Rising lead, crime linked

[dannyboy]

link (http://news.enquirer.com/apps/pbcs.dll/article?AID=/20080528/NEWS01/805280382/1077/COL02)

BY CLIFF PEALE | CPEALE@ENQUIRER.COM

LaQuisha Graber remembers that as a child, she chewed on peeling lead-based paint in the Over-the-Rhine apartment where she lived.

Since then, Graber has been in plenty of trouble. She's been in fights at various jobs, dropped out of school after the eighth grade and spent two years in state prison at Marysville for drug possession and assault.

A new study from the University of Cincinnati suggests that there's a connection between young children with high levels of lead in their blood and whether they commit crimes as adults.

Researchers have followed Graber since before she was born, testing prenatal lead levels in her mother's blood and then testing her quarterly until almost age 7.

The new study is to be published today in the Public Library of Science Journal.

"It's like a disease. I can't control it," Graber, now 23 and living in Silverton, said of her temper. "I just can't control it, no matter how much I try."

Researchers established years ago that lead poisoning can cause brain damage and even be deadly to children, and it can cost billions of dollars in lost work productivity and medical care. The same UC team concluded several years ago that high lead levels were linked to delinquent behavior in children.

The researchers now have taken that study to the next step.

Kim Dietrich, a professor of environmental health at UC and one of the lead researchers, said almost all of about 250 participants in the study showed lead levels that would concern the Centers for Disease Control and Prevention.

Of those participants, 55 percent, most with higher lead levels, have been arrested at least once.

As lead levels in the blood increased, the chance of being arrested for a violent crime jumped 30 percent, the study found. The study measured the criminal records of children with high lead levels, compared to those with lower levels.

600 POISONED SINCE '02

Although researchers caution there are many reasons for criminal behavior, the study is the latest confirmation of lead poisoning's toxic effect among residents of city neighborhoods with old, decaying housing. Lead poisoning affects hundreds of children in the city.

Since 2002, more than 600 Cincinnati children have been poisoned by lead.

That's not hard to understand when looking at Cincinnati's housing stock.

U.S. Census figures show that 154,667 of the city's 169,945 homes were built before 1979 and are likely tainted with lead. More than 93 percent of the city's homes could have lead paint, a substance banned in homes 30 years ago.

The Cincinnati Health Department received $3 million last year from the U.S. Department of Housing and Urban Development to rid 210 older homes of lead paint.

A companion study of the same group of children, by a team of UC researchers led by Kim Cecil of Cincinnati Children's Hospital Medical Center, shows links between high lead levels and trouble with impulse control and decision-making, Dietrich said. He said the conclusions for poor children in urban areas, many of them black, are obvious and chilling.

"For some children, it's almost pulling the trigger," he said.

STUDY STARTS ON CITY POOR

The study started in 1979, with researchers following 376 families in neighborhood clinics in Over-the-Rhine, the West End, Avondale and Price Hill. Participants were examined at a clinic and at Children's and matched with arrest records from Hamilton County.

Researchers eventually collected information on 250 children and compared the ones with higher blood lead levels to those with lower levels, leading to the increased level associated with adult arrests.

They included only arrests for serious offenses through October 2005.

Women were enrolled in their first trimester or early in their second, and excluded if they showed a drug addiction or certain diseases.

The study was paid for by the National Institute of Environmental Health Sciences and the U.S. Environmental Protection Agency.

Graber, who never finished high school or got her equivalency degree, said she remembers fainting at school when she was younger and getting dust on her hands from windowsills that could have increased her lead exposure.

She has been to court-ordered anger-management classes and has gotten into several confrontations at her job at a McDonald's.

"I'm really the nicest person you would ever want to meet," she said. "It's just that other side of me that I can't control."

[jneale]

that sounds like someone who has an excuse for everything

[frizgolf]

that sounds like someone who has an excuse for everything

Just what I thought.
"You mean I have an excuse for being an asshole? Good. Now I can keep being one."

[Sushi]

that sounds like someone who has an excuse for everything

Including an excuse for being a kid dumb enough to eat paint.

[Shlep]

A companion study of the same group of children, by a team of UC researchers led by Kim Cecil of Cincinnati Children's Hospital Medical Center, shows links between high lead levels and trouble with impulse control and decision-making, Dietrich said. He said the conclusions for poor children in urban areas, many of them black, are obvious and chilling.

