Safeguarding the Immunocompromised through Indoor Air Quality

The quality of indoor air influences immune responses. Components like mould spores, pollutants, allergens, and irritants in the air can affect immune cell function, which can lead to respiratory issues, allergies, and other health issues.

Those with compromised immune systems are at greater risk from poor indoor air quality, as well as people over 65 years of age, infants and young children, pregnant women, and people with cardiovascular or respiratory health conditions, like asthma.

Maintaining optimal indoor air quality is essential for creating a healthier living space which helps to support our immune system defenses and promote overall well-being.

These cells form part of the immune system and help the body fight infections and other diseases. Immune cells develop from stem cells in the bone marrow to become different types of white blood cells. These include neutrophils, eosinophils, basophils, mast cells, monocytes, macrophages, dendritic cells, natural killer cells, and lymphocytes (B cells and T cells).

All cells of the immune system are created in the bone marrow from a common type of starting cell, called a stem cell. These stem cells later develop into specific cell types, including red blood cells, platelets (important for blood clotting), and white blood cells (important for immune responses).

The body is armed with an immune system and cells to help heal itself. These cells play a critical role in maintaining your health and wellbeing. Here's what they are and how they work:

Dendritic Cells

  • Part of the body's first line of defense against threats
  • Found in parts of the body that integrates between internal and external
    • Skin
    • Stomach
    • Lungs
  • Check the body for antigens

Innate Lymphoid Cells (ILC)

  • Aid in the body's response against helminth infections 
  • Recognize distressed cells 
  • Regulate inflammation

T Cells

  • Type of white blood cell
  • Scan the body for pathogens
  • Remembers pathogens encountered previously 
  • Eradicate infected cells, including cancer cells 
  • Activate other cells 
  • Assist other cells in the creation of antibodies
  • Cytotoxic T-can directly kill infected cells
  • T helper-assists B cells and memory B cells

Natural Killer (NK) Cells

  • Type of white blood cell that exhibits cytotoxic properties 
  • Aid in the body's response

Myeloid-derived Suppressor Cells (MDSC)

  • Natural immunosuppressant 

Expand during:

  • Infection 
  • Inflammation 
  • Cancer
  • Regulate T-cell, dendritic cell, and macrophage functions


  • Produced in bone marrow 
  • 150,000 to 450,000 platelets per microliter of blood
    • Low count increases bleeding vulnerability
    • High count causes stroke
  • Stop bleeding of blood vessel damage
  • Create clotting 
  • Help heal wounds

Red Blood Cells

  • Develop in the adult bone marrow and fetal liver 
  • Deliver oxygen to various body parts
  • Barriers against: Infections, Bacteria, Blood parasites 
  • Modulate immune system response



  • Precursors to T cells
  • Develop in the thymus 
  • Mature into T cells through thymopoiesis
  • Respond to foreign pathogens

B Cells (MDSC)

  • Essential components of the humoral immune response 
  • Develop in the bone marrow 
  • Contain a receptor protein called B cell receptors
    • Generate antibodies to specific antigens 
    • Initiate specific response to antigens



  • Type of white blood cell
  • Granules are present in their cytoplasms
  • Released during infections and allergic reactions 
  • Three types of granulocytes: 
    • Neutrophils - Release enzymes to kill ingested microorganisms 
    • Eosinophils - Regulate immune cell functions
    • Basophils - Release histamine when damaged



  • Bone marrow cell
  • 10 to 15 times bigger that the typical RBC
  • Essential for blood clotting


  • A type of white blood cell 
  • Differentiate into:Macrophages that engulf and digest pathogens and Dendritic cells

Just as immune cells are vital for defending our bodies against infections and diseases, the quality of the air we breathe indoors can significantly impact our well-being. Indoor air quality can affect our respiratory system, making it important to understand its components. 

Improving indoor air quality is essential for maintaining a healthy environment. Measures like proper ventilation, air filtration systems, and reducing indoor pollution sources can help ensure that the air we breathe inside our workplaces, public spaces and home residences supports our respiratory health, much like immune cells work to protect our bodies from diseases.

Safe indoor air from a serviced HVAC system means a lower particle count and less breathing difficulties for occupants of the building.