Regarding diesel, it has been some time since I have studied, but do searching for these terms:
World Health Organization diesel lung bladder cancer press release
Great Britain occupational study diesel bladder cancer
Look closely for words such as those, and even add the specific occupation / job in military. Then go into your personal military records and find any evidence of military exposure to diesel fumes / exhaust.
helpdesk.vetsfirst.org/index.php?pg=kb.printer.friendly&id=76 Look at 3.5 Nexus to understand the role your treating physicians letter would play in the claim and how to ask your physician to word the letter.
If you have not found the free online version of the IOM's NAP book Veterans and Agent Orange Update 2014 (published March 2016), then download a free copy from National Academies Press and look at the bladder cancer section - last two or three pages of that chapter in particular. I think veterans are now adding those pages to their claims.
You will find the Korean Vietnam Veterans Health study listed in that chapter...find the condensed version about bladder cancer from the actual Korean study, showing an increase in bladder cancer for their Vietnam Veterans.
Look at the other evidence presented by the IOM in their publication above. Find that published evidence and share all of this with your doctor......just the few pages of each report that apply, as the files get thick at VA - per our VSO. Underscore the key words in dark ink.....these reviewers have a lot to read so make it easy for them to find what you are sending in as few pages as possible to show the results of each report.
Things change and you must stay on top of all of this. My understanding has increased over the last 3 years, but still just an average person searching - just determination as I was reading day and night and sharing with anyone who would read and listen.
Hopefully Secretary McDonald will get feedback from the other committee he asked to review the IOM's changes - very soon we hope - and can make a proper determination to add BC to the list.
None of us are in this alone....we are all searching for answers. I hope some of my suggestions can be of help....but it is really up to you to jump in as get it presented clearly and concisely. Someone told me that they are keeping their claims open with more evidence as they find more. Wishing you all well.