Smoking causes genetic mutations.

Smoking fathers pass on damaged DNA to their children raising the risk of cancer
Another Daily Mail article about wierd and wonderful ways to get cancer.

Fathers who smoke pass on damaged DNA to their children – raising the risk of cancer, research shows.
A study found that smoking harms the father’s DNA, and these damaged genes can be inherited by his children.
This raises the risk of youngsters developing childhood cancers, particularly leukaemia, warn researchers at the University of Bradford.

So let me get this straight. Smoking changes the DNA makeup of sperm so that it carries a cancer causing gene? One a child is concieved, this child then carries the cancer gene and becomes more likely to get cancer as it grows up, which means that smoking causes cancer intergenerationally?

Is this even possible? Leg Iron might have an answer. As for 'science' in the media, I'll take it with a pinch of salt unless independently verified through a more trustworthy source.

Because a fertile sperm cell takes three months to fully develop, fathers should kick the habit 12 weeks before conceiving to avoid the risk, Dr Diana Anderson said.
She added: ‘Smoking by fathers at the time around conception can lead to genetic changes in their children. These changes may raise the risk of developing cancer.’
Kicking the habit: Fathers are advised to give up smoking 12 weeks before conceiving to reduce the risk of their children getting cancer

The genetically modified child of a smoker