Indoor air quality during renovation actions: a case study

Abstract

A temporary renovation activity releases considerably high concentrations of particulate matter, viable and non-viable, into air. These pollutants are a potential contributor to unacceptable indoor air quality (IAQ). Particulate matter and its constituents lead, sulfate, nitrate, chloride, ammonium and fungi as well as fungal spores in air were evaluated in a building during renovation action. Suspended dust was recorded at a mean value of 6.1 mg m⁻³ which exceeded the Egyptian limit values for indoor air (0.15 mg m⁻³) and occupational environments (5 mg m⁻³). The highest particle frequency (23%) of aerodynamic diameter (dae) was 1.7 µm. Particulate sulfate (SO₄²⁻), nitrate (NO₃⁻), chloride (Cl⁻), ammonium (NH₄⁺) and lead components of suspended dust averaged 2960, 28, 1350, 100 and 13.3 µg m⁻³, respectively. Viable fungi associated with suspended dust and that in air averaged 1.11 × 10⁶ colony forming unit per gram (cfu g⁻¹) and 92 colony forming unit per plate per hour (cfu p⁻¹ h⁻¹), respectively. Cladosporium (33%), Aspergillus (25.6%), Alternaria (11.2%) and Penicillium (6.6%) were the most frequent fungal genera in air, whereas Aspergillus (56.8%), Penicillium (10.3%) and Eurotium (10.3%) were the most common fungal genera associated with suspended dust. The detection of Aureobasidium, Epicoccum, Exophiala, Paecilomyces, Scopulariopsis, Ulocladium and Trichoderma is an indication of moisture-damaged building materials. Alternaria, Aureobasidium, Cladosporium, Scopulariopsis and Nigrospora have dae >5 µm whereas Aspergillus, Penicillium and Verticillium have dae <5 µm which are suited to penetrate deeply into lungs. Particulate matter from the working area infiltrates the occupied zones if precautionary measures are inadequate. This may cause deterioration of IAQ, discomfort and acute health problems. Renovation should be carefully designed and managed, in order to minimize degradation of the indoor and outdoor air quality.