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#633 - Carcinogens Everywhere, 13-Jan-1999

U.S. EPA [Environmental Protection Agency] published a report in 1998
saying that 100% of the outdoor air in the continental U.S. is
contaminated with eight cancer-causing industrial chemicals at levels
that exceed EPA's "benchmark" safety standards.[1] Alaska and Hawaii
were excluded from the analysis for lack of available data.~

Using 1990 data on toxic industrial emissions, EPA applied well-known
mathematical models to estimate year-round average outdoor air
concentrations for 148 industrial poisons in each of the nation's
60,803 census tracts.

For each of the 148 toxicants, EPA established a "benchmark" level that
the agency considers safe. Eight of the 148 industrial poisons exceed
EPA's benchmark safety levels all of the time in all 60,803 census
tracts. All eight are carcinogens, that is, they are known to cause
cancer: bis(2-ethylhexyl) phthalate; benzene; carbon tetrachloride;
chloroform; ethylene dibromide; ethylene dichloride; formaldehyde; and
methyl chloride.

In its report, EPA said that outdoor air concentrations provide a
reasonable estimate of toxic concentrations "that occur both outdoors
and indoors, given the high rates of penetration into indoor
environments for various HAPs [hazardous air pollutants]." In other
words, EPA believes that being inside your home or workplace does not
protect you from constant exposure to these eight carcinogens.

EPA said its mathematical models probably underestimate the true levels
to which the population is exposed. Where actual measurements of toxic
contaminants were available, EPA found that the measured levels
exceeded the levels estimated by their mathematical models.

In its report, EPA also acknowledged that it may have underestimated
the health effects because the eight chemicals, combined, may have
additive or multiplier effects since people experience all of them
simultaneously. However, the agency also acknowledged that it has no
way to take such combined effects into account.

The agency also acknowledged that many of the chemicals may have health
effects for which the agency has established no "benchmark" standards.
For example, benzene and 1,3-butadiene have both been associated with
reproductive and developmental effects, but EPA currently has set no
benchmark safety levels for such effects, and so those effects were
ignored in this study.

And finally, most (if not all) individuals are exposed to far more than
just eight industrial poisons. These eight merely provide a toxic
background to which other toxicants are added, depending upon a
person's (or a community's) individual situation: automobile and truck
exhaust, second-hand cigarette smoke, prescription drugs, emissions
from power plants, smelters, incinerators, and so on.

Several of the eight chemicals exceed EPA "benchmark" safety levels by
a wide margin. For example, the average day-in-and-day-out
concentration of carbon tetrachloride exceeds EPA's benchmark level by
a factor of 13, and bis(2-ethylhexyl) phthalate exceeds EPA's benchmark
by a factor of 6.4.

=====

LEAD IN CHILDREN: OLD STORY, NEW DATA

In 1998, the federal Centers for Disease Control and Prevention (CDCP)
in Atlanta issued a report saying that only 4.4% of American children
between the ages of 1 and 5 have the toxic metal lead in their blood at
"levels of health concern," which CDCP defines as concentrations of 10
micrograms of lead per deciliter of blood (10 ug/dL) or higher.[2] A
microgram is a millionth of a gram and there are 28 grams in an ounce;
a deciliter is a tenth of a liter and a liter is about a quart. The
reporting period was 1991-1994.

Although 4.4% sounds like a small percentage, it represents 890,000
individual children whose intellectual capacity is being permanently
diminished by exposure to excessive amounts of lead.

CDCP established 10 ug/dL as the "unsafe" level of lead in blood in
1991.[3] The limit was set at 10 ug/dL not because 10 is a magic number
that protects children but because it was the lowest level that could
be detected with an inexpensive test, and because, CDCP said, setting
the standard lower would burden the country's health-care system.

