Subject: #551: Toxics and Violent Crime
. .
. ---June 19, 1997--- .
. HEADLINES: .
. TOXICS AND VIOLENT CRIME .
. ========== .
. Environmental Research Foundation .
. P.O. Box 5036, Annapolis, MD 21403 .
. Fax (410) 263-8944; Internet: erf@rachel.clark.net .
. ========== .
. and from http://www.monitor.net/rachel/k97aphics/mailing_list.html .
=================================================================
TOXICS AND VIOLENT CRIME
Pollution causes people to commit violent crimes --homicide,
aggravated assault, sexual assault and robbery --according to new
research by Roger D. Masters and co-workers at Dartmouth
College.[1] Sociologists have known for a long time that violent
crimes occur more in some places than in others. Some U.S.
counties have only 100 violent crimes per 100,000 people per
year; other counties have rates of violent crime that are 30
times as high. The question is why some places have high crime
rates and others don't. Masters says pollution is part of the
answer.
Masters has developed what he calls the neurotoxicity hypothesis
of violent crime. According to this hypothesis, toxic pollutants
--specifically the toxic metals lead and manganese --cause
learning disabilities, an increase in aggressive behavior, and
--most importantly --loss of control over impulsive behavior.
These traits combine with poverty, social stress, alcohol and
drug abuse, individual character, and other social factors to
produce individuals who commit violent crimes.
Masters argues that, to be taken seriously, such a hypothesis
must pass five tests. He then demonstrates how the neurotoxicity
hypothesis meets all five, as follows:
1) It must be shown that individuals who engage in criminal
behavior are more likely to have absorbed toxic chemicals than a
comparable control population. Masters cites studies showing
that low-level poisoning by lead, and by manganese, is associated
with learning disabilities and attention deficit disorder, which
are themselves associated with deviant behavior. (We reviewed
some of this evidence for lead in REHW #529). Masters cites
seven other studies showing that violent prisoners have
significantly elevated levels of lead, manganese, cadmium,
mercury or other toxic metals, compared to prisoners who are not
violent.
2) If it is valid, the neurotoxicity hypothesis must be able to
predict future violent behavior of young people exposed to
toxins. Masters cites two prospective studies (and suggests we
need more) showing that lead uptake at age 7 is associated with
juvenile delinquency and/or increased aggression in teenage and
early adult years. (See also REHW #529.) The largest study, of
1000 black children in Philadelphia, showed that both lead
levels, and anemia, were predictors of the number of juvenile
offenses, the seriousness of juvenile offenses, and the number of
adult offenses, for males.
3) Is there a biological basis for believing that lead, manganese
and other toxic metals could cause a person to lose control over
impulsive and aggressive behavior? Here Masters cites a wealth
of studies showing how lead and manganese cause changes in the
development of the brain, and in the functioning of
neurotransmitters in the brain.
Different pollutants harm the brain differently. Lead in the
brain damages glia, a kind of cell associated with inhibition and
detoxification. Manganese has the effect of lowering levels of
serotonin and dopamine, which are neurotransmitters associated
with impulse control and planning. Masters notes that low levels
of serotonin in the brain are known to cause mood disturbances,
poor impulse control, and increases in aggressive behavior
--effects that are increasingly treated with Prozac.
Masters emphasizes that children who are raised from birth on
infant formula and who are not breast fed will absorb five times
as much manganese as breast-fed infants. Calcium deficiency
increases the absorption of manganese. A combination of
manganese toxicity and calcium deficiency adds up to "reverse
Prozac," Masters says.
Masters says toxic metals affect individuals in complex ways.
For example, because lead diminishes a person's normal ability to
detoxify poisons, lead may heighten the effects of alcohol and
drugs.
4) For the neurotoxicity hypothesis to hold up, individuals must
receive doses of toxic metals sufficient to be associated with
violent behavior. Masters argues that, despite recent
significant decreases in lead in the environment (because leaded
gasoline and lead paint have been banned in the U.S.), in
neighborhoods where automobile traffic has historically been
high, and in towns where industries have released large
quantities of toxic metals for years, many local soils still
contain toxic quantities of lead, cadmium, and manganese
sufficient to poison children who play in the dirt. He also
argues that aging water delivery systems very likely contribute
lead and manganese because lead pipes and even iron pipes contain
these toxins.
Masters argues that (a) children absorb up to 50% of the lead
they ingest (compared to 8% for adults); (b) even low exposures
in the womb and in early childhood can have permanent effects on
intelligence and behavior; (c) current lead levels are known to
have direct effects on neurotransmitters that are known to affect
cognition and to influence impulse control; and (d) the highest
levels of lead uptake are reported in precisely the demographic
groups most likely to commit violent crimes (inner city minority
youths).
Masters emphasizes the importance of studies showing a
synergistic effect (multiplier effect) between toxic metals and
poor diet. For example, it has been thoroughly documented that
uptake of lead is greatly increased among individuals who have a
diet low in calcium, zinc, and essential vitamins. Similarly, as
noted above, calcium deficiency greatly increases one's
absorption of manganese. Thus, Masters argues, amounts of lead
and manganese that wouldn't harm a well-nourished individual may
poison undernourished children.
Masters cites federal studies of nutrition to make the point that
black teenage males consume, on average, only about 65% as much
calcium as whites. The calcium needs of pregnant or
breast-feeding women are higher than average, which creates a
particular problem for minority women. And non-Hispanic black
women get only 467 milligrams of calcium per day (mg/d), compared
to 642 mg/d for white women, government studies show.
