excerpted from the book
a scientist's personal investigation of cancer
and the environment
by Sandra Steingraber
Vintage Books, 1998 (paper)
Industrialized countries have disproportionately more cancers
than countries with little or no industry (after adjusting for
age and population size. One-half of all the world's cancers occur
among people living in industrialized countries, even though we
are only one-fifth of the world's population. Closely tracking
industrialization are breast cancer rates, which are highest in
North America and northern Europe, intermediate in southern Europe
and Latin America, and lowest in Asia and Africa. Breast cancer
rates are thirty times higher in the United States than in parts
of Africa, for example. Breast cancer incidence in the United
States is five times higher than it is in Japan, but this gap
is rapidly narrowing. Of all the world's nations, Japan has the
most rapidly rising rate of breast cancer.
Among the nations of the developed world, similar time trends
are in motion for a number of major cancers. Mortality rates of
breast cancer and prostate cancer are rising in almost all industrialized
countries. The accelerating U.S. rates of brain cancer, kidney
cancer, multiple myeloma, non-Hodgkin's lymphoma, and melanoma
are replicated in France, West Germany, England, Japan, and Italy.
... a little-known office of the World Health Organization. Located
in Lyon, France, the International Agency for Research on Cancer
is charged with the daunting job of monitoring cancer incidence
around the world. It does so by collecting registry data from
as many countries as possible. The United States, for example,
sends its Surveillance, Epidemiology, and End Results Program
data on to Lyon. The World Health Organization also collects and
analyzes cancer mortality data gleaned from death certificates
in seventy different countries. From these data, the organization
concluded that at least 80 percent of all cancer is attributable
to environmental influences.
Coffee consumption, at first glance, seems like a classic lifestyle
choice. But the coffee we drink includes the water we pour through
the beans-and this may be the same water used for showering and
cooking food. If our tap water contains, say, traces of weed killer
and dry-cleaning fluids, we are being exposed to environmental
carcinogens through multiple pathways and through no individual
choice of our own, even as we freely determine our own bathing,
cooking, and coffee-drinking habits.
However culturally distinct immigrants may remain in their adopted
| country, their cancer rates assimilate. According to the International
Agency for Research on Cancer, "The most important single
conclusion to derive from migrant studies is that, for a group
as a whole, it is the new 'environment' that determines cancer
risk and not the genetic component associated with the ethnic
stock of the migrants." The quotation marks around that slippery
word environment acknowledge its many meanings.
Migrants to Australia, Canada, Israel, and the United States
all illustrate this pattern. Consider Jewish women who migrate
from North Africa, where breast cancer is rare, to Israel, a nation
with high incidence. Initially, their breast cancer risk is one-half
that of their Israeli counterparts. But risk rises rapidly with
duration of stay: within thirty years, African-born and Israeli-born
Jews show identical breast cancer rates. Jewish women from the
Middle East and Asia also increase their risk of breast cancer
upon arrival in Israel, although the pace at which they do so
is considerably slower.
Likewise, in the United States, the breast cancer rates of
European, Chinese, and Japanese women immigrants all eventually
rise to conform to the U.S. rate, but they do so at different
speeds. Polish women assume U.S. rates of breast cancer quickly.
Japanese women migrating to the U.S. mainland require two generations
to achieve our breast cancer rate. First-generation Japanese immigrants
show a rate intermediate between that for Japan and the United
States; their daughters, however, reflect the U.S. rates completely.
Happily, the reverse is also true. Women moving to a new country
with lower breast cancer rates experience a decline in their chances
of contracting the disease-as when, for example, an English woman
immigrates to Australia.
These results lead us back to the Mobius strip of lifestyle
and environment. Both change simultaneously when someone moves
from one part of the world to another. At present, no one understands
precisely how these changes interact to create the patterns described
People in at least sixty different occupations have elevated death
rates from cancer. One of these is farming.
Farmers from industrialized countries around the world exhibit
consistently higher rates of many of the same cancers that are
also on the rise among the general population. Farmers, in other
words, die more often from the same types of tumors that are also
afflicting, with increasing frequency, the rest of us. These include
multiple myeloma, melanoma, and prostate cancer. Farmers also
suffer from rates of non-Hodgkin's lymphoma and brain cancers
higher than those of the general population-although these excesses
are more modest. In spite of lower overall mortality and lower
rates of heart disease, farmers also die significantly more often
than the general public from Hodgkin's disease, leukemia, and
cancers of the lip and stomach. Likewise, migrant farmworkers
suffer excess rates of multiple myeloma, as well as of stomach,
prostate, and testicular cancers.
