Who it affects: The disorder primarily impacts people who work with insulated‑metal‑arc welding (MMA), gas‑metal‑arc welding (GMAW), or other processes that generate fine metal particles. This includes:

• Professional welders and fabricators
• Shipyard and construction workers
• Auto‑body technicians
• Hobbyist welders and metal‑working enthusiasts

Prevalence: Exact global rates are difficult to capture because symptoms often resolve without medical care. In the United States, the Occupational Safety and Health Administration (OSHA) estimates that ≈ 300,000 workers are potentially exposed to metal fumes each year, with an incidence of metal fume fever ranging from 1‑5 % among newly hired welders (CDC, 2022). Higher rates are reported in developing nations where protective equipment is less common.

Symptoms

The presentation is abrupt, usually appearing 2–10 hours after exposure and lasting 12–48 hours. The classic “flu‑like” picture can be confused with viral infections, but a clear exposure history is key.

• Fever (≥38 °C / 100.4 °F): Often the first recognized sign.
• Chills and shivering: May occur suddenly.
• Headache: Described as dull or throbbing.
• Generalized malaise & fatigue: Persistent tiredness that can last several days.
• Myalgia (muscle aches): Common in the neck, shoulders, and back.
• Cough: Usually dry, non‑productive.
• Sore throat & hoarseness: Irritation of the upper airway.
• Nasal congestion or rhinitis: Often mistaken for a cold.
• Chest tightness or mild dyspnea: Shortness of breath that improves with rest.
• Metallic taste: A distinct “tinny” sensation in the mouth.
• Lymphadenopathy: Tender swelling of the cervical lymph nodes in about 10 % of cases.

Symptoms typically resolve without treatment; however, recurrence after continued exposure is common.

Causes and Risk Factors

What causes metal fume fever?

The disease results from inhalation of **tiny (<1 µm) metal oxide particles** generated when welding currents vaporize metals. The most common culprits are:

• Zinc oxide: Produced during welding of galvanized steel; responsible for >80 % of reported cases.
• Copper, nickel, chromium, iron, manganese: Also generate reactive fumes.
• Aluminum and titanium: Can produce less severe reactions but still contribute to chronic lung injury.

The particles dissolve in the lung lining fluid, releasing metal ions that trigger an inflammatory response mediated by cytokines (IL‑6, TNF‑α) and neutrophils, producing the flu‑like syndrome.

Who is at higher risk?

• New or inexperienced welders: Lack of acclimatization, improper technique.
• Workers without proper respiratory protection: No respirator, poor ventilation.
• Those welding zinc‑coated materials: Galvanized steel is a notorious source of zinc fumes.
• Exposures in confined spaces: Higher concentration of fumes.
• Smoking: Impairs mucociliary clearance, increasing particle retention.
• Pre‑existing lung disease (asthma, COPD): May amplify symptom severity.

Diagnosis

Because metal fume fever mimics viral infections, a thorough occupational history is essential. The diagnostic process includes:

1. Clinical evaluation

• Detailed timeline linking symptom onset to a welding or metal‑working task.
• Physical exam: usually normal lung sounds; low‑grade fever.

2. Laboratory tests

• Complete blood count (CBC): May show mild leukocytosis.
• Serum inflammatory markers: Elevated CRP or ESR, but non‑specific.

3. Imaging

• Chest X‑ray: Typically normal; rule out pneumonia.
• High‑resolution CT (HRCT): Reserved for chronic cases; may reveal centrilobular nodules or ground‑glass opacities.

4. Pulmonary function tests (PFTs)

• In acute MFF, PFTs are usually unchanged. Repeated exposures can cause a mild obstructive pattern.

5. Occupational exposure assessment

• Air‑sampling data (if available) showing concentrations of zinc or other metal fumes >0.1 mg/m³, the OSHA permissible exposure limit (PEL), supports the diagnosis.

Diagnosis is essentially **clinical**—the combination of exposure, rapid onset of flu‑like symptoms, and exclusion of infection.

Treatment Options

Most cases are self‑limited; the main goal is symptom relief and preventing recurrence.

1. Immediate measures

• Remove from exposure: Cease welding and move to fresh air.
• Hydration: Oral fluids help reduce fever and flush metal ions.

