lead levels connected to violent crime

i read the other day that lead levels in the atmosphere have been linked to the level of violent crime in society . an american study has shown that twenty years after a high atmospheric lead count violent crime increases ..and conversely ..when lead levels have lowered then 20 years later ,so has the violent crime.six cities were studied and the findings are consistent with lead levels having an affect on violent behaviour ...regardless of the different civic responses to tackling crime in those cities .the good news is ... violent crime is continuing to fall in line with our modern anti pollution attitude.

So, is violent crime spiking in China and India? Because pollution and lead levels there are off the hook.

yeah box' that occurred to me too ..it would be interesting to see comparisons with those countries. i'd imagine the people doing the research must have considered that ... however , if it's a correct scientific finding ... then china and india (if there lead levels are high ) will be experiencing a very noticeable rise in violent crime in the next 10 to 20 years .