Renovating moisture-damaged schools reduces the number of microbes present and can improve pupils' health, according to researchers in Finland.

Ulla Lignell at the Finnish National Public Health Institute and colleagues studied two schools for five years.  One had been designated moisture-damaged and was repaired during the study; the other was a reference school.  'We wanted to evaluate the whole process, starting before repairs, during them and thereafter in order to get a better picture about microbial fluctuation and the concurrent health status of the pupils,' said Lignell.

The group collected samples of air from around the schools each year.  They measured the number of bacterial and fungal colonies that grew from the samples from the moisture-damaged (or index) school and compared these to the reference school samples.  Before any renovation work was done, the microbial concentrations were higher in the index school than in the reference school.  However, once the repairs and cleaning had been completed, the group found that the levels in both schools were the same.

They also asked the pupils to fill in health questionnaires each year and found that the health of the children in the index school improved once the renovation work was complete.  The number of respiratory problems reported decreased to the same level as in the reference school.  

Tiina Reponen, an environmental scientist at the University of Cincinnati, Ohio, US, said that the research 'presents a unique dataset on 5-year follow-up of microbial concentrations in two buildings.[and] will be useful for investigators and practitioners dealing with mould-contaminated buildings.' 

Rachel Warfield