Air quality is of fundamental importance to our health. If the air that we breathe in contains particular pollutants it can trigger asthma attacks, heart attacks. Pollutants can be gasses, vapours and particulates. All are capable of penetrating deep into our lungs to some of the most sensitive tissues we have that are exposed to the outside air. Once in our
Harmful air pollutants are classified into the following categories:
- Nitrogen Dioxide
- Sulphur Dioxide
- Particles < 2.5µm (PM2.5)
- Particles < 10µm (PM10)
A committee of medical experts advises the UK government on the health implications of the measured levels of air pollutants (COMEAP).
Air Pollution - Moulds
Moulds such as Aspergillus and Penicillium are frequently found suspended in the air that we breathe throughout the year in the UK. This diagram (taken from the Midlands Asthma & Allergy Research Association website - MAARA) shows that different types of moulds and fungi proliferate at different times of the year in warm temperate areas such as the UK, but all tend to peak in the period from June to August.
Counts taken by MAARA show fungal spores in the air exceeded 50 000 spores per cubic metre of air during this time - mainly Cladosporium,
Analysis of the impact on our health of all these airborne spores is complicated as plant pollens are also plentiful at these times of the year. Hayfever is probably the predominant allergy noted at these times but there is also allergy to all the fungal spores. The symptoms are similar (sore eyes, runny nose, skin rashes) so it is difficult to know if you are suffering from hay (pollen) allergy or allergy to fungi - medical tests are often necessary to distinguish the two.
Fungal spores (2-30
Indoor air - Moulds
Some estimates are that we spend 90% of our time indoors so the quality of our indoor air is likely to be very important for our health. We know that outdoor air fundamentally influences indoor air with respect to the numbers of microbes it contains so we should expect that allergy symptoms will continue indoors. Perhaps that is not surprising as other than when we open our windows and doors (which we are likely to do more in the warm summer months when outdoor moulds are at their peak) few homes are completely airtight - if they were we would suffocate overnight! Even very small cracks and gaps seem to be sufficient to allow spores into our homes in large numbers.
In the more developed countries of the
At the same
The net effect of all these changes is that although our homes are warmer, they are more prone to damp as warmer air can hold more moisture which is then released when the air cools e.g. at night when heating is lower. This is particularly a problem in colder weather as walls and windows become colder. Damp is a requirement for mould growth - prevention of damp often requires specialist advice and is a result of both occupant habits and building structure/management.
Health Effects - Moulds
Many people are vulnerable to developing allergies in ways we do not yet fully understand. For the most
Allergic fungal infection
All allergic fungal infections affect the upper or lower respiratory tract, although in a sense all allergies are generalised. There can be an inflammatory component to some skin and mucosal fungal infections, but this is not usually driven predominantly by IgE, eosinophils, mast cells and basophils, the key features of
Many allergies are mild and have a minor
An allergic tendency (or atopy) is often apparent early in
Most allergic fungal infection probably has an important genetic component.
The important allergic fungal infections are:
- Allergic Bronchopulmonary Aspergillosis (estimates of 100 000 cases in
- Occupational Lung Disease
- Severe Asthma with Fungal Sensitisation (estimates of 500 000 cases in
- Thunderstorm Asthma
- Allergic Fungal Rhinosinusitis
Chronic fungal infection
Certain groups are vulnerable because of pre-existing damage to their lungs e.g. those who have had TB, have Cystic Fibrosis and those with COPD. Genetic research on people with ABPA is starting to reveal consistent genetic features in people who get that chronic infection rendering them slightly less able to quickly fight off a fungal infection,
It might be appropriate to assume that if someone from these vulnerable groups was to be exposed to higher levels of fungal spores in the air, they might run a higher risk of infection compared with the rest of the population. At the moment there is no way to screen for people with many of these genetic differences but that is a primary aim of the research being undertaken.
Some fungi are persistent, defying treatment aimed at cure and leading to
The inclusion of fungal keratitis and fungus ball of the sinus together in this section is one of convenience, as all patients in this category are not immunocompromised, unlike those with invasive fungal infections.
It is likely that important genetic
The common chronic and destructive Aspergillus fungal infections are:
- Chronic pulmonary aspergillosis
- Fungal keratitis
- Fungus ball of the sinus
- Granulomatous invasive fungal rhinosinusitis
This group of infections are important almost exclusively in hospitalised patients who are
This can be an extremely difficult infection to treat so every effort is made to avoid infection. The air is the main source of infection both in the operating theatre and in recovery as the main site of infection is the lungs, so indoor air quality is closely monitored in the hospital and cleaned via HEPA grade filtration systems where possible. There have been several research papers that strongly suggest local building works are a factor leading to outbreaks of invasive aspergillosis in some hospitals so local policies have to be put in place to reduce the risk accordingly. Sadly at the
Clinician experience, combined with
The most common Aspergillus invasive fungal infections are:
Articles on various aspects of the impact air pollution
has on health
Fumifugium: John Evelyn was a
Fumifugium is the name that Evelyn gave to a 1661 essay on air pollution in London that he sent to King Charles II. Evelyn was enraged by the heavy smog that often fouled the air in his home city. In Fumifugium he aimed to document the impacts of the smog
on people’s health and the environment. He also put forward some solutions to help resolve the problem.
Microbiomes - a rapidly expanding study of the world of microbes that surround us in our environment, and live within us.
Microbiomes of the Built Environment: A Research Agenda for Indoor Microbiology, Human Health, and Buildings (2017). National Academies of Sciences, Engineering, and Medicine.
Air Quality control in Healthcare facilities
Aspergillus and Penicillium Polyphasic identification - This is an interactive key for the identification of Aspergillus and Penicillium species.
Workshops & courses on airborne fungi and other IAQ issues
- Institute of Specialist Surveyors and Engineers (UK) run Diploma and Certificate of Education courses in a variety of subjects: Damp & mould, Condensation & Damp Control, Damp & Timber, Building Health Compliance. Courses are provided via industry education leader ABBE and require a substantial commitment of up to 500 hours to complete. ISSE graduates have passed the highest standards of training currently available in the UK. If in the UK/EU and are looking for professional training, or if you are a member of the public looking for a surveyor for a damp home, always ensure that the training is to a standard recognised by Ofqual. NB Damp surveyors in the UK commonly refer to a qualification denoted CSRT which used to be the highest qualification routinely attainable in the UK but is, in fact, a
3 daycourse that is not recognised by Ofqual. Buyer be aware!
- Healthy Air - Healthy Homes Workshops (US - designed for the public)
- Autodesk Indoor Air Quality (free online access to tutorials)
- Indoor Air Quality Association (US)
- EU workshop drafts indoor air ventilation guidelines
Information & advice on the diagnosis and the source of damp
IAQ radio Online radio show based in
- Ken Larsen, CR, WLS - Principles of Drying Water Damaged Structures