Like most folks, I usually couldn't give less of a fuck if poor kids in urban areas were gnawing on lead paint to the point where it made them act like GG Allin in the middle of a non-stop three-day crank binge; hence, I was about to shrug this off and never give a second thought. But now that I see that many of them are black, I am inspired to marshal up a small army of volunteers to go into the poor sections of town, scrap off every last fleck of lead paint, and redo the joint using a nice, subdued, off-white oil- or latex-based variety. 'Scuse me while I call Home Depot and see if they're running a special.

















Seriously: what the hell was the point of adding that distinction?

[Macpherson]

Seriously: what the hell was the point of adding that distinction?

and it wasn't an actual quote. makes you wonder if dietrich really said that or if it was an embellishment by the writer of a lousy publication.

[Sushi]

Seriously: what the hell was the point of adding that distinction?
It's the Political Rorschach test. If you're a knee-jerk conservative reactionary, you think, "Well, they're black, which is tantamount to being a criminal. It has nothing to do with lead paint." If you're a knee-jerk liberal reactionary, you think, "Oh, they're black, which is tantamount to being discriminated against. No wonder they're having problems. It has nothing to do with lead paint."

Personally, I saw a butterfly.

[the_birds]

This just in...

Poor people blamed on being poor.

Now back to your regularly scheduled program...

[BigSugar]

so let me get this straight:

they studied this child prenatally. they tested her at birth. they watched this child growing up. they continue to study this person as an adult.

at any point in her life did these focking morons ever say "hey honey, don't eat that lead paint!"??? or did they place grape flavored lead paint chips in her house to insure the viability of the study? LOL! was there a control group that was fed regular latex or water based paints who are all doctors and CEO's now? bunch of MIT grads in the control group?

we paid for this study folks. i guess we gotta keep PhD's employed somehow. :)

[Buzzstein]

In poorer neighborhoods there are more older houses with lead paint. It might have more to do with growing up in a poor neighborhood than growing up in an environment with a lot of lead. Hard to say, but it's definitely worth investigating the possible effects of lead paint.

[C. Doves]

Lead poisoning is not a joke or an excuse. I've known people who worked in stained glass, 2 in particular, that have it. The lead stays in your body and accumulates. The rages are of a particular type and suddeness far beyond ordinary peevishness.

Children in old houses chew on windowsills, get the dust in their mouths from their hands, the floors, etc. I mean, a kid only has to chomp on a window sill once without anyone looking to get a nice lead amount.

Some people should learn up before they go a-judging, maybe.

[C. Doves]

P.s. The people I knew who had trouble were white, does that legitimize it for anyone? :mad:

[Shlep]

they studied this child prenatally. they tested her at birth. they watched this child growing up. they continue to study this person as an adult.

I'm not sure if you were trying to convey the point I'm about to; be advised that I'm not consciously try to go about cribbing your material. ;)


So then: am I to understand that a collection of medical doctors and /or researchers knocked heads, formed a research team, and created a prolonged study that involved testing newborn infants at (and before in some cases) birth all the way to adulthood so as to empirically measure and track the level of certain toxic substances-- that being lead, of course-- in their blood?

Am I likewise correct in thinking that the researchers collated their findings and then approached local law enforcement for the purpose of comparing the test subjects' medical data against their criminal data in order to see if there were any logical inferences to be drawn vis-a-vis a hypothesis suggesting that there is a directly proportional relationship between criminally antisocial behavior and TODDLERS WHO EAT FRIGGIN' POISON?!?!!

I'm not the expert here, but I have had formal instruction relating to things like academically disciplined research and epidemiological studies. I must say that I am at a loss to reckon how in the hell the idea for this study successfully stood up to being peer-reviewed and passed muster, and then continued to hold up under scrutiny for decades.

Of course this assumes that any of the latter two items ever took place; I'd say it must have. This would be by virtue of the fact that it's going to be published in at least one, if not more, scholarly journals. In my experience with such publications, I've gathered that the editors were not typically of a mind to shit-can a large chunk of their credibility by lending the appearance of legitimacy to sloppy or unethical research, especially research conducted using a paradigm that bears a rather disturbing similarity to the Tuskeegee Syphilis Experiment.

[Frost]

Wow, look at that. Freely available on the web, for all the semiamateur shit talkers to dissect.

http://medicine.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pmed.0050101

Introduction

Early onset of aggressive or violent behavior is a precursor to a life course marred by limited social and educational achievement, incarceration, underemployment, and premature mortality [1,2]. These maladaptive behavioral patterns, which often emerge early in life, remain highly stable [3]. These facts highlight the importance of identifying risk factors that may place youth on an early developmental trajectory toward a career of crime and violence.

