Good Lord, what doesn't cause cancer? Did they dye those white mice to test this? I think eventually we'll discover that white mice are the cause of cancer ;)
When a time frame of 20 years is used, it means they're not sure. In 20 years almost anything can happen. In financial statements, anything past a 10 year look into the future is extremely speculative, to put it mildly.
A researcher wants to show results because a study that shows no results will not give them more research funds as easily and attention for their "findings" can only help them. Therefore one way of doing this is that they excessly dose a test animal and say, "See that causes cancer". Almost anything in overuse could cause cancer. If they drowned an animal in hair dye, would that mean it's fatal?
A lot of people might use hair dye because their hair becomes grayer faster if they have cancer for all we know. I once saw a study that people in hospitals are far more likely to be sick than any other group. That doesn't mean that hospitals are health hazards; it just means that sick people are taken to hospitals as they should be. We must use a little common sense here.
A lot of these cancer causing studies are then refuted and you won't see that on the news. People aren't interested in a story on how non-cancer causing a product is. In fact, a researcher would have to be careful saying anything could not possibly cause cancer, because then they would be liable if they're wrong.
Anybody who gets an advanced degree that normally doesn't require math except for statistics to do studies are usually not in love with math and statistics and are often quite bad at it. They're human and they make mistakes and they didn't study their field to learn math and statistics usually. I tutored many of these people in statistics years ago and I saw that most of them don't really understand why statistics works and don't care to know, they just apply the formulas and have faith. Any tool, no matter how good, is more likely to be faulty in the hands of someone who doesn't understand how it works and doesn't like using it.
There are some things that certainly increase risks for cancer. However I suggest that good intelligent people trying to take care of their health don't stop using a product because of only one study. If we get second opinions before surgery, we also need more than one study before concluding such things.
I've found many times that studies are wrong in my personal experience. I once saw a news report that all batteries, regardless of brand last about the same amount of time. The study looked to be done really well to me. They tested it in a number of products and they all stopped functioning after many hours of continual use within a few minutes of each other, regardless of the brand name of the battery. The more expensive battery brands dismissed it as saying products are almost never used without shutting them on and off and that their products last far longer in actual use. That seemed like a weak excuse to me and I thought that cheap brands of batteries were fine, partly because I wanted to save money.
In my experience, the cheap brands don't last nearly as long as the more expensive brands. Usually the difference is quite dramatic. Even dollar for dollar I don't think I get my money's worth from cheap brands usually and I don't like to constantly replace batteries.
I believed the study because it gave a result I wanted to see and from what little I saw of the facts of the study from the news report, it made it look like it was very well done. For all I know, the study intended to conduct it in the way they did, but made many mistakes or cut corners or even made up their findings or were just wrong. Perhaps the news reported it wrong?
When we see a study on the news, we are getting the information from a reporter who questioned an administrator who looked at the study. Therefore it's usually at least 3rd hand information and should be looked at skeptically. The children's game of Telephone shows how garbled even simple information can get if passed on again and again.
All I'm saying is if something is working for you, stick with it regardless of what one study is saying, no matter how well intentioned it is. A study is not gospel or fact. If studies start agreeing, then they can be taken more seriously. Even this can be manupulated though.
Many executives have assistants (who hide that they are assistants) who are given the task to simply repeat what their boss said for the purpose of convincing a person more. They realize that if a person hears something twice they are more likely to believe it regardless of the fact contact.
Is there a moral here? All I say is that a little skeptism can be healthy and do your best. We will make mistakes regardless, but try to consider as much as you can.