It's everywhere

Thousands of workers are exposed to crystalline silica dust at work every day. Is it a silent killer?

As long as you work in construction, chances are good (too good, in fact) that at some time you will be exposed to silica dust. When you cut, core or drill concrete, rock or masonry you create silica dust. Sandblasting operations can also be a source of silica dust. Overexposure to the ultra-fine silica particles may take your breath away as the dust scars your lungs.

The condition is called silicosis, and could be a silent killer if you don’t take the proper precautions.

The National Institute of Occupational Safety and Health has assembled some good information on what silicosis is, how it manifests itself and what you can do to protect yourself and fellow workers. Here, it answers many common questions about the disease and how to prevent it.

What is silicosis?
Silicosis is permanent lung damage caused by breathing dust containing extremely fine particles of crystalline silica. It’s found in materials such as concrete, masonry and rock. It can be totally disabling and may lead to death.

Silicosis symptoms
NIOSH has researched this disease carefully and has found that, initially victims show no symptoms. Months or years later, the victim may have difficulty breathing and may develop a cough. Other symptoms may include fever, weight loss, and night sweats.

See a physician if you experience these symptoms and suspect that you have been exposed to crystalline silica. All workers breathing crystalline silica dust should have a medical examination.

How do construction workers get exposed?
Concrete and masonry products contain silica sand. Since concrete and masonry are primary building materials, there are many ways construction workers get exposed.

They include:
• Abrasive blasting using silica sand as the abrasive.
• Abrasive blasting of concrete.
• Chipping, hammering and drilling rock.
• Crushing, loading, hauling and dumping rock.
• Chipping, hammering, drilling, sawing and grinding concrete or masonry.
• Demolition of concrete and masonry structures.
• Dry sweeping or pressurized air blowing of concrete or sand dust.

Only you can prevent silicosis
The key to silicosis prevention is to prevent dust from being in the air. The Occupational Safety and Health Administration (OSHA) requires that dust be controlled whenever possible.

A simple control may work. For example, water can be used to wet and settle the dust at the point of generation.

NIOSH suggests you can protect yourself in the following ways:
• When cutting concrete or masonry, use wet-sawing methods whenever possible.
• During rock drilling, use water through the drill stem to reduce the amount of dust in the air.
• Use dust collection systems installed on the drilling or cutting equipment and use local exhaust ventilation to prevent dust from being released into the air. Keep them in good repair.
• Minimize exposures to nearby workers.
• Use abrasives containing less than one percent crystalline silica during abrasive blasting. This minimizes harmful quartz dust from being released in the air.
• Measure dust levels in the air.

Respirators are your last line of defense
Respirators should not be the primary method of protection. They should only be used until adequate dust controls are in place. If controls cannot keep dust levels below the NIOSH Recommended Exposure Level (REL), then respirators should be used.

Select respirators that provide enough protection. Your distributor can help you select the right models for your operation.

Through OSHA standard 29 CFR 1910.134, employers must provide respirators for work where breathing contaminated air is a health risk.

It’s up to the employer to identify the risk and implement engineering controls to minimize that risk.

If engineering controls cannot adequately eliminate the exposure, it must identify and supply respirators that can protect the worker from the contaminated air.

Keeping respirators fit for use requires ongoing maintenance. When respirators are used, employers must establish a comprehensive respiratory protection program.

Medical examinations needed
All workers breathing crystalline silica dust should have a medical examination that includes a chest X-ray, a pulmonary function test and an annual evaluation for tuberculosis.

Published in the September/October 2001 issue of Contractor Tools and Supplies magazine.

back to top