Occupational safety risks during maintenance of telecommunication towers

Ribeiro, Rafhael Friederiche; Barkokébas Junior, Béda; Lago, Eliane Maria Gorga; Martins, Ana Rosa Bezerra; Cruz, Felipe Mendes da; Zlatar, Tomi

doi:10.1590/0103-6513.20200108

person Rafhael Friederiche Ribeiro

schoolUniversidade de Pernambuco, Escola Politécnica, Laboratório de Segurança e Higiene do Trabalho, Recife, PE, Brasil

person Béda Barkokébas Junior

schoolUniversidade de Pernambuco, Escola Politécnica, Laboratório de Segurança e Higiene do Trabalho, Recife, PE, Brasil

0000-0003-3130-3277

person Eliane Maria Gorga Lago

schoolUniversidade de Pernambuco, Escola Politécnica, Laboratório de Segurança e Higiene do Trabalho, Recife, PE, Brasil

0000-0003-0987-3492

person Ana Rosa Bezerra Martins

schoolUniversidade de Pernambuco, Escola Politécnica, Laboratório de Segurança e Higiene do Trabalho, Recife, PE, Brasil

0000-0003-4013-3011

person Felipe Mendes da Cruz

schoolUniversidade de Pernambuco, Escola Politécnica, Laboratório de Segurança e Higiene do Trabalho, Recife, PE, Brasil

0000-0002-0163-465X

person Tomi Zlatar *

schoolUniversidade de Pernambuco, Escola Politécnica, Laboratório de Segurança e Higiene do Trabalho, Recife, PE, Brasil

0000-0002-8915-908X

person* tomi.zlatar@gmail.com

Figures (2)
Tables (9)

Thumbnail

Figure 1 Fluxogram of a working day and activities.

Thumbnail

Figure 2 Checklist results.

Thumbnail

Table 1 Antenna characteristics.

Thumbnail

Table 2 Hazard Rating Number.

Thumbnail

Table 3 Main results from the questionnaires 1 and 2.

Thumbnail

Table 4 Classification and Hazard Rating Number of identified risks.

Thumbnail

Table 5 Suggested control measures for falling objects and falls from height.

Thumbnail

Table 6 Suggested control measures for electrocutions and attacks from wild animals.

Thumbnail

Item Question Answer 1 Name 2 What is your education level? () Elementary School () High School () University 3 Admission date ______/______/______ 4 Function 5 Hours Daily: _______ ; Weekly: _______ Monthly: _____ ; Days off: ___ 6 Weight 7 Height 8 Number of Years with experience in the activity 9 Date of last training _____/______/______ 10 Have you ever suffered an accident at work? Which? For how long were you on sick leave? 11 What is your marital status? ()Not married ; () Married 12 Are you an employee of? () Operator ; () Subcontracted company 13 Do you have training for working at height? () yes ; () no 14 Did you do any additional tower maintenance training? () yes ; () no 15 Is training for working at height valid? () yes ; () no 16 How long of experience in this field? () Less than 3 months () 3-6 months () 6-12 months () 1-5 years () More than 5 years 17 How many hours do you normally work? () 4 hours () 8 hours () More than 8 hours 18 How many hours do you normally rest per day? () 4 hours () 8 hours () More than 8 hours 19 How many meals a day do you eat? ()1 () 2 () 3 () 4 () 5 () More than 5. 20 What is the time when meals are usually taken (breakfast, lunch and dinner)? 1. Coffee __:___ 2. Lunch __:___ 3. Dinner __:___ 21 Have you ever suffered any type of accident while performing this activity? If so, what was the accident? () yes ; () no Which?____________________ 22 Have you ever suffered any attack from snakes, spiders, scorpions or centipedes when performing the service? If so, from which animal? () yes ; () no Which?____________________ 23 How many people are on your maintenance team? 24 Are there people who are hired locally to help with the activity? If so, what is her role? () yes ; () no Which?____________________ 25 Is there an inspection by the occupational safety technician when they are carrying out the activity? If so, how often does the safety technician visit the site? () yes ; () no Which?____________________ 26 Was a Daily Safety Dialogue held prior to the start of the activity? () yes ; () no

