Type 1 geographic hot spots?

I grew up in a town in Long Island, NY. I developed Type 1 in the late 1960’s as a teenager. No one else in my immediate or extended family has had it. I have recently discovered that one of my good friends developed late onset type 1 some time 30 years later. So did her younger sister. Now I hear of another friend whose son just developed Type 1 around age 16. (In California). This could be a coincidence, (very small sample size) but who knows! Something in the water, radiation, dumb luck! Any one know of any research in this regards or have similar tales to tell?

Thanks

Some researchers think that there is a correlation between longitude and the incident rate of type 1 (see here). The more away from the equator the less sunlight we get, the less vitamin D we will produce, the less vitamin D the higher the risk for type 1. But the incident rate in sunny areas is not null. It is only statistically lower than in Finland for example. Supplementation of vitamin D for our children seems to be advisable.

Dan Hurley in his book “Diabetes Rising” talks about geographtical clusters of T1 in kids. You might find the book either interesting or deeply disturbing.

There’s a book out called Diabetes Rising by science journalist Dan Hurley that you might want to take a look at - documents a sudden surge in T1D diagnosis in and around Weston, Sudbury, and Marlborough MA, all towns that are uncomfortably close to the superfund site in Woburn that was the object of the movie A Civil Action. I can’t tell you how irked I was to learn about this connection given that I spent much of my pregnancy with Eric (my son with T1D) in that exact general area, drinking the local water (!) and developing autoimmune thyroid disease (!!). It discusses in detail the various hypotheses for environmental and genetic causes.

I would love to see research on this.
What we’re all exposed to, and how our cells react to it, would be fascinatingly muddling, I suppose. But in depth case studies of “firsts in family” might bring out some factors.
Of course, we already know about high stress. But what if our stressed cells also reacted to high iron deposits near water supplies, high electrical wave stimulation - waves of varying frequencies, the smells of toxic chemical factories, and/or the ingestion of a high flour diet. Each of us no doubt has had our own triggers to autoimmunity - with or without parental hand-me-downs.
All fascinating to contemplate.