December 2023

PM found indoors includes particles that come from outdoor air and particles that are generated indoors. In residential environments, EPA notes that it is often generated by:

• Cooking;
• Some cleaning activities;
• Combustion activities – such as burning candles; use of fireplaces, unvented space heaters, and kerosene heaters; and by smoking tobacco or other products;
• Biological contaminants – such as animals, pests, plants and mold;
• Printers; and
• Indoor chemical reactions.

EPA also states that indoor dust is settled PM from a variety of sources that may contain:

• Outdoor soil and dust that has been blown or tracked indoors;
• Biological particles, also known as biological contaminants, including pollen, mold spores, pet dander, dust mites, and human skin flakes and hair;
• Particles from human activities, such as cooking, cleaning and burning candles;
• Particles from consumer and personal care products;
• Plastics, flame retardant and pesticides; and
• Sometimes industrial chemicals and heavy metals, such as lead.

“In the work environment, exposure to particulate matter that includes hazardous materials, such as crystalline silica, lead, asbestos or any of the many regulated substances, could result in debilitating diseases and even death,” said Zahid Iqbal, MPH, CIH and Technical Director at Clark Seif Clark (CSC). “This is why there are state and federal regulations to mitigate occupational exposure to so many substances. At CSC, we utilize advanced laboratory analyses, highly sensitive field instrumentation and decades of expertise to identify potential exposure concerns in all types of built environments. This allows our professionals to design plans to mitigate exposure hazards, train workers on respiratory protection and provide ongoing monitoring, safeguard building occupants, and steer companies and institutions towards regulatory compliance.”

CSC also recently sponsored an educational video about common sources of indoor particulate matter that can be seen below: 

To learn more about this or other indoor air quality, industrial hygiene, environmental, health and safety services, please:

Reducing Building Occupant Exposure to Microorganisms and Minerals from Humidifiers

Heated and dry air inside of homes, offices, schools and other indoor environments during the cold winter months can cause physical discomfort to building occupants. People may suffer from dry nose, throat, lips and skin. Additionally, the dry air can also cause static electricity, peeling wallpaper, and cracks in paint and furniture.

To reintroduce moisture into the air to help alleviate these conditions, HVAC engineers can turn to a number of different building humidifier options. In buildings where these system are not operating properly, or do not exist, people often turn to portable humidifiers to create a more comfortable environment.

A word of caution regarding the use of portable humidifiers, the U.S. Environmental Protection Agency (EPA) warns that excess moisture in the air can encourage the growth of biological organisms. These organisms include dust mites, which are microscopic animals that produce materials causing allergic reactions, and mold. EPA also states that microorganisms often grow in humidifiers equipped with tanks containing standing water. Breathing air containing these contaminants could cause respiratory issues.

The Consumer Product Safety Commission (CPSC) has even released a Safety Alert about how dirty humidifiers may cause health problems. In it, CPSC reports that breathing dirty mist may cause lung problems ranging from flu-like symptoms to serious infections. CPSC also reports that humidifiers can release minerals into the air that will settle as fine white dust. These particles are small and can easily enter the lungs.

“Unclean humidifiers are a perfect breeding ground for disease-causing microorganisms. Bacteria like Legionella pneumophila, which causes Legionnaires disease and Pontiac fever, can proliferate and then be dispersed as humidifiers aerosolize water droplets that can then be readily inhaled,” said Derrick A. Denis, Vice President of Indoor Environmental Quality for Clark Seif Clark (CSC). “With a 10% fatality rate in the general population and a 40% fatality rate in healthcare, Legionnaires disease is a significant risk to human health. Other pathogens are similarly bred and spread by these devices unless they are regularly and vigilantly maintained, cleaned and sanitized.”

Helping clients optimize indoor environmental conditions in residential, commercial and institutional properties are the building science and indoor air quality professionals at CSC. They provide the expertise to create comfortable indoor environments all year long. They also identify and mitigate exposure risks to a wide range of microbial and chemical contaminants. CSC has even sponsored an educational video with tips to reduce the dispersal of microorganisms and minerals from humidifiers that can be seen below:

To learn more about this or other indoor air quality, building science, environmental, health and safety services, please visit www.csceng.com, email csc@csceng.com or call (800) 807-1118.