A meta-analysis of 34 independent studies identified and prioritized risk factors for serious, violent criminal behavior [4]. The most consistent risk factors were male gender, prenatal exposure to tobacco smoke, having antisocial parents, and low family socioeconomic status. In contrast, few studies have evaluated the consequences of childhood lead exposure as a risk factor for criminal behavior.

Some epidemiological studies have found a relationship between childhood lead exposure and antisocial behavior. In a study of Philadelphia youth, a history of lead poisoning was among the most significant predictors of adolescent delinquency and adult criminality in males [5]. Bone lead levels were associated with delinquent behavior in a retrospective cohort study of 11-year-old Pittsburgh children [6]. In Cincinnati, prenatal and childhood blood lead concentrations were associated with an increased risk for antisocial behavior and delinquency in adolescence [7]. Finally, elevated bone lead levels were observed in juvenile court–adjudicated delinquents residing in Allegheny County, Pennsylvania compared to matched controls [8]. These studies suggest that exposure to environmental lead during childhood is associated with the development of conduct problems and delinquent behavior. In consideration of these findings, it is noteworthy that a number of recent ecological investigations correlating leaded gasoline sales or atmospheric lead levels with crime rates also support an association between lead exposure and criminal behavior [9–12]. Questions remain, however, because these studies were cross-sectional (hence causality cannot be firmly established), relied on indirect measures of lead exposure, or did not follow participants into adulthood.

Here, we report the results of a long-term prospective study on the effects of one potential childhood risk factor of adult arrests, elevated prenatal and childhood blood lead concentrations.
Methods
Participants

The Cincinnati Lead Study (CLS) is a birth cohort recruited from late 1979 to early 1984. The CLS enrolled women in their first or early second trimester of pregnancy who attended four prenatal clinics within impoverished Cincinnati neighborhoods with a high concentration of older, lead-contaminated housing [13]. Women were excluded or ineligible if they were known to be addicted to drugs, were known to have diabetes or a neurological or psychiatric condition, or refused prenatal participation. Newborns were excluded if their gestational age was less than 35 wk, birth weight less than 1,500 g, Apgar score at 5 min less than 6, or if genetic or other serious medical issues were present at birth. This process netted 376 newborns who were recruited at birth (i.e., informed oral and written consent was obtained from the mother in the hospital and a blood lead sample was obtained from the newborn). Of these newborns 305 were developmentally examined at the CLS follow-up clinic when they were 3 and 6 mo of age [14]. They were followed up quarterly through age 5 y and semiannually from age 5 to 6.5 y [15].

A total of 250 CLS participants who were between 19 and 24 y of age and had been followed at least through the first 6 y of life participated in the current study. Thus, individuals in the current analysis had serial blood lead concentrations spanning the entire preschool and early school-age period of development. Written informed consent was obtained by the investigator or a senior member of the research staff at each stage of this longitudinal study after it was determined that the participant or the participant's legal guardian understood the nature of the research. This protocol has been reviewed and approved by the institutional review boards of the University of Cincinnati College of Medicine and the Cincinnati Children's Hospital Medical Center.

The 250 participants in this analysis were not substantially different from those with missing data with regard to baseline perinatal characteristics such as birth weight (3,134 versus 3,138 g), sex (50% versus 54% male), 6-y average Hollingshead [16] socioeconomic status (SES) total score (18.0 versus 18.3), years of maternal education (11.2 versus 11.1 y), scores on the Home Observation for Measurement of the Environment (the preschool version of a quantitative observational measure of early nurturing and environmental stimulation [17]) (32.3 versus 33.4), and average childhood blood lead (13.4 versus 14.2 μg/dl).
Exposure and Outcome Assessments

We examined three measures of blood lead. Prenatal maternal blood lead concentration [μg/dl]) was measured during the first or early second trimester of pregnancy. Approximately 50% of the prenatal samples were obtained during the first trimester of pregnancy. The difference between maternal blood lead concentration assessed in the first and second trimesters was not statistically significant (p = 0.76) [14]. Postnatal blood lead indices included average childhood blood lead (average of 23 blood lead concentrations obtained quarterly from age 3 to 60 mo and semiannually from 66 to 78 mo), and 6.5-y blood lead. If a 6.5-y blood lead value was not available for a child, we used the blood lead test from 6 y. We selected 6.5 y blood lead over other serial blood lead measures because preliminary analyses indicated that blood lead measured at 6 y was more highly associated with the number of arrests than blood lead measured at other ages. Complete blood lead data were available for 89%–92% of the cohort at any particular quarterly assessment from 3 mo to 5 y of age. Missing postnatal blood lead concentrations were imputed from a weighted average of a within-participant regression of blood lead on age. This imputation was done to avoid excluding those participants who may have one or only a few missing blood lead tests. Prenatal blood lead concentrations were available for 87% (217/250) of the participants.

