contagious

Humans

0.8

Mycobacterium kansasii

BACTERIA

cavitary pulmonary

Non Contagious

unknown

0.86

Mycobacterium tuberculosis

BACTERIA

TB

Contagious

Humans

0.86

Streptococcus pneumoniae

BACTERIA

pneumonia, otitis media

Contagious

Humans

0.9

Staphylococcus aureus

BACTERIA

opportunistic infections

Endogenous

Humans

0.95

Staphylococcus epidermis

BACTERIA

nonrespiratory airborne(?)

Endogenous

Humans

0.95

Corynebacteria diphtheria

BACTERIA

diptheria

Contagious

Humans

1

Clostridium tetani

BACTERIA

nonrespiratory airborne(?)

Non Contagious

Environmental

1

Haemophilus parainfluenzae

BACTERIA

opportunistic infections

Endogenous

Humans

1

Moraxella lacunata

BACTERIA

opportunistic infections

Endogenous

Humans

1

Bacillus anthracis

BACTERIA

anthrax

Non Contagious

Cattle, sheep

1.13

Mycobacterium avium

BACTERIA

cavitary pulmonary

Non Contagious

Environmental

1.2

Mycobacterium intracellulare

BACTERIA

cavitary pulmonary

Non Contagious

Environmental

1.2

Acinetobacter

BACTERIA

opportunistic infections

Endogenous

Environmental

1.25

Moraxella catarrhalis

BACTERIA

opportunistic infections

Endogenous

Humans

1.25

Serratia marcescens

BACTERIA

opportunistic infections

Endogenous

Environmental

1.25

Saccharomonospora viridis

ACTINOMYCETES

Farmer's Lung

Non Contagious

Agricultural

0.6

Thermomonospora viridis

ACTINOMYCETES

Farmer's Lung, HP

Non Contagious

Agricultural

0.6

Micropolyspora faeni

ACTINOMYCETES

Farmer's Lung

Non Contagious

Agricultural

0.69

Thermoactinomyces sacchari

ACTINOMYCETES

bagassosis, HP

Non Contagious

Agricultural

0.7

Micromonospora faeni

ACTINOMYCETES

Farmer's Lung

Non Contagious

Agricultural

1

Thermoactinomyces vulgaris

ACTINOMYCETES

Farmer's Lung, HP

Non Contagious

Agricultural

1

Nocardia asteroides

ACTINOMYCETES

nocardiosis

Non Contagious

Environmental

1.14

Nocardia brasiliensis

ACTINOMYCETES

pulmonary mycetoma

Non Contagious

Environmental

1.5

Nocardia caviae

ACTINOMYCETES

nocardiosis

Non Contagious

Environmental

1.5

Phialaphora parasitica

FUNGI

allergic alveolitis

Non Contagious

Environmental

1.5

Phialaphora repens

FUNGI

allergic alveolitis

Non Contagious

Environmental

1.5

Exophiala jeanselmei

FUNGI

humidifier water

Non Contagious

Environmental

1.95

Phialaphora hoffmannii

FUNGI

allergic alveolitis

Non Contagious

Environmental

2

Phialaphora richardsiae

FUNGI

allergic alveolitis

Non Contagious

Environmental

2

Pneumocystis carinii

Protozoa

pneumocystosis

Non Contagious

Environmental

2

Phialaphora mutabilis

FUNGI

allergic alveolitis

Non Contagious

Environmental

2.15

Acremonium spp.

FUNGI

allergic alveolitis

Non Contagious

Environmental

2.5

Trichoderma harzianum

FUNGI

allergic alveolitis

Non Contagious

Environmental

2.65

Oidiodendron tenuissimum

FUNGI

allergic alveolitis

Non Contagious

Environmental

2.75

Geomyces pannorum

FUNGI

allergic alveolitis

Non Contagious

Environmental

3

Histoplasma capsulatum

FUNGI

histoplasmosis

Non Contagious

Environmental

3

Paecilomyces variotii

FUNGI

allergic alveolitis

Non Contagious

Environmental

3

Wallemia sebi

FUNGI

allergic alveolitis

Non Contagious

Environmental

3

Emericella nidulans

FUNGI

allergic alveolitis

Non Contagious

Environmental

3.25

Phoma spp.

