Occupational health

We proudly maintained our certification for ISO 14001:2004 in 2017.

We firmly believe that occupational disease and illness can be prevented, provided that risks are properly identified, managed and controlled. Our occupational health, hygiene and wellness programmes are aimed at preventing ill health, but also promoting good health and well-being.

We identify and quantify health hazards to enable us to minimise exposure and prevent injury and illness that may otherwise develop. In adherence to legislative requirements as well as to the risk-based occupational health standards of Rio Tinto, some of our key programmes include, but are not limited to:

  • noise exposure control;
  • workplace ergonomics management;
  • health and medical monitoring;
  • hazardous substances exposure control; and
  • fitness for work and fatigue management.

Occupational medical surveillance
Occupational medical surveillance examinations provide baseline and periodic measurements to detect abnormalities in workers exposed to work-related health hazards early enough to prevent or limit disease progression through exposure modification or medical intervention.

At Rössing Uranium, a risk-based periodic medical programme is followed with consideration of the exposures of employees and contractor employees in different similar exposure groups (SEGs). These require employees and contractors to undergo preemployment, periodical and exit medicals.

SEGs refer to groups of Rössing Uranium workers and site contractors who experience exposures similar enough that collecting exposure samples from any representative from the sub-group of workers provide useful data in terms of predicting exposures of the remaining workers.

Other medical examinations during employment include transfer medicals and return-to-work fitness medicals. Through the mine’s workplace wellness programmes employees are encouraged to undergo additional medical screening tests to manage their own health and as a means of detecting chronic and/or life threatening illness.

Wellness
Our workplace wellness programmes are designed to help us in creating a work environment that is healthy for our employees. Encouraging employees to look after their health and well-being is a critical component of our overall approach to health and safety. The programmes also involve increasing knowledge and awareness through campaigns and education sessions and introducing policies that help employees make healthier choices. Various activities were undertaken during 2017 to support the following programmes:

Wellness week
In collaboration with Namibia Health Plan (NHP), Rössing Uranium’s annual Wellness week was held on site for the fourth consecutive year during August 2017. A total of 334 employees and 244 contractors received wellness screenings during this week.

Blood donation clinics
The Blood Transfusion Service of Namibia held three blood donation clinics on site, during which a total of 160 units of blood were donated. In recognition of the employees' support, we received the Namibian Blood Transfusion Coastal Industrial Award (Gold) at a special event.

Occupational hygiene
Our workplace health exposure monitoring programmes are designed to quantify potential emissions and exposures with the aim of controlling harmful health risks and agents. We have a risk-based monitoring plan which is reviewed annually. During 2017, we had 20 SEGs which were monitored.

Monitoring data is used to better evaluate the risk to people in our workplace and to assist in determining the effectiveness of risk-mitigating controls, compliance with legal requirements, our requirements of the Rio Tinto management system and health performance standards and progress against our objectives and targets.

To ensure that collected data is accurate, comparable and representative statistical analysis and validation is conducted. Internal criteria are established to protect the health of all our workplace personnel, including contractors, and they are defined as occupational exposure limits (OELs). Non-conforming monitoring results are investigated though the incident management process and appropriate actions are developed and implemented to rectify the non-conformance.

Laboratory technician, Cornelius Manjara, of the chemical laboratory at the mine is preparing a test sample from milled rock from the open pit.

 

Some of the health risks and agents at our workplace include exposure to noise, dust (silica), musculoskeletal stressors and microbiological agents found in the water system.

During 2017 our occupational hygiene monitoring programme included measurements of noise levels, respirable dust (including crystalline silica quartz), welding fumes, compressed-air quality (aero testing) and water-borne bacterium (Legionella and potable water).

Dust Our mining activities, such as the blasting, drilling, loading and hauling of ore on unpaved roads are typically the major sources of dust emissions. Transfer and pulverising of ore, which is mostly dry, at the primary crushing circuit and Fine Crushing Plant hugely contribute to high levels of fine dust concentrations, which are experienced at the Processing Plant and surrounding work areas.

