After a wildfire, the air is thick with smoke and the scent of burnt vegetation—remnants of a once vibrant landscape now reduced to charred earth. The rebuilding process includes assessing fire risks and implementing strategies to improve resilience against future wildfires. But even after the fires have subsided, the danger remains. Dust and debris can hide harmful contaminants, such as crystalline silica, which pose health risks to construction workers.
With wildfires becoming more frequent and intense, the industry’s risk of silica exposure is a pressing concern. Artificial stone has increased this risk due to the higher levels of silica released. Addressing these risks is essential for occupational safety and is critical in environmental, social and governance strategies. By adopting comprehensive ESG solutions, construction firms can protect their workforce, comply with health and safety regulations, and commit to sustainable practices.
Crystalline Silica and Silicosis
Crystalline silica is a mineral found in concrete, brick and sand, as well as in the ash and dust from wildfires. When these materials are disturbed, tiny silica particles can become airborne. Inhaling these particles poses serious health risks, leading to conditions such as lung cancer, chronic obstructive pulmonary disease and silicosis. Consequently, breathing in silica dust after wildfires is a significant health concern that cannot be understated.
Construction workers should know the symptoms of silicosis. Watch for shortness of breath, coughing, fatigue or chest pain. Symptoms should be reported immediately. Early detection and treatment are key to slowing the disease. Practical steps to avoid occupational exposure to silica include the following:
- Wearing respirators correctly
- Using dust-suppression tools
- Reporting hazards to a site supervisor
- Practicing good hygiene (e.g., washing hands often)
Wildfires: A Catalyst for Silica Release
Wildfires and silica are connected because silica dust—predominantly crystalline silica—can be released into the air during and after wildfires. Wildfires churn up soil and construction debris, sending even more silica dust into the air. Smoke plumes can travel far, exposing workers miles away from the actual fire. Even after the fire is out, the danger remains as disturbed soil continues to release silica. It’s essential to extinguish fires by combining them with alkaline ash to manage the situation.
Alkaline Ash: Benefits and Risks
Alkaline ash is a byproduct created during the combustion of organic materials, particularly those that contain high levels of minerals, such as wood, crop residues and other plant matter. Its mineral content and ability to suppress flames can help control fires, especially those difficult to extinguish with water alone. Alkaline ash is also used in various industrial processes, such as the manufacturing of glass and ceramics, in which silica is a key ingredient.
Alkali-Silica Reaction
The alkali-silica reaction is a complex chemical process that occurs when the alkalis in concrete (e.g., sodium, potassium) react with reactive silica found in certain aggregates. This reaction produces a gel-like substance that absorbs water and expands. As this expansion continues, it can lead to significant cracking, warping and other forms of structural damage to the concrete.
ASR and Its Impact on ESG Efforts
ASR is relevant to ESG and sustainability efforts in construction for several reasons:
- Environmental Impact: ASR can lead to severe structural damage to concrete, resulting in costly repairs and increased carbon emissions.
- Material Efficiency: Managing ASR facilitates using safer aggregates and recycled materials, reducing waste and ASR risk.
- Lifecycle Assessment: ASR understanding is essential for evaluating building lifespan and maintenance costs.
- Social Responsibility: ASR-related damage can pose public safety risks. Ensuring safe and durable concrete structures promotes community wellbeing.
- Governance and Standards: Addressing ASR is crucial for complying with certain building safety and sustainability codes.
ASR Mitigation Strategies
To mitigate the effects of ASR in construction, firms can adopt several strategies, including:
- Utilizing alternative materials like fly ash or slag to minimize the risk of alkali-silica reaction
- Implementing strict testing and quality control to ensure suitable aggregates are selected
- Promoting sustainable practices (e.g., recycling, waste reduction) to align with ESG goals and enhance construction resilience
OSHA Rules on Silica
The Occupational Safety and Health Administration has regulations established to protect construction workers from silica exposure. The permissible exposure limit is 50 micrograms of respirable crystalline silica per cubic meter of air over an eight-hour workday, while the action level is 25 micrograms per cubic meter. If exposure reaches the action level, employers must take steps to reduce it, such as implementing control methods, providing respirators and offering medical exams.
Hierarchy of Controls
As outlined in OSHA’s silica guidance, the hierarchy of controls is essential for reducing silica exposure among construction workers, especially during wildfire events. With the ultimate goal of eliminating silica sources altogether, this systematic approach helps identify and replace hazardous materials with safer alternatives. These measures protect worker health and safety and align with ESG principles, showcasing a commitment to sustainable practices. Companies can also demonstrate their commitment to minimizing their ecological footprint by focusing on responsible environmental stewardship.
Strategies for Controlling Silica Exposure
- Engineering Controls: Wet-cutting methods, local exhaust ventilation and enclosed blasting systems should be utilized to minimize dust at the source.
- Respiratory Protection: When necessary, provide the appropriate respirators, such as N95 masks or full-face respirators, ensuring proper fit and training for practical use.
- Work Practices: Adopt habits that reduce dust generation, like using water for dust suppression and scheduling work during less dusty times.
- Worker Training: Provide training to inform workers about silica hazards and how to protect themselves.
- Medical Surveillance: Conduct regular medical exams, including chest X-rays and pulmonary function tests, to detect lung damage early.
Along with OSHA, other organizations like the National Institute for Occupational Safety and Health offer resources on silica risks and exposure. Occupational health providers can also assist employers with medical screening and surveillance services for better workforce safety and OSHA compliance.
Safeguarding Workers and the Environment
Wildfires greatly affect the construction industry, posing challenges and opportunities. Protecting worker health, particularly from silica exposure, is essential, highlighting the need to adhere to OSHA standards. Employers must assess silica exposure, implement a written control plan, use engineering controls like wet cutting, provide respiratory protection and ensure medical surveillance. Training and documentation of these efforts is crucial, as employers have legal and ethical duties to safeguard their employees.
Additionally, the construction industry has a chance to adopt sustainable practices. Proactively embracing environmentally friendly methods enhances competitiveness and reflects a commitment to the community and the planet.
SEE ALSO: BUILDING RESILIENCY: WITHSTANDING WILDFIRES AND OTHER NATURAL DISASTERS
