The Chinese company Zijin (Zijin Copper) identified elevated levels of heavy metals at the smelter but failed to take measures to protect employees working there, according to the findings of the competent inspection authority.
“No assessment of the risk of harm to workers’ health was carried out, and no measures were envisaged to eliminate or reduce the risk,” states a Labour Inspectorate decision from December 2025. The inspection of the Mining and Smelting Basin Bor facility in eastern Serbia, majority-owned by Zijin, was initiated following a complaint by workers.
The Labour Inspectorate established that no measures to reduce health risks to employees had been planned, even though a full year earlier the company had determined that concentrations of certain heavy metals in the smelter’s working environment “exceeded the values set by standards”. Workers at the smelter, which is part of the industrial mining complex in Bor, say they were never officially informed of this.
“The employer did not warn either employees or trade unions. There were some cosmetic changes and instructions to wear masks and spend less time in certain parts of the plant, but the test results were never communicated to us,” Slađan Ilić, head of the Bor Smelter Trade Union Organisation, told RSE.
Under Serbia’s Law on Occupational Safety and Health, the employer is obliged to amend the Risk Assessment Act and take measures in the event of changes in working conditions, including situations where elevated concentrations of hazardous substances are identified at the workplace. In the case of the Chinese company in Bor, this was done only upon the order of the Labour Inspectorate – one year after elevated concentrations of heavy metals had been measured at the smelter.
Neither the Labour Inspectorate nor the Ministry of Labour responded to RSE’s inquiries about how the measurements of metal concentrations in Bor remained undisclosed for a year, or whether proceedings have been initiated against Zijin. The company itself also failed to respond to multiple inquiries from RSE.
What did workers discover through testing?
Oversight and checks of conditions at the production facilities in the Bor mining complex began at the initiative of workers, after a group of them, due to health problems, suspected that something was wrong.
“Following a doctor’s recommendation to carry out additional tests, it was discovered that they had elevated levels of lead in their blood,” said trade union leader Slađan Ilić. The Bor smelter is a key industrial facility for processing copper concentrate, and since entering the Serbian market in 2018, Zijin has significantly increased processing volumes – from 80,000 to 200,000 tonnes annually.
Trade unions and environmental organisations published laboratory test results on social media in November 2025 showing that some smelter workers had blood lead levels several times above the permitted limits.
Chinese owner rejects accusations
Zijin denied the validity of those findings at the time.
“Workers who independently carried out blood tests for heavy metals in private laboratories should be aware that reference values are presented in two forms – for the general population and for occupational exposure – and these values differ,” company representatives stated in November 2025.
They added that everything is clearly explained in the “Rulebook on Preventive Measures for Safe and Healthy Work when Exposed to Chemical Substances”. This regulation sets higher permissible blood lead levels for workers exposed professionally than for the general population. However, in the same statement in which it claimed that occupational exposure limits applied to its workers, Zijin also stated that “no workplace in the Smelter division has been identified as posing a risk of occupational exposure to lead”.
Documentation provided to the RSE editorial team by the trade union, however, shows that elevated levels of lead and other heavy metals had already been identified at the smelter at that time.
A document relating to testing conducted on 6 November 2024 by an external specialised firm states that the results of testing for chemical hazards – heavy metals – in the smelter’s working environment “exceed the values set by standards”. As the document shows, the measurements were carried out a year before workers conducted blood tests for lead. The report notes that excessive levels of heavy metals can cause respiratory irritation, severe headaches and chronic bronchitis. It also states that a ventilation system should be installed, protective equipment provided, and employee exposure reduced.
Under Serbian regulations, employers are required to inform employees about hazardous chemical substances present in the workplace and to provide appropriate protective measures.
Zijin complied only after an order from the Labour Inspectorate – one year after it had established that certain heavy metal levels in the smelter exceeded permitted limits.
“Training sessions are currently being held to familiarise workers with the hazards and their duties, particularly regarding the use of protective equipment,” said Slađan Ilić from the smelter trade union. He added that workers are not aware of whether Zijin has taken steps to eliminate the hazard, nor have they been informed about the cause of the elevated lead concentrations. Ilić also said that workers have been told that blood lead levels will be measured during regular medical check-ups, which, he adds, had not previously been the case.
What do occupational health experts say?
Due to the company’s delayed response to potential health risks, the Bor Smelter Trade Union Organisation sought an expert opinion in occupational medicine in November last year. In his opinion, Dr Jovica Jovanović, a specialist in occupational medicine, stated that Zijin could not rely on permissible blood lead levels for occupational exposure if an increased workplace risk had not been identified in the Risk Assessment Act.
“Based on my own experience and a review of the available literature, I believe that for the vast majority of workers at the Serbia Zijin Copper smelter in Bor, reference values applicable to the general population should be used when analysing biological samples,” Dr Jovanović stated.
The threshold for blood lead levels in the general population is below 50 µg/L, while trade union representatives say some smelter workers had levels exceeding 200 µg/L. “Regardless of occupation, levels above 100 µg/L of blood are harmful to health,” Jovanović stated in correspondence with the union.
As an argument for applying general population limits, he also pointed out that “lead in the air should not represent a significant occupational risk if standard copper concentrates are used”. “We suspect poor-quality raw materials and inadequate handling of waste dust, but only the company knows the real cause,” said union representative Slađan Ilić.
As RSE previously reported, analyses by the Bor Institute for Mining and Metallurgy showed that Zijin processes concentrate with elevated levels of heavy metals – a fact confirmed in February by the President of Serbia, who announced he would “ask the company to ensure this does not happen”.
Elevated blood lead levels can cause damage to the nervous system, anaemia, kidney and cardiovascular disorders, as well as reproductive problems, while prolonged exposure may result in permanent consequences.
Criminal complaint filed
The Bor Smelter Trade Union Organisation, along with the non-governmental organisation RERI (Regulatory Institute for Renewable Energy and Environment), filed a criminal complaint against Zijin in March this year for failing to implement occupational safety measures, causing danger, and violating the right to information on environmental conditions. “The essence of the matter is that the employer, Zijin, remained silent and that reports on heavy metal measurements at the smelter were concealed until workers filed a complaint with the Labour Inspectorate,” Marko Pavlović from RERI told RSE.
He also noted that the Criminal Code stipulates sanctions if an employer fails to ensure adequate workplace health protection. “The case is now with the Basic Public Prosecutor’s Office in Bor. According to the information we recently received, an investigation is underway and the prosecutor’s office has ordered the collection of necessary information,” lawyer Pavlović told RSE.
The Basic Public Prosecutor’s Office in Bor declined to provide information on the criminal complaints they are handling, stating that doing so could jeopardise the pre-investigation and criminal proceedings.
(Radio Free Europe, 29.04.2026)
https://www.slobodnaevropa.org/a/srbija-zidjin-radnici-teski-metali/33743695.html