Elevated cancer rates are also found among painters, welders,
asbestos workers, plastics manufacturers, dye and fabric makers,
firefighters, miners, printers, and radiation workers. People
who work in a number of so-called professional jobs are also at
higher risk: for example, chemists, chemical engineers, dentists
and dental assistants, and-perhaps most ironically-chemotherapy
nurses. Many of the chemicals used to treat cancer are themselves
carcinogenic, as the high rate of adult cancers among childhood
leukemia survivors attests. Thus, we should not be surprised that
those who work daily with these substances in an attempt to save
others' lives themselves succumb in numbers higher than average.
The children of adults who work in specific occupations also
have higher rates of cancer. Childhood brain cancers and leukemias
are consistently associated with parental exposure to paint, petroleum
products, solvents, and pesticides. Some exposures may occur before
birth. Children can also be exposed when these materials are carried
into the home on their parents' clothes and shoes, through breast
milk (which can be contaminated directly or through maternal contact
with the father's clothing), or even through exhaled air: because
solvents are, in part, cleared by the lungs, parents can expose
their children to carcinogens simply by breathing on them. In
this way, a father's homecoming kiss and work-clothed embrace
can contaminate his child.
Consider vinyl chloride, which is used in the manufacture of a
substance familiar to us all: polyvinvl chloride, otherwise known
as PVC or simply vinyl. Credit cards are made of PVC, as are garden
hoses, lawn furniture, floor coverings, children's toys, and food
packaging materials. PVC, in turn, is made of vinyl chloride molecules
all bonded together. Vinyl chloride, a sweet-smelling gas at room
temperature, has long been classified as a known human carcinogen.
Its cancer-causing properties were discovered when high numbers
of male vinyl chloride workers began contracting angiosarcoma,
a rare cancer that causes tumors to grow inside the liver's blood
vessels. The incidence among vinyl chloride workers was found
to be three thousand times higher than among the general population.
Animal studies, as well as further studies of male workers, also
revealed the ability of vinyl chloride to contribute to lung and
brain cancers. In response to these results, allowable workplace
air levels of vinyl chloride were drastically reduced. But it
was not until researchers also studied female workers that vinyl
chloride's potential as a breast carcinogen was uncovered. In
a 1977 study, women who breathed vinyl chloride vapors on the
job had elevated death rates from breast cancer. Subsequent laboratory
studies showed that atmospheric vinyl chloride triggers breast
tumors in female rats, even at the lowest dosages; so does ingestion
of PVC dust. Such an association is certainly biologically plausible,
since vinyl chloride has an affinity for fat tissue.
Evidence for a link between vinyl chloride and breast cancer
in women workers has broad implications for the rest of us. While
vinyl chloride levels are very much lower outside the factory,
significant exposures can occur among residents living near vinyl
chloride and PVC facilities. The air currents that blow across
hazardous waste sites also contain elevated levels of vinyl chloride.
Vinyl chloride is a frequent contaminant of groundwater, where
it can remain for months or years because there is no pathway
to the atmosphere. The flesh of freshwater fish can also contain
According to the U.S. Agency for Toxic Substances and Disease
Registry (ATSDR), each of these pathways exposes the general public
to "negligible amounts" of this known carcinogen. However,
no one knows what the cumulative lifetime risk from all of these
negligible exposures is. The ATSDR also states that "exposure
to vinyl chloride either in the prenatal period or during early
childhood years may result in an increased risk of cancer"
later in life. If vinyl chloride caused only a very rare form
of liver cancer, perhaps these multiple routes of tiny exposures
would be less cause for alarm. However, breast cancer is now the
leading cause of death of American women aged thirty-five to fifty,
and we are the first generation of women born after World War
II, when chlorinated chemicals such as vinyl chloride were first
widely dispersed in the general environment.
