“Are there (purported) environmental concerns about the production of argon?”
The funny thing is, that you can’t even “produce” it*. What is on Earth is mostly produced by the Earth itself by radioactive decay.
*except in minute quantities in a reactor.
Produce in the sense of producing coal or oil, i.e., extracting it and making it commercially useful. I did a little on-line research, and sure enough, the greatest cost in producing oxygen and nitrogen is the cost of the electricity used to liquefy the raw stock (air), and it is produced by fractional distillation of liquid air.