The primary outcome variable in this study was the individual's number of criminal arrests since turning 18 y of age. We did not collect data on convictions. Arrest is a more proximate measure of criminal behavior than are conviction data. Arrest typically occurs at the scene of the criminal event or immediately thereafter. Arrest decisions, moreover, usually reflect the seriousness of the offense, the offender's prior record, and the desire of the victim to have the individual arrested. Conversely, conviction data are distal indicators of criminal behavior. Actual criminal convictions derived from a trial represent less than 10% of all criminal arrests. Over 90% of all criminal cases are subject to plea bargaining, in which a plea of “guilty” is usually rewarded with a reduced charge and/or sentence. From the time of arrest it can take upward of 2 y or more before a defendant is tried in a court, or it can take over 1 y from the time of arrest to the time at which a plea deal is accepted by the court. Furthermore, a range of extra-legal variables can enter into the plea and trial process, including the defendant's economic status, support system, and access to quality defense counsel. We should also add that Hamilton County, Ohio (the study's catchment area) makes extensive use of “diversion” programs. These programs select individuals with specified problems or offenses, such as drunken driving or drug abuse and “divert” them from jail or prison into community-based rehabilitation programs. Upon successful completion of the program and a probationary term, many of these programs “erase” the individual's legal conviction, but not the arrest. Finally, at least for this study, arrest data are substantially more complete than are conviction data. Arrest data in Hamilton County, Ohio are compiled into a single county-wide database and are updated at regular intervals. Court data, however, are not updated regularly. This problem is endemic to court systems nationwide, because courts operate at different levels (city, county, state, Federal) and are under the guidance of individual judges.

[Frost]

Data on Criminal Arrests

Data on criminal arrests for participants and their mothers were obtained from a computer search of Hamilton County, Ohio criminal justice records. These records provided information on the nature, number, and disposition of arrests. Two reviewers who were blind to participants' blood lead concentrations independently coded each arrest into one of the following categories: violent offenses (e.g., murder, rape, domestic violence, assault, robbery, or possession of a weapon); offenses against property (e.g., burglary or arson); drug offenses (e.g., trafficking, abuse, or possession); fraud; obstruction of justice; serious motor vehicle offenses (e.g., driving without a license, driving under the influence of alcohol, or driving under suspension); disorderly conduct; and other offenses, which included offenses that did not fit in any previously mentioned category. Minor motor vehicle offenses, such as speeding, safety restraint violations, lights burned out, failing to stop, and pedestrian offenses were excluded from the analyses. We counted the number of arrests and coded the nature of the offense that led to each arrest. If an individual was charged with more than one offense during a single arrest, then the most serious offense was used for classification. Thus, arrest counts were lower than the total number of offenses. Legally determined guilt was not a factor in our coding. Only those offenses that were filed before 31 October 2005 were included in the analyses.

Inter-reviewer differences with respect to arrest and category of offense were resolved by a third reviewer who conducted the initial training for criminal record coding. Interobserver agreement as assessed by Cohen's kappa was 0.93 for maternal offenses and 0.97 for participant offenses.
Statistical Analyses

We used negative binomial regression models to analyze these data because the counts of arrests were overdispersed when originally examined using Poisson regression models [18]. This model provided a very good fit to these data in terms of the estimated scale parameter. These models were used to estimate the association between blood lead concentrations and arrest rates adjusted for other important risk factors. We calculated separate models for each blood lead measure. Our dependent variable was the number of criminal arrests for each participant measured as discrete counts, which were positively skewed. To account for the number of years at risk of arrest, we used the log of current age as an offset in all models. To control for potential confounding, we examined variables reflecting the effects of other neurotoxicants such as maternal cigarette and marijuana smoking and consumption of narcotics during pregnancy, as well as variables related to adult criminal involvement in prior studies. Our list of candidate covariates included: sex; a validated measure of the quality of early care-giving and environmental stimulation called the Home Observation for Measurement of the Environment (HOME) inventory score [17]; birth weight (g); maternal smoking during pregnancy (half-packs consumed per day); maternal alcohol, marijuana, or narcotic use (Y/N); maternal education level (highest grade); maternal IQ [19]; total prior maternal arrests; SES (average Hollingshead [16] score); number of children in the home; and whether the mother was on public assistance during the participant's childhood (Y/N). Data on fathers or male caregivers in the home were not available, since 84% of the households were headed by the mother or a male caregiver was not consistently present. Continuous covariates were examined using linear, polynomial, and log-transformed functions to assess whether simple linear terms were adequate for adjustment of covariate or confounder influences.

