Which statement about Endothall environmental fate is true?

• A. Endothall is broken down by microbes into C, H, and O.
• B. Endothall is completely non-degradable in water.
• C. Endothall is only degraded by sunlight, not microbes.
• D. Endothall has no mobility.

Answer: (A)

Biodegradation by microbes is a primary pathway for Endothall in aquatic environments. Microbes metabolize Endothall and break it down into simpler substances, eventually mineralizing it to carbon dioxide and water. That’s why this statement is the best: it reflects a key fate process for Endothall in water, where microbial action reduces residues by converting them into basic elements like carbon, hydrogen, and oxygen.

It isn’t correct to say it’s completely non-degradable in water, since microbial degradation and other processes like hydrolysis can reduce or remove residues. It isn’t accurate to claim it’s degraded only by sunlight, because microbial action contributes as well. And saying it has no mobility isn’t right either; Endothall is water-soluble and can move with the water column, even though some sorption to sediments can occur.