shopify
analytics tool
Global Indoor Health Network 

Health Effects

Health Effects
Global Indoor Health Network - Health effects of indoor air pollution
There are many different types of contaminants in our indoor environments, and research shows these contaminants can cause a wide variety of health effects. 

Contamination in water-damaged buildings is a very complex situation that can result in multi-symptom, multi-system health problems.

There are thousands of articles, studies, books and papers available on this topic.  We have numerous research papers, reports by government agencies and other reports posted on our website.

A few of the key statements and conclusions regarding the health effects are provided below. 


From the 2016 UNICEF report:


The UNICEF report highlights the significant impact of indoor and outdoor pollution on children and emphasizes the urgent need for countries to take action now. They say it very succinctly with the comment “the impact is commensurately shocking."

Children breathe twice as quickly as adults, and take in more air relative to their body weight. Their respiratory tracks are more permeable and thus more vulnerable. Their immune systems are weaker. Their brains are still developing.

Pollutants don't only harm children's developing lungs, they can actually cross the blood brain barrier and permanently damage their developing brains and, thus, their futures. No society can afford to ignore air pollution.

Ultrafine, airborne pollutants -- caused primarily by smoke and fumes -- can more easily enter and irritate children’s lungs, causing and exacerbating life-threatening disease. Studies show these tiny particles can also cross the blood-brain barrier, which is less resistant in children, causing inflammation, damaging brain tissue, and permanently impairing cognitive development. They even can cross the placental barrier, injuring the developing fetus when the mother is exposed to toxic pollutants.

From a 2016 World Health Organization report:


"Air pollution continues to take a toll on the health of the most vulnerable populations – women, children and the older adults," adds Dr. Bustreo. "For people to be healthy, they must breathe clean air from their first breath to their last."

From the 2009 World Health Organization report:


WHO Guidelines for Indoor Air Quality: Dampness and Mould

Indoor air pollution--such as from dampness and mould, chemicals and other biological agents--is a major cause of morbidity and mortality worldwide.

Many of the health effects may result from recurrent activation of immune defence, leading to exaggerated immune responses and prolonged production of inflammatory mediators. Overproduction of these compounds damages the surrounding tissues and may manifest itself as chronic inflammation and inflammation-related diseases, such as asthma.

From the Executive Summary:

Exposure to microbial contaminants is clinically associated with respiratory symptoms, allergies, asthma and immunological reactions. 

Toxicological evidence obtained in vivo and in vitro supports these findings, showing the occurrence of diverse inflammatory and toxic responses after exposure to microorganisms isolated from damp buildings, including their spores, metabolites and components.

From the Introduction, page 1:

Exposure to microbial contaminants is clinically associated with respiratory symptoms, allergies, asthma and immunological reactions.

From the Introduction, page 5:

Mechanisms of injury include exposure to Beta-glucans, toxins, spores, cell fragments and chemicals followed by immune stimulation, suppression and autoimmunity as well as neurotoxic effects.

From Chapter 2:

Mycotoxins, or fungal toxins, are low-relative-molecular-mass biomolecules produced by fungi, some of which are toxic to animals and human beings. Mycotoxins are known to interfere with RNA synthesis and may cause DNA damage.

From a report by Dr. Ruth Etzel:

What the Primary Care Pediatrician Should Know about Syndromes Associated with Exposures to Mycotoxins

Mycotoxins can have protean manifestations; the symptoms depend on the specific toxin or mixture of toxins, the age, sex, and diet of the child, the dose, and whether exposure is by ingestion, inhalation, skin and mucosal exposure, or a combination of two or more of these routes.  The most well-characterized presentations among infants and children are summarized in Table 2 under four headings: vomiting illness, bone marrow failure, acute pulmonary hemorrhage, and recurrent episodes of apnea and/or pneumonia.


From a report by Jack Thrasher, Ph.D.:

The Biocontaminants and Complexity of Damp Indoor Spaces: More Than What Meets the Eyes

Exposure of occupants mainly results from inhalation and, to a lesser extent, skin absorption and ingestion.  Molds produce mycotoxins during rapid growth.  At low concentrations, they cause mycotoxicosis in humans and animals. The mycotoxins causing disease include aflatoxins, ochratoxin A, trichothecenes, citreviridins, fumonisins and gliotoxins.  Mycotoxins can regulate the immune system up or down as well as inhibit synthesis of protein, RNA and DNA.  Moreover, they can form DNA adducts, protein adducts and cause oxidative stress as well as mitochondrial directed apoptosis.

Toxic encephalopathy involves multiple symptoms, including loss of balance, recent memory decline, headaches, lightheadedness, spaciness/disorientation, insomnia, loss of coordination.