Candidate covariates or confounders remained in the final multivariable models if they were either statistically significant (p ≤ 0.05) or if their inclusion in the model caused a change of ≥ 10% in the rate ratio estimates for lead, regardless of their level of statistical significance. We tested the interaction of lead by sex, since some studies have indicated that developing male central nervous systems may be more vulnerable than females' to environmental insults leading to later behavioral problems [20]. Before deciding upon a final multivariable model, regression diagnostics for collinearity and influence using the methods described in Belsley, et al. were employed [21]. As a measure of the absolute change in arrest rates between participants with higher levels of blood lead compared to those with lower blood lead levels, we defined attributable risk as the average difference in annual arrest rates between participants at the 95th percentile of blood lead and those at the 5th percentile. All significance tests were two-tailed. Results for blood lead variables are presented as adjusted rate ratios (RR) for total arrests and arrests for violent crimes. All statistical analyses were conducted with SAS (Statistical Analysis System), version 9.1 [22].

Results

The sample was largely African-American (90%), 50% of the participants were male, and 73% of families scored in the lowest two levels of the Hollingshead Four-Factor Index of Social Position [16]. A single female caregiver headed 84% of households.

Mean blood lead concentrations (μg/dl) were 8.3 (0.40 μmol/l) (range 1–26) for maternal prenatal, 13.4 (0.65 μmol/l) (range 4–37) for average childhood, and 8.3 (0.40 μmol/l) (range 2–33) for 6-y. The mean postnatal blood lead concentration of CLS participants increased to a peak of 17.7 (standard deviation [SD] 9.7) μg/dl (0.85 μmol/l) at 21 mo. After age 21 mo, average blood lead concentrations declined to a mean of 8.4 (SD 4.9) μg/dl (0.40 μmol/l) at 6.5 y. At 6.5 y of age, 67 children (26.9%) had a blood lead concentration above 10 μg/dl (0.48 μmol/l) (Table 1). Pearson correlations between blood lead indices examined in this study were 0.32 and 0.28 between prenatal and average childhood and 6-y respectively, and 0.80 between average childhood and 6 y.

We identified a total of 800 arrests within the sample. Of these arrests, 108 (14%) were for violent offenses, 90 (11%) involved theft or fraud, 216 (28%) involved drugs, 35 (5%) were for obstruction of justice, 211 (27%) were related to serious motor vehicle offenses, 35 (5%) were for disorderly conduct, and 82 (11%) other. Approximately 55% of participants (62.8% of males, 36.3% of females) had at least one arrest. The mean number of arrests among males was 5.2, which was significantly higher than the mean number of 1.1 for females (p < 0.001). The overall mean arrest rate was 0.68 per year after age 18, but the mean arrest rate for males was 4.5 times higher than the female arrest rate (1.1 versus 0.25 per year).

Preliminary analysis of the association between blood lead measures and covariates revealed generally weak correlation coefficients ranging from 0.24 to 0.35, indicating a relatively small potential for confounding. In multivariable regression analyses of the total number of arrests, we found that the associations between prenatal and 6-y blood lead concentrations were statistically significant. In each model, the blood lead association was adjusted for the cofactors of maternal IQ, sex, SES score, and maternal education. The RRs for total arrests increased for each 5 μg/dl (0.24 μmol/l) increment in blood lead concentration; the RRs were 1.40 (95% confidence interval [CI] 1.07–1.85) for prenatal blood lead, 1.07 (95% CI 0.88–1.29) for average childhood blood lead, and 1.27 (95% CI 1.03–1.57) for 6-y blood lead. The attributable risk was 0.48 arrests/year (95% CI 0.29–0.79) for prenatal blood lead, 0.13 (95% CI 0.03–0.33) for average childhood blood lead, and 0.39 (95% CI 0.21–0.68) for 6-y blood lead (Table 2). The rate of total arrests was modeled as a log-linear function of increasing blood lead concentrations for each of the three blood lead assessments: maternal prenatal (Figure 1A), early childhood (Figure 1B), and 6 y (Figure 1C).