Because of increased manganese absorption by babies who drink
infant formula and who are not breast fed, Masters considers
infant formula toxic. He emphasizes that poor mothers tend not
to breast-feed their babies. By 1986-87, 73 percent of infants
born to mothers with more than 12 years of education were
breastfed compared with 49 percent of infants born to mothers
with 12 years of education, and 31 percent of mothers with less
than 12 years of education. Furthermore, white infants are more
than three times as likely to be breast fed as black infants.
"The effects of manganese toxicity associated with infant formula
are thus greatest for the poor, for ethnic minorities, and for
those with little education," Masters says.
Masters cites studies showing that alcohol increases the uptake
of toxic metals, at least in laboratory animals, and probably has
a similar effect on humans.
5) If the neurotoxicity hypothesis is valid, then measures of
environmental pollution should correlate with higher rates of
violent crime.
To test his hypothesis, Masters acquired data from the FBI for
violent crimes in all counties of the U.S. He correlated this
with data on industrial releases of lead and manganese into the
environment of each county, using data from the U.S.
Environmental Protection Agency's TRI [toxic release inventory]
database. He also examined other variables for each county
--population size, population density, housing built before 1950,
number of police officers per person, number of school dropouts
and high school dropouts, educational achievement, unemployment
rate, race and ethnicity [white, black, hispanic], persons below
the poverty level, number of people on welfare, infant deaths per
1000 live births, all alcohol-related causes of death, and all
causes of death with explicit mention of alcohol.
The EPA's recorded releases of toxic metals are not predicted by
these demographic or socio-economic variables. In fact, less
that 5% of the variance of reported releases of lead is accounted
for by 19 socio-economic factors (many of them listed in the
previous paragraph).
Masters split all U.S. counties into six groups --those with and
without industrial lead releases; those with and without
industrial manganese releases; and those with higher-than-average
or lower-than-average rates of alcohol-related deaths. After
controlling for all the conventional measures of social
deterioration (poverty, school dropouts, etc.), Masters found
that counties having all three measures of neurotoxicity --lead,
manganese, and high alcohol --have rates of violent crime three
times the national average.
In other words, environmental pollution and alcohol have a strong
effect on violent crimes, completely independent of any of the
"traditional" predictors of violent crime (poverty, poor
education, etc.)
As Masters says, neurotoxicity is only one of many factors
contributing to violence, but he believes it may be especially
important in explaining why violent crime rates differ so widely
between geographic areas and by ethnic group. Masters says that
traditional sociological approaches to crime cannot explain why
the availability of handguns or drugs triggers violent behavior
in only a small proportion of the population, a proportion that
varies greatly from place to place. Part of the explanation may
be the way the physical environment affects brain chemistry and
behavior, Masters says.
"The presence of pollution is as big a factor as poverty,"
Masters said recently in an interview in NEW SCIENTIST
magazine.[2] "It's the breakdown of the inhibition mechanism
that's the key to violent behavior," he says. When our brain
chemistry is altered by exposure to toxins, we lose the natural
restraint that holds our violent tendencies in check, Masters
believes.
Former U.S. Surgeon General C. Everett Koop has said, "Regarding
violence in our society as purely a sociologic matter, or one of
law enforcement, has led to an unmitigated failure. It is time
to test further whether violence can be amenable to
medical/public health interventions."[3]
For decades, researchers have focused on the human health
consequences of toxic metals --mainly asking, do they cause
cancer? This new research seems to be telling us that we should
also be looking at the way these pollutants are affecting human
BEHAVIOR.
--Peter Montague
(National Writers Union, UAW Local 1981/AFL-CIO)
===============
[1] Roger D. Masters, Brian Hone, and Anil Doshi, "Environmental
Pollution, Neurotoxicity, and Criminal Violence," in J. Rose,
editor, ENVIRONMENTAL TOXICOLOGY (In press. [London and New York:
Gordon and Breach Publishers, 1997]).
The particular crimes are defined as follows:
Murder and nonnegligent manslaughter: the willful (nonnegligent)
killing of one human being by another.
Forcible rape: carnal knowledge of a female forcibly and against
her will. Assaults or attempts to commit rape by force are also
included; however, statutory rape (without force) and other sex
offenses are excluded.
Robbery: taking or attempting to take anything of value from the
care, custody, or control of a person or persons by force or by
threat of force or violence and/or by putting the victim in fear/
Aggravated assault: unlawful attack by one person upon another
for the purpose of inflicting severe or aggravated bodily injury.
[2] Alison Motluck, "Pollution may lead to a life of crime," NEW
SCIENTIST Vol 154, No. 2084 (May 31, 1997), pg. 4.
[3] C.E. Koop and G.D. Lundberg, "Violence in America: A Public
Health Emergency," JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION,"
Vol. 267, No. 22 (1992), pgs. 3075-3076.
Descriptor terms: crime; lead; manganese; homicide; aggravated
assault; sexual assault; robbery; toxic heavy metals; human
behavior; roger d. masters; dartmouth college; cadmium; mercury;
violence; aggression; glia; serotonin; dopamine; prozac; infant
formula; breast feeding; nutrition; calcium deficiency; poverty;
################################################################
NOTICE
Environmental Research Foundation provides this electronic
version of RACHEL'S ENVIRONMENT & HEALTH WEEKLY free of charge
even though it costs our organization considerable time and money
to produce it. We would like to continue to provide this service
free. You could help by making a tax-deductible contribution
(anything you can afford, whether $5.00 or $500.00). Please send
your tax-deductible contribution to: Environmental Research
Foundation, P.O. Box 5036, Annapolis, MD 21403-7036. Please do
not send credit card information via E-mail. For further
information about making tax-deductible contributions to E.R.F.
by credit card please phone us toll free at 1-888-2RACHEL.
--Peter Montague, Editor
################################################################