5 June 2007: ...even unto the fourth generation

Everyone knows that smoking damages the health of the smoker, and can also damage the people around them through passive smoking. But now Canadian researchers have established that a man's smoking can damage his children before they are even conceived.

Their study shows that cigarette smoke causes changes in the DNA of sperm cells. Such mutations, know as germline mutations, are known to be permanent.

"We have long known that mothers who smoke can harm their foetuses, and here we have evidence that fathers can potentially damage their offspring long before they even meet their future mate." said one of the team.

They also established that the longer you smoke, the more the mutations accumulate, so the more likely you are to create defects in your children.

However, as heavy smoking in men is known to cause impotence, maybe it won’t matter anyway.

[The title is a quotation from The Bible, Exodos 20 v4: "...punishing the children for the sin of the fathers to the third and fourth generation..."]