Screening among workers in a dockyard in the city of Varna

Hearing reduction and hearing loss are common among the industrial workers exposed to continuous and intensive occupational noise, although they are completely preventable. Hearing protection devices are more and more widely used in modern industry, however, they are not efficient enough. That is why preventive otorhinolaryngologic examinations should regularly been performed to enable the early diagnosis and timely treatment of this severe pathology. Several recent investigations deal with the damage of the medium and inner ear as well as of the hearing characteristics caused by intensive and longlasting industrial noise, especially in construction in the USA (Wu, et al., 1998; Edelson, et al., 2009), in dockyards (Sliwinska-Kowalska, et al., 2004; Zamyslowska-Szmytke, et al., 2007), in a liquefied petroleum gas cylinder infusion factory in Taiwan (Chang, et al., 2009), in a semiconductor factory (Chou, et al., 2009), in steel mills, lumber mills and marble shops in Brazil (Boger, et al., 2009), among truck drivers (Krishnamurti, 2009; Karimi, et al., 2010), etc. The combined harmful effects of workplace noise and various agents such as chemicals (Morata, et al., 1993; Sliwinska-Kowalska, et al., 2004; Sliwinska- Kowalska, et al., 2005) and heat (Singh, et al., 2010) are intensively studied, too. Binaurial hearing impairment caused by simultaneous exposure to occupational noise and cigarette smoke is proved, too (Mohammadi, et al., 2010). The role of shift-work on noise-induced hearing loss is emphasized (Borchgrevink, 2009; Chou, et al., 2009). The purpose of the present paper is to analyze the dynamics of hearing reduction of dockyard workers by twofold comprehensive screening examinations as a first step in a broad prevention programme.