Fly ash, which is used to make fly ash bricks, is a byproduct of burning coal in power plants and can contain heavy metals and other pollutants. These can include toxic metals like mercury, arsenic, antimony, chromium, and more. This suggests that fly ash bricks could potentially contain these toxic materials.
However, it’s important to note that the manufacturing process of fly ash bricks involves high temperatures, which can help neutralize some of these toxic elements. Researchers have even suggested that bricks made from fly ash may be safer than previously thought.
Additionally, before fly ash can be reused (for example, in the production of bricks), it often has to be treated or washed to reduce its content of heavy metals and toxic organics.
Even with these precautions, there are debates about the safety and environmental impact of using fly ash in construction materials. Therefore, while fly ash bricks offer several benefits, such as improved strength and durability, their potential environmental and health impacts should be considered.