Thumbnail

Item Question Answer 1 How many employees does the company have? 2 Do you use your own or outsourced team to perform the antenna maintenance activity? 3 What is your education level? 4 How many hours do teams work per day? 5 How many hours do teams rest per day? 6 Does everyone on the team have training in working at height according to NR 35? Is it valid? 7 What is the average experience of teams in this field? 8 Have there been any accidents at work with your team? If so, what was the accident? What was the cause, how many people, how long ago, what preventive measures were adopted? 9 Has any worker ever suffered any kind of attack by poisonous animals during the execution of the services? Such as: snake, spider, scorpion or centipede. 10 How many teams and how many people are part of each team in the activity? 11 In case of outsourcing the service, do you know if there is hiring of people locally to help the activity? If so, what is the function? 12 Is there an inspection by the occupational safety technician when they are carrying out the activity? If so, how often does the security technician visit the site? 13 Is there someone guiding safety procedures for teams performing the service? 14 Is there a PPE Checklist? 15 Has the Preliminary Risk Analysis of the activity been prepared?

Thumbnail

CHECKLIST NR 6 - Personal Protective Equipment - PPE Item Description C/NC/NA Observation 6.2 The Personal Protective Equipment – PPE comes with the indication of the Certificate of Approval - CA. 6.9.2 Is the validity of the Certificate of Approval – CA of the PPE in force? 6.3 Does the company provide risk-appropriate PPE? 6.3 Does the company provide employees with PPE in perfect condition and working order? 6.6.1 Does the company require the use of PPE? 6.6.1 Does the company guide and train the worker on the proper use, storage and conservation of PPE? 6.6.1 Does the company register the provision of PPE to the worker through books, records or electronic system? 6.7.1 Does the employee use PPE only for its intended purpose? 6.7.1 Is the employee responsible for guarding and preserving the PPE? CHECK-LIST NR 7 – Occupational health medical control program Item Description C/NC/NA Observation 7.4.4 Is the Occupational Health Certificate – OHS issued? 7.4.4.3 Does the OHS have the worker data? 7.4.4.3 Does the OHS have the existing specific occupational hazards or the absence of them? 7.4.4.3 Does the OHS have an indication of the medical procedures to which the worker was submitted, including the complementary exams and their respective dates? 7.4.4.3 Does the HSO contain the name and CRM of the coordinating physician? 7.4.4.3 Is there a field in the HSO indicating whether the worker is able or unable to perform his duties? CHECK-LIST NR 10 - Security in electricity facilities and services Item Description C/NC/NA Observation 10.6.5 Does the person responsible for performing the service have the duty to suspend activities when he/she finds a situation or unforeseen risk condition, whose immediate elimination or neutralization is not possible? 10.8.9 Are workers with activities not related to electrical installations developed in a free zone and in the vicinity of the controlled zone, as defined by NR-10, formally instructed with knowledge that allows them to identify and assess their possible risks and take appropriate precautions? 10.11.7 Before starting team work, do its members, together with the person responsible for performing the service, perform the Preliminary Risk Assessment (PRA) of the work? 10.8.8 Did the workers receive a basic NR-10 course? 10.8.8.1 Has the company granted authorization in the form of NR-10 to trained or qualified workers and to qualified professionals who have participated with satisfactory evaluation and use of the courses listed in ANNEX II of NR-10? 10.8.8.2 Is there a biennial refresher training and whenever there is a change of function or change of company, return to work or inactivity for a period exceeding three months and significant changes in electrical installations or change of methods, processes and work organization? 10.12 Does the staff have emergency training? CHECK-LIST NR 17 - Ergonomics (Brasil, 2018) Item Description C/NC/NA Observation 17.1 Before starting activities, do workers perform gymnastics at work? 17.1.2 Is there an ergonomic analysis of the work? 17.2.1.1 In the transport and unloading of materials made by impulsion or traction, is the physical effort made by the worker compatible with his/her strength capacity and that it does not compromise his/her health or safety? 17.3.2 Do they have dimensional characteristics that enable proper positioning and movement of body segments? 17.5.3.2 Is the lighting designed to prevent glare, annoying reflections, shadows and excessive contrast? CHECK-LIST NR 35 - Work at height Item Description C/NC/NA Observation 35.4.6.1 Are there operational procedures for routine work at height activities? 35.2.1 Does the company have a prior study of the conditions at the place where work will be carried out at height? 35.2.1 Does the company adopt the necessary measures to monitor compliance with the protection measures established in this Standard for contracted companies? 35.2.1 Do workers have access to up-to-date information on risks and control measures? 35.2.1 Does the company guarantee that any work at height will only start after the protection measures defined in NR 35 have been adopted? 35.2.1 Does the company ensure the suspension of work at heights when it finds an unforeseen risk situation or condition, whose immediate elimination or neutralization is not possible? 35.2.1 Does the company establish an authorization system for workers to work at heights? 35.2.1 Does the company ensure that all work at heights is carried out under supervision, the form of which will be defined by the risk analysis according to the peculiarities of the activity? 35.2.2 Do workers comply with the expedited procedures regarding work at height, collaborating with the employer? 35.2.2 Are workers instructed to ensure their safety and health and that of other people who may be affected by their actions or omissions at work? 35.2.1 Has the employer promoted training of workers to carry out work at height? 35.2.2 Were workers trained and approved in theoretical and practical training to work at heights with a workload of at least 8 hours? 35.4.8 Is all documentation relating to work at height on file? 35.2.2 Do workers contribute to safety at work at heights? CHECK-LIST NR 35 - Work at height Item Description C/NC/NA Observation IN THE TRAINING PROVIDED, WORKERS WERE SUBMITTED TO APPROACHES ON: 35.3.2 The rules and regulations applicable to working at height? 35.3.2 Risk analysis and impeding conditions? 35.3.2 Potential risks inherent in working at heights and prevention and control measures? 35.3.2 Personal Protective Equipment for work at heights: selection, inspection, conservation and limitation of use? 35.3.2 Discussions about typical accidents at work at heights? 35.3.2 Conduct in emergency situations, including notions of rescue techniques and first aid? THE EMPLOYER PERFORMS PERIODIC BIENAL TRAINING WHENEVER ANY OF THE FOLLOWING SITUATIONS OCCURS: 35.3.3 Change in work procedures, conditions or operations? 35.3.3 Did the periodical biennial training have a minimum workload of eight hours, according to the syllabus defined by the employer? 35.3.5.1 Is the training carried out preferably during normal working hours, and is the training time valid for all purposes as effective working time? 35.3.6 Is the training given by instructors with proven proficiency in the subject, under the responsibility of a qualified professional in occupational safety? 35.3.7 At the end of the training, is a certificate issued containing the name of the worker, program content, workload, date, location of the training, name and qualification of instructors and signature of the person responsible? 35.3.7.1 Is the certificate given to the worker and a copy filed at the company? 35.4.1 Is all work at height planned, organized and carried out by a trained and authorized worker? 35.4.1.2 Does the company assess the health status of workers who work at heights? 35.4.1.2 Are the examinations and evaluation system part of the Occupational Health Medical Control Program - PCMSO included in it? 35.4.1.2 Is the assessment carried out periodically, considering the risks involved in each situation? 35.4.1.2.1 Is the aptitude to work at heights included in the worker's occupational health certificate? 35.4.3 Is all work at heights carried out under supervision, the form of which will be defined by the risk analysis according to the peculiarities of the activity? 35.4.4 Does the execution of the service consider external influences that may change the conditions of the workplace already foreseen in the risk analysis? 35.4.5 Is all work at height preceded by Risk Analysis? CHECK-LIST NR 35 - Work at height Item Description C/NC/NA Observation THE RISK ANALYSIS (AR) MADE BY THE COMPANY, IN ADDITION TO THE RISKS INHERENT TO WORKING AT HEIGHTS, CONSIDERS: 35.4.5.1 The location where the services will be performed and its surroundings? 35.4.5.1 Isolation and signage around the work area? 35.4.5.1 The establishment of systems and anchorage points? 35.4.5.1 Adverse weather conditions? 35.4.5.1 The selection, inspection, form of use and limitation of use of collective and individual protection systems, in compliance with current technical standards, manufacturers' guidelines and the principles of impact reduction and fall factors? 35.4.5.1 The risk of falling materials and tools? 35.4.5.1 The simultaneous works that present specific risks? 35.4.5.1 Compliance with the health and safety requirements contained in other regulatory standards? 35.4.5.1 Additional risks? 35.4.5.1 The impeding conditions? 35.4.5.1 Emergency situations and rescue and first aid planning, in order to reduce the worker's inert suspension time? 35.4.5.1 The need for a communication system? 35.4.5.1 The form of supervision? 35.4.6 Are non-routine work activities at heights previously authorized by means of a Work Permit? 35.4.7.1 For non-routine activities are the control measures evidenced in the Risk Analysis and Work Permit? 35.4.8 Is the Work Permit issued, approved by the person responsible for authorizing the permit, made available at the place of execution of the activity and, at the end, closed and filed in order to allow its traceability? 35.4.8.2 Is the Work Permit valid for the duration of the activity, restricted to the work shift, and may it be revalidated by the person responsible for approval in situations where there are no changes in the established conditions or in the work team? xxx Are PPE's, accessories and anchoring systems specified and selected considering their efficiency, comfort, the load applied to them and the respective safety factor in antenna maintenance? 35.4.5.1 In the selection of PPE, are additional risks considered, in addition to the risks to which the worker is exposed? xxx Are inspections done periodically, on the use of PPE, accessories and anchorage systems? CHECK-LIST NR 35 - Work at height Item Description C/NC/NA Observation 35.5.6.1 Is it a routine inspection of all PPE, accessories and anchoring systems carried out before starting to work? 35.5.6.2 Are the results of periodic and routine inspections recorded on acquisition when PPE, accessories and anchorage systems are refused? 35.5.6.3 Are the PPE, accessories and anchorage systems that present defects, degradation, deformations or suffer impacts from falling unusable and discarded? The exception is when their restoration is provided according to national technical standards or, in their absence, international standards. 35.5.9.1 Is the safety belt the parachute type? Is it equipped with a device for connection to an anchorage system? 35.5.2 Is the anchoring system established by Risk Analysis? 35.5.11 Does the worker remain connected to the anchorage system throughout the period of exposure to the risk of falling? 35.5.11.1 Are the lanyard and fall arrest device fixed above the level of the worker's waist, adjusted to restrict the fall height and ensure that, in the event of an occurrence of fall, it minimizes the chances of the worker colliding with an inferior structure? 35.5.11 Does the energy absorber have a drop factor greater than 1? 35.5.10 Does the energy absorber have a lanyard longer than 0.9m? 35.5.2 Is the anchorage point selected by a legally qualified professional, is it resistant to withstand the maximum applicable load, is it inspected for integrity before use? 35.6.1 oes the employer provide emergency response personnel for work at heights? Note: The team can be own, external or composed of workers who perform the work at height, depending on the characteristics of the activities. 35.6.2 Does the employer ensure that staff have the resources needed to respond to emergencies? 35.6.3 Are emergency response actions that involve working at height included in the company's emergency plan? 35.6.4 Are the people responsible for carrying out the rescue measures able to perform the rescue, provide first aid and have physical and mental fitness compatible with the activity to be performed? CHECK-LIST NBR 5419 - Protection of structures against lightning (Associação Brasileira de Normas Técnicas, 2001) Item Description C/NC/NA Observation 5.1.1 Are the roof's metallic structures interconnected with the LPS capture subsystem? 5.1.1 Verify, when the capture subsystem is of the mesh type, whether the cables/ribbons are installed on the perimeter of the entire coverage, with emphasis on the location of the capture elements in corners, corners, edges and significant protrusions? 5.1.2 Check whether the LPS descent subsystem is interconnected to the LPS capture subsystem? 5.1.2 Check, when possible, if the intermediate rings are properly connected to the LPS descending subsystem? 5.1.2 Check whether the LPS descent subsystem is interconnected to the grounding subsystem? 5.1.3 Check, when possible, that the grounding electrodes are located at least 1.0 meter away from the external walls of the building? C = Compliance; NC = Non Compliance; NA = Not applicable.

