From Graham Jones
The decline in suicides following the adoption of environmentally friendly components in cars is an example of a well known pattern (7 September, p 24). The classic example in Britain was the switch in fuel from coal gas supplies to North Sea methane, which had a similar effect to that noted by Joshua Mott and colleagues in regard to catalytic converters. My own experience as a psychiatrist suggests that the increasingly widespread adoption of diesel engines in private cars has had a similar effect.
Sadly, the effect doesn’t last. Would-be suicide victims simply switch to other methods. I suspect that Mott and his colleagues will find that overall suicide rates for all methods have changed little.
Elgin, Morayshire
