Cancer from welding fumes? We do know!

Every day, several million people worldwide come into contact with welding fumes. It is not disputed today that dangerous substances in welding fumes are dangerous to health, and some are even carcinogenic. But it wasn't until 2017 that the International Agency for Research on Cancer (IARC) officially confirmed this finding. Since then, experts have continued to work on research into the health consequences of welding fumes. A look at past studies and the current state of research.

According to IARC estimates, around 11 million people worldwide were considered professional welders in 2017. Another 110 million employees were regularly exposed to welding emissions. These include fumes, gases, ultraviolet radiation and electromagnetic fields. Smokes are mainly generated during electrical welding at arc temperatures of more than 15,000 °C. The consequence is that components, especially those in the filling material, evaporate and condense into small particles which, without special protective measures, can be inhaled by employees.

A group of experts convened by IARC evaluated all scientific studies published in March 2017 and this time was able to prove it: welding fumes are carcinogenic to humans, regardless of the process used or the type of welded metal. Only the extension is different for each method. Five years earlier, the agency had classified intense UV radiation from arc welding as carcinogenic. Researchers also confirmed this classification in 2017, proving that radiation causes eye tumors.

The cancer risk from welding fumes was completely unknown 50 years ago.

A look back shows that the carcinogenic effect of these dangerous substances was completely unknown to welders. In the 1970s, the general health hazard posed by welding fumes was still unknown, in part even considered healthy. In 1989, IARC, an agency of the World Health Organization (WHO), classified welding fumes as 'potentially carcinogenic'. At that time, research data were not sufficient to provide a reliable basis for classifying welding fumes as actually carcinogenic.

In the years following this classification, further studies followed which provided other important findings on dangerous carcinogens. One of the most important studies is the work of the SYNERGY project, which was published in the IPA Journal in 2013. The researchers investigated the risk of lung cancer for welders and people in occasional welding occupations. The investigation was coordinated by IARC among others. The researchers investigated a total of 33,871 men, including 15,483 cases of lung cancer and 18,388 control subjects. Compared with previous studies, their smoking behaviour, duration of activity and welding procedures were also taken into account.

High risk of lung cancer found in welders

The result: researchers found an increased risk of lung cancer for full-time welders as well as for people who welded occasionally. The risk increased in both groups as the duration of employment increased, but was lower for casual welders. Researchers also observed an increased risk of cancer in nonsmokers. In addition, industry sectors were included in the assessment.

For example, welders in shipbuilding, construction, machinery manufacturing and transport equipment repair have a higher risk of lung cancer than welders in vehicle manufacturing. Automation and welding robots are increasingly used in the latest branch of industry. In this study, however, they could not identify any reference to individual carcinogenic hazardous substances in welding fumes. Factors such as the welding process, smoke composition and exposure level could also not be taken into account.

Various dangerous substances in welding fumes.

To understand the full extent of the health risks of welding fumes, it is important to know that hazardous substances produced during welding have different effects on humans. Substances are composed of a number of components: basic and complementary materials, inert gases, coatings, pollution and ambient air. Experts distinguish between substances harmful to the lungs, toxic and carcinogenic.

The carcinogenic substances in welding fumes can not only cause malignant tumors in the body, but can often also have a toxic effect. However, other factors, such as hereditary factors and environmental pollution, influence the risk of cancer.

Cancer risk, especially with precious metals.

Carcinogens include chromium VI compounds and nickel oxide, for example. In 2018, the IPA Journal published the results of its collaboration with the German Social Accident Insurance Institute (DGUV). Together, they evaluated the measured data for workplace emissions. The focus here was on welding fumes containing compounds of chromium VI, nickel oxide and manganese.

The researchers found that: The welding process and filling materials used have a decisive influence on exposure. Particularly in high emission processes, such as active gas welding with metal (MAG) and metal inert gas welding (MIG) of low alloy steel, welders were exposed to higher exposures compared to dangerous carcinogens in welding fumes and manganese compared to inert tungsten gas welding (TIG).

The carcinogenic effect of welding fumes has not yet been fully investigated.

Since the 1970s, several scientific studies have investigated the carcinogenic effect of certain dangerous substances on welding fumes and finally clearly demonstrated this in 2017. However, this does not mean that we know everything about it today. More research is needed to learn more about complex dose/response relationships, for example. The aim is to be able to assess the health risks of welders more accurately in the future and to interpret occupational safety even more effectively. In any case, effective extraction is required to protect employees from welding fumes, and this requires powerful and reliable extraction systems.

The Commission therefore concludes that the aid is compatible with the internal market