In spite of all this preliminary evidence, no comprehensive
study has ever been undertaken to examine vinyl chloride's contribution
to breast cancer. In fact, the 1977 study of women PVC fabricators
has never been followed up, even though cohorts of men exposed
to vinyl chloride, and who demonstrate excesses of brain, liver,
and lung cancer, have been periodically updated. This omission
is especially frustrating to Peter Infante, the director of the
Health Standards Program at the Occupational Safety and Health
Administration, whose job it is to set limits on vinyl chloride
levels in workplace air. Lack of interest in investigating a possible
vinyl chloride-breast cancer link, says Infante, serves as an
example of indifference to the plight of women in the workplace-indeed,
to the plight of women everywhere.
... inclusive evidence does not exist on the link between cancer
and hazardous waste because money has never been appropriated
to conduct the necessary studies. As long as the evidence remains
inconclusive, the methods currently used to remediate risks to
public health cannot be evaluated. With this evaluation, the notion
that there is no proof environmental contamination causes cancer
can continue to enjoy common currency.
Men living in hazardous waste counties suffered significantly
higher mortality from cancers of the lung, bladder, esophagus,
colon, and stomach than did their contemporaries residing in counties
without such sites. Women living in hazardous waste counties suffered
significantly higher mortality from lung, breast, bladder, colon,
and stomach cancers. Indeed, counties with hazardous waste sites
were 6.5 times more likely to have elevated breast cancer rates
than counties without such sites.
Most of us are also exposed regularly to molecules of [trichloroethylene]
TCE. Used by industry to degrease metal parts, TCE is now estimated
to be in 34 percent of the nation's drinking water. Most processed
foods contain traces as well. TCE is also found in paint removers,
spot removers, cosmetics, and rug cleaners. An estimated 3.5 million
workers are exposed to TCE on the job. Not so long ago, TCE was
also used as an obstetrical anesthetic, a fumigant for grain,
an ingredient in typewriter correction fluid, and a coffee decaffeinater.
These uses have been phased out, but there is still sufficient
release of TCE into the general environment to ensure that traces
of vaporized metal degreaser persist in the ambient air that we
Since the 1930s, [perchlorethylene (perc)] has been the chemical
of choice for dry-cleaning clothes. Compared to the general population,
dry cleaners have twice the rate of esophageal cancer and twice
the rate of bladder cancer. Thus, a discovery of a bladder cancer
cluster among the folk of the Upper Cape should come as no surprise.
Further studies of the Upper Cape's water pipes, published in
1993, showed that people's actual exposure to perc varied widely,
depending on the length, shape, size, and age of the water pipe,
the pattern of water flow, and the person's length of residence
in that house. For those people with highest exposure, bladder
cancer risk was four times higher and leukemia nearly twice as
high when compared to people without such pipes.
One ... is benzene the human carcinogen known to cause leukemia
and suspected of playing a role in multiple myeloma and non-Hodgkin's
Iymphoma. Another is perchloroethylene, the probable human carcinogen
used to dry-clean clothes. A third represents production of vinyl
chloride, a known cause of angiosarcoma and a possible breast
carcinogen. They all look like ski slopes. After 1940, the lines
begin to rise significantly and then shoot upward after 1960.
By the end of the 1980s, total production [of synthetic organic
chemicals] had exceeded two hundred billion pounds per year. In
other words, production of synthetic organic chemicals increased
100-fold between the time my mother was born and the year I finished
graduate school. Two human generations.
The terms organic and synthetic are slippery ones and require
explanation. Organic has two definitions that very nearly contradict
each other. In popular usage, organic describes that which is
simple, healthful, and close to nature. Similarly, in the language
of agriculture, organic refers to food grown only with the aid
of substances derived from plant and animal matter. Food certified
as organic is supposed to be free from manufactured pesticides,
antibiotics, hormones, and other additives-that is, fruits, vegetables,
meat, eggs, and milk produced without the use of artificial, synthetic
In the parlance of chemistry, however, organic simply refers
to any chemical with carbon in it. The study of organic chemistry
is the study of carbon compounds. The word synthetic means essentially
the same as it does in everyday conversation: a synthetic chemical
is one that has been formulated in a chemical laboratory, usually
by combining smaller substances into larger ones. Most often,
these substances contain carbon. Indeed, many organic chemicals
now in daily use are synthetic-they do not exist in nature.