FUNGI

allergic alveolitis

Non Contagious

Environmental

3.25

Penicillium brevicompactum

FUNGI

allergic alveolitis

Non Contagious

Environmental

3.3

Penicillium chrysogenum

FUNGI

allergic alveolitis

Non Contagious

Environmental

3.3

Penicillium citreonigrum

FUNGI

allergen(?)

Non Contagious

Environmental

3.3

Penicillium commune

FUNGI

allergic alveolitis

Non Contagious

Environmental

3.3

Penicillium corylophilum

FUNGI

allergic alveolitis

Non Contagious

Environmental

3.3

Penicillium cyclopium

FUNGI

allergen(?)

Non Contagious

Environmental

3.3

Penicillium expansum

FUNGI

allergic alveolitis

Non Contagious

Environmental

3.3

Penicillium freii

FUNGI

allergen(?)

Non Contagious

Environmental

3.3

Penicillium glabrum

FUNGI

allergic alveolitis

Non Contagious

Environmental

3.3

Penicillium hordei

FUNGI

allergen(?)

Non Contagious

Environmental

3.3

Penicillium olsonii

FUNGI

allergic alveolitis

Non Contagious

Environmental

3.3

Penicillium polonicum

FUNGI

allergic alveolitis

Non Contagious

Environmental

3.3

Penicillium rugulosum

FUNGI

allergen(?)

Non Contagious

Environmental

3.3

Penicillium solitum

FUNGI

allergen(?)

Non Contagious

Environmental

3.3

Aspergillus flavus

FUNGI

aspergillosis

Non Contagious

Environmental

3.5

Aspergillus fumigatus

FUNGI

aspergillosis

Non Contagious

Environmental

3.5

Aspergillus niger

FUNGI

aspergillosis

Non Contagious

Environmental

3.5

Aspergillus versicolor

FUNGI

aspergillosis

Non Contagious

Environmental

3.5

Absidia corymbifera

FUNGI

zygomycosis

Non Contagious

Environmental

3.75

Coccidioides immitis

FUNGI

coccidioidomycosis

Non Contagious

Environmental

4

Trichoderma viride

FUNGI

allergic alveolitis

Non Contagious

Environmental

4.05

Rhizomucor pusillus

FUNGI

allergic alveolitis

Non Contagious

Environmental

4.25

Aureobasidium pullulans

FUNGI

allergic alveolitis

Non Contagious

Environmental

5

Candida albicans

FUNGI

nonrespiratory airborne(?)

Non Contagious

Environmental

5

Chaetomium globosum

FUNGI

allergic alveolitis

Non Contagious

Environmental

5.5

Cryptococcus albidus

FUNGI

allergen(?)

Non Contagious

Environmental

5.5

Cryptococcus laurentii

FUNGI

allergen(?)