During the reporting year, our dust monitoring was focused mostly on crystalline silica quartz. Silica is a natural substance found in our ore; when the ore is processed, dust is created. Some of this dust is fine enough to reach deep inside the lung; this is known as respirable crystalline silica (RCS).

During 2017 we collected 84 RCS samples from ten SEGs, applying the Rio Tinto OEL of 0.1 mg/m3 for RCS. Monitoring results are reported not taking into consideration the protection factor of personal protection equipment (PPE). Although the laboratory workers SEG exceeded the OEL, they are adequately protected through the use of respiratory protection. Respiratory protection is mandatory in this area. Figure 7 on the next page depicts the average personal respirable silica dust based on the OEL of 0.1 mg/m3.

The primary reasons that the dust recorded in 2017 was excessive include, among others, engineering controls which were not effective, inconsistent application of work practices aimed at reducing dust, and limited water resources. A review of all dust control and the implementation of the dust-control strategy will be the main focus in 2018.

Noise The aim of our hearing-conservation programme is to protect our workers' hearing, mainly because over-exposure to sound above the stipulated OEL of 85 dB (A) can result in noise-induced hearing loss, which is irreversible. This can be aggravated by simultaneous exposure to some chemical substances, for example carbon monoxide and solvents. Noise may also have an adverse effect on other systems, including the body’s cardiovascular system.

Mining equipment, combined with high volume settings on two-way and FM stereo radios in the equipment cabins, as well as general plant and equipment noise, are the main sources of over-exposure to noise at the mine site. Noise zoning is applied in high-risk areas, together with the application of customised hearing-protection devices. In other areas, disposable ear plugs are used, as and when necessary.

Advisor for Occupational hygiene, Lulia Hamutenya, taking a noise level reading at one of the mine's workshops.

 

 

 

Monitoring results are reported not taking into consideration the protection factor of personal protection equipment (PPE). All employees who work in dust or noise high-risk areas are issued with customised respiratory- or hearingprotection devices. These devices are maintained and fit-tested on an annual basis. Measured exposures indicated in Figures 7 and 8 do not take into account the protection factor provided by these devices.

 

During 2017, eight of the 12 SEGs that were monitored exceeded the occupational exposure limit of 85 dB (A). These measured exposures do not take into account the protection factor provided by the hearing-protection devices in use. The primary reason for these eight exceedances include the use of impact tools, general plant noise, noise from heavy mobile equipment, maintenance tasks, and high volumes on two-way radios.

Figure 8 on the previous page depicts the average annual personal noise exposures measured for the different similar exposure groups in the reporting year.

Hearing-protection devices (ear plugs, ear muffs and customised hearing-protection devices) are our critical control for noise exposure. In 2018 we will continue to focus on ensuring consistent and correct usage of these devices. Supporting these actions, we will implement a hearing-protection, fit testing validation programme for disposable ear plugs.

We also plan to roll out a technology-based, fatigue risk assessment programme to enhance understanding of our risk and improving on the mine’s fatigue management controls.

To remain aligned with global and local, emerging health threats and managing these pro-actively, a mental health programme will be designed and rolled out.

Monitoring dust exposure and supporting the implementation of the dust management plan will remain a key focus area throughout 2018.

Radiation safety

The primary aim of radiation safety is to assess, quantify and control the risk of radiation exposures in the workplace. In our Radiation Management Plan (RMP) we provide a comprehensive summary of the risk assessments, sources and receptors, and controls implemented. Our RMP is updated annually and anyone can access it via our website via the ‘Reports and Research’ tab.

The National Radiation Protection Authority (NRPA) audits the implementation of our RMP annually and we provide a narrative report on it to the NRPA. The RMP implementation reports for the past few years are also available for download on our website.

Workers who are considered to be at an elevated risk for radiation exposure are termed ‘radiation workers’. We consider anyone at risk of receiving an annual dose of 5 milli-sieverts (mSv) (from all exposure pathways combined) or more, to be a radiation worker.