In multivariable analyses of violent criminal arrests, we found statistically significant associations with both average childhood and 6-y blood lead variables. The RRs for arrests involving violent crimes increased for each 5 μg/dl (0.24 μmol/l) increment in blood lead; the RRs were1.34 (95% CI 0.88–2.03) for prenatal blood lead, 1.30 (95% CI 1.03–1.64) for average childhood blood lead, and 1.48 (95% CI 1.15–1.89) for 6-y blood lead. The attributable risk was 0.055 arrests/year (95% CI 0.026–0.118) for prenatal blood lead, 0.077 (95% CI 0.039–0.156) for average childhood blood lead, and 0.087 (95% CI 0.049–0.152) for 6-y blood lead (Table 3). As with the analyses for total arrests, the rate of arrests for violent offenses was modeled as a log-linear function of each of the blood lead indices: maternal prenatal (Figure 2A), early childhood (Figure 2B), and 6 y (Figure 2C).

The results for analyses restricted to arrests for nonviolent crimes were similar to those found for all arrests. Specifically, the RRs for nonviolent arrests for each 5 μg/dl (0.24 μmol/l) in blood lead were 1.40 (95% CI 1.06–1.84) for prenatal blood lead, 1.05 (95% CI 0.86–1.28) for average childhood blood lead, and 1.22 (95% CI 0.97–1.53) for 6-y blood lead.

There was no statistical evidence that the shape of the exposure-response relationship differed by sex with any of the blood lead indices for total arrests or arrests for violent offenses. The interaction term for sex was statistically nonsignificant (p-values for interaction term ranged from 0.42 to 0.79). However, the attributable risk for males was considerably higher than for females. For example, the attributable risk for 6-y blood lead rate was 0.85 arrests/year (95% CI 0.48–1.47) for males and 0.18 (95% CI 0.09–0.33) for females.

[Frost]

Discussion

In a prospective birth cohort, we found that prenatal and childhood blood lead concentrations were predictors of adult arrests. Prenatal and 6-y blood lead concentrations were significantly associated with higher RRs for total arrests. Average childhood as well as later (6-y) blood lead concentrations were significantly associated with higher RRs for arrests involving a violent offense. Data from several recent prospective studies suggest that blood lead concentrations in the later preschool years may be more predictive of cognitive and behavioral problems [23]. However, the potential importance of prenatal blood lead concentrations should not be underestimated, as they were predictive of total arrests in our data. The number of arrests in the CLS cohort was significantly higher in males. However, no significant interactions between sex and blood lead with arrest rates were found.

Environmental lead levels as well as crime have dropped over the last 30 y in the US [9]. However, the overall reduction was not uniform; inner-city children, who are predominately African-American, remain particularly vulnerable [24]. Crime and violent crime are concentrated in urban centers in the US where many poor African-Americans reside. One factor in the disproportional representation of African-Americans in crime statistics could well be the historically higher exposures to lead in these communities. Furthermore, recent data from epidemiological studies implicate blood lead concentrations well below the current level of concern adopted by the United States Centers for Disease Control in the development of neurobehavioral deficits [25]. We were unable to explore racial differences in our data since almost all participants were African-American. However, Needleman found that the lead-associated risk for juvenile court-adjudicated delinquency was present in both African-American and white youth, indicating that these findings are not restricted to any one racial or ethnic group [8].

The neurodevelopmental consequences associated with lead exposure in previous studies, such as lower IQ, less tolerance for frustration, deficits in attention, hyperactivity, and weak executive control functions, are potent predictors of delinquent and criminal behaviors [26–29]. Attention deficit hyperactivity disorder (ADHD) is a common finding among juvenile delinquents, and those with ADHD are more likely to have severe cognitive impairments [30]. ADHD is also a known risk factor for criminal behavior in adulthood [31]. A recent analysis of data from the third National Health and Nutrition Examination Survey (NHANES-III) found that higher blood lead concentrations were significantly associated with ADHD. Children with blood lead concentrations greater than 2 μg/dl were at a 4.1-fold increased risk of ADHD [32]. Similarly, in experiments with rodents, felines, and nonhuman primates, early lead exposure was associated with increased impulsivity, aggression, antagonistic interactions, reduced social play and abnormal mother–infant interaction [33–36]. Childhood lead exposure therefore seems to place individuals at risk for multiple underlying neurobehavioral deficits associated with a higher probability of later criminal behavior.

