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Biology 202, Spring 2005
Third Web Papers
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Brain Damage from Lead Poisoning as a Criminal Defense

Jenna Rosania

Last summer, I worked at the California Appellate Project (CAP) in San Francisco, CA, which is a non-profit law firm working for indigent death row inmates who are approaching their appeals. We assist the counsel appointed to the inmates for their appeals and we collect records that might help their case for mitigation of culpability for their crimes so that their sentences might be reduced. This work is very dependent on sources of information outside the legal system that deal with causes of behavior, such as effects of abuse and trauma and exposure to violence; in general the effects environment can have on the brain. We argue that when the brain is damaged in areas that effect judgment, planning, decision-making, and other areas that dramatically influence people's actions, the resulting crime is caused by the brain, not by the free will of the person committing the crime. This is usually acceptable by the legal system as mitigating of the personal culpability of offenders, and is thus validated by the most basic foundational institution organizing our society.

I also worked at Clean Water Action (CWA), located a city block away from CAP, so during my summer I became completely immersed in both criminal justice and public health issues. I learned the value of replacing nave idealism with optimistic realism when it comes to issues of public health. I feel that this is also a useful attitude when approaching the criminal justice system, because I believe the justice system is always changing, if very slowly, and that it is our job to help it progress in the right direction.

Therefore, I am very interested in the implications lead poisoning can have on the way our society handles deviance. Looking at the issue of lead poisoning in Philadelphia is a pragmatic way to deal with the anti-death penalty cause because it allows one to explore the roots of violent crime in society. When some of the underlying causes of crime, such as lead poisoning, can be obliterated from society, perhaps the purpose and need for capital punishment in our society may eventually be negated as well. Therefore, it is important to gather as much information that we can call "truth" as possible, so that the greater knowledge the scientific world can supply can be applied to institutions that could use that knowledge to more aptly manage, organize, and cohere society.

Lead poisoning has been an epidemic in the city of Philadelphia for decades (1). It is estimated that 2.2 percent of all preschoolers in the US, totaling approximately 434,000 children, have elevated lead levels sufficient to interfere with their neurological development (2). Studies about lead exposure in Philadelphia show that 5 percent or 5,000 of all Philadelphia children between the ages of six months and five years have lead levels in their blood capable of causing learning and central nervous disorders (2). Once used as an additive for house paint and plumbing alloys, lead was banned from use in homes and public institutions by the Environmental Protection Agency (EPA) in 1978, after human exposure to lead was connected to a host of physiological and neurological disorders. As I researched the well-established harmful effects of this pervasive toxin on those exposed to it, I was surprised to find that human exposure to lead continues to be a crisis of public health, criminal justice, and environmental racism. Few people have been able to create enough public and federal support for its complete elimination in schools and housing, perhaps due to the expense of remedial measures and the fact that those who suffer most are poor minorities in the inner city with little political organization and influence.

The people who are usually exposed to lead tend to live in older homes and come from poorer families who cannot afford to replace the two most common sources of lead to children in their homes, lead paint and lead plumbing (3). Although lead can affect several areas of the body, the neurological damage is often quite severe for individuals exposed to even slight amounts of lead during brain development. This damage often results in behavioral problems, reasoning and attention deficits, and low IQ and mental retardation; conditions that occasionally lead to deviant behavior. The National Mental Health Information Center of the US Department of Health and Human Services state: "Many environmental factors...put young people at risk for developing mental health disorders...[including] exposure to environmental toxins, such as high levels of lead..." (4). In neighborhoods where lead exposure is so common and unavoidable due to the impoverished state of the inhabitants, the lead exposure of the children that develop neurological deficits and subsequently exhibit deviant behavior must be considered when determining their degree of culpability for a crime. If the physical state and composition of the brain determine the behavior of an individual, a brain damaged by lead poisoning can be the source of socially abnormal behavior.

Dr. Herbert Needleman of the Psychiatry Department at University of Pittsburgh has conducted several studies in the past decades dealing with children's exposure to lead, sources of lead exposure, and social, behavioral, and neurological consequences of lead exposure. In 2002 he examined 194 youths convicted in the Juvenile Court of Allegheny County, PA, and 146 non-delinquent controls from high schools in Pittsburgh, PA. Lead levels measured from the tibias of the subjects using K X-ray fluorescence spectroscopy revealed substantially higher lead levels in the bones of the delinquent youths at an average of 11 parts per million (ppm) compared to 1.5 ppm in the non-delinquent group (5). Dr. Needleman described this study, which was the first to show lead exposure is higher in convicted delinquents than in non-delinquents, as a positive step towards connecting lead poisoning with delinquency, stating "This study provides further evidence that delinquent behavior can be caused, in part, by childhood exposure to lead. For years parents have been telling their pediatricians that their children's behavior changed after they were lead poisoned, and the children became irritable, overactive and aggressive" (6).

