Airborne particles pose significant potential health hazards for welders. That’s because there’s a co-relation between the chemical and physical properties of airborne particles and respiratory diseases. Protecting these workers from inhaling particles is key to protecting their health.
The greatest risk comes from particles that are between 1 and 100 microns in diameter, such as dust produced during industrial processes like welding and grinding. These particles are able to work their way through the nose and throat and penetrate the gas exchange region of the lungs where they settle, causing inflammation and swelling of the blood vessels. Inhaling these particles over the long-term can lead to lung cancer.
Lung cancer begins with changes in the lungs that are characterized by the development of abnormal cells on the lining of the bronchi, the large air tubes that carry air to and from the lungs. These cells multiply with continued exposure and eventually become cancerous, and develop into tumors. Symptoms of lung cancer include chronic cough, hoarseness, chest pain, shortness of breath and numerous episodes of bronchitis and pneumonia.
Another less serious exposure-related illness that affects welders is metal fever. This is an acute allergic condition that causes headache, fever, chills, muscle aches, thirst, nausea, vomiting, chest soreness, gastrointestinal pain, and weakness. These symptoms usually last from 6-24 hours and complete recovery happens within 48 hours.
To prevent workers from contracting illnesses associated with airborne particles, it is imperative that the workplace offers adequate ventilation that removes contaminants generated during the welding process. The most effective way to accomplish this is through a combination of dilution ventilation and local exhaust ventilation techniques.
Dilution ventilation is used to decontaminate air in a whole building or room by blowing in large amounts of clean air and exhausting dirty air. This process dilutes the concentration of contaminants within the air to less dangerous levels. The most common methods of dilution ventilation include roof exhaust fans and wall fans.
One significant drawback of this method is that it allows the contaminants to enter the welder’s breathing zone before they are removed from the environment. If used exclusively, dilution ventilation may not be adequate to control exposure. For best results, dilution ventilation should be used in combination with local exhaust ventilation. This method captures contaminates at or very near the source and exhausts them outside.
Some welding equipment includes local exhaust ventilation, which removes the contaminates at the point of origin. Other local exhaust ventilation systems include a hood that can be placed as near as practical to the work being welded and provided with an airflow in the direction of the hood, or a fixed enclosure with a top and at least two sides that surround the welding work and provided with an airflow away from the enclosure.
Local exhaust ventilation prevent contaminates from entering the welder’s breathing zone. In addition to being discharged outside the building, local exhaust can be re-circulated through an air cleaner.