All the workers belonging to the Final Product Recovery and the Recovery similar exposure groups (SEGs) are classified radiation workers. Workers in these groups receive a continuous gamma monitor in the form of a thermo-luminescent dosimeter, replaced at intervals of three months. They also undergo monthly urine testing to check for accidental ingestion of uranium. Female radiation workers undergo monthly pregnancy testing to enable prompt removal of pregnant employees from this working area.

In 2017 we performed 800 urine samples, without exceeding the warning level for uranium in urine which is 20 micro-grammes per litre (μg/L). We also performed 37 pregnancy tests of female radiation workers, as well as 65 pregnancy tests of females not classified as radiation workers who submitted to the testing on a voluntary basis — seven of these tests were positive.

Over the years we have gathered a comprehensive database of radiation exposure measurements by pathway and by SEG. Although not needed in terms of risk, we continue to monitor three radiation exposure pathways for each SEG randomly every year.

In 2017 we collected over 600 personal radiation exposure samples and many more additional samples of area dose rates. In addition, we have a continuous record of the gamma dose for radiation workers. No worker received a dose exceeding 5 mSv during the reporting year. The average annual dose when averaging over the entire workforce was again 1 mSv, as has been recorded consistently for the past five years.

Assuming a working year of 2,000 hours, the annualised and averaged dose by SEG is displayed in Figure 11 on page 34. The average annual dose is shown for each SEG, broken down into contributions from gamma radiation, dust inhalation and radon inhalation. The dose value recorded in 2016 is shown to indicate the variability of the measurements. The weighted annual dose, 1 mSv per annum, is displayed as a dotted green line.

The area exhibiting the highest risk in terms of radiation exposure is the Final Product Recovery (FPR) area. The area is a controlled radiation area with access restriction, fingerprint access and contamination checks for exiting personnel. We perform regular monitoring of surface contamination, inhalation dose rates for radioactive dust and area gamma dose rates.

To optimise these variables, we set a target of a maximum average surface contamination of 1 Bq per square centimetre (Bq/cm2) for the area, and a maximum average dust inhalation dose rate of 10 micro-sieverts per annum (μSv/h).

In 2017 we significantly improved on the controls for dust and contamination in the area. And we have been able to meet both of the targets with an average surface contamination measured at 1.0 Bq/cm2 exactly, and an average dust inhalation dose rate (without taking into consideration the protective factor offered by the use of respiratory protection) of 4 μSv/h.

The FPR area exhibits five stacks, three of which are low-emission venting stacks from the FPR building and two of which hail from the FPR roasters. As the latter two are fed with the exhausts from the uranium-roasting process, the emissions need to be closely monitored and controlled.

For the past ten years the emissions from each stack were monitored on an annual basis by an external, accredited consultant. This monitoring allows us to draw conclusions about the efficiency of the water-based, stack-scrubbing systems. It also enables us to calculate the annual emission of the total particulate matter from the stacks by extrapolation from the sampling result.

Because of the large variability of stack volumetric flow rate and scrubbing efficiency, the annual monitoring frequency proved to be unreliable in yielding representative results. Based on the extrapolated results from the past years, we realised that the stack scrubbing efficiency needs to be improved and monitoring needs to take place continuously.


Advisor Radiation Safety, Nelao Endjala, at one of the tanks in the Processing Plant, with an Automess Teletector Probe instrument which is used to measure levels of gamma radiation in hard-to-access places, such as inside tanks.

 

Safe operations

We therefore designed a new stack-scrubbing system due to replace the old scrubbers in 2018 and procured equipment to transition from annual to continuous monitoring.

Mid-year we discovered that one of our officers had falsified some results that were to be collected for monitoring radioactive surface contamination in the FPR area. While this type of monitoring does not form part of our legal reporting requirements, it does represent an integral part of our site specific controls and the incident was taken very seriously.

The officer was suspended immediately upon discovery of the falsification. We reported this transgression to the NRPA. Disciplinary action resulted.

Raising awareness of radiation and maintaining appropriate perspective on the associated risks in the workplace remain important focal areas. We continued providing individualised training, tailor-made for each work area.