Of course, not all organic substances are synthetic. Wood,
leather, crude oil, sugar, blood, coal-these are all carbon-based,
organic substances found in the natural world. But, insofar as
they have carbon atoms in their structures somewhere, the vast
majority of synthesized chemicals are also organic. Plastic, detergent,
nylon, trichloroethylene, DDT, PCBs, and CFCs are all synthetic
organic compounds. The close alignment between organic and synthetic
leads to the absurd but truthful concept that organic farmers
are those who shun the use of (synthetic) organic chemicals.
Most synthetic organic compounds are derived from either petroleum
or coal. Recognizing this fact brings the widely divergent definitions
of the word organic together. To a biologist, organic substances
are those that come from organisms-living or dead. Long chains
of carbon atoms compose the chemical infrastructure of all life
forms, including the liquefied organisms and the petrified organisms
who lived on the planet eons ago and who have since been extracted
from their burial grounds. Nothing manufactured from these so-called
fossil fuels is really "unnatural." A molecule of DDT
is made up of rearranged carbon atoms distilled from some creature's
And here lies the problem. Many synthetic molecules are chemically
similar enough to substances naturally found in the bodies of
living organisms that, as a group, they tend to be biologically
active. Our blood, lungs, liver, kidneys, colon-with the help
of an elaborate enzyme system-are all designed to shuttle around,
break apart, recycle, and reconstruct carbon-containing molecules.
Thus, synthetic organics easily interact with the various naturally
occurring biochemicals that constitute our anatomy and participate
in the various physiological processes that keep us alive. By
design, petroleum-derived pesticides have the power to kill because
they chemically interfere with one or another of these processes.
DDT, for example, interferes with the conduction of nerve impulses.
The weed killer atrazine hinders the process of photosynthesis.
The phenoxy herbicides bring about death by mimicking the effect
of plant growth hormones.
... chlorofluorocarbons (CFCs), the famous ozone depleters,
were exceptional because they did not share this property of biological
activity. And because they are so chemically stable, CFC molecules
can be swept into the stratosphere in their still intact state.
Only when hit by a beam of ultraviolet light do they finally fall
apart, releasing the chlorine atom that begins the destructive
chain reaction culminating in the loss of ozone. CFCs were invented
in 1928 but came into large-scale production only after World
War II. Since the 1950s, the total amount of chlorine in the stratosphere
has increased by a factor of ten.
Plenty of other synthetic organics are similarly inert in
their finished forms. Indeed, this is why they are not biodegradable:
their molecules are so large or otherwise so complex that they
do not decay. They are thus exempt from the global carbon cycle
that is constantly building up and breaking down organic molecules.
And, of course, this exemption is what you want in a roof gutter,
a water pipe, or a window frame.
For several reasons, however, this unreactiveness is misleading.
First, many of these compounds are themselves synthesized
from synthetic chemicals that are highly reactive. By accident
or on purpose, these industrial feedstocks are routinely released,
dumped, or spilled in the general environment. While PVC plastic
is, biochemically speaking, quite lethargic, the vinyl chloride
from which it is manufactured exerts striking effects on the human
liver. Second, inactive synthetic substances can shed or off-gas
the smaller, more reactive molecules from which they are made.
Third, new reactive chemicals can be created if these substances
are subsequently burned-as when perfectly benign piles of vinyl
siding are shoveled into a garbage incinerator, and poisonous
dioxin rises from the stack. The incinerator itself, in this case,
acts as a de facto chemical laboratory synthesizing new organic
compounds from feedstocks of discarded consumer products.
Through all of these routes, we find ourselves facing a rising
tide of biologically active, synthetic organic chemicals. Some
interfere with our hormones, some attach themselves to our chromosomes,
some cripple the immune system, and some overstimulate the activity
of certain enzymes. If we could metabolize these chemicals into
completely benign breakdown products and excrete them, they would
pose less of a hazard. Instead, a good many of them accumulate.
In essence, synthetic organic chemicals confront us with the worst
of both worlds. They are similar enough to naturally occurring
chemicals to react with us but different enough to not go away
A number of these chemicals are soluble in fat and so collect
in tissues high in fat content. Synthetic organic solvents, such
as perchloroethylene and trichloroethylene, are an example. They
are specifically designed to dissolve other oil- and fat-soluble
chemicals. In paint, they work well to carry oil-based pigments.
