Data on the main working conditions with influence on the development of hearing loss amongst the occupational population in Spain

Obtaining reliable and objective data on certain working conditions is necessary to analyse the causes and variables that can influence the development of hearing loss amongst the working population. Objective occupational data have been collected from a heterogeneous sample of 1418 workers in Spain, see “How activity type, time on the job and noise level on the job affect the hearing of the working population. Using Bayesian networks to predict the development of hipoacusia” (Barrero et al., 2018) [1]. Among the main factors analysed are the noise levels to which these workers are exposed, measured at their respective workstations, and the assessment of their hearing status, evaluated by audiometric medical tests. These factors provide information to predict the development of hypoacusia.


a b s t r a c t
Obtaining reliable and objective data on certain working conditions is necessary to analyse the causes and variables that can influence the development of hearing loss amongst the working population. Objective occupational data have been collected from a heterogeneous sample of 1418 workers in Spain, see "How activity type, time on the job and noise level on the job affect the hearing of the working population. Using Bayesian networks to predict the development of hipoacusia" (Barrero et al., 2018) [1]. Among the main factors analysed are the noise levels to which these workers are exposed, measured at their respective workstations, and the assessment of their hearing status, evaluated by audiometric medical tests. These factors provide information to predict the development of hypoacusia. &

Value of data
The dataset shows the average noise levels to which workers from different sectors of activity are exposed and can be used to match data from other countries or sectors of activity.
The dataset can be used to show different aspects of occupational exposure to noise, such as daily noise exposure (hours), number of years in the workplace, noise exposure in previous employment, noise protection system based on hearing protection or time limitation.
The dataset can be useful for researchers to see the results of the audiometric studies carried out on workers. The workers hearing health has been compared to international indices of auditory assessment.
The dataset provides information for future health and safety at work studies, with special interest for Health and Safety Technical Experts and medical professionals.

Data
Medical and occupational environment data were collected over a period of approximately two years from a sample of 1418 workers from different activity sectors, ages and nationalities, who were working in the provinces of Burgos and Valladolid, Spain. Ingemédica S.L., an occupational health and safety consultancy, has collaborated with the University of Burgos to collect the data.
The dataset was designed to answer the basic questions of how and why some workers develop hypoacusia. The variables are classified as demographic and personal factors (meaning those that characterise a specific population) occupational factors (those related to the working conditions in different companies) and non-occupational factors (those that are manifested outside the work environment) [1].
Data from 1418 workers have been obtained including demographic/personal data (age, gender, height, weight, nationality, blood pressure, etc), data on occupational factors (the type of sector or activity of the company where these people work, job title, noise levels, daily exposure, number of years at work, the use or not of hearing protection, whether or not there is any limitation of temporary exposure to noise, occupational exposure to noise in previous employment, exposure to ototoxic agents) and data on non occupational factors (pre-existing auditive diseases, and the use of medicines that may have otic side effects).
All the data were anonymised and collected with the consent of the companies and individuals involved.

Experimental design, materials and methods
The necessary data has been achieved through two main lines of work. The first, focused on obtaining the data referring to the noise levels at the workstations, has been carried out using sound level meters and noise dosimeters. These measurements have been made by qualified occupational hygienists. The second line of work was consisted of carrying out medical tests which included audiometries and questionnaires. The questionnaire, based on Occupational Health Surveillance Protocols, was developed by the Department of Health and Welfare of the Junta de Castilla y León and authorised by the Ministry of Health and Consumer Affairs of Spain [2]. In compliance with the Health Surveillance Protocols and the current Spanish regulations on Health and Safety at work [3,4] the audiometric tests were carried out by specialised personnel (occupational physicians and nurses) using audiometers and soundproofed cabins.
This section considers the frequencies and categories associated with the main occupational factors selected as influential in the development of hearing loss:

Noise level by activity sector
The sample has been divided into the traditional economic sectors which are: Construction, Agriculture/Livestock, Industry and Services. The percentage frequency of each would be 54.16%, 0.35%, 22.85% and 22.64%, respectively.

Sector: Construction.
The noise level distribution for the sample related to the construction sector can be seen in Table 1.
Sector: Agriculture/Livestock Table 2 shows the noise level distribution related to the sector of Agriculture/Livestock.

Sector: Industry
Noise level distribution for the industry related sample can be seen in Table 3.

