human
I've been hearing a lot of talk about the dangers of e-cigarettes. Is there any evidence that they're harmful?
assistant
There is some evidence that e-cigarette use can cause health problems, such as heart disease and lung damage. It's also possible that long term use could be associated with an increased risk of cancer. However, it's important to note that these risks are still being studied and more research needs to be done before we have a full understanding of their effects.