Welder's Anthrax: Understanding The New Welding and Metalworking Hazard and How to Prevent It

The U.S. Centers for Disease Control and Prevention (CDC) and National Institute for Occupational Safety and Health (NIOSH) have recently identified a new occupational hazard within the metalworking and welding industries known as welder’s anthrax.

Keep reading to learn more about what this disease is, what causes it, what its short- and long-term health effects are, and what type of personal protective equipment (PPE) and control measures can help prevent welder's anthrax from developing in your workforce.

What is Welder's Anthrax?

According to the CDC, welder's anthrax is a type of pneumonia (bacterial lung inflammation) that develops in welders and metalworkers due to exposure to bacteria from the group Bacillus cereus, which are known to produce the anthrax toxin. B. cereus bacteria are commonly found in soil and dust.

Anthrax, a rare but serious infectious disease caused by the Bacillus anthracis, is uncommon in the United States and is generally found more often within agricultural regions of places like sub-Saharan Africa, Central and South American, the Caribbean, and parts of Asia and eastern Europe.

When Was Welder's Anthrax First Identified?

Between 1994 and 2020, seven people—six men and one woman from the states of Texas and Louisiana—were diagnosed with what the CDC and NIOSH today call welder's anthrax. These cases were reported to the CDC; all seven individuals were either welders or metalworkers.

Details about these seven individuals' specific work duties, work environments, and related information were largely limited, although at least two of the patients were known to be wearing respiratory protection during all welding-related activities.

What Causes Welder's Anthrax?

Researchers are still learning about how exposure to metal fumes and mineral dusts, which is common in metalworking and welding, can lead to infectious lung diseases like welder's anthrax.

The co-authors of a 2022 review paper published in Pathogens describe a current leading theory, which states that the iron predominantly found in metal fumes may act as a "growth nutrient" for bacteria and can help the bacteria bind to lung tissue, as well as disrupt immune activity within the lungs due to cellular and tissue damage. Notably, soil surrounding welding sites has been repeatedly found to be much higher in iron compared to other areas.

It has also been hypothesized that by irritating an individual's lungs, metal fumes and welding contaminants may thereby make a person more susceptible to lung infections, even from infectious agents usually considered relatively harmless.

Short- and Long-Term Health Effects of Welder's Anthrax: What's Currently Known

Though rare, welder's anthrax is a serious and potentially fatal disease. Of the seven patients discussed earlier who were diagnosed with welder's anthrax between 1994 and 2020, all seven required hospitalization and admission to the intensive care unit (ICU), and only two survived.

Given the potential severity of this condition, it's important to be aware of the possible warning signs and symptoms of welder's anthrax. These include:

  • Fever and chills
  • Cough, and in particular coughing up blood (hemoptysis)
  • Shortness of breath
  • Abnormal chest imaging (e.g., the appearance of lung infiltrates on a chest X-ray) and abnormal laboratory tests (e.g., excess iron build-up in the lungs or blood)

Acute exposure to welding fumes is also known to cause irritation to the eyes, nose, and throat, along with dizziness and nausea.

While little is known about the long-term health effects of welder's anthrax specifically, prior research has found that welding activities are associated with an increased risk of various health problems. According to the Occupational Health and Safety Administration (OSHA), long-term or prolonged exposure to welding fumes has been linked to:

  • Cancers of the lung, larynx, and urinary tract
  • Stomach ulcers
  • Kidney damage
  • Nervous system damage

Prior research has also shown that welders have an increased risk of mortality from pneumonia compared to workers in other industries.

Presently, the recommended treatment of individuals experiencing welder's anthrax is similar to the treatment of individuals with inhalation anthrax, which generally involves prolonged use (e.g., 60 days) of intravenous antibiotics. If welder's anthrax progresses, advanced critical care treatment can be required, including mechanical ventilation and additional supportive therapies.

Welding PPE and Other Control Measures to Prevent Welder's Anthrax

Do members of your team regularly perform welding and metalworking duties? If so, it's essential that you enact all appropriate prevention and control measures to optimize their safety—ideally, while still allowing them to perform their expected work duties with comfort, precision, and efficiency. To this end, ensuring your workforce has access to appropriate welding PPE is a top priority.

Welding PPE may include:

  • A respirator that covers the nose and mouth with a firm seal (e.g., N95 or N100 mask)
  • PAPR (power air purifying respirator)
  • Welding helmet and goggles
  • Hand shields
  • Flame-retardant clothing, aprons, or coveralls (disposable welding PPE options offer the additional benefit of reducing the risk of cross-contamination and preventing workers from accidentally bringing contaminants home)
  • Hearing protection
  • Insulated gloves
  • Rubber-soled work boots

While critical, PPE is not sufficient on its own to optimize protection for welders and metalworkers. Additional steps are necessary to ensure your team's safety. The CDC and NIOSH advise the following:

  • Regularly clean the worksite to minimize the amount of debris and thereby reduce worker exposure (if vacuuming, use one that features a high-efficiency particulate air (HEPA) filter)
  • Install physical barriers or designate specific areas for any work task that generates metal shavings or metal fumes
  • Increase ventilation—both indoors and outdoors—via general and local exhaust ventilation systems
  • Do not use compressed air or fans near welding and metalworking sites
  • When possible, increase the distance between workers and the hazard

Finally, it is everyone's job in the occupational setting to make workplace safety a priority, but it is the employer's responsibility to ensure that all workers are properly trained on workplace hazards, safe practices, and protective measures, including how to properly don and doff welding PPE.


Welder's anthrax is a newly identified health concern affecting individuals within the welding, construction, industrial, and manufacturing industries. While there is still much to learn about this condition, including its long-term health effects and how welding can increase a person's susceptibility to lung infections, the scientific and medical communities do agree that prevention is possible.