Food contaminated with metals and other materials can lead to aggressive or anti-social behaviour and must be urgently addressed, claims a University of Surrey study. It linked high levels of lead with a “reduction in IQ, negative classroom behaviour, juvenile delinquency and increased violent behaviour”. The researchers also quoted findings published in the New England journal of Medicine, JAMA and Neurotoxic Teratology. It is well known that some elements (such as copper, manganese and zinc) act as nutrients and are essential for health, while others (such as arsenic, cadmium, lead and mercury) might be toxic for the human body. The researchers however said that further study in this area is needed.