A number of mechanisms may be at work. Lead interferes with synapse formation, disrupts dopamine systems, and lowers serotonin levels. Lead exposure has been shown to reduce MAO A (monoamine oxidase A) activity, and low MAO A activity has been associated with violent and criminal behaviors [37]. One consequence of these alterations could be neural dysfunction in areas of the brain involved in arousal, emotion, judgment, and behavioral inhibition such as the prefrontal cortex [38].

This study has several limitations. First, most criminal behavior never comes to the attention of authorities; thus, our measure of arrest underestimates actual criminal activity. Had we been able to account for all criminal acts, it is possible that the results of our study may have been different. For example, it could be argued that lead-associated lower intelligence makes it more likely that an offender will be caught (i.e., arrested). However, a recent large-scale prospective study of school-aged children with early blood lead levels similar to those in the CLS suggests that lead impacts social behaviors somewhat independently of IQ [39]. Furthermore, we did not adjust arrest rates for child IQ in our analyses because controlling for a variable that might potentially be on the causal pathway is clearly inappropriate in studies of this kind. Variables along the causal pathway between exposure and outcome cannot be bona fide confounders [40]. Second, we examined only Hamilton County, Ohio records. Although most participants in our cohort continued to reside in Hamilton County, we may have missed some arrests that occurred in other counties. Third, official records of arrest were available only when the participants reached 18 y of age. Thus, the average follow-up was under 5 y. The possibility of bias introduced by nonrandom attrition in the CLS cohort cannot be ruled out, although we found no important differences on key exposure and demographic variables. Fourth, it is always possible in observational studies to have uncontrolled confounding. This can be problematic when it comes to measuring SES, since global assessments of social standing such as the one used in this [16] and many other studies fail to capture all potentially relevant factors [41]. As pointed out by Weiss and Bellinger [42] in their discussion of the social ecology of exposure to environmental pollutants, neurotoxicant exposures are not randomly distributed, but are “chained” to many other risks to normal development that are sometimes quite difficult to partition. Finally, as with all studies of this kind, our measure of dose to the critical organ (brain) was indirect. Blood, as well as other tissues in which lead is often measured such as teeth or bone, are surrogates for dose to the central nervous system.

On the other hand, this study has a number of qualities that contribute to the validity of our findings. To our knowledge this is the first prospective study to directly examine the relationship between early exposure to lead and official documentation of arrests in adulthood. Lead dose as assessed by frequent serial blood lead determinations, assessment of a large number of potentially important covariate factors, and careful documentation of criminal arrests were unique aspects of this investigation. Furthermore, the sample was relatively homogenous with respect to sociodemographic variables such as SES and ethnicity; thus decreasing the extent to which strong confounding factors might generate spurious associations. Therefore, we conclude that these data implicate early exposure to lead as a risk factor for behaviors leading to criminal arrest.
Acknowledgments

We are grateful to members of the Cincinnati Lead Study cohort and their families for their participation.

[Frost]

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[patio]

This is a interesting study, not sure what is with all the haters...

[akip]

i'll print it up and read it tonight, but at first glance, it wouldn't surprise me if environmental chemical triggers don't factor in, as well as the usual social ones. one doesn't preclude the other.

the list of researchers looks credible.

[C. Doves]

Ya, factors in the environment...like lead.

The neurodevelopmental consequences associated with lead exposure in previous studies, such as lower IQ, less tolerance for frustration, deficits in attention, hyperactivity, and weak executive control functions, are potent predictors of delinquent and criminal behaviors [26–29]. Attention deficit hyperactivity disorder (ADHD) is a common finding among juvenile delinquents, and those with ADHD are more likely to have severe cognitive impairments [30]. ADHD is also a known risk factor for criminal behavior in adulthood [31]. A recent analysis of data from the third National Health and Nutrition Examination Survey (NHANES-III) found that higher blood lead concentrations were significantly associated with ADHD. Children with blood lead concentrations greater than 2 μg/dl were at a 4.1-fold increased risk of ADHD [32]. Similarly, in experiments with rodents, felines, and nonhuman primates, early lead exposure was associated with increased impulsivity, aggression, antagonistic interactions, reduced social play and abnormal mother–infant interaction [33–36]. Childhood lead exposure therefore seems to place individuals at risk for multiple underlying neurobehavioral deficits associated with a higher probability of later criminal behavior.


