Setting aside its effects on violent tendencies, Drum notes that lead does lasting damage to the intelligence:
Neurological research is demonstrating that lead's effects are even more appalling, more permanent, and appear at far lower levels than we ever thought. For starters, it turns out that childhood lead exposure at nearly any level can seriously and permanently reduce IQ. Blood lead levels are measured in micrograms per deciliter, and levels once believed safe—65 µg/dL, then 25, then 15, then 10—are now known to cause serious damage. The EPA now says flatly that there is "no demonstrated safe concentration of lead in blood," and it turns out that even levels under 10 µg/dL can reduce IQ by as much as seven points. An estimated 2.5 percent of children nationwide have lead levels above 5 µg/dL.The Economist makes a similar case. In its new-year issue: "The World in 2013" the magazine published an obituary for lead, because 2013 marks the year a UN deadline will take effect demanding that all nations around the globe phase out mass consumer sales of leaded gasoline. What countries still have lead at the pumps? Take a look at a 2009 graphic:
The Economist lists the 2013 nations by name:
They are an interesting bunch: Afghanistan, Algeria, Iraq, Myanmar, North Korea, Sierra Leone, Yemen. None is a happy place. All are afflicted by violence, and three by long-running wars. Opponents of lead in petrol, or in anything else, might conclude that their case is closed. Lead’s pernicious presence lowers intelligence and increases aggression, typified by the urge to roar through dusty cities in heavily armed, pollution-spewing trucks.In other words, there is good news ahead for some of the most dangerous places on earth... and if it comes, it will be thanks to science, regulation, and globalism.