As degreasing agents, they work well to clean lubricated machine
parts. As dry-cleaning fluids, they excel at dissolving human
body oils and greasy fabric stains. They also all work splendidly
to dissolve human body oils still on our skin and can thus easily
enter our bodies upon touch. In addition, they are readily absorbed
across the membranes of our lungs. Once inside, they take up residence
in fat-containing tissues.
Many such tissues exist. Breasts are famous for their high
fat content and often serve as repositories for synthetic organic
chemicals circulating within the female body. But organs less
renowned for fat content also collect these chemicals. The liver,
for example, is surprisingly high in fat. So is bone marrow, the
target organ for benzene. And, amazingly enough, because nerve
cells are swathed in a fatty coating, so are our brains. Consider
that many solvents have been used as anesthetic gases due to their
ability to affect brain functioning. Chloroform is one.
Its medical uses long since discontinued, chloroform continues
to be used as a solvent, fumigant, and ingredient in the manufacture
of refrigerants, pesticides, and synthetic dyes. U.S. annual production
of chloroform is currently about 600 million pounds, and it is
found in nearly half of the hazardous waste sites on the Superfund
National Priorities List. (s we shall see in Chapter Nine) trace
amounts are also formed when drinking water is chlorinated. Chloroform
is classified as a probable human carcinogen. Its residence time
in the body is actually quite brief. DDT, for example, has a half-life
of at least seven years, while that of chloroform is a mere eight
hours. (Half-life is the time required to convert half the body's
burden of a given substance into excretable by-products.) The
problem, then, with chloroform is not so much biological persistence
but the fact that we are continuously exposed through multiple
routes. All human beings, according to the U.S. Agency for Toxic
Substances and Disease Registry' receive at least low levels through
water, food, and inhalation.
... in the last half of the twentieth century, cancers of
the brain, liver, breast, and bone marrow (multiple myeloma) have
been on the rise. These are all human organs with high fat content.
In the last half of the twentieth century, the production of fat-soluble,
synthetic chemicals has also been on the rise. Many are classified
as known, probable, or possible carcinogens. We need to ask what
connections might exist between these two time trends.
First synthesized in 1874, DDT languished without purpose
until drafted into World War II, and it proved its mettle by halting
a typhus epidemic in Naples. My father arrived in this occupied
city not long after. According to his wartime account, Naples
lay in ruins, its people hungry, dirty, and in great despair.
Little wonder they were also vulnerable to typhus. DDT's ability
to annihilate the insect carriers of this disease-fleas, lice,
and mites-must have seemed miraculous. Shortly thereafter, DDT
was loaded onto American bombers and sprayed over the Pacific
Islands to control mosquitoes. War production of DDT soon exceeded
military requirements, and by 1945, the U.S. government allowed
the surplus to be released for general civilian use.
As documented by the historians Thomas Dunlap and Edmund Russell,
this decision marked a profound change in purpose. It is one thing
to fumigate war refugees falling ill from insect-borne epidemics
and quite another to douse the food supply of an entire nation
not at risk for such diseases. It is one thing to rain insecticide
over war zones ravaged by malaria and quite another to drench
suburban Long Island. The skillful advertising that accompanied
this transformation advocated a whole new approach to the insect
world. Various insect species-some, mere nuisances-were recast
in the public's imagination as deadly fiends to be rooted out
at all cost. Cohabitation was no longer acceptable. In demonizing
the home front's new enemy, one cartoon ad even went so far as
to place Adolf Hitler's head on the body of a beetle.
Synthetic pesticide use thus began in the United States in
the 1940s. Two other chemicals participated in this debut: parathion
and the phenoxy herbicides 2,4-D and 2,4,5-T. Parathion-and its
sibling malathion-belong to a group of synthetic chemicals called
organophosphates, which are created by surrounding phosphate molecules
with various carbon chains and rings. Like the chlorinated pesticides,
they attack an insect's nervous system, but they do so by interfering
with the chemical receptor molecules between the nerve cells rather
than by affecting the conduction of electricity, which is DDT's
mode of action. Like the chlorinated pesticides, organophosphate
poisons played a starring role during the war-but as villain rather
than hero. Developed by a German company as a nerve gas, members
of the first generation of organophosphate poisons were tested
on prisoners in the concentration camps of Auschwitz.
