There are a lot of people, usually men who say there there are no numbers or valid studies confirming a correlation.
Now, for their edification, we could take the tremendous increase in radiation in Washington State and other areas were radioactive material processing has taken place (if you get the breast cancer charts for the United States per ratio of population you can see all the sites where fuel was processed or reactors have been in operation). Witness Eastern Idaho where there is a very high rate of breast cancer. The Winds usually (not always) blow from the west there.
So what was in Central Idaho or Western Idaho that caused this contamination that is killing thousands of women?
The answer, of course is Arco, Idaho where there were several nuclear accidents. At one nuclear site a control rod had an operator pinned to the ceiling after the less than intelligent individual went to the top of the experimental reactor and pulled on the rod to free it because it was hung up on something. When he yanked on it it came loose and he created a super critical reactor and it exploded (Shades of Fukushima!) and launched him fifty feet into the air and pinned him on the ceiling for all to see and say, "Damn that fool was stupid!"
There was some debate as to whether or not they should take his body down. Some wanted to leave it up there as a warning to future generations about improper reactor operation. They eventually had to take his body down as his wife wanted it. They sealed it in a lead lined coffin so the family would not be irradiated during the religious services for his burial. There were other releases out there at that US Government site in central Idaho. In Idaho Falls and Pocotello Idaho they wonder why they have such a high incidence of breast cancer. The US government will not tell them, but I know.
All across America the breast cancer rates point to nuclear sites. And if you test with radiation meters, the increase in background is clear but small. San Onofre in Southern California is famous for the half million women who have died from breast cancer withing fifty miles of the plant and for 100 miles to the east of it. (The wind again is usually from the west.) The background radiation is only slightly elevated over background, but the cancer rate is very high. What have they been doing at San Onofre to kill all those poor women? The nuclear insustry will tell you they are not at fault. Something like mass psychosis is causing all of these women to get sick and die.