Indoor air quality in London schools. Part 2: long-term integrated assessment

Abstract

The overall aim of the study is to provide empirical evidence on indoor pollution levels to assist the formation of indoor air quality (IAQ) benchmarking of school buildings under operational conditions. This article is the second part of the study and aims to quantify seasonal variation of chemical and microbial levels in London schools. Passive diffusive sampling was employed for radon, NO₂, and O₃ measurements. Fungal and bacterial groups and allergens were sampled with suction-based methods in settled dust and endotoxin levels were sampled in dust collected with natural deposition. Biological contaminants were analysed with molecular, cultivation-independent methods. The strong temporal and spatial variability of outdoor NO₂ levels affected indoor levels and is therefore an important consideration when selecting sites for new school buildings. There is a need to further clarify on the effect of finishing, such as wall-to-wall carpeting, which may act as a significant reservoir of irritants and allergens and impact school IAQ.

Keywords:

• allergens
• bacteria
• endotoxin
• fungi
• nitrogen dioxide (NO₂)
• ozone (O₃)
• volatile organic compounds