Table 1.

Evaluation of the alive microbial biomass retrieved from either untreated or differently treated stone material.

	Days of treatment
	2 (days)	10 (days)	6 (months)	12 (months)
Sample	Colony forming units per gram of stone (CFU/g)
Untreated stone	5 ± 2	13 ± 3	10 ± 4	15 ± 2
Preventol RI-80 treated stone	0	0	1 ± 1	3 ± 2
Preventol RI-80@MSN-treated stone	0	0	0	0