Non Contagious

Environmental

5.5

Cryptococcus neoformans

FUNGI

cryptococcosis

Non Contagious

Environmental

5.5

Stachybotris atra

FUNGI

allergic alveolitis

Non Contagious

Environmental

5.65

Stachybotris chartarum

FUNGI

allergic alveolitis

Non Contagious

Environmental

5.65

Eurotium amstelodami

FUNGI

allergic alveolitis

Non Contagious

Environmental

5.75

Eurotium herbariorium

FUNGI

allergic alveolitis

Non Contagious

Environmental

5.75

Eurotium rubrum

FUNGI

allergic alveolitis

Non Contagious

Environmental

5.75

Scopulariopsis brevicaulis

FUNGI

onychomycosis

Non Contagious

Environmental

6

Scopulariopsis fusca

FUNGI

onychomycosis

Non Contagious

Environmental

6

Sporothrix schenckii

FUNGI

sporotrichosis

Non Contagious

Environmental

6.5

Botrytis cinera

FUNGI

allergic alveolitis

Non Contagious

Environmental

7

Mucor plumbeus

FUNGI

mucormycosis

Non Contagious

Environmental

7.5

Rhizopus stolonifer

FUNGI

zygomycosis

Non Contagious

Environmental

8

Cladosporium cladosporioides

FUNGI

chromoblastomycosis

Non Contagious

Environmental

9

Cladosporium herbarum

FUNGI

chromoblastomycosis

Non Contagious

Environmental

9

Cladosporium sphaerospermum

FUNGI

chromoblastomycosis

Non Contagious

Environmental

9

Fusarium culmorum

FUNGI

allergic alveolitis

Non Contagious

Environmental

11.5

Fusarium graminearum

FUNGI

allergic alveolitis

Non Contagious

Environmental

11.5

Fusarium moniliforme

FUNGI

allergic alveolitis

Non Contagious

Environmental

11.5

Fusarium solani

FUNGI

allergic alveolitis

Non Contagious

Environmental

11.5

Fusarium sporotrichioides

FUNGI

allergic alveolitis

Non Contagious

Environmental

11.5

Helminthosporium

FUNGI

allergic alveolitis

Non Contagious

Environmental

12.47

Blastomyces dermatitidis

FUNGI

blastomycosis

Non Contagious

Environmental

14

Rhodoturula glutinus

FUNGI

allergic alveolitis

Non Contagious

Environmental

14

Rhodoturula minuta

FUNGI

allergic alveolitis

Non Contagious

Environmental

14

Rhodoturula mucilaginosa

FUNGI

allergic alveolitis

Non Contagious

Environmental

14

Alternaria alternata

FUNGI

allergic alveolitis

Non Contagious

Environmental

14.39

Ulocladium botrytis

FUNGI

allergic alveolitis

Non Contagious

Environmental

15

Ulocladium chartarum

FUNGI

allergic alveolitis

Non Contagious

Environmental

15

Paracoccidioides brasiliensis

FUNGI

paracoccidioidomycosis

Non Contagious

Environmental

18.25

Epicoccum nigrum

FUNGI

allergen(?)

Non Contagious

Environmental

20



Mold, dust mites, fungi, spores, and pollen:
Bioaerosols in the human environment

What are bioaerosols?

A healthy indoor environment is important to you and your family. This includes keeping the air free of biological contaminants, which can cause health problems. Scientists call these airborne contaminants bioaerosols.

Bioaerosols are extremely small living organisms or fragments of living things suspended in the air. Dust mites, molds, fungi, spores, pollen, bacteria, viruses, amoebas, fragments of plant materials, and human and pet dander (skin which has been shed) are some examples. They cannot be seen without a magnifying glass or microscope.

Can bioaerosols cause health problems?

They can cause severe health problems. Some, like viruses and bacteria, cause infections (like a cold or pneumonia). Others cause allergies. Both allergic responses and infections may be serious or even fatal.

An allergic reaction occurs when a substance provokes formation of antibodies in a susceptible person. We call substances which will cause an allergic reaction in some people antigens or allergens. Bioaerosols may cause allergic reactions on the skin or in the respiratory tract. Rashes, hay fever, asthma (tightness in the chest, difficulty in breathing), and runny noses are common allergic reactions.

A few people develop a severe allergic reaction in the lung, which can destroy lung tissue. This is called hypersensitivity pneumonitis. It is not an infection, but repeated episodes can lead to infections of the lung, such as bacterial pneumonia.

Hypersensitivity pneumonitis can be triggered by exposure to very small amounts of the allergen, once a person is sensitive to it. Symptoms can range from tightness in the chest, cough, and difficulty in breathing, to low-grade fever, muscle aches, and headaches.

What are sources of bioaerosols in the home?

