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A culture problem?

After anthrax and ricin, US Environmental Agents are now targeting that well-known biological threat - mould

A situation nearing hysteria has arisen in the US stemming from litigation concerning the negative health impacts of 'toxic mould'. In Florida, an architect and builders were made to pay $11.5 million when 15 construction workers became ill as a result of mould problems. In another state, a landlord had to pay more than a million dollars for failing to correct mould problems that caused two women asthma attacks and other health problems.

The fungus causing most concern is Stachybotrys chartarum. This is a greenish black mould that grows on materials with a high cellulose content - including timber, dry linings and ceiling tiles. Exposure to high levels of the fungus may affect health by causing cold-like symptoms, rashes and the aggravation of asthma. Operatives involved in building work where there is widespread fungal contamination could be at risk of developing Organic Dust Toxic Syndrome.

Fungal growth does occur in buildings in the UK, and the importance of regular maintenance, careful design and remediation to ensure healthy indoor environments has been understood for some time.

However, there is enough concern to warrant the Royal Institution of Chartered Surveyors to commission research to examine the issue here in the UK, as the incidence of particular moulds and risks they may pose are not fully understood.

It was reported that toxic mould is estimated to affect three million homes in the UK 1.Mould spores cannot be excluded from buildings and fungi are likely to grow where there is a high moisture content, such as in poorly ventilated bathrooms and kitchens or where water leaks into a building. This leaves low-cost or social housing particularly vulnerable as these buildings are often poorly ventilated as a means of reducing heat loss. Furthermore, spores can be distributed through air-conditioning ducting, and humidifiers can provide a source of contamination in nondomestic environments.

Condensation and dampness control has been the primary method of reducing the occurrence of mould in design. Fungicides and biocides have also been used in paints and products.

As professionals who are primarily involved in design and construction there may be implications for architects from this US litigation about how mould-related issues could impact on design liability and latent defects.

There could also be implications for the design, installation, commissioning and maintenance of environmental control and services installations (which could provide a source and means of distribution for mould spores).

Given the increasingly litigious climate in the UK construction industry, those involved with construction operations must consider the health and safety implications for site operatives, especially where existing structures are involved.

Toxic mould issues could be considered in risk assessments for the Construction (Design and Management) Regulations 1994.

What does this mean for architects in the UK? 'When America sneezes' are we to catch the US toxic mould paranoia? We seem to have co-existed with moulds for some time without major concern and have established the design of building envelopes and indoor environments to reduce water penetration and avoid condensation.

However, undoubtedly construction defects can still occur that will encourage mould growth and certain sections of the community are more vulnerable than others to environmental pollutants.

We know, for example, that Aspergillosis is dangerous to those with weak immunity, and therefore common sense dictates that more care must be taken for designing hospital environments and the like.What we do not know is to what extent these moulds exist in our environment, as the technology to establish this has only recently emerged. Also, although a definite causal link has not been proven between some moulds and health problems, it is worth noting that this has not hindered US courts in awarding damages.

John Reyers is a consultant for Healthy Office and a senior lecturer at Nottingham Trent University. Contact john. reyers@ntu. ac. uk RICS (2002) In Brief: Risk of Toxic Mould in Business, the magazine of the RICS, London. Atom Publishing lSee US Environmental Protection Agency's Brief guide to Mold [sic], moisture and your home and other information relating to school buildings, and New York City Department of Health's updated guidelines.

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