Development of WHO Guidelines for Indoor Air Quality – Dampness and Mold

World Health Organization – Report of a Working Group on Mold  (published 2008) 

This very significant document provides an overview of the known risks from mold exposure, and what should be done about them (recommendations). As a primarily European workgroup, it is interesting to note the difference in what the U.S. Centers for Disease Control is telling us about mold and health and what this workgroup from the esteemed World Health Organization found to be true. At The Center for School Mold Help, we find this document as an accurate beginning in describing the problem of mold on health, as experienced in damp buildings – and in the case of the United States, this describes most schools (SMH).


Microbial pollution is one of the key constituents of indoor air pollution. It consists of hundreds of species of bacteria and fungi, and in particular filamentous fungi (moulds) growing indoors when sufficient moisture is available. Health problems associated with moisture and biological agents include increased prevalence of respiratory symptoms, allergies, and asthma as well asperturbation of the immunological system. Based on the extensive review of the scientific evidence, this WHO working group identified the main health risks due to excess moisture,associated with microbial growth and contamination of indoor spaces. It also formulated WHO guidelines for protecting public health, recommending that persistent dampness and microbial growth on interior surfaces and in building structures should be prevented (or minimized) as they may lead to adverse health effects.


Summary of the health risk evaluation

1. Sufficient epidemiological evidence from studies conducted in different countries and climatic conditions shows that occupants of damp or mouldy buildings, both homes and public buildings, are at increased risk of experiencing respiratory symptoms, respiratory infections and exacerbations of asthma. Some evidence suggests an increased risk of developing allergic rhinitis and asthma. Although not many intervention studies are available, their results show that remediation of dampness problems leads to a reduction in adverse health outcomes. 

2. There is clinical evidence that exposures to moulds and other dampness-related microbial agents increase the risk of rare conditions, such as hypersensitivity pneumonitis/allergic alveolitis, chronic rhinosinusitis and allergic fungal sinusitis.

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

4. While groups such as atopic and allergic individuals are particularly susceptible to exposures to biological and chemical agents in damp indoor environments, adverse health effects have also been widely demonstrated in non-atopic populations.

5. The increased prevalence of asthma and allergies in many countries increases the number of people susceptible to the effects of dampness and mould in buildings.

6. The prevalence of indoor dampness ranges widely within and among countries, continents and climate zones. It is estimated to be in the order of 10–50% of the indoor environments in Europe and North America, as well as in Australia, India and Japan. In some specific settings, such as river valleys or coastal areas, conditions of dampness are substantially higher than national averages.

7. The amount of water available on/in materials is the most important factor triggering the growth of microorganisms, including fungi, actinomycetes and other bacteria.

8. Microorganisms in general are ubiquitous in all general environments. Microbes propagate rapidly whenever water is available. The dust and dirt normally present in most indoor spaces provide sufficient nutrients to support extensive microbial growth. While mould growth is possible on all materials, appropriate material selection is nevertheless important to prevent dirt accumulation, moisture penetration and mould growth.

9. Microbial growth may result in elevated levels of spores, cell fragments, allergens,
mycotoxins, endotoxins, ß-glucans, and microbial volatile organic compounds (MVOCs) in indoor air. The causative agents of adverse health effects have not been conclusively identified, but excessive levels of any of these in the indoor environment indicates a potential health hazard.

10. Microbial interactions and moisture-related physical and chemical emissions from building materials may also play a role in dampness-related health issues.

11. Building standards and regulations on comfort and health do not sufficiently emphasize requirements to prevent and control excess moisture and dampness.

12. Besides occasional events – such as water leaks, excess rain, floods, etc. – most moisture enters buildings through incoming air, including that infiltrating though the envelope, or is due to occupants’ activities.

13. Allowing surfaces to become cooler than the surrounding air may result in unwanted condensation. Thermal bridges (such as metal window frames), inadequate insulation and unplanned air pathways, or cold water plumbing and cool parts of air conditioning units can result in surface temperatures below the dew point of the air that contribute to dampness problems.

14. The problem of excess moisture and dampness can be tackled by controlling the quality of the building envelope regarding air infiltration, exfiltration, and pathways of water intrusion, by ensuring adequate thermal insulation and by avoiding condensation indoors through the control of moisture sources and of temperature, humidity and velocity of the air in the proximity of the surfaces.


1. Persistent dampness and microbial growth on interior surfaces and in building structures should be avoided or minimized, as they may lead to adverse health effects.

