CARCINOGENS EVERYWHERE
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? |