2. Medications

• Antipyretics (acetaminophen or ibuprofen): Lower fever and relieve myalgia.
• Bronchodilators (short‑acting inhalers): For transient dyspnea, especially in asthmatics.
• Corticosteroids: Not routinely required; may be considered for severe or prolonged symptoms.

3. Supportive care

• Rest and avoidance of strenuous activity for 24‑48 hours.
• Monitor temperature; seek care if fever >39.5 °C (103 °F) persists.

4. Long‑term strategies

• Implement engineering controls (local exhaust ventilation).
• Fit‑tested respirators (N‑95 or higher) when engineering controls are insufficient.
• Regular medical surveillance for workers with chronic exposure.

Living with Welders' Lung (Metal Fume Fever)

Even when the acute episodes are brief, repeated bouts can affect quality of life. Below are practical tips for everyday management.

Symptom tracking

• Keep a **work‑exposure diary** noting dates, materials welded, ventilation status, and any symptoms.
• Use a simple app or notebook to record temperature and duration of fever.

Optimizing the work environment

• Ensure **local exhaust ventilation** (LEV) hoods are positioned correctly and maintained.
• Check that the welding area is well‑ventilated; open windows or use fans when possible.
• Schedule **breaks** every 30‑45 minutes to reduce cumulative inhalation.

Personal protective equipment (PPE)

• Wear a **fit‑tested half‑face respirator** with P100 filters for zinc‑containing work.
• Replace filters according to manufacturer recommendations or when breathing resistance increases.
• Use flame‑resistant clothing, gloves, and safety glasses to protect against burns and UV exposure.

Health‑maintenance habits

• Quit smoking; nicotine impairs clearance of metal particles.
• Stay hydrated; adequate fluid intake supports mucociliary function.
• Engage in regular aerobic exercise to improve lung capacity.
• Schedule annual occupational health exams, including spirometry if you have chronic exposure.

When to talk to your doctor

• Symptoms lasting >48 hours or returning daily.
• Worsening shortness of breath, chest pain, or coughing up sputum.
• Development of asthma‑like wheezing or reduced exercise tolerance.

Prevention

Prevention is a combination of engineering controls, administrative policies, and personal protection.

Engineering controls

• Install **local exhaust ventilation** that captures fumes at the source (capture velocity ≥100 ft/min).
• Use **wet‑cutting** or **laser welding** where possible; these methods generate fewer fumes.
• Maintain equipment regularly to ensure optimal combustion and minimal fume production.

Administrative controls

• Implement a **job‑rotation schedule** to limit individual exposure time.
• Provide comprehensive training on safe welding practices and proper respirator use.
• Post clear signage indicating when ventilation or respirators are required.
• Conduct regular workplace air‑monitoring; if metal‑fume concentrations exceed OSHA PEL, corrective action must be taken.

Personal protective equipment

• Respirators: N‑95 (for short tasks) or **P100** (for zinc‑rich fumes). Ensure a seal check each use.
• Eye protection: ANSI‑Z87.1 approved goggles or face shields.
• Gloves and aprons: Flame‑resistant, insulated as needed.

Health surveillance

• Baseline and periodic **spirometry** for workers with >5 years of exposure.
• Quarterly questionnaires about respiratory symptoms.
• Prompt medical evaluation for any episode of metal fume fever.

Complications

While most cases resolve quickly, untreated or repeated exposure can lead to significant health problems:

• Chronic bronchitis: Persistent cough and sputum production due to airway irritation.
• Obstructive lung disease (COPD-like): Seen in long‑term welders, especially smokers.
• Metal‑induced pneumonitis: Inflammation that may progress to fibrosis.
• Metal fume-induced asthma: Hyper‑reactive airways triggered by metal particles.
• Systemic effects: Rarely, high zinc exposure can cause copper deficiency (hypocupremia) leading to anemia and neurological symptoms.

Early identification and control of exposure are crucial to prevent these outcomes.

When to Seek Emergency Care

Sources: Mayo Clinic. Metal Fume Fever. 2023; CDC. Occupational Safety and Health – Welding, Cutting, and Brazing. 2022; OSHA. Permissible Exposure Limits (PELs) – Zinc Oxide. 2021; National Institute for Occupational Safety & Health (NIOSH). Welding Fumes. 2022; WHO. Guidelines for Workplace Air Quality. 2020; Cleveland Clinic. Respiratory Effects of Metal Exposure. 2023.