I'm no doctor, so can't speak to that. I would suggest, regardless if there is a correlation or not, to avoid any situation where the DE can be described as "dusty" which is the exact opposite of what we want. We suggest following all handling precautions as indicated on the product packaging, and if not prohibited by the instructions, mixing it with water in a bucket before pouring that slowly into the skimmer. I have only seen positive reports of these techniques, and you are the first person to use the word "dusty" which again, could suggest you can improve your procedures, in my non-expert opinion. I've watched videos of people using it, but have not myself, and have read up on it as well, but again, zero hands on experience. I would suggest to you, and anyone, to provide your doctor with all potential information that could be relevant - and to insist they listen until you explain everything, or find a new doctor that will listen to all reasonable and efficient information sharing. If your backwash location is dry and also dusty, you may want to consider a DE capture box. I would be concerned if a pile of DE like powder was accumulating in my backwash spot and attempt to resolve that. If you have any concerns, I suggest you contact the manufacturer for clarification. If your doctor does prove a link, and if you followed all instructions, perhaps seek legal advice and see if they find the manufacturer's instructions sufficient. If you happen to get more information about the medical or legal, please post back as we would like to share any updates with the community and continue to get the best info possible out there.