Molds, mildews, bacteria, and dust mites like the same conditions that we do--warmth and moderate to high humidity. They need little more than a constant moisture supply for survival. You may find bacteria, molds, and mildews in air conditioning equipment, humidifier reservoirs, dehumidifier drip pans, shower heads, toilets, and ice machines. Water damaged carpets, ceiling panels, walls, and paneling are prime sites for new growth if they are allowed to stay damp. When molds, mildew, dust mites, and bacteria are disrupted or release their spores into the air, this results in bioaerosol formation.

Molds and mildews develop from spores, which are in the air all around you. As soon as spores settle in an area with the right conditions for growth, they establish colonies, which are often visible to the naked eye. These colonies are a source of more spores, can cause unsightly stains, and may release low levels of toxic chemicals called mycotoxins into the air.

Humidifiers are such a common source of bioaeorsols that cause health problems that doctors now use the term humidifier fever. Protozoa, amoebas, and strains of bacteria have been found in humidifiers, and these are readily released into the air with the moisture produced by humidifiers. These have ben linked to allergic responses in sensitive people.

Mold and mildew may be found in the ductwork of your heating or cooling systems. If there are leaks in the ductwork, or places where moisture and outside air get into the system, mold and mildew can grow. Sometimes they are found in the coils of an air conditioner or in the connection between the unit and the ductwork. Moisture problems are worse where ductwork insulation is on the inside as opposed to the outside of the duct. The insulation's porous surface collects dust and moisture. Mold and mildew may also grow on dirty furnace and air conditioning filters. Plumbing leaks and dampness in attics, basements, and crawl spaces can increase humidity inside your home and promote the growth of agents that will be released as bioaerosols. Bathrooms without outside-vented exhaust fans, combustion appliances like kerosene space heaters, drying laundry indoors, and venting clothes dryers to attics or crawl spaces can also increase the humidity levels in your home.

Dust mites and their waste products are the most common allergens in indoor air. Dust mites eat human and pet skin (dander) as it is shed. It has been estimated that we shed about seven million cells per minute! Dust mites live in rugs and carpets, sheets, mattresses and pillows, and upholstered furniture. Ten to 15 percent of people are allergic to dust mites. Of the people who have other allergies, 40 percent are also allergic to dust mites.

What measures can be taken to control bioaerosols in the home?

First, lower the relative humidity in your home, basement or crawl space, and attic. Relative humidity is the amount of moisture in the air at a given temperature. The humidity fluctuates in your home, depending on:

·         How warm or cool the air is indoors.

·         How many moisture-producing activities (drying clothes indoors, showers) are taking place.

·         Whether there is a constant source of moisture (leaks, damp foundations and attics).

·         How much moisture is being vented to the outside.

If you can keep relative humidity below 50 percent, you can reduce problems with dust mites, mold, and mildew. A hygrometer can be used to measure indoor humidity levels. You can buy a hygrometer from some nursery or garden stores, and from hardware stores.

There is little medical research supporting the use of a humidifier, so try to avoid using one. If your home is extremely dry and you must use a humidifier, a steam vaporizer or warm mist humidifier causes fewer problems. Do not humidify indoor air to a relative humidity level higher than 50 percent.

Ultrasonic and cool mist (impeller-type) humidifiers can send microorganisms from their water tanks into the air. Ultrasonic humidifiers use sound vibrations to create a cool mist. Impeller humidifiers create a cool mist by means of a high-speed rotating disk. If you do use a humidifier:

·         Empty the tank, wipe all surfaces dry, and refill the water in portable humidifiers each day.

·         Clean portable humidifiers every third day. Unplug the humidifier before cleaning and follow the manufacturer's recommendations on the use of cleaning agents or disinfectants.

If you have no specific instructions on cleaning your humidifier, use a 3 percent solution of hydrogen peroxide. Never use the humidifier with any of the cleaning agent or disinfectant in the tank. Rinse the tank thoroughly several times with tap water to keep cleaning or disinfecting chemicals out of the air.

How can I control the causes of bioaerosols?

Molds, mildew, and dust mites are the most common causes of problems in the home. These bioaerosols can be controlled relatively easily.