From the 1989  report by the Massachusetts Special Legislative Commission on Indoor Air Pollution:

The Commonwealth of Massachusetts, Special Legislative Commission on Indoor Air Pollution: Indoor Air Pollution in Massachusetts

The Commission's efforts confirm the seriousness of the indoor air pollution health threat, which worsened with the energy conservation efforts of the 1970s.  More insulation and tighter construction led to lower ventilation rates and build-up of contaminants.  Many 'sick' buildings have been identified where occupants suffer severe or recurring discomforts such as headaches, dizziness, fatigue, eye irritation, and respiratory problems.  Other conditions attributable to indoor air contaminants include: cancer; bronchitis; pneumonia; heart, circulatory and respiratory problems; impaired vision; skin rash; chemical sensitivity; birth defects; and mental, nervous and immunological disorders.
From a 2016 report by United Kingdom's Royal College of Physicians:


In this report, they discuss the impact of indoor air pollution and also mention new indoor air pollutants that need to be considered such as advanced materials and three-dimensional printing.

The multiplicity of contaminants can make it more problematic to determine the precise source of an exposure-triggered illness and more difficult for epidemiologists to quantify cases. However, the report estimates indoor air pollutants “cause, at a minimum, several thousands of deaths per year in the U.K., and associated with healthcare costs in the order of tens of millions of pounds.”

In the report, they estimate that 40,000 deaths per year are attributable to outdoor air pollution, with an annual cost of 20 billion pounds. And, they also include information about indoor air pollutants (including radon, tobacco smoke, carbon monoxide, lead, nitrogen dioxide, particulate matter, PCBs, VOCs, formaldehyde, asbestos, kitchen products, faulty boilers, open fires, fly sprays, air fresheners, biological materials, mould, etc.).

"When our patients are exposed to such a clear and avoidable cause of death, illness and disability, it is our duty as doctors to speak out."

From a November 12, 2016, article about the effects of indoor and outdoor pollution in India:


Studies across the world and also in India prove that outdoor and indoor air pollution is a serious environmental risk factor that causes or aggravates acute and chronic diseases and has been identified as the fifth highest cause of morbidity in India.

Four kids could be dying every hour in UP (Uttar Pradesh ) of pneumonia caused by respirable suspended particulate matter (PM) 1, 2.5 and 10, which form a large part of the air we breathe. Alarmingly, the number adds up to 104 deaths per day and 38,000 a year.

From a report by Dr. Harriet Ammann:

Is Indoor Mold Contamination a Threat to Health? 

Health effects from exposures to molds in indoor environments can result from allergy, infection, mucous membrane and sensory irritation and toxicity alone, or in combination.

Mycotoxins are nearly all cytotoxic, disrupting various cellular structures such as membranes, and interfering with vital cellular processes such as protein, RNA and DNA synthesis.
  • Vascular system (increased vascular fragility, hemorrhage into body tissues, or from lung, e.g., aflatoxin, satratoxin, roridins).
  • Digestive system (diarrhea, vomiting, intestinal hemorrhage, liver effects, i.e., necrosis, fibrosis: aflatoxin; caustic effects on mucous membranes: T-2 toxin; anorexia: vomitoxin.
  • Respiratory system: respiratory distress, bleeding from lungs e.g., trichothecenes.
  • Nervous system, tremors, incoordination, depression, headache, e.g., tremorgens, trichothecenes.
  • Cutaneous system: rash, burning sensation sloughing of skin, photosensitization, e.g., trichothecenes.
  • Urinary system, nephrotoxicity, e.g. ochratoxin, citrinin.
  • Reproductive system; infertility, changes in reproductive cycles, e.g., T-2 toxin, zearalenone
  • Immune system: changes or suppression: many mycotoxins.

From a 1989 U.S. EPA Report for Congress on Indoor Air Pollution:

U.S. EPA Report for Congress on Indoor Air Quality. Volume II: Assessment and Control of Indoor Air Pollution

Health effects from indoor air pollution cover the range of acute and chronic effects, and include eye, nose, and throat irritation, respiratory effects, neurotoxicity, kidney and liver effects, heart functions, allergic and infectious diseases, developmental effects, mutagenicity, and carcinogenicity.

From a report on the neurotoxic effects of toxigenic mold and mycotoxins:

Neurotoxic Effects of Toxigenic Molds and Mycotoxins 

Exposure to mycotoxins may occur via enteric, inhalation, or direct contact to skin and mucosa.  Acute and chronic disorders, irritation, systemic reactions and even cancer may develop after the exposure to these toxins.  

Symptoms include respiratory complaints that involve the nose and lungs; eye symptoms, and mucous membrane irritation. The major presentations are headache, general debilitating pains, nose bleeding, fevers with body temperatures up to 40 degrees C (104 degrees F), cough, memory loss, depression, mood swings, sleep disturbances, anxiety, chronic fatigue, vertigo/dizziness, and in some cases, seizures.

Mycotic demyelinating optic neuritis is a neurological disorder of the visual system caused by mycotoxins released by indoor toxic molds. 

Other neurobehavioral manifestations in the mold-exposed individuals are abnormal decrease in steady balance, reaction time, blink-reflex latency, color discrimination, visual fields, and grip, compared to control. Hence, most exposed patients have reduced cognitive functioning in multiple domains, with memory and executive functions the most commonly affected areas. 

Share by: