Mould is everywhere - in the air we breath and the food we eat - and there is little doubt that it can be a health hazard. But there"s no reason to panic; it"s only a problem in large quantities, reports Dermott White from RIMS.

Ever felt sick at work? Ever thought maybe it was something to do with your environment, the building you were working in? Might those mouldy patches in the parking lot and the basement office have something to do with it? Well, they might. But before you start dialling the number of that smiling TV personal injury lawyer, or worrying that your staff are about to lodge a group workers" compensation claim against the company, remember that mould is very unlikely to be the cause of your symptoms. And the fact that people appear to be unwell does not necessarily mean that you or your employees have a "building-related illness" or are suffering because of a fall in indoor air quality (IAQ).

At the 2003 RIMS conference, held in early April in Chicago, Dr Howard Sandler, the founder of US occupational and environmental health consultancy Sandler Occupational Medicine Association (SOMA), defined a building- related illness as: "A specific well-defined illness for which a direct building-related condition can be shown as the cause of the illness." Legionnaire"s Disease is an example of this.

However, a variety of things can cause people in a particular building to feel unwell and give rise to allegations of "sick building syndrome".

Dr Sandler defined sick building syndrome as: "A situation where some building occupants experience health and comfort issues associated with being in the building. No specific illness or cause is identified."

"(This) is simply people ... who are complaining at a higher level in a building. That doesn"t necessarily mean there has been exposure there [to chemicals, mould or an airborne disease], it just means people are complaining," he said.

Tangible triggers
Some of the tangible factors that have been known to trigger IAQ complaints include: a new building; recent refurbishments or renovations, like painting or carpeting; pest control activities; poor housekeeping - heavy dust; seasonal changes; water damage; and real or perceived toxic incidents.

But other, less obvious factors have also been identified: labour/management conflict and major workplace changes, like mergers or moves.

"Let"s face it," said Dr Sandler, "you"re not supposed to feel right all the time. You don"t wake up with your hair well coiffed, something hurts somewhere ... the problem is that there is always something wrong with people. But just because you feel bad does not necessarily mean that there is a problem. The other big issue is, we spend 93% of our time indoors, so it makes sense that if something is making you feel bad, that it is something indoors. But what is indoors? There are chemicals, biologics, there are mental stresses, there are mixtures of all those physical agents like heat and noise."

The bottom line, it seems, is that the majority of IAQ complaints are the result of perceived exposure to a harmful substance. And the higher the perception of exposure, the more serious the symptoms are likely to be.

Dr Sandler referred to one case study, from the US National Center for Health Statistics, of a community living near a hazardous waste site in California. It was found that the incidence of illness in the community was no higher than in a comparison group, but the prevalence of exposure symptoms was dramatically higher. The community"s members showed a range of flu-like symptoms as well as others, including nervousness, poor memory, difficulty sleeping, poor concentration, toothache and skin irritation.

"Here"s the rub. They weren"t higher exposed, they thought they were higher exposed. The real correlation was if you thought you were exposed, thanks to the odour and worry, there was the correlation. People have symptoms all the time, we have them very commonly. And most of the mould claims are not from asthma or allergic rhinitis (hay fever) or anything else. Most of them are, "I don"t feel good. I have flu-like illness,"" said Dr Sandler.

Common complaints
The same is largely true for exposure to mould, especially in a building. The most common complaints associated with mould at the moment are neuro-psychological - memory, cognitive problems and mood - according to Dr Sandler. But some of the more "real" things which can be related to mould are respiratory difficulties, hay fever, serious sinus infections, asthma and pneumonitis, which is an allergic pneumonia commonly know as "farmer"s lung" or "humidifier fever". Those were typically the result of mould exposure, he said.

However, Dr Sandler said he was yet to be convinced that a small exposure to mould could actually make a person unwell.

"If you look at moulds and allergies, you"ll find that some studies show a dose-response, that if you are exposed to more mould, you"ll have more symptoms. But many studies don"t. It"s really not clear at this point whether moulds do in fact create allergy problems," Dr Sandler said. "I"ve looked at hundreds of buildings across this country and what I"ve found is that typically the people who have mould allergies, and they"re very common, are not allergic to the specific moulds that are in the building. They may be allergic to other moulds but I"ve not seen that cross-correlation."

He added that there were certain diseases that are actually named in parts of Asia from people who had consumed grains or food products that were heavily mould contaminated.

"So this is not something new but that shows you that you need a heck of a dose. The average amount in the air is just not going to give you that dose ... If you go outside during the fall and rake up the leaves on your lawn, I guarantee you"re putting more mould into the air than you"ll ever have in most of your homes or buildings," he said. "I think the real issue here is that the true intoxication is from ingestion. You just don"t get enough from inhalation. Have you ever seen a silo and the amount of mould that can come off it? It"s a huge amount. And there is a disease called "silo filler"s disease". But I can guarantee you won"t see that in a typical house, apartment or office building."

Increased risk
He continued: "There is no increased risk in buildings or homes that I have been seeing. No safe or unsafe levels [of mould] have been established. I think it"s an individual thing at this time. Typically indoor levels are much less than outdoor levels and none of the remediation that you see is health based. There could be problems with structural integrity. It could be that it smells, or that it doesn"t look good - all good reasons to do remediation. If you have any odour, if you have people who have mould allergies to that specific mould, you should remediate but ... as long as it"s not any different to the outside, it really shouldn"t be a problem."

Indoor air quality - what"s all the fuss about?
Concerns with indoor air quality (IAQ) have increased since energy conservation measures were instituted in office buildings during the 1970s, minimising the infiltration of outside air and contributing to the build-up of indoor air contaminants. IAQ generally refers to the quality of the air in an office environment. Other terms related to IAQ include Indoor Environmental Quality (IEQ) and "sick building syndrome". Complaints about IAQ range from simple complaints such as the air smelling odd to more complex, where the air quality causes illness and lost work time. It may not be easy to identify a single reason for IAQ complaints because of the number and variety of possible sources, causes and varying individual sensitivities.

IAQ problems can be caused by ventilation system deficiencies, overcrowding, tobacco smoke, microbiological contamination, outside air pollutants and gasses from office materials and mechanical equipment. Related problems also may include comfort problems due to improper temperature and relative humidity conditions, poor lighting and unacceptable noise levels, as well as adverse ergonomic conditions, and job-related psycho-social stressors. Typical symptoms may include headaches, unusual fatigue, itching or burning eyes, skin irritation, nasal congestion, dry or irritated throats, and nausea.

According to the US National Institute for Occupational Safety and Health (Niosh), moulds and mildew are fungi that grow on the surfaces of objects, within pores, and in deteriorated materials. They can cause discoloration and odour problems, deteriorate building materials, and lead to allergic reactions in susceptible individuals, as well as other health problems.

The following conditions are necessary for mould growth to occur on surfaces:

  • temperature range above 40°F and below 100°F;
  • mould spores;
  • nutrient base (most surfaces contain nutrients); and
  • moisture.
  • Human comfort constraints limit the use of temperature control. Spores are almost always present in outdoor and indoor air, and almost all commonly used construction materials and furnishings can provide nutrients to support mould growth. Dirt on surfaces provides additional nutrients. Cleaning and disinfecting with non-polluting cleaners and antimicrobial agents provides protection against mold growth.

    By Dermott White

    Dermott White is a journalist on Global Reinsurance.