Section C
A researcher says lead in the environment could be a major
cause of violence by young people. Doctor Herbert Needleman is a professor at
the University of Pittsburgh School of Medicine in
Pennsylvania. He says the (36) of lead in the brain changes
the neurons that control actions and that can cause a person to act in
antisocial and (37) ways. Lead is a metal
that is (38) dangerous to babies and young children. They
can get it into their bodies by breathing or (39) lead
dust, or by eating soil or pieces of lead paint. Children with high levels of
lead can (40) brain and nervous system damage, learning
(41) , slow growth, headaches and hearing loss.
In the 19th century, Doctor Needleman found lower scores on (42)
tests even in children who did not have such signs of lead
(43) . After that, lead was removed from gasoline and paint in the
United States. Yet many homes still have old lead paint. Lead was also used in
older water pipes. In fact, (44) . The newest research
shows that even very small amounts of lead in bones can affect brain
development. (45) . In 2008, such tests were done on 190
young people who were in jail and the findings showed that their average levels
were higher than normal. And, in 2002, (46) . Yet these
levels were still considered safe by the government.