The thing is, toys with lead paint were discovered and rightly pulled off the market. Entire houses coated in lead paint, or flaking of lead-paint dust, okay for kids (& people) to live in? I don't get it with the haters or "I need other factors too." Other factors or not, lead is bad for living things and this study proves it, again. That symptoms include cognitive impairment, hostility and aggression instead of just big tumors or blindness seems to bring out the judgemental side in some.

If those recalled lead-paint toys were shipped to this neighborhood with all the lead paint houses, wouldn't there be an outcry? I mean, wouldn't that be ridiculous? But to find out children are living in conditions that make those toys a blip on the radar, and some of you go 'meh, excuse,' or "Gosh I need other factors..." That's boggling my mind. Holy hell.

[the happy prole]

With all things scientific don't confuse the story you read in the papers from the actual scientific study. I think control for various outside factors and all is cuts to the validity of the study and is therefore acceptable scientific criticism.

But beyond that, science is science. If there's a statistical link between lead eating and violent behavior later on, then you report what the data shows. It's only an excuse for bad behavior if we judge it to be. That's a human moral and legal distinction, not a scientific one.

I personally don't consider "I ate lead paint as a child" to be a valid defense to violent behavior. At the same time, if not eating lead paint can stop such actions it's prevention might well be a better option than to act only after the crime is committed. Or it might not. Depends on what kind of prevention we're talking about.

Science simply informs. It's up to us to act on that information in ways we deem appropriate. If lead paint fucks people up, it's important to know that. I understand the hate towards the policy implications that might be come about, but I don't get the hate for the study itself.

[akip]

The thing is, toys with lead paint were discovered and rightly pulled off the market.

good point. it's not JUST the thugs in the ghetto and the fall-out to their victims and the taxpayers, but maybe, just maybe our little angelic suburban kids at risk as well. can't turn your back on those chinese devils, can you.;)

lead dust is an issue with old city homes i've lived in too. the paint gets scraped off and gets into the dirt around the house, probably gets into the heating ducts. you don't necessarily think about these things when you're finally getting around to painting exterior trim that hasn't been touched for eons. and anyone who's had a kid or been around them knows that babies put every piece of crap they encounter, as well as their fingers and toes, into their mouths. they don't have to be chewing on the windowsill while irresponsible crackwhore mom lights another rock.

anyway, i read the whole thing and seems very legit. 250 subjects is a respectable sampling. it's impressive they had the ambition to test lead levels on 356 subjects prenatally and over a period of time when brain/cognitive/behavior development is most significant. the study is placed in a relationship to other studies and advances those studies in testing methods.

the study also notes all these "other factors" people who only read the general interest fluff-piece are shouting about, adjusts conclusions accordingly as any legit studies does. it also identifies its own shortcomings, such as using "number of arrests" as a measure, since the number of crimes committed that the subject got away is unknown. but, again, "other factors" are considered in whether that measure supports these conclusions (data collected regarding each subject's history of violent or antisocial behavior). anyway, the data obviously points to some intriguing issues that will hopefully be submitted to further study. and that's what has to happen.

and i see nowhere in the conclusions "...therefore, we should let criminals with high lead blood levels out of jail and compensate them for their suffering." but life's no fun unless there's something to scream about, is it.:p

[C. Doves]

"Chinese Devils?" "Something to scream about?"

Uh, what are you talking about exactly? :confused:

[akip]

"Chinese Devils?" "Something to scream about?"

Uh, what are you talking about exactly? :confused:

have another cup of coffee and relax. i'm backing you up.;)

[C. Doves]

have another cup of coffee and relax. i'm backing you up.;)


You scared me there for a minute. :eek:

[akip]

speaking of coffee, i just told the spouse about this study---without mentioning toys, but just lead paint, lowered IQ and higher rates of violent crime---and the first thing he said was, "see---this is exactly what i told XXX (his chinese-american co-worker): the chinese are trying to take over the world. any people who eat snake cannot be trusted."

and yes, he was kidding.:p

[akip]

You scared me there for a minute. :eek:

sorry. sometimes i forget people are just skimming and it's easily misconstrued.

[C. Doves]

Some fun stuff from Harvard on "Lead Chelation Therapy for Children:"
http://64.233.167.104/search?q=cache:UTB1fnJHfMQJ:www.hsph.harvard.edu/organizations/DDIL/chelation.htm+lead+chelation+therapy&hl=en&ct=clnk&cd=1&gl=us

Not an easy undertaking. Risky too.