When it set the official safety level at 10, CDCP acknowledged that
something besides pure concern for public health went into the
decision. "The recommendations [of 10 ug/dL]... are based mainly on the
scientific data showing adverse effects of lead in young children at
increasingly lower blood lead levels. They are tempered, however, by
practical considerations, for example, of the numbers of children who
would require followup and the resources required to prevent this
disease," wrote Vernon Houck on behalf of CDCP.[3,pg.iii] In other
words, when it set 10 as the "safe" standard, CDCP acknowledged that it
was reluctant to set the standard lower because too many children would
then qualify for medical help, and too much money would have to be
spent removing lead from the environment.

Numerous studies have now shown that there is no "safe" dose of lead in
children's blood. Five years ago the National Research Council (NRC)
said, "There is growing evidence that even very small exposures to lead
can produce subtle effects in humans. Therefore, there is the
possibility that future [safety] guidelines may drop below 10 ug/dL as
the mechanisms of lead toxicity become better understood."[4,pg.3] The
NRC offered evidence that lead at 5 ug/dL (half the official "safe"
level) can cause attention deficit in children and in monkeys; reduced
birthweight in children; and hearing loss in children.[4,pgs.69,254-
256]

In 1993 the NRC summarized a series of recent studies, then said,
"Those studies support the general conclusion that there is growing
evidence that there is no effective threshold for some of the adverse
effects of lead."[4,pg.67] In other words, in 1993 there was good
evidence that there is no safe level of lead.

According to careful measurements of human bones, pre-Columbian
inhabitants of North America had average blood lead levels of 0.016
ug/dL -- 625 times as low as the 10 ug/dL now established as "safe" for
children. On the face of it, it seems unlikely that levels of a potent
nerve poison 625 times as high as natural background --or even 300
times as high as natural background -- can be "safe" for children.[5]

The CDCP's 1998 study reported that the average (geometric mean)
concentration of lead in all 20 million American children between the
ages of 1 and 5 was 2.7 ug/dL, or 43 times as high as natural
background.

The main effect of lead in blood is to reduce a child's IQ. Five years
ago, the American Academy of Pediatrics reviewed 18 scientific studies
showing that lead diminishes a child's mental abilities. "The
relationship between lead levels and IQ deficits was found to be
remarkably consistent," the Academy said. "A number of studies have
found that for every 10 ug/dL increase in blood lead levels, there was
a lowering of mean [average] IQ in children by 4 to 7 points." This may
not sound like a major loss, but an average IQ loss of 5 points puts
50% more children into the IQ 80 category, which is borderline for
normal intelligence. It also reduces the number of high IQs; for
example, one small group that should have contained 5 children with IQs
of 125, contained none.[6]

In recent years, many studies have shown that lead not only diminishes
intellectual capacity, but it also causes loss of hearing, reduces
hand-eye coordination, impairs the ability to pay attention, and
creates a propensity toward violence. Children who have been poisoned
by lead are less able to handle stress and are more prone to violent
outbursts. (See REHW #529, #551.)

The source of the lead poisoning children today is chiefly paint
containing lead. In the U.S., approximately 83% of privately owned
housing units and 86% of public housing units built before 1980 contain
some lead-based paints.

Public health authorities have acknowledged openly since 1952 that
black children are being preferentially poisoned by lead in paint. (See
REHW #294.) The City of Baltimore began a lead-toxicity screening
program in 1931. With 20 years of data in hand, the head of the
Baltimore health department wrote in 1952, that the rate of poisoning
among children was "7.5 times as high among the Negro population as it
was among the white population.... The high rates among Negro children
are a problem of considerable public health significance since 30
percent of Baltimore's pre-school population is Negro. The racial
difference in incidence is believed to be due to environmental factors
probably resulting chiefly from economic disadvantage."[7]

Today, 47 years later, the situation has changed little. According to
CDCP's 1998 study, today the highest concentrations of lead are
occurring in non-Hispanic black children. Among non-Hispanic black
children ages 1 to 5 living in housing built before 1946, 21.9% have
blood lead levels at or above 10 ug/dL, and among those living in
housing built between 1946 and 1973, 13.7% had blood lead levels at or
above 10 ug/dL, CDCP's 1998 study says.