2. Indicators of dampness and microbial growth include the presence of condensation on surfaces or in structures, visible mould, perceived mould odour and a history of water damage, leakage or penetration. Thorough inspection and – if needed – appropriate measurements may be used to confirm indoor problems related to moisture and microbial growth.

3. Currently, the relationship between dampness, microbial exposure and health effects cannot be precisely quantified, so no quantitative health-based guideline values or thresholds can be recommended for acceptable levels of specific microorganism contamination. Instead, it is recommended that dampness and mould-related problems be prevented. When they occur, they should be remediated because of the increased risk of hazardous microbial and chemical exposures.

4. Well-designed, -constructed and -maintained building envelopes are critical to the prevention and control of excess moisture and microbial growth by avoiding thermal bridges and preventing intrusion by liquid or vapour-phase water. Management of moisture requires proper control of temperatures and ventilation to avoid high humidity, condensation on surfaces and excess moisture in materials. Ventilation should be distributed effectively in spaces, and stagnant air zones should be avoided.

5. Building owners are responsible for providing a healthful workplaces or living environments free of excessive moisture and mould problems by ensuring proper building construction and maintenance. Occupants are responsible for managing water use, heating, ventilation, appliances, etc. in a proper manner that does not lead to dampness and mould growth.

6. Local recommendations in different climatic regions should be updated to control dampness-mediated microbial growth in buildings and to ensure the achievement of desirable indoor air quality. Dampness and mould may be particularly prevalent in poorly maintained housing for low income people. Remediation of conditions related to adverse exposures should be given priority to prevent additional contributions to poor health in populations already living with an increased burden of disease.

full document – Development of WHO Guidelines for Indoor Air Quality: Dampness and Mold

World Health Organization – The Right to Healthy Indoor Air

After reading about IAQ and health issues explained in terms of basic human rights and the laws that should protect those rights but don’t – it is obvious that the justice system is under the control of those who don’t want to be held accountable for “criminal exposures” in their toxic houses, apartments, buildings etc. and by the insurance industry.

They have purchased the justice system and attorneys know this so they don’t get involved anymore because even with overwhelming evidence the decision has already been paid for.

The greedy and unethical will continue to make more millions while exposing people to very dangerous toxins that can make even healthy people ill.

We have lost our rights to others greed.

The evidence is overwhelming as to the very serious and widespread health affects of mold. katy

This is an excerpt from the document.


Indoor air quality is an important determinant of health and wellbeing. However, the control of indoor air quality is often inadequate, one reason being the poor articulation, appreciation and understanding of basic principles underlying policies and action related to indoor air quality. As a result, the general public is familiar neither with those principles nor with their associated rights.

A WHO Working Group was convened to agree on a set of statements on “The right to healthy indoor air”, derived fromfundamental principles in the fields of human rights, biomedical ethics and ecological sustainability.

This document presents the conclusions of the Working Group, informs individuals and groups responsible for healthy indoor air about their rights and obligations, and individuals by bringing those rights to their attention.









Indoor air quality (IAQ) is an important determinant of population health and well being. People in modern societies spend most of their time in indoor spaces such as at home, work, school and in vehicles. Exposure to the hazardous airborne agents present in many indoor spaces causes adverse effects such as respiratory disease, allergy and irritation of the respiratory tract.Improperly or poorly ventilated combustion appliances pose a real risk of acute poisoning bycarbon monoxide. Indoor exposure to radon and environmental tobacco smoke increases the risk of lung cancer. Many chemicals encountered indoors cause adverse sensory effects, giving rise to a sense of discomfort and other symptoms.

The control of indoor air quality is often inadequate in spite of its significant role in determining health.

Tensions and conflicts often occur between individuals suffering from indoor air pollution and those whose actions negatively influence indoor air quality. Most exposure to indoor air occurs in private homes, where intervention by public regulation is often considered a violation of personal freedom. Furthermore, commercial interests have often delayed the implementation of indoor air pollution controls in spite of scientific evidence of the harmful impact of such pollution on health.

To a large extent, the inadequate quality of indoor air arises from a poor articulation, appreciation and understanding of the basic principles underlying the policies and actions related to indoor air quality. As a result, the general public is familiar neither with those principles nor with their associated rights.

A WHO Working Group was convened to agree on a set of statements on “The right to healthy indoor air”, derived from fundamental principles in the fields of human rights, biomedical ethics and ecological sustainability.

