Air Toxics in a New Australian Dwelling over an 8-Month Period

A 'healthy house' was constructed in Sunbury, a suburb north of Melbourne, Australia, in early 1998. It was designed with a tight building envelope to minimise air infiltration and a ducted mechanical ventilation (and heat recovery) system providing a minimum ventilation rate of 0.35 air changes per hour. This system also included partial filtration and dehumidification of the air. Many (but not all) construction materials were selected to be low-VOC emission products (e.g. paint topcoat and lac quers, laminated flooring and cupboards). Total volatile organic compound (TVOC) concentrations were approxi mately 4,000 μg.m -3 just after construction, decreasing by a double-exponential model to 300 μg.m-3 by 8 months, which is below the National Health and Medical Research Council (NHMRC) goal of 500 μg.m-3. Formal dehyde concentration was near the NHMRC goal of 130 μg.m-3 at construction, and also decreased by a double-exponential model, but to a long-term (months to years) concentration of 60 μg.m-3. Concentrations of nitrogen dioxide, microbial pollutants and dust mite allergens were also monitored.