Hydrogen power and water?

The public is led to believe that output of water or water vapor by using hydrogen power is harmless! Don't worry!

Here is a typical statement! From the U.S. Department of Energy Hydrogen Fuel Basics: "Hydrogen is a clean fuel that, when consumed in a fuel cell, produces only water."

Is that really the case? Or what happens when hydrogen power is used at scale to supply energy for millions of households and businesses etc.? How much water or water vapor would be released in this scenario? What are the effects?

We also know that even natural, clean, drinkable water can be toxic especially when drinking too much! The dosage matters! 😊

Panacea do not exist as we all well know for thousands of years!