>Anderson points to another example where simply making a change in people's access to instruments of suicide dramatically lowered the suicide rate. In England, death by asphyxiation from breathing oven fumes had accounted for roughly half of all suicides up until the 1970s, when Britain began converting ovens from coal gas, which contains lots of carbon monoxide, to natural gas, which has almost none. During that time, suicides plummeted roughly 30 percent — and the numbers haven't changed since.