Molds and Mildews

·         Reduce relative humidity.

·         If you find mold or mildew in your home, try to find and eliminate sources of moisture, such as plumbing leaks.

·         Dry the air. Use a chemical or mechanical dehumidifier. Empty collecting (drip) pan daily.

·         Open closet doors to allow air to circulate. Use a 40-watt light bulb to dry and heat air in closets.

·         Vent bathrooms and clothes dryers to the outside.

·         Do not use humidifiers.

·         Trim back trees and shrubs around the house to reduce shade.

·         Remove debris from your yard, roof, and gutters.

·         Clean mold and mildew growth from walls with water mixed with chlorine bleach, diluted three parts water to one part bleach. Commercial products can also remove mildew and mold. Follow product instructions carefully. Very moldy items should be replaced.

·         Change heating and cooling system filters monthly.

·         Vacuum air return covers or screens regularly.

·         Check air conditioners for mold before each cooling season and have coils cleaned as needed.

·         Have heating/cooling system ductwork checked for loose insulation, leaks, or signs of condensation where the system enters the house. Insulate ducts on the outside of the ductwork.

·         Air cleaners and filters are other options. Electronic and hePA (high efficiency particulate absolute) cleaners and filters are best at taking mold, mildew, and dust out of the air.

·         Make sure that crawl space vents work and are not blocked. If your cooling ductwork runs through the crawl space, consider closing crawl space vents during summer cooling months.

·         Using vent fans in crawl spaces during the summer when humidity is high may increase the relative humidity in the crawl space and inside the home. Use fans only when outside humidity is well below 50 percent.

·         Mechanical dehumidifiers reduce humidity in basements, but they should not be used in crawl spaces when vents are open.

·         Heating/cooling contractors or duct cleaning firms can clean the ductwork in your home to reduce mold and mildew growth.

Duct cleaning may involve compressed air-washing, vacuuming and/or scrubbing of duct surfaces. Some firms advertise disinfectants and sealants to prevent further fungal growth. It is uncertain whether these processes are appropriate for most homes. Have microbial contamination verified by an industrial hygienist or other environmental testing agency before sanitizing products are used in your ductwork. Commercial fogging or misting agents should not be used because of possible health problems from breathing these chemicals. Use of a sealant in the ductwork is generally not appropriate unless the mold, mildew, or dust source has been removed.

Dust Mites

It is not known how well any single measure controls dust mite populations. However, it is known that effective mite control requires that relative humidity be maintained below 50 percent. In addition, since you spend about a third of each day in your bedroom, concentrate your efforts there.

·         Wash sheets, pillowcases, and mattress covers frequently in hot soapy water. If someone in your family is allergic to dust mites, buy special vinyl covers for the pillow and mattress.

·         Ordinary vacuuming does not remove or reduce mite populations. Mites are so tiny that they pass through the vacuum cleaner bag. High-efficiency filters for vacuum cleaners may be used in place of conventional filters.

·         Remove stuffed animals and objects that collect dust. If carpeting is used, short-pile is best.

·         Some new products may help reduce dust mite populations. Ask your doctor about control solutions for upholstered furniture and bedding.

SUMMARY

Bioaerosols, such as mold, mildew, and dust mites, are commonly found in indoor air. Control measures include reducing sources of moisture, reducing the relative humidity, and removing materials which contribute to the growth of these agents. Make your house a healthier house. Check periodically for moisture problems and maintain the air handling systems and filters.

Definition of Terms

Allergens -- medical term for foreign proteins that cause allergic reactions in susceptible individuals
Biocides -- chemicals or processes that kill living cells
Dander -- skin and hair fragments shed by humans and other animals
Disinfection -- process of killing disease-causing organisms
Dust Mites -- microscopic organisms that feed on human and animal dander
Hygrometer -- instrument used to measure relative humidity
Mycotoxins -- toxic substances produced by fungi
Sanitizing -- process to reduce the number of disease-causing organisms

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