Team	Antenna type	Weight (kg)	Dimensions (cm)
1	KATHRIEN 80010767	≈31	144 x 37.7 x 16.9
2	RFS APXVBBLL15X-C-I20	≈33	185 x 58.5 x 28.0
3	ODV-065R15NB18JJ02-G	≈34	196.5 x 49 x 27.0

Level	degree of severity (DS)		exposure frequency (EF)		probability of damage occurring (PD)		number of people at risk (NP)		HRN with risk classification
Low	1	no damage (0)	1	rarely (0.1)	1	impossible – will not occur (0)	1	1-2 people (1)	1	from 0 to 5 (the risk is negligible)
Low	2	slight scratch, injury or bruise (0.1)	2	annual (0.5)	2	almost impossible - only in extreme circumstances (0.033)
Medium	3	injury, laceration or moderate disease (0.5)	3	monthly (1)	3	not expected - although conceivable (1)	2	3-7 people (2)	2	recommended improvement action for RC from 5 to 50 (the risk is low)
	4	injury, minor fracture or mild - temporary illness (2)	4	weekly (1.5)	4	possible - but it is not common to occur (2)	3	8-15 (4)
	5	more serious injury, fracture or illness - temporary (4)			5	some chance - may occur (5)
High	6	injury, loss of limb, eye or hearing - permanent (6)	5	daily (2.5)	6	likely - it would not be a surprise or something unexpected (8)	4	16-50 people (8)	3	improvement action required for RC from 50 to 500 (the risk is high)
	7	loss of two limbs or eyes - permanent (10)	6	hourly (4)	7	expected (10)	5	more than 50 people (12)	4	improvement action required for RC above 500 (the risk is unacceptable)
	8	fatality (15)	7	constantly (5)	8	certainly - no doubt (15)

Questionnaire 1 – with workers			Team 1	Team 2		Team 3	Mean		*±SD
Working experience	Supervisors	Total (years)	10	13		11	11.33		1.53
	Supervisors	Present activity (years	More than five years
	Technician	Total (years)	5	8		7	6.67		1.53
	Technician	Present activity (years)	From one to five years
	Support-worker	Total (years)	2	6		4	4.00		2.00
	Support-worker	Present activity (years)	Less than three years
Working time	Daily (hours)		12	10		9	10.33		1.53
	Weekly (hours)		72	60		54	62.00		9.17
	Monthly (hours)		288	240		216	248.00		36.66
	Rest (days per month)		12	10		9	10.33		1.53
Questionnaire 2 – with employers			Company 1		Company 2			Company 3
General information	Workers (number)		11		21			16
	Education (level)		high school		high school			high school
	Working experience		Mean 6		Mean 7			Mean 5
Accidents	In the company		no		no			Yes (minor)
Accidents	From wild animals		no		no			Yes (minor)
Safety and health measures	Inspections during working activities		no		no			no
	Who supervise the OSH during the activity		Team leader		Team leader			Team leader
	Existence of PPE checklist		no		no			no
	Existence of the Preliminary Risk Analysis		no		no			no

Risk type		degree of severity (DS)		exposure frequency (EF)		probability of damage occurring (PD)		number of people at risk (NP)		HRN with risk classification
Falling objects	tools	8	fatality (15)	7	constantly (5)	4	* possible (2)	2	3-7 people (2)	3	300 (high)
Falling objects	antenna	8	fatality (15)	7	constantly (5)	4	*possible (2)	2	3-7 people (2)	3	300 (high)
Falls from height		8	fatality (15)	7	constantly (5)	4	*possible (2)	2	3-7 people (2)	3	300 (high)
Electrocution		8	fatality (15)	6	hourly (4)	5	some chance - may occur (5)	2	3-7 people (2)	4	600 (Unacceptable)
Attacks from wild animals		5	more serious injury, fracture or illness - temporary (4)	4	weekly (1.5)	4	*possible (2)	2	3-7 people (2)	2	24 (low)

