mould

Describes how laboratory experiments were conducted to assess the susceptibility of three types of ventilation duct materials to fungal growth. They were fibrous glass ductboard, galvanized steel, and insulated flexible duct. The results showed that only the flexible duct supported moderate growth of P. chrysogenum. The other duct materials showed no growth. Soiling with dust from residential heating and air conditioning systems increased the susceptibility of all three types, albeit at different levels of soiling, with the galvanized steel the least susceptible.

Documents a study of airborne fungal concentration in a newly constructed building on the Gulf coast. States that fungal concentrations indoors were consistently below those outdoors, and samples did not clearly indicate contamination in the building, although visible growth was evident in the ventilation system. Concludes that the intrusion of most of the outdoor fungal aerosol is prevented by modern mechanically ventilated buildings, and that even extensive air sampling may not give the whole picture.

Two out of fourteen workers in a clerical office suffered bronchial problems. An investigation found gross contamination with Penicillium mould of forced-air heater-cooler units which had not been properly maintained. A 50 to 80 fold excess in the number of colony-forming units per cubic meter or air in the affected office compared with a control office were found. Persistent alveolitis was diagnosed in one worker, while the other suffered from asthma, exacerbated by the poor indoor air quality.

Describes the investigation in 1994 of a suspected case of sick building syndrome at a communications centre. The building's central HVAC systems had a poor record of maintenance, and there had been continual structural modifications to the building. Inspection revealed the presence of fungal growth in the HVAC system. Remediation included employing a dedicated mechanic to implement a preventive maintenance programme. A significant drop in fungal concentrations was revealed as a result.

Explores how water gets into a structure, why it doesn't leave, and how these architectural flaws become HVAC problems. States that mechanical engineers need to understand the roots of the problems in order to defend their work if IAQ becomes a problem once the building is occupied. The article reviews air control and pressurization, ventilation and humidity control and provides some resources to help expand the reader's knowledge of design and construction errors that lead to HVAC problems.

States that there is an evident relationship between the occurrence of mould indoors and medical conditions such as inflammation of the airways, and that glucans, found in active and inactive mould, can be used as a measure of the biomass of mould. Elevated quantities of glucans have been found in buildings where complaints had been made, but where there was no visible mould or mouldy smell. An investigation of an estate of terraced housed found that the quantity of airborne glucans was determined as an indication of the quantity of mould spores in the air in 70 houses.

Describes the indoor air quality remediation of a US elementary school. The school was in a poor state, with very high humidity levels due to steam from the boilers infiltrating walls and crawlspaces and roof leaks. Cockroaches and birds had entered the building. Leaking chemical drums were found in the basement. There were high rates of respiratory illness and absenteeism. The remediation included eliminating extensive mould in the wall cavities, repairing roof leaks and adding a new heating, ventilation and air conditioning system.

Moulds are a health concern. High levels of moulds in a building environment are to be avoided. Some species or high concentrations of mould are a serious health risk, and must be dealt with if we want to maintain healthy indoor environments. Gives New York City remediation guidelines, and lists methods to control mould growth: 1) Repair indoor and outdoor water leaks, 2) Clean and disinfect smooth surfaces, 3) Clean and dry other materials or remove them, 4) Discard porous contaminated materials, 5) Control moisture sources (e.g.