## 3 Results
Table 4 shows the results of microbial contamination based on the GIMC/m\({}^{3}\) and on the IMC measured in the gyms. Because of the elevated fungal count observed in this period, the mean of GIMC/m\({}^{3}\) was higher during air conditioning (\(p=0.019\)), with a maximum value of 15,248. The mean of the IMC values was always <1, which implies that the counts of the psychrophilic bacteria were almost always higher than the counts of the mesophilic bacteria; however, no significant differences in the index were observed when central heating was on or off. Similar sampling and monitoring methods were adopted for the evaluation of the air quality of libraries. The average levels of contamination detected during air sampling showed small oscillations with very restricted values of CFU/m\({}^{3}\) both for bacterial loads (mesophilic and psychrophilic) and for fungi. The results of airborne bacteria and fungi recovered from the libraries showed that the CFU/m\({}^{3}\) values were higher during heating than during simple ventilation or air conditioning. However, no significant differences in the concentrations of all microbial counts were evidenced in the three functioning modes of the ventilation system (Table 5). In addition, the transformation of total microbial count values into the indices evidenced a general reduction of the GIMC/m\({}^{3}\) values and of the IMC values in air conditioning compared to heating, but the statistical analysis showed no significant differences. The IMC index assumed values lower \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Functioning Modes** & **N** & **GIMC/m\({}^{3}\)** & **IMC** \\ \hline  & & M \(\pm\) SD & Min-max & M \(\pm\) SD & Min-max \\ Heating & 10 & 2703.50 \(\pm\) 2144.84 & 1160-7090 & 0.90 \(\pm\) 0.74 & 0.12 -24.0 \\ Simple ventilation & 10 & 2420.90 \(\pm\) 1645.70 & 910–6548 & 0.50 \(\pm\) 0.30 & 0.17–1.20 \\ Air Conditioning & 10 & 4606.40 \(\pm\) 4428.70 & 1480-15,248 & 0.60 \(\pm\) 0.39 & 0.20–1.40 \\ \hline \hline \end{tabular} The number of samples (N), mean (M), standard deviation (SD), and range of values are indicated for each sampling period.  
\end{table} 
Table 4: GIMC/m\({}^{3}\) and IMC measured in gyms during heating, air conditioning, and simple ventilation. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Functioning Modes** & **N** & \multicolumn{2}{c}{**Mesophilic Bacteria**} & \multicolumn{2}{c}{**Psychrophilic Bacteria**} & \multicolumn{2}{c}{**Fungal Count**} \\  & & \multicolumn{2}{c}{**CFU/m\({}^{3}\)**} & \multicolumn{2}{c}{**CFU/m\({}^{3}\)**} & \multicolumn{2}{c}{**CFU/m\({}^{3}\)**} \\ \hline  & & M \(\pm\) SD & Min-max & M \(\pm\) SD & Min-max & M \(\pm\) SD & Min-max \\ Heating & 10 & 1096.60 \(\pm\) 294.40 & 140–2850 & 1446.40 \(\pm\) 1356.82 & 180–4650 & 187.50 \(\pm\) 167.02 & 20–568 \\ Simple ventilation & 10 & 393.00 \(\pm\) 257.00 & 120–980 & 819.00 \(\pm\) 432.40 & 330–1800 & 1208.90 \(\pm\) 1459.60 & 90–4848 \\ Air Conditioning & 10 & 666.50 \(\pm\) 477.76 & 200–1800 & 1509.00 \(\pm\) 1354.02 & 440–4400 & 2430.90 \(\pm\) 3678.31 & 8–10,848 \\ \hline \hline \end{tabular} The number of samples (N), mean (M), standard deviation (SD), and range of values are indicated for each sampling period.  
\end{table} 
Table 3: Total microbial concentrations measured in gyms during heating, air conditioning, and simple ventilation. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Functioning Modes** & **N** & **GIMC/m\({}^{3}\)** & **IMC** \\ \hline  & & M \(\pm\) SD & Min-max & M \(\pm\) SD & Min-max \\ Heating & 10 & 2703.50 \(\pm\) 2144.84 & 1160–7090 & 0.90 \(\pm\) 0.74 & 0.12 -24.0 \\ Simple ventilation & 10 & 2420.90 \(\pm\) 1645.70 & 910–6548 & 0.50 \(\pm\) 0.30 & 0.17–1.20 \\ Air Conditioning & 10 & 4606.40 \(\pm\) 4428.70 & 1480–15,248 & 0.60 \(\pm\) 0.39 & 0.20–1.40 \\ \hline \hline \end{tabular} The number of samples (N), mean (M), standard deviation (SD), and range of values are indicated for each sampling period.  
\end{table}