By contrast, the phenoxy herbicides were an Allied weapon(As
we have already seen in Chapter Three) they were mobilized in
the 1940s with the goal of destroying enemy crops. Another American
invention-the atomic bomb-ended that war before field testing
could yield to full-scale chemical warfare. Twenty more years
would pass before 2,4-D and 2,4,5-T would reenter combat-this
time in Vietnam's rainforests under the nom de guerre Agent Orange.
In the meantime, they were introduced into U.S. agriculture for
weed control and into forestry for shrub control. By 1960,2,4-D
accounted for half of all U.S. herbicide production. The hoe was
fast on its way to becoming obsolete.
The graphical picture of pesticide use in the United States
closely resembles the graphs of synthetic chemical production:
a long, gentle rise between 1850 and 1945 and then, like the side
of a mesa rising from the desert, the lines shoot up. Insecticide
use begins ascending first; herbicide use closely follows. The
line for fungicide use rises more gradually. All together, within
ten years of their introduction in 1945, synthetic organic chemicals
captured 90 percent of the agricultural pest-control market and
had almost completely routed the pest-control methods of the prewar
years. In 1939, there were 32 pesticidal active ingredients registered
with the federal government. At present, 860 active ingredients
are so registered and are formulated into 20,000 different pesticidal
products. Current U.S. annual use is estimated at 2.23 billion
While agriculture consumes the lion's share of this total,
with only about 5 percent used by private households, family pesticide
use is emerging as an important source of exposure for those of
us not living on farms. According to the EPA's National Home and
Garden Pesticide Survey, 82 percent of U.S. households use pesticides
of some kind. In a survey of families in Missouri, nearly 98 percent
said they use pesticides at least once a year, and almost two-thirds
said they use them five or more times. Yard and garden weed killers
are used by about 50 percent of U.S. families, as are insecticidal
flea collars, sprays, dusts, shampoos, and dips for household
pets. These kinds of uses place us in intimate contact with pesticide
residues, which can easily find their way into bedding, clothing,
carpets, and food. Pesticidal residues persist much longer indoors
than outdoors, where sunlight, flowing water, and soil microbes
help break them down or carry them away. Yard chemicals tracked
indoors on the bottoms of shoes can remain impregnated in carpet
fibers for years. Some researchers now believe that infants and
toddlers experience significant exposure to pesticides by crawling
on carpets and ingesting house dust-perhaps even more so than
by ingesting pesticide residues on food.
Several studies have linked childhood cancer to home pesticide
use. Childhood cancer in Los Angeles was found to be associated
with parental exposure to pesticides during pregnancy or nursing.
In a 1995 study in Denver, children whose yards were treated with
pesticides were four times more likely to have soft tissue cancers
than children living in households that did not use yard chemicals.
In another case-control study, researchers found statistically
significant associations between the incidence of brain humors
in children and the use of several household pesticidal products:
pest-repelling strips, lindane-containing lice shampoos, flea
collars on pets, and weed killers on the lawn. All together, these
findings may represent the beginning of an explanation as to why
brain cancer in children under age fourteen has risen sharply
during the past twenty years.
Formaldehyde serves as an embalming fluid in funeral homes. It
is also sprayed on fabric to create permanent press. In the 1970s,
formaldehyde-based foams became popular for thermal insulation
of houses. But nearly half of formaldehyde's annual production
is used for synthetic resins to hold pieces of wood together as
plywood and particle board. The subsequent evaporation of formaldehyde
vapors from construction materials and furniture makes this chemical
a significant contributor to indoor air pollution. As with chloroform,
the problem with formaldehyde is not that it accumulates in our
tissues but that we are exposed to small amounts of it almost
continuously and from so many sources-from our subflooring to
our wrinkle-free sheets.
