Coal ash and tailings are waste associated with coal mining and burning containing toxic metals such as arsenic, lead, and mercury. Which category best describes coal ash and tailings?

• A. Fertilizer
• B. Composite material
• C. Toxic waste containing arsenic, lead, and mercury
• D. Plastic byproduct

Answer: (C)

Coal ash and tailings come from coal extraction and combustion and often contain toxic metals such as arsenic, lead, and mercury. Because these metals can leach into soil and groundwater and accumulate in organisms, this waste is categorized as hazardous or toxic waste. That makes the best description a toxic waste containing arsenic, lead, and mercury. They aren’t fertilizers, since introducing toxic metals to soil is dangerous; they aren’t a useful composite material, and they aren’t a plastic byproduct.