Commitment to Using Good Science

In an industry-leading initiative, the Sudbury Smelter, part of our Sudbury Integrated Nickel Operations, began a urinary nickel biological monitoring program in 2012. The program was started in response to a movement to stigmatize, regulate and ban nickel, based partly on misinterpretation about some of the available scientific information about nickel, and partly on gaps in the information.

According to Marc Butler, Sudbury INO’s Director of Regulatory Affairs: “As part of the commitment to using good science to counter misinformation around the health effects of nickel, we began a urinary nickel monitoring program that tracks nickel exposures of smelter workers over time. Between the hygiene monitoring data, ambient air quality results, and the urine work, we can build up a good understanding of exposures in the smelter.”

Workers at the Sudbury Smelter follow the SafeNickel work programs by managing hazards using the hierarchy of controls. Controls such as engineered ventilation systems, procedures, using the right personal protective equipment (PPE) and following good hygiene to keep their exposures low are just some of the components to their occupational hygiene program. While the occupational hygiene air monitoring program addresses the direct health effects of nickel exposure on the respiratory system, it does not provide information on the total amount of nickel absorbed into the body by all routes and whether controls in the workplace are effective in limiting the amount of systemic (whole body) nickel exposure.

From the outset, the program had important goals beyond just documenting urinary nickel levels in workers at the smelter. The program was implemented to advance Glencore’s goal of zero harm, and more generally to promote further research into occupational exposure to nickel. There are currently no health-based occupational limits for nickel in urine. 

According to Marc, there were some challenges getting the program started. Some were technical, like achieving a low enough detection limit, or deciding how to report results so they could be compared between individuals and with other studies. As with any voluntary program, recruitment of employees required a great deal of communication with management and staff to ensure enough representation in both active smelter workers and administrative workers, who served as the control group. Marc notes that participation was somewhat inconvenient, requiring time and following specific procedures before sample collection. Fortunately, the employees got on board. At the time of this article, 430 workers have been sampled since 2012. More than 1,250 samples have been collected in all. 

Maneesh Walia has been involved in the monitoring program since the beginning when he was a Production Operator. Now a Production Supervisor, he still gets tested regularly, saying, “It always made me feel safer. It showed the precautions and controls were making a difference. I knew my protection was working when results came back normal.” He also encourages his crews to participate and thinks that, “there should be a line up for this voluntary testing. It keeps you aware of what’s going on in your body and provides a record for your doctor.” 

The participation of the workers in the administrative control group, who live in the same community and have similar exposure to nickel outside of work, was particularly valuable in identifying the impact of PPE and hygiene practices. It was encouraging that smelter workers had urinary nickel levels similar to the control group and to other Canadians. Urinary nickel levels tend to be highest in exposure groups who are most highly exposed based on hygiene monitoring, but this relationship is heavily influenced by use of PPE and hygiene practices.

By complementing the occupational hygiene monitoring results, the urinary nickel monitoring program at the smelter has provided important insights. Overall averages and trends over time have been established for smelter and administrative workers as a group, and for different sub-groups of workers. Trends over time are used to evaluate how process improvements, PPE use and good hygiene practices affect urinary nickel levels. When an employee’s result is higher than expected based upon the overall results or the worker’s historical levels, follow-up is completed to understand possible reasons for the increase, and to identify ways to reduce exposure. 

Looking to the future, our Sudbury Smelter data is supporting work by The Nickel Producers Environmental Research Association (NiPERA), the Nickel Institute's independently-incorporated science division, to develop a way to assess exposures to nickel on an individual basis. This is very different from most exposure limits, which apply a single value to all workers.  

The new Biological Exposure Action Level (BEAL) will be a personal exposure limit based on an individual’s biology. The initial tool for calculating BEALs has been built and tested with our smelter data. The next step is to obtain urinary nickel levels from other worker populations in the nickel industry. NiPERA would like to publish the results in a peer-reviewed journal, such as Regulatory Toxicology and Pharmacology to help drive the work forward.

Marc is optimistic: “Our program will hopefully lead to a BEAL approach not only for nickel, but also for other  metals and metalloids in a range of industries.”

Monitoring urinary nickel in workers cannot and should not replace occupational hygiene  monitoring. The occupational hygiene monitoring reflects what workers could be exposed to by inhalation, the most important route of exposure for nickel toxicity. However, nickel can cause effects outside the respiratory system, so another tool – urinary nickel monitoring – is needed to understand total exposure. 

This work will continue because it provides a win-win-win opportunity to help our employees reduce their exposure, drive our “zero harm” goal forward in the prevention of occupational disease, continually improving our occupational hygiene performance, and promoting science-based approaches to ensure that nickel is produced safely and sustainably.