Received: 24 July 2019
Accepted: 21 September 2019
First Online: 30 September 2019
Ethical approval and consent to participate
: Informed and written consent was obtained from all participants. All subjects were informed that data from the research protocol would be treated in an anonymous and collective way, with scientific methods and for scientific purposes in accordance with the principles of the Helsinki Declaration.Ethical approval is not necessary because all medical and instrumental examinations were performed according to Italian law concerning the protection of workers exposed to occupational risks (D.Lgs. 81/2008).
: Not applicable.
: The authors declare that they have no competing interests.