# Analysis of Chainsaw Emissions during Chestnut Wood Operations and Their Health Implications
## 3 Results and discussion  
### Noise Exposure  
In order to assess the levels of acoustic pressure on the hearing apparatus of operators, a statistical analysis was carried out on a total sample of 1260 observations. For each operation, the three most representative diametric classes were identified:  
1. Delimbing (DE): 5 cm; 7 cm; 9 cm;
2. Bucking (BU): 12 cm; 16 cm; 18 cm;
3. Felling (FE): 10 cm; 15 cm; 20 cm. It should be noted that according to the current legislation in Italy (D.P.R. 81/2008), which is the Consolidated Law on occupational health and safety, the following weighted limits of exposure are set for workers operating on construction sites:  
1. Lim1--80 dB (below this limit, there is no risk to the health of workers);
2. Lim2--85 dB (between 80 and 85 dB, the employer provides PPE, trains operators, and appoints a competent physician);
3. Lim3--87 dB (between 85 and 87 dB, workers are required to use PPE, health surveillance is activated, and workplaces must be properly cordoned off and marked). Above 87 dB, measures are required to bring exposure below the limit value. Consolidation Act 81/2008 also sets peak values, that is, the maximum value of instantaneous sound pressure. These limits are as follows:  
1. Lim1_peak: 135 dB;
2. Lim2_peak: 137 dB;
3. Lim3_peak: 140 dB. For each diametric class related to a specific silvicultural operation, the following noise emission values (dB) were identified:  
1. Average of the sound emission values;
2. Median of the sound emission values;
3. Maximum sound emission value recorded;
4. Standard deviation;
5. Coefficient of variability. The analysis of the data from the various samples revealed coefficients of variation (CVs) below 15 percent. This indicates moderate relative variability from the mean, suggesting a good quality of the data acquisition methodology. Consequently, the mean and median values can serve as reliable indicators for conducting further analyses. Table 1 presents the descriptive statistics for each silvicultural operation and for each diametric class. It is evident from Table 2 that the legal limits are consistently exceeded, and this situation is further exacerbated by the lack of proper personal protective equipment at forestry sites [8]. However, it is worth noting that the recorded values do not come close to the peak values mandated by law. Further investigations have been conducted to provide a more detailed understanding of the dynamics present in these contexts. Values exceeding 1 indicate the surpassing of the analysed critical threshold, along with a percentage indicator relative to the threshold itself. For instance, in the case of falling operations on logs with a diameter falling within the 7 cm class, an exceedance of 10% for Lim1 is reported. The percentage of exceedance ranges from 8% to 27%, with an average of 11% for DE, 19% for FE, and 16% for BU, in relation to Lim1. It is important to emphasize that even small differences of a few dB in noise levels can result in a significant increase in perceived noise intensity. Noise is measured on a logarithmic scale, where a 3 dB increase corresponds to a doubling of perceived noise intensity. Figure 3 shows the comparison between the average values of sound emissions detected for each diametric class, along with the respective legal limits (a-c). Additionally, it presents the maximum recorded values for each diametric class, along with the corresponding peak limit set by law (d). The analysis also confirms that in at least 50 percent of the activities the limits imposed by current regulations are exceeded. The rate at which the thresholds, set by current regulations, are exceeded for each individual operation and for each diametric class were calculated; the results are shown below, in Table 3.  
In relation to Lim1, during DE operations, the exceedance rate varies from 57% for the smallest diameter trees to 69% for the largest diameters. Similarly, for FE and BU operations, the rates vary from 65% to 83% and 69% to 77%, respectively.