These statements inform the individuals and groups responsible for healthy indoor air about their rights and obligations, and empower the general public by makingpeople familiar with those rights. The statements were formulated at a meeting of the Working Group convened by the WHO European Centre for Environment and Health (WHO/ECEH), Bilthoven Division, in Bilthoven on 15–17 May 2000. The invited experts, who represented a wide range of specialties and countries, were recommended to WHO by contacts in governmental institutions and through expert groups involved in the assessment and maintenance of indoor air quality, bioethics and environmental ethics (list of participants in Annex 1). The Chairperson of the meeting was Dr Lars Mølhave and Dr Nadia Boschi acted as Rapporteur. Those invited received in advance of the meeting a background paper prepared by a small group convened by WHO/ECEH in November 1999.

The exact text of the principles recommended, and most of the text of the commentary was agreed at the meeting. A smaller editorial group worked on it directly after the meeting, and the entire text of this report was reviewed and accepted by all members of the Working Group within a few weeks following the meeting. The report summarizes the main conclusions and recommendations of the Working Group, and sets out the statements on The Right to Healthy Indoor Air.

Statements on the right to healthy indoor air – Introduction

Everyone has a right to healthy indoor air. It is the dual purpose of this document to:

1. Inform those who have an influence on public health about this right and of their obligations related to this right, and

2. empower the general public by making people familiar with this right.

The right to healthy indoor air applies across the world. While it is an individual responsibility to prevent air pollution indoors, decision-makers both inside and outside the public health sector have important additional tasks in this respect. In particular, the building and energy sectors have pertinent roles to play. Many factors influence indoor air quality, including the design, construction, equipment, operation and maintenance of buildings or other indoor spaces, as well as outdoor air quality and the occupants’ preferences or activities. All individual groups, whether private or public, associated with a building or other indoor space, bear responsibility for healthyindoor air and the protection of the health of its occupants.

Human rights are the rights of individuals that should apply to all people around the world, representing fundamental freedoms or needs that every state ought to recognize and protect. Specific human rights law is listed in several key documents; foremost of these is the Universal Declaration of Human Rights, which was drawn up to give more specific definition to the rights and freedoms referred to in the United Nations Charter. The Charter, the International Covenant on Civil and Political Rights and the International Covenant on Economic, Social and Cultural Rights constitute what is often called the “International Bill of Human Rights”. These humanrights apply globally, irrespective of gender, age, religion, economic status, national origin, ethnicity and the like.

Dissemination of knowledge of the principles that determine individual rights to healthy indoor air will help people to understand what values are being given priority in any specific context, be it at the home, office or government level of decision-making and/or policy formulation. At the same time, encouraging individual behaviour towards sustainability will also help to ensuresustainable indoor air quality.

The principles below derive from the fundamental principles in the fields of human rights, biomedical ethics and ecological sustainability, and focus on interactions among them.


Principle 1 – Under the principle of the human right to health, everyone has the right to breathe healthy indoor air.

Principle 2 – Under the principle of respect for autonomy (“self-determination”), everyone has the right to adequate information about potentially harmful exposures, and to be provided with effective means for controlling at least part of their indoor exposures.

Principle 3 – Under the principle of non-maleficence (“doing no harm”), no agent at a concentration that exposes any occupant to an unnecessary health risk should be introduced into indoor air.

Principle 4 – Under the principle of beneficence (“doing good”), all individuals, groups and organizations associated with a building, whether private, public, or governmental, bear responsibility to advocate or work for acceptable air qualityfor the occupants.

Principle 5 – Under the principle of social justice, the socioeconomic status of occupants should have no bearing on their access to healthy indoor air, but health status maydetermine special needs for some groups.

Principle 6 – Under the principle of accountability, all relevant organizations should establish explicit criteria for evaluating and assessing building air quality and its impact on the health of the population and on the environment.

Principle 7 – Under the precautionary principle, where there is a risk of harmful indoor air exposure, the presence of uncertainty shall not be used as a reason for postponing cost-effective measures to prevent such exposure.

Principle 8 – Under the “polluter pays” principle, the polluter is accountable for any harm to health and /or welfare resulting from unhealthy indoor air exposure(s). In addition, the polluter is responsible for mitigation and remediation.

Principle 9 – Under the principle of sustainability, health and environmental concerns cannot be separated, and the provision of healthy indoor air should not compromise global or local ecological integrity, or the rights of future generations.


In this part of the document, the application of the above principles is placed into context and explained. The principles and the commentary are mutually supportive. It may happen that any of the principles could be in apparent conflict with others. It is the object of any rights – or ethics-based analysis to be transparent in the rationale as to how a decision to act was reached. Inproviding such a rationale, any principle could take precedence over any other. The articulation of the rationale for invoking any one principle over another establishes transparency.

