Silica exposure remains a serious threat to nearly 2 million U.S. workers. Silica has been classified as a human lung carcinogen, which means it is known to cause cancer. Additionally, breathing silica dust can cause silicosis. The silica dust enters the lungs and causes the formation of scar tissues. This reduces the lungs' ability to take in oxygen. There is no cure for silicosis. In addition, smoking causes lung damage and adds to the damage caused by breathing silica dust.
As the disease progresses, the worker experience shortness of breath. In the later stages, the worker may experience fatigue, extreme shortness of breath, chest pain, or respiratory failure. In the final stages of the disease, many of those affected have to use medical oxygen and are bedridden or require a wheelchair.
Exposure occurs during many different construction activities. The most severe exposures have occurred during abrasive blasting with sand to remove paint and rust from bridges, tanks, concrete structures, and other surfaces. Other construction activities that may result in exposure include: jack hammering, concrete demolition, drilling and grinding, brick and concrete block cutting and sawing. This also includes the use of dry cement products like Quikrete during mixing. Sanding of drywall mud is also a source of exposure, along with flooring underlayment removal, such as self-leveling compound. Any time dry cement products become airborne, it is possible to breathe it into your lungs.
OSHA has identified a permissible exposure limit (PEL) for silica. This is the maximum amount of dust that a worker can be exposed to during a work day, without using PPE or engineering controls like HEPA vacuums. OSHA also requires hazard communication training for workers exposed to silica, and requires a respirator program until engineering controls are implemented.
What can employers/employees do to protect against exposures to crystalline silica?
- Replace silica safer substitutes. Sand has been replaced with garnet for blasting.
- Provide engineering or administrative controls, such as a HEPA vacuum or ventilation.
- Use work practices to control dust exposures, water sprays, working upwind from dust.
- Wear only a NIOSH-certified respirator. Do not alter the respirator. Do not wear a tight-fitting respirator with a beard or mustache that prevents a good seal between the respirator and the face.
- Vacuum the dust from your clothes and change into clean clothing before leaving the work site. Do not blow off the dust. Dust on your clothing can harm your family.
- Participate in training and exposure monitoring to determine our exposures.
- Be aware of the operations that create silica exposures in your area and protect yourself.
- Be aware of the health hazards related to exposures to silica. Smoking adds to the lung damage.
- Do not eat, drink, smoke, or apply cosmetics in areas where silica dust is present.
- Wash your hands and face outside of dusty areas before performing any of these activities.
- If concrete dust is visible in the air, you are probably exceeding the safe limit and need protection.