To render the workplace rules and regulations more accessible for our employees, we embarked on two initiatives:

  • We developed a radiation safety calendar for the 2018 calendar year, which contains 26 fact sheets about radiation safety. The calendars were distributed to all employees.
  • We developed an online radiation safety refresher training course. The online course will be implemented in 2018 and should supplement the teaching and awareness materials which are contained in the calendar.

To share information of our radiation protection programmes with the public, we post many of our reports, fact sheets and booklets on Rössing Uranium’s website, under the ‘Reports and Research’ tab. Apart from the RMP and RMP implementation reports mentioned earlier, we share technical reports on environmental risk, as well as fact sheets and booklets on radiation protection in uranium mining.

Development of professional skills in radiation safety in the Erongo Region is important and continuously deliverable. In 2017 we again supported the Namibian Uranium Institute with the presentation of several courses to improve the skills of radiation safety officers and mining professionals. The ongoing training support also included an annual radiation safety refresher course for radiation safety officers.

 

Raising awareness of radiation and maintaining appropriate perspective on the associated risks in the workplace remain important focal areas.

 

Epidemiology
From 2011 onwards we began preparations for an epidemiological study on the potential effects of occupational radiation exposures on mine workers, designed to stand up to scientific scrutiny. The scoping for the study, which included an investigation on the available data and the study designs possible, was started in 2014 and concluded in 2015.

The study project was awarded to the Centre for Occupational and Environmental Health at the University of Manchester in the UK and the study kicked off in October 2015. The study design, chosen for best statistical power, was that of a case-cohort study, where a sub-group of the workers who have been diagnosed with specific cancers of interest (the cases) are compared with a larger subgroup of workers (the cohort).

We embarked on a media campaign to inform former workers about the study and to allow them to withdraw their consent for the use of their data, although all data was anonymised. We obtained ethics approval from the Ministry of Health and Social Services, from the University of Manchester and from the South African cancer registry, based on the study design submitted.

We appointed an external oversight committee, consisting of community leaders and Government representatives to provide external input and oversight. We also closely worked with the Namibian and South African cancer registries to identify as many cancer cases within our workforce as possible. The study design
ensured that all information about cancer cases is anonymised before it was communicated to the research team, to ensure no personal information is conveyed.

In 2017 we completed the collection of human resources data and cancer data from the cancer registries and gathered the relevant occupational hygiene data for the past 40 years. The statistical analysis of this information will be completed in 2018, with a final report expected towards the end of 2018. More information about the epidemiology study is available on Rössing Uranium's website, under the ‘Reports and Research’ tab.

Process safety management

Process safety management (PSM) is a systematic approach of controlling the unwanted release of hazardous substances, process solutions or fires and explosions that have the potential to significantly impact the health and safety of employees, the environment or the business.

Rössing Uranium’s PSM team forms part of the Rio Tinto process safety working group sub-committee, which is tasked with the development of training packages for the Rio Tinto Group. The Institute of Chemical Engineers (IChemE) provided training to the PSM team on the fundamentals of process safety management. This knowledge will be applied when implementing PSM standards and developing training packages for management and first-line leaders.

In 2017 the PSM team started an analysis of all process hazards. Chlorine gas was identified as one such hazard at the mine. A trialrun to substitute chlorine with calcium hypochlorite (which is in a granular format) was successfully completed during the second half of 2017 and the positive results will steer the mine to eliminate the chlorine gas hazard from site.

In collaboration with the asset management team, the PSM team also identified all critical process safety assets at the mine. The teams are formalising controls to manage these hazards.

Towards the end of 2017, Rössing Uranium had its first process safety audit with exceptional results, showing the commitment and
progress being made towards making the mine a safer place by implementing process safety management controls.

In 2018 the focus will be on the accelerated deployment of the controlled-focused approach as being mandated by the Rio Tinto Energy and Minerals product group. The baseline assessment for both sulphuric acid and anhydrous ammonia was completed and is being managed.

A process safety engineer with a chemical engineering background and experience in a processing environment was appointed to assist with driving the process safety culture, to implement Rio Tinto’s D6 Process Safety standard and to accelerate the deployment of the controlled-focused approach.