... What formaldehyde shares with the soybean is an ability
to act as an adhesive. Before formaldehyde was synthesized in
such gargantuan quantities, soybean resins were used to hold particle
board and plywood together. Soybean oil was also used in fire-suppressant
foam and wallpaper glue, and as a base for paints, varnishes,
Other plant-based oils also played leading roles in industry
before the war. Oils extracted from corn, olives, rice, grape
seeds, and other plant parts were used to make paint, inks, soaps,
emulsifiers, and even floor covering. The word linoleum echoes
the name of its original key ingredient: linseed oil. Castor oil,
from the tropical castor bean tree, was used to lubricate machine
The rapid birthrate of new synthetic products that began in
1945 far surpassed the ability of government to regulate their
use and disposal. Between 45,000 and 100,000 chemicals are now
in common commercial use; 75,000 is the most frequently cited
estimate. Of these, only about 1.5 to 3 percent (1,200 to 1,500
chemicals) have been tested for carcinogenicity. The vast majority
of commercially used chemicals were brought to market before 1979,
when the federal Toxics Substances Control Act (TSCA) mandated
the review of new chemicals. Thus, many carcinogenic environmental
contaminants likely remain unidentified, unmonitored, and unregulated.
Too often, this lack of basic information is paraphrased as "there
is lack of evidence of harm," which in turn is translated
as "the chemical is harmless."
Pesticides are regulated by twin laws: the Federal Food, Drug,
and Cosmetic Act (FFDCA) and the Federal Insecticide, Fungicide,
and Rodenticide Act (FIFRA). FFDCA governs pesticide tolerances
on agricultural commodities-that is, it sets legal limits for
pesticide residues allowed in foodstuffs ranging from raw vegetables
to animal feed. FIFRA, on the other hand, requires companies manufacturing
pesticides to test their products for toxicity and submit the
results to the federal government. Amendments to FIFRA require
reevaluation of old, untested pesticides approved before the current
requirements for scientific testing were put into place. Initially
scheduled to be completed in 1976, this reregistration process
is still under way, has been repeatedly delayed, and is now scheduled
for completion in the year 2010. Until then, the old, untested
pesticides can be sold and used. As one critic has noted, it is
as if the bureau of motor vehicles issued everyone a driver's
license but did not get around to giving us a road test until
decades later. According to the National Research Council, only
10 percent of pesticides in common use have been adequately assessed
for hazards; for 38 percent, nothing useful is known; the remaining
S2 percent fall somewhere in between.
... Of all the unexpected consequences of World War II, perhaps
the most ironic is the discovery that a remarkable number of the
new chemicals it ushered in are estrogenic-that is, at low levels
inside the human body, they mimic the female hormone estrogen.
Many of the hypermasculine weapons of conquest and progress, are,
biologically speaking, emasculating.
This effect occurs through a variety of biochemical mechanisms.
Some chemicals imitate the hormone directly, while others interfere
with the various systems that regulate the body's production and
metabolism of natural estrogens. Still others seem to work by
blocking the receptor sites for male hormones, which are collectively
called androgens. In 1995, fifty years after its triumphant return
from the war and entry into civilian life, DDT again made headlines
when new animal studies showed that DDT's main metabolic breakdown
product, DDE, is an androgen-blocker.
Our enzymes quickly convert DDT into DDE. But because the
next step is much slower (recall DDT's seven-year half-life),
we accumulate DDE as we age-much as a fine stream of sand grains
gradually forms a heap at the bottom of an hourglass. DDE molecules
can cross the human placenta and can also accumulate in breast
milk. Thus, those of us too young to have been sprayed by DDT
directly nevertheless have accumulated DDE in our bodies through
at least two routes: from our mothers (both before and after
birth) and our consumption of milk, meat, eggs, and fish. Animals,
like the humans who eat them, lack the biochemical hardware needed
for efficient conversion of DDE to something excretable.
For boys and men, the consequences may include physical deformities
such as undescended testicles, lowered sperm counts, and testicular
cancer. No one knows what effect DDE exposure has on the reproductive
development of girls or women; no research has been done. The
only thing we know for a fact is that DDE is biochemically different
enough from anything else in the human body- male or female-that
it is not completely metabolized as are our own natural sex hormones.
This is one reason why, more than two decades after DDT's forced
retirement in the United States, we still have DDE molecules floating
around in our tissues.
About half of the synthetic materials known to function as endocrine
disrupters belong to a chemical group called organochlorines.