Dr. Needleman's groundbreaking work in the area of lead exposure and behavior warrants further investigation into the area of responsibility for behavior when an affected individual commits crime. According to all the studies, lead poisoning is a disease of poverty and is in no way the fault of the person afflicted. Therefore, the effects of lead poisoning, increased aggressive behavior, low intelligence, learning disabilities, and anti-social behavior, all of which are known predictors of crime, should be mitigation of the culpability of the offenders afflicted with lead poisoning.

The neurological damage resulting from exposure to lead can result in abnormal behavior, exhibited through increased irritability and violence, learning disabilities, mental retardation, and other functional difficulties. The social effects of these abnormal behaviors through disciplinary actions, peer isolation, falling behind in school, drug abuse, domestic abuse, and a lack of understanding about the basis of an individual's impairments may also compound the neurological damage, resulting in psychological trauma, which studies show can cause other types of brain damage (7). Additionally, lead exposure is known to cause attention problems for children (8) making academic success and effectively adapting to society difficult. All these conditions have been known to result in an individual's inability to function in society or possess adaptive skills. Inability to function in society often results in deviancy of various kinds, and at times the deviancy that is a symptom of an individual's neurological damage is so seriously a breach of the mores of social structure that it is viewed by our legal system as criminal.

A question that arises when assessing degrees of criminal culpability is whether all crimes can be traced back to some mitigator that makes it inappropriate for the application of harsh penalties to an offender under the Eighth Amendment, which states no one be exposed to cruel and unusual punishment sanctioned by the state. A professor at the University of Illinois School of Law, Michael S. Moore, commented that such an argument leads to the "absurd conclusion that no one is responsible for anything" (9). The question is particularly important as the knowledge about predictors of criminal activity increases, and includes more and more mitigating factors that wouldn't previously have been acceptable excuses for crime. In the case of lead poisoning, the statistics for the number of children exposed to lead before it was as relatively controlled as it is today means that now those children who may be committing crimes as adults will be a significant population of the criminals who are subjected to the justice system, and a substantial group of offenders may be collectively excused for their crimes due to the pervasiveness of lead poisoning.

Lead poisoning has been epidemic in the city of Philadelphia for decades. Although it would seem the problem of lead in the US as well as in Philadelphia is being ameliorated and that the numbers of children being exposed is decreasing, the children who were affected by the high doses of lead far more common and rampant in the last century are now adults, trying to function in society with the effects of their exposure. In addition, those children who are currently being exposed to lead need a society that will be able to better understand the implications of this environmental toxin for delinquency and execute justice more effectively when they become adults. Human exposure to lead continues to be a crisis of public health, criminal justice, and environmental racism, and what is necessary for its complete elimination in schools and housing is a change in people's attitudes about the extent of lead poisoning in order to gain more public and federal support and make this problem of poor minorities in the inner-city with little political organization and influence everyone's problem.


1) US Department of Health and Human Services, The Nature and Extent of Lead Poisoning in Children in the United States: A Report to Congress 1 (July 1988).

2) Centers for Disease Control and Prevention. 2003. Second National Report on Human Exposure to Environmental Chemicals. NCEH Pub. No. 02-0716.

3) Center for Disease Control and Prevention. 1991. Preventing Lead Poisoning in Young Children: A Statement by the Centers for Disease Control. Atlanta, GA.

4)US Department of Health and Human Services, Substance Abuse and Mental Health Services (SAMHSA), National Mental Health Information Center, under heading, "The Causes are Complicated."

5) Needleman, Herbert L., et al.. 2002. Bone Lead Levels in Adjudicated Delinquents: A Case Control Study. Neurotoxicology and Teratology, Vol. 24.

6)Lead link to youth crime, BBC News Online, 7 January, 2003

7) Rosen J. F., Mushak P.. 2001. Primary Prevention of Childhood Lead Poisoning The Only Solution, New England Journal of Medicine, 344.

8) Minder, Barbara, et al.. 1994. Exposure to Lead and Specific Attentional Problems in Schoolchildren. Journal of Learning Disabilities, Vol. 27.

9) Moore, Michael S. 1985. Causation and the Excuses. California Law Review, Vol. 73, pp. 1118-1119.

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