Environmental pollution is responsible for a significant share ofviolent crime and antisocial behaviour, according to an analysis byRoger Masters of DartmouthCollege, New Hampshire. He saysmetals in, drinki,disrupt the neurosocial, economic and psychologicalfactors cannot fully explain whysome counties in the US have only100 violent crimes per 100,000people each year, while others haveover 3,000. He points to experiments on cell cultures which haveshown that lead partly incapacitatesglial cells, which are responsiblefor "housekeeping" in the brain,mopping up unwanted chemicals.And in people suffering from calcium deficiency, which afflicts someof the poorest citizens in the US,manganese inhibits the uptake ofthe neuro-transmitters serotoninand dopamine in parts of the brain.These chemicals are known to con-trol impulsive behaviour (NewScientist, Vol 154, No 2084).