A recent study of children visiting a pediatric clinic in
Philadelphia's inner city reported that 68% of the children there have
lead levels that exceed the "safe" 10 ug/dL.[8]

In sum, roughly a million black children who live in the inner cities
are being continuously poisoned by exposure to lead.

In 1991, the Centers for Disease Control published a study showing that
the nation's taxpayers would save $60 billion in health-care and
special-education costs by spending $32 billion to eradicate lead from
inner city homes.[9] Congress has never been willing to adopt this
cost-effective prevention strategy, evidently preferring to produce
generation after generation of black inner city children with
diminished intellectual capacity and a propensity toward violence.

Children, can you spell R-A-C-I-S-M?

--Peter Montague (National Writers Union, UAW Local 1981/AFL-CIO)

=====

[1] Tracey J. Woodruff and others, "Public Health Implications of 1990
Air Toxics Concentrations across the United States," ENVIRONMENTAL
HEALTH PERSPECTIVES Vol. 106, No. 5 (May 1998), pgs. 245-251.

[2] James L. Pirkle and others, "Exposure of the U.S. Population to
Lead, 1991-1994," ENVIRONMENTAL HEALTH PERSPECTIVES Vol. 106, No. 11
(November 1998), pgs. 745-750.

[3] William L. Roper and others, PREVENTING LEAD POISONING IN YOUNG
CHILDREN (Atlanta, Ga.: Centers for Disease Control, October, 1991).

[4] National Research Council (Bruce A. Fowler and others, editors),
MEASURING LEAD EXPOSURE IN INFANTS, CHILDREN, AND OTHER SENSITIVE
POPULATIONS (Washington, D.C.: National Academy Press, 1993).

[5] A. Russell Flegal and Donald R. Smith, "Lead Levels in
Preindustrial Humans," NEW ENGLAND JOURNAL OF MEDICINE Vol. 326 (May 7,
1992), pgs. 1293-1294.

[6] Committee on Environmental Health, American Academy of Pediatrics,
"Lead Poisoning: From Screening to Primary Prevention," PEDIATRICS Vol.
92 (July 1993), pgs. 176-183. And see: John F. Rosen, "Health Effects
of Lead at Low Exposure Levels," AMERICAN JOURNAL OF DISEASES OF
CHILDREN Vol. 146 (November 1992), pgs. 1278-1281. And see: John F.
Rosen, "Effects of Low Levels of Lead Exposure," SCIENCE Vol. 256
(April 17, 1992), pg. 294. And: Herbert L. Needleman and others,
"Deficits in Psychologic and Classroom Performance of Children with
Elevated Dentine Lead Levels," NEW ENGLAND JOURNAL OF MEDICINE Vol.
300, No. 13 (March 29, 1979), pgs. 689-695. And see: Joel Schwartz,
"Low-Level Lead Exposure and Children's IQ: A Meta-analysis and Search
for a Threshold," ENVIRONMENTAL RESEARCH Vol. 65 (1994), pgs. 42-55.
And see: Herbert L. Needleman and Constantine A. Gastonis, "Low-Level
Exposure and the IQ of Children," JOURNAL OF THE AMERICAN MEDICAL
ASSOCIATION Vol. 263, No. 5 (February 2, 1990), pgs. 673-678.

[7] Huntington Williams and others, "Lead Poisoning in Young Children,"
PUBLIC HEALTH REPORTS Vol. 67 (March, 1952), pgs. 230-236.

[8] Shoshana T. Melman and others, "Prevalence of Elevated Blood Lead
Levels in an Inner-city Pediatric Clinic Population," ENVIRONMENTAL
HEALTH PERSPECTIVES Vol. 106, No. 10 (October 1998), pgs. 655-657.

[9] This study was described in Marianne C. Fahs, "White House Should
Stay With Lead Cleanup [letter to the editor]," NEW YORK TIMES
September 18, 1991, pg. A18.

Descriptor terms: lead; children; children's health; racism; air
pollution; carcinogens; epa;