4.1 Introduction to Bioaerosols

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Do curso por The Hong Kong University of Science and Technology

Introduction to Indoor Air Quality

37 classificações

The Hong Kong University of Science and Technology

Introduction to Indoor Air Quality

37 classificações

Course Overview: https://youtu.be/LLVb4FOn4uU This course provides a basic knowledge of an emerging area – Indoor Air Quality (IAQ) in buildings. Learners will realize the importance of maintaining proper IAQ. Characteristics associated with indoor air contaminants (IAC) are demonstrated, such as • Particulate matters (PM2.5, PM10) • Radon • Volatile organic compounds (VOCs) • Asbestos • Bio-aerosols, and more Safe exposure levels, resulting health effects, measurement techniques, mitigate and control measures of these IAC are discussed. Other important areas related to IAQ such as building ventilation systems, indoor flow characteristics, sick building syndrome, and thermal comfort are also covered in this course.

Na lição

Bioaerosols and Asbestos

In the last module of course, we look into the two other major indoor air contaminants - Bioaerosols and Asbestos. Staying in a clean environment does not mean the environment is comfortable. "Thermal Comfort" is also an issue that we need to consider. We also look into "Thermal Comfort" in this module.

4.1 Introduction to Bioaerosols5:42

4.2 Sources of Bioaerosols3:36

4.3 Health Effects of Bioaerosols7:46

4.4 Measuring and Removing Bioaerosols6:15

Conheça os instrutores

Christopher Chao
Adjunct Professor
Department of Mechanical and Aerospace Engineering
Edwin Tso
Research Assistant Professor
Department of Mechanical and Aerospace Engineering

[MUSIC]

Hello everyone. In this video, we will introduce bioaerosols.

Bioaerosols are one type of particulate matter.

They are airborne particles, large molecules or volatile compounds that

are living, containing whole or parts of biological materials.

Composition of the bioaerosol particles in a place varies with sources and

environmental conditions.

Their sizes vary from less than 1 micron up to 100 microns.

Common bioaerosol particles found in indoor air are bacteria,

fungi, and viruses.

Bacteria are single-celled structures and

have no membrane to separate the nucleus material from other cell components.

Bacteria range in size from about 0.5 microns to 5 microns.

Bacteria usually form colonies that are composed of

millions of single cells and large enough to be visible.

You find bacteria everywhere, particularly in dusty,

dirty places inhabited by humans or animals.

Some bacteria are harmful, while some are beneficial to humans.

Mycobacterium tuberculosis, MTB,

is a type of bacteria that can cause disease.

It is the causative agent of tuberculosis - TB.

TB is one of the greatest modern health since it is highly contagious.

Single bacilli is capable of causing an infection in laboratory animals.

In an indoor environment, fungi refer to the group of

microorganisms whose cells have a membrane

separating the nuclear material from the rest of the cell protoplasm.

Fungi reproduce sexually and asexually, often with an abundance of spores,

or seeds, which can be carried in airstreams.

Fungi are ubiquitous in nature and inevitably enter buildings from

the outdoors to set up colonies wherever the conditions for growth are favorable.

Fungi need external organic food sources and water to survive.

They are very difficult to eradicate completely once established in a building.

There are various groups of fungi such as yeasts, rusts, mold, mildews, and smuts.

Alternaria is an example of fungi.

Alternaria does not cause any disease, but

can cause considerable distress to allergic patients.

It is known as a fungal allergen and is associated with Sick building syndrome.

Cladosporium is another example of fungi.

It is also a common indoor air contaminant.

You can find cladosporium on living and

dead plant materials and wet building materials.

It does not cause disease normally, but is associated with Sick building syndrome.

Viruses are the smallest among the microbe group.

Their size, shape, content, and activity vary significantly.

The size of a virus ranges from 0.02 micron to 0.3 micron.

Unlike other living cells, viruses do not contain enzymes that

can transform complex compounds to simpler substances for nutrition.

Therefore, viruses must rely on a host cell to live and reproduce.

Some viruses are transmitted from person to person by droplets in the air.

Orthomyxoviridae is an influenza virus that is highly contagious.

Influenza virus is transmitted from person to person,

mainly in droplets released by sneezing and coughing.

Influenza is a febrile disease of the respiratory tract and

periodically sweeps the world, sometimes causing tens of thousands,

and sometimes millions, of deaths.

Variola is a virus that can cause smallpox.

It is transmitted by direct contact, and

some evidence show, it can also be transmitted by airborne routes.

Variola is a pathogen that can lead to death, but

thanks to global vaccination, it has been eradicated.

To conclude, in this video, we introduced what bioaerosols are and

different types of bioaerosols, bacteria, fungi, and viruses, and their examples.

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