Sector: Services
Noise level distribution for the sample related to the Services sector can be seen in Table 4. Table 5 shows how the sample is distributed according to the different jobs analysed.   Job title: Administration Table 6 shows the noise level distribution for the administration personnel.

Job title: Warehouse operative
The noise level distribution for warehouse operatives is presented in Table 7.  Job title: Carpenter Table 8 shows the noise level distribution for the carpenter's workstation.

Job title: Sales representative
The noise level distribution for the sales representative position can be seen in Table 9.
Job title: Driver Table 10 shows the noise levels for the driver position.   The noise level distribution for the shop assistant/receptionist is shown in Table 11.
Job title: Nurse/Assistant nurse Table 12 shows the noise level distribution for nurse/assistant nurse position.

Job title: Electrician/Technician/Installer
The noise level distribution for the electrician, technician and installer workstations is shown in Table 13.
Job title: Section Manager/Site manager Table 14 shows the noise level distribution for the workstation: Manager/Site manager.   Job title: Plumber The noise level distribution for the plumber's workstation can be seen in Table 15.

Job title: General Manager/Director
The noise level distribution for the General Manager/Director is shown in Table 16. Table 17 shows the noise level distribution for the Engineer/Architect position.   Job title: Gardener

Job title: Engineer/Architect
The noise level distribution for the gardener position is shown in Table 18. Table 19 shows the noise level distribution for the cleaners.

Job title: Production operator
The job title "production operator" includes several job titles, e.g. construction worker, industry worker, food production worker, concrete production worker, manufacturing industry worker, paper production worker and chemical production worker. Table 20 shows the noise level distribution for the production operator.   Job title: Delivery driver Table 21 shows the noise level distribution for the delivery driver position.
Job title: Welder Table 22 shows the noise level distribution for the welder workstation.
• Job title: Security guard Table 23 shows the noise level distribution for the security guard position. Table 24 shows the daily noise exposure in hours.     Fig. 1 shows the distribution of the sample according to the number of years the employees have been at their work locations. The average is 10.2 years, with a minimum value of 0 years and a maximum of 49 years.

Years on the job
This variable has been discretized as shown in Table 25. Fig. 2 shows the sample distribution according to the number of years of noise exposure in previous employment. The average is in 5.2 years, with a minimum value of 0 years and a maximum of 46 years. Table 26 shows the sample distribution according to the number of years in previous employment.

Noise protection system based on hearing protection
The sample is divided into two unique groups, depending on whether or not the worker uses hearing protection as a noise protection system. The results of the distribution can be seen in Table 27. Table 28 shows the sample distribution by noise protection based on time limits.

Occupational exposure to ototoxic agents
The sample has been divided into two groups, depending on whether the worker has been exposed to ototoxic agents or not, such as: carbon monoxide, lead, benzene and mercury. The results of their distribution in the two groups can be seen in Table 29.

SAL index
The SAL index (Speech Average Loss), evaluates the conversation frequencies in 500 Hz, 1000 Hz and 2000 Hz to then perform the arithmetic mean of the hearing loss in decibels of those frequencies.
The SAL index classifies the results from A to G depending on the worsening of hearing; SAL-A meaning both ears are within normal limits and SAL-G total deafness [2]. Table 30 shows the distribution of the sample in accordance with the SAL index.

ELI index
The ELI index (Early Loss Index) is calculated by subtracting a correction value for presbycusis from the loss in the frequency of 4000 Hz (weighting the loss by age and by gender). The frequency of 4000 Hz is evaluated and the acoustic traumas are classified according to an increasing scale A-B-C-D-E, from higher to lower auditory capacity, assessing the two ears individually [2]. Table 31 shows the sample distribution according to the ELI Index.

Percentage of Global Hearing Loss
This variable has been classified by establishing groups in Percentage of Hearing Loss intervals. This index considers each ear individually (monaaural) and both ears collectively (binaural) [2].
With respect to the Hearing Loss Percentage Index for the Right Ear, the average is a hearing loss of 1.45%, with a minimum value of 0% and a maximum value of 88.13%. In reference to the Hearing Loss Percentage Index for the Left Ear, the average is 1.66%, with a minimum value of 0% and a maximum  value of 91.12%. Once it has been discretized and divided into groups. Finally, with respect to the Binaural Percentage Index, the average is 1%, with a minimum value of 0% and a maximum of 67%. Table 32 shows the results obtained.

Transparency document. Supporting information
Transparency data associated with this article can be found in the online version at http://dx.doi. org/10.1016/j.dib.2018.08.054.