silicosis

Silicosis

Silicosis is lung damage caused by breathing dust containing extremely fine particles of crystalline silica. Crystalline silica is found in materials such as concrete, masonry and rock. When these materials are made into a fine dust and suspended in the air, breathing in these fine particles can produce lung damage. Silicosis can lead to heart failure and increase the risk of other diseases such as TB (tuberculosis).

Symptoms of Silicosis:

Initially there may be no symptoms. Later there may be difficulty in breathing and cough may be present. Infectious complications may cause fever, weight loss, and night sweats.

How are Construction Workers Exposed to Crystalline Silica?

Most crystalline silica comes in the form of quartz. Common sand can be as much as 100% quartz. Concrete and masonry products contain quartz in the form of sand. Therefore, there are many ways to be exposed at construction sites.

Activities That Produce Quartz Dust:

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.

Prevention:

The key to silicosis prevention is to prevent dust from being in the air. The Occupational Safety and Health Administration (OSHA) requires administrative or engineering controls be used whenever possible. A simple control may work. Example: A water hose to wet dust down at the point of generation. Other steps that can taken to protect workers:

Always use the dust control system and keep it in good maintenance.
When sawing concrete or masonry use saws that provide water to the blade.
During rock drilling use water through the drill stem to reduce the amount of dust in the air.
Use dust collection systems which are available for many types of dust generating equipment.
Use local exhaust ventilation to prevent dust from being released into the air.
Use abrasives containing less than 1% crystalline silica during abrasive blasting Measure dust levels in the air.
Respirators should only be used after dust controls are in place.

Respirators should not be the primary method of protection. If controls cannot keep dust levels below the NIOSH Recommended Exposure Level (REL) then respirators should be used. Select respirators that provide enough protection. Keeping respirators fit for use requires continuous maintenance.

Medical Examinations:

All workers breathing crystalline silica dust should have a medical examination which includes:

Chest X-ray
Pulmonary function test
Annual evaluation for TB (tuberculosis).

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Last Update: April 30, 2000

By: Serdar Z. Elgun