Principle 1 – The human right to health

The severity of symptoms and the duration of any negative health effects are primary criteria for determining the seriousness and importance of various indoor air pollution health impacts. Shortened life expectancy, diminished quality of life, disability and hospitalization are key indicators. Symptoms of health effects resulting from indoor pollutant exposure can be classified by severity and duration. Short-term acute effects resulting from infectious agents are often affected by building practices.

Examples include –

Respiratory diseases such as legionnaires’ disease and hypersensitivity pneumonitis. Asthma and allergy, or chronic upper respiratory obstructive diseases may have less severe acute symptoms but are important because of their lengthy (often life-long) duration. The quality of indoor air not only has a bearing on health, but also on the quality of life.

This interpretation derives from the 1977 World Health Assembly, which resolved that by the year 2000, all people should attain a level of health permitting them to lead socially and economically productive lives. Exposure to pollutants that qualitatively decrease the health, functioning or comfort of occupants is, therefore, unacceptable. Indoor air pollution from the use of solid fuels in simple unvented stoves is common in developing countries. As their economies develop, populations tend to use cleaner fuels and less polluting stoves. That this occurs, however, does not imply that waiting for economic development is a necessary or desirable approach to achieving better indoor air quality. Indeed, the great triumphs in public health are in identifying ways to help people improve their health even before they participate in the fruits of economic development.

Principle 2 – Respect for autonomy (“self-determination”)

Everyone has the right to expect others to respect their individual judgement in their own evaluation of personal exposure and its effects. For example, if a person finds the air quality uncomfortable or offensive enough to warrant a formal comment or complaint, that person’s assessment needs to be respected.

Those responsible for public health and education have a duty to inform people regarding the relationship of indoor air quality to health. Article 26 of the United Nations Declaration on Human Rights states:

Article 26: (1) Everyone has the right to education…(2) Education shall be directed to the full development of the human personality and the strengthening of respect for human rights and fundamental freedoms. It follows from Article 26(1) that education programmes for the general population should underline the importance of indoor air quality for health and provide insight into the basic mechanisms and sources of pollutants.

It is essential that individuals have some level of personal control over their own indoor environment and air quality. The personal control is necessary because the evaluation of an “optimal indoor environment” differs from person to person. However, public health authorities should recommend minimum standards.

People have the right to adequate, understandable information about the environments that they inhabit. This includes balanced and objective information on the exposures and associated risks.

The right to self-determination requires that full information be available to people making decisions about actions affecting their indoor air exposure. Therefore, those with access to relevant information should make it available to others. The providers are accountable for the adequacy of the information they provide. The population should be protected against factors which may change their sensitivity to indoor air exposures as well as against misinformation causing people to set wrong priorities. All reasonable measures should be taken to inform the general public of national and international laws pertaining to indoor air quality, and their rights in relation to these laws.

Principle 3 – Non-maleficence (“do no harm”)

Indoor air should contain no pollutants without a justifiable reason or purpose for their presence.

It is recognized that a balance must be struck between indoor air requirements and considerations such as the economy and health.

Unwanted or unacceptable exposures are defined as the presence of indoor exposures that cause undesirable effects on the occupant(s).

Those who design, provide, build, maintain and occupy indoor environments have a duty to do no harm to indoor air quality in that environment.

Ignorance about indoor air quality matters is not an excuse for causing harm. The facts on indoor air quality must therefore be readilyavailable to, and used by, all the parties concerned.

Exposures indoors should not occur as the result of mitigation of environmental problems in occupational or outdoor environments (e.g. by discharge, dilution or substitution that migrates to the indoor environment).

Environmental tobacco smoke is a special case of an indoor air pollutant with serious, large-scale negative health consequences. As such, environmental tobacco smoke should be excluded from indoor environments.

Principle 4 – Beneficence (“doing good”)

Those who provide, maintain and occupy indoor environments have a responsibility to promote good indoor air quality. Protection of the health and comfort of the most sensitive occupants is required under the principle of beneficence.

When convincing evidence exists on health risks due to indoor air exposures, the appropriate societal authorities should organize or initiate action to prevent or eliminate these exposures.

Principle 5 – Social justice

Social justice refers to the equitable distribution of burdens and benefits within society.

Unhealthy indoor air is a burden, and healthy indoor air is a benefit. Therefore, there should be social and economic equity in the distribution of healthy indoor air. Those involved in public health should recognize this unequal distribution of healthy air by virtue of social or demographic factors. Special attention may need to be paid to affected groups, as well as to others vulnerable by virtue of their health status, to reduce health inequalities and ensure progress toward more egalitarian societies. Various groups experience different exposures to unhealthy indoor air, e.g. the economically disadvantaged (more exposure to environmental tobacco smoke, more poor quality combustion devices), women and the elderly (more time spent indoors), and ethnic minorities (lack of information in an appropriate language).