Control Measures		* Falling objects (antenna/tools)	*Falls from height
Elimination		In some cases, it would be possible to use drones to minimize the work at heights, but this solution would not be applicable for all activities conducted at telecommunication towers (therefore this would offer only partial risk elimination).
Substitution
Engineering		Always use adequate equipment and tools to perform the service and add adequate lighting in the working area.
		Isolate (rope off) the area, where fall or drop hazards may exist.	Install adequate guardrails and barriers.
		For antennas: Install a mini electric winch for hoisting the antenna.	Install ladder cages and a ladder fall arrest system (vertical cable lifeline).
		For tools: Utilization of tool lanyards for preventing tolls from falling. Ensure toe boards are in place and inspected frequently.
Administrative	Procedures	Conduct a work in accordance to the project for equipment installation and a specific technical responsibility note. Develop procedures and a work plan, work as a team and remain vigilant of these procedures at all times. Organize a plan and procedures for emergency cases. Whenever possible, conduct working activities in good weather (avoiding strong winds and rain).
	Procedures	Keep all material from a leading edge. Remove items from all loose or unsealed pockets, especially top shirt pockets, such as phones, pens, and tools. Do not hang objects over guardrails.
	Supervision	Develop periodic audit verifications. Release of work permits. Ensure supervisory guidance. Conduct initial onsite inspection check-lists and daily inspection check-lists. Conduct daily occupational safety and health meetings with workers prior to conducting the activity.
	Training and certification	Training for the correct use of all working equipment (including personal protective equipment).
		Training for the implementation procedures of all specific services and how to give first aid assistance.
		Training for working at heights.
	Signalization	Warning labels informing workers use personal protective equipment.
	Signalization	Use warning labels regarding risks of falling objects.	Use warning labels regarding risks of falls from height.
	Medical exams	Conduct necessary medical exams, with adequate certificate and the identification badge.
Personal Protective Equipment		Inspect all PPE on regular basis to confirm if it still meets manufacturers’ recommendations. Purchase, supply and registered all personal protective equipment.
Personal Protective Equipment		Wear hard hats and boots with protective cap.	Wear slip resistant shoes, work restraint systems, fall arrest systems, horizontal lifelines (lanyard, anchor and hook)

Control Measure		* Electrocution	*Attacks from wild animals
Elimination		In some cases, it would be possible to use drones to minimize the work at heights, but this solution would not be applicable for all activities conducted at telecommunication towers (therefore this would offer only partial risk elimination).
Substitution		Additionally, the risk of electrocution might be eliminated by de-energizing or insulating before all works.
Engineering		Always use adequate equipment and tools to perform the service and add adequate lighting in the working area.
		Ensure electrical parts are adequately isolated.	Isolate with barriers or fences the area of the antenna.
		Ensure proper grounding.	Isolate with barriers or fences the area of the antenna.
Administrative	Procedures	Conduct a work in accordance to the project for equipment installation and a specific technical responsibility note. Develop procedures and a work plan, work as a team and remain vigilant of these procedures at all times. Organize a plan and procedures for emergency cases. Whenever possible, conduct working activities in good weather (avoiding strong winds and rain).
		· An electrical hazard survey should be conducted at jobsite to identify potential electrical hazards and intervention measures before work.	· Maintain the area of the antenna in good condition (mowing the lawn on periodic basis).
		· Lock-out and tag-out all electrical parts.	· In wild areas, make noise to keep animals distant.
			· The workers should not approach wild animals, give them room for animals to escape.
	Supervision	Develop periodic audit verifications. Release of work permits. Ensure supervisory guidance. Conduct initial onsite inspection check-lists and daily inspection check-lists. Conduct daily occupational safety and health meetings with workers prior to conducting the activity.
	Training and certification	Training for the correct use of all working equipment (including personal protective equipment).
		Training for the implementation procedures of all specific services and how to give first aid assistance.
		Training for electrical safety to enhance the electrical hazard cognition and the avoidance of unsafe conditions in workplace.	Training for safety with wild animals. Be aware of which animals could be expected in the working area, where the animals could be hided and what to do in case of fronting one. Some animals and insects might have built their nests or hives in holes and parts of the antenna.
	Signalization	Warning labels informing workers use personal protective equipment.
	Signalization	Use warning labels regarding risks of electrocution.	Use warning labels regarding risks of attacks from wild animals.
	Medical exams	Conduct necessary medical exams, with adequate certificate and the identification badge.
	Medical exams		Be vaccinated against possible wild animals’ attacks (anti rabies, anti-tetanus vaccinations, among others).
Personal Protective Equipment		Inspect all PPE on regular basis to confirm if it still meets manufacturers’ recommendations. Purchase, supply and registered all personal protective equipment.
Well-designed non-conductive personal protective equipment.		Wear long sleeved shirt and jeans, wear gloves and boots.

[TFN1] ^*
SD = Standard Deviation.