Many Western nations have experienced significant declines in crime in recent decades, but could the removal of lead from petrol explain that? Working away in his laboratory in 1921, Thomas Midgley wanted to fuel a brighter tomorrow. He created tetraethyl lead – a compound that would make car engines more efficient than ever. But did the lead that we added to our petrol do something so much worse? Was it the cause of a decades-long crime wave that is only now abating as the poisonous element is removed from our environment?
For most of the 20th Century crime rose and rose and rose. Every time a new home secretary took office in the UK – or their equivalents in justice and interior ministries elsewhere – officials would show them graphs and mumble apologetically that there was nothing they could do to stop crime rising. Then, about 20 years ago, the trend reversed – and all the broad measures of key crimes have been falling ever since.
Offending has fallen in nations whose governments have implemented completely different policies to their neighbours. If your nation locks up more criminals than the average, crime has fallen. If it locks up fewer… crime has fallen. Nobody seems to know for sure why. But there are some people that believe the removal of lead from petrol was a key factor. More here Did removing lead from petrol spark a decline in crime?.