The right to quality indoor air is equally essential for people of all nations and at all socio-economic levels. Economically disadvantaged individuals must be given due consideration whenever decisions affecting their indoor air quality are to be made by either public or private organizations. All minorities (including susceptible groups such as children) have the same rights to protection as the general population. In particular, sensitive groups within the population have the right to adequate means for ensuring them an indoor air quality that meets their specific needs. Solidarity with the less privileged urges rectification of the unequal distribution of resources and prevention of and a response to human suffering.

Principle 6 – Accountability

As a minimum, all applicable laws and regulations should be followed. In addition, all relevant standards of practice and guidelines should be followed. Transparency provides the basis for understanding the rationale for decision-making.

Those responsible for and concerned with human and environmental health, both in governments and in nongovernmental organizations, should develop and adopt indicators of healthy indoor air and its achievement for the whole population. These indicators should include exposure and risk assessment related to indoor pollutants with significance for health. They should also include factors that have an impact on indoor air quality as well as determinants of general environmental quality that directly and indirectly affect and are affected by the quality of the built environment.

It is sometimes argued that household air pollution should not be the concern of government public health bodies. After all, it is said, the occupants themselves are responsible for most of the activities that produce the indoor air pollution they experience. Indoor air pollution, by this reasoning, is not an “externality” and thus does not need to be addressed by society at large. However, there are several problems with this argument.

• Governments and other outside agencies clearly do have a role in research and education to inform householders of the risks. Householders alone are not in a position to conduct or interpret such research.

• Through appliance standards, building codes, fuel standards and pricing, consumer product standards and labelling and other measures, governments already exercise a number ofcontrols over indoor air quality and have the responsibility to see that such controls reflect actual risks.

• Households are not democracies with every person having an equal say. Children, in particular, are not in a position to make the kind of judgment needed to protect themselves. In many societies, women have little say in many household economic decisions, such as the purchase of fuel, even though they may experience most of the indoor air pollution exposure.

• Children are a vulnerable group. Therefore, particularly stringent controls should be applied to afford their protection from involuntary exposure to indoor air pollutants. This includes exposure in home, hospitals, kindergartens and schools.

• Lastly, distinguishing hazards as being externalities or not may fit some economic decision-making models but is not congruent with public health practice. From a public health standpoint, the task is to reduce human exposures to harmful substances no matter what their origin or where they occur.

Principle 7 – Precautionary principle

Prevention is better than restitution, mitigation and restoration, not only for reasons related to health, but also because prevention is cost-effective. Prevention is better than cure.

Principle 8 – “Polluter pays”

Regardless of the primary responsibility, no party is exempt from the responsibility to act for the achievement of healthy indoor air. Polluters cannot avoid their responsibility to compensate the affected parties. Economic, operational or administrative arguments are insufficient justification for not acting against the pollution of indoor air.

Principle 9 – Sustainability

The provision of healthy indoor air is a fundamental aspect of the design, construction, operation, maintenance, replacement/demolition or conservation of sustainable buildings. However, in providing healthy indoor air, the minimization of environmental impacts is also essential for sustainability. Considerations of sustainable development, sustainable living and sustainable health are all relevant to the promotion of healthy indoor air. The policies of public health and energy programmes should be coordinated. It is also important that private sector actions consider both indoor air quality and energy. Luxury services that improve the short-term quality of life should not take precedence over longer-term global or local ecological considerations. Global ecological integrity is dependent not only on consumption and the population, but also on technology. The inappropriate uses of technology in conjunction with over-consumption have a negative impact on the sustainability of life-support systems. The latter are based in the services provided to humanity from the natural world. Over-exploitation and pollution are destroying these natural systems. In other words, humans are threatening global ecological integrity by over-consumption, the growth in populations and the inappropriate uses of technology. A dilemma emerges when considerations of human comfort, not essential to human health and wellbeing, place in jeopardy the ability of life-support systems to be self-sustaining because of over-exploitation and pollution.

Thus, where human health needs conflict with the health needs of other species, human health needs should prevail; but where human comfort jeopardizes the sustainability of life-support systems, the protection of the life-support systems should prevail.

document – WHO – Right to Healthy Indoor Air (2000)

About Sharon Kramer

Hi, I'm an advocate for integrity in health marketing and in the courts.
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