Not all estrogenic materials are organochlorines, and not all
organochlorines are estrogenic, but the overlap is impressive.
Moreover, organochlorines are such a large group-around eleven
thousand exist-and they tend to be so persistent in the environment,
so reactive within human tissues, and so frequently associated
with cancer that they merit special consideration.
... Lindane, DDT, heptachlor, chlordane, PCBs, CFCs, TCE,
perc, 2,4-D, methyl chloride, vinyl chloride, polyvinyl chloride,
dioxin, and chloroform are all organochlorines. Benzene, formaldehyde,
nonylphenol, and phthalates are not.
Organochlorines, which involve a chemical marriage between
chlorine and carbon atoms, are not strictly a human invention.
A few are formed during volcanic eruptions and forest fires and
some by living organisms such as marine algae. For the most part,
however, chlorine and carbon move in separate spheres in the natural
world-and in the bodies of humans and other mammals. To force
the two together, elemental chlorine gas is required.
Although it holds a rightful place in the periodic table of
elements, pure chlorine is a human invention. It can be produced
by passing electricity through salt water in a procedure that
was first undertaken on an industrial scale in 1893. A powerful
poison, chlorine gas became known to the world during World War
I, but its manufacture grew slowly until World War II, then rose
exponentially. About 1 percent of this production is used for
disinfecting water and about 10 percent for bleaching paper, and
the majority is combined with various carbon compounds, usually
derived from petroleum, to make organochlorines.
As a group, organochlorines tend to be persistent in air and water.
When they evaporate and are swept into the wind currents, some
fall back to the earth close to their origins, while others can
circulate for thousands of miles before being redeposited into
water, vegetation, and soil. From there, they enter the food chain.
Diet is thus believed to be a major route of exposure for us.
Not all organochlorines are deliberately constructed. Whenever
elemental chlorine is present, the natural environment will synthesize
additional, unwanted organochlorine molecules. These reactions
can take place when water containing organic matter, such as decayed
leaves, is chlorinated. It can happen in pulp and paper mills
during the process of bleaching or when chlorinated plastics are
burned. It can happen during the manufacture of other organochlorines.
The production of 2,4,5-T, the burning of plastic, and certain
methods of bleaching paper all contribute to the birth of dioxin.
A chemical of no known usefulness and never manufactured on purpose,
dioxin has been linked to a variety of cancers and is now believed
to inhabit the body tissues of every person living in the United
Sweeping changes are immediately possible in the dry-cleaning
industry. Most clothing tagged as "dry-clean only" can
in fact be professionally cleaned with the use of water, special
soaps, and reengineered washing machines that allow computerized
control over humidity, agitation, and heat. (Pressurized carbon
dioxide also holds promise as a nontoxic solvent for cleaning
textiles.) The Boston area, for example, is home to one such wet-cleaning
operation, a pilot project of the Toxics Use Reduction Institute.
I recently delivered to this shop a down coat, a silk dress, a
badly stained antique kimono, and a pile of my best wool, cashmere,
and rayon suits. All came back clean, beautifully pressed, and
odor-free. The white streak across the sleeve of the green blazer-the
result of an encounter with a freshly painted doorframe-was gone.
Best of all, the proprietor, who appeared about eight months pregnant,
expressed to me her relief at not having to be exposed to perc.
Most of the perchloroethylene manufactured in the United States
is used by the textile and dry-cleaning industry. In 1992 alone,
12.3 million pounds of this organochlorine and suspected carcinogen
was released into air, ten thousand pounds to rivers and streams,
and nine thousand pounds to land. Thirteen thousand pounds were
directly injected into underground wells. The recycling of perchloroethylene
produces contaminated sludge and filters, which are subsequently
deposited in landfills where they poison soil. Traces of perchloroethylene
have been found in breast milk, cow's milk, meat, oil, fruit,
fish, shellfish, and algae. Perc has been detected in rainwater,
seawater, river water, groundwater, and tap water. More than 650,000
workers are thought to be exposed to perc on the job, and an estimated
99,000 New York City dwellers are exposed to elevated levels just
from breathing-many because their office or apartment shares the
same building with a dry-cleaner. A 1993 survey found that 83
percent of New York City apartments located above a drycleaning
establishment had ambient perc levels in excess of state health