I did this review in 2018. While I disagree pretty strongly with
Steingraber’s activism against natural gas development, her advocacy for the
Precautionary Principle, and some of her other proposed solutions, I also think
her personal story is a compelling one and I respect her work in investigating
links between synthetic chemicals and cancer.
This is an interesting account of the possible relationships
between chemicals, particularly synthetic organic chemicals, and the incidence of
cancer. By nature, it is difficult to discern the prime causes of cancer and what
might just be influences. The environment a body encounters and imbibes is
certainly a factor. She does a good job of stating evidence and trying to tease
out relationships in light of both her scientific prowess and her very personal
long and thus far successful battle with bladder cancer, diagnosed when she was
20. It is also good as a personal account of the anxieties, hopes and fears, of
having cancer, quite touching at times. She is a veteran of over 70 cystoscopic
exams where tubes were inserted into her bladder.
In the intro to the 2nd edition she notes that it has been
thirty years since she was first diagnosed. When she was diagnosed she was
asked by her urologist if she ever worked in a tire factory, the aluminum
industry, or with textile dyes. She was asked because bladder cancer is the
cancer most thought to be due to exposure to hazardous chemicals. Of all the
chemicals used in our society very few have been specifically tested for
carcinogenicity – about 2%, although that increases if we extrapolate and categorize
by type. Many chemicals known to cause cancer in animals are used in food and
consumer products. Genetic factors are extremely important in susceptibility to
cancer so it makes sense that the genetically susceptible are very
sensitive to exposure to carcinogens in the environment.
Steingraber’s information sources include the Harvard
Medical School library where she did post-doctoral research, right-to-know
laws, cancer registries, published studies, and reports about levels of
environmental contaminants like pesticides and other chemicals and air
pollution. She notes the 1986 federal right-to-know law which requires
industrial interests to keep databases of the release of initially some 650
toxic substances into the environment. The database became the Toxics Release
Inventory (TRI). This allowed researchers to compare where those releases
occurred with local cancer rates and patterns. From 2001 to 2008 the TRI was
scaled back and thousands of facilities were no longer required to report.
Steingraber does acknowledge that cancer causation is
complex and a recent analysis from Johns Hopkins University notes that most
cancers to not have a discernable cause. She notes cancer causation used to be
divided among three variables: genes, lifestyle, and environment. Newer
analyses indicate that those variables often intermingle in complex ways.
Genetic factors may involve epigenetic factors – genetic predisposition to
cancer is too simplistic. Substances, natural and synthetic may alter gene expression
and change gene behavior. She also mentions endocrine disruption, whereby
certain chemicals disrupt our endocrine system which affects hormone
production, metabolism, and reproduction. Basically, chemicals can interfere
with and mimic hormones. She notes the old toxicology adage – “the dose makes
the poison,” but also adds that in endocrine disruption the timing is often
very important, particularly exposure early in life. Another complicating
factor is chemical mixtures and how they interact with one another and with the
body as a whole. Steingraber is an advocate of the Precautionary Principle,
which is favored in Europe but has always been a hard sell in the U.S. I don’t
agree with her on this – sometimes being overly cautious can cause more harm than
good and I think each individual case should be evaluated separately rather
than fall under a single regulatory principle. She favors ‘green chemistry’ but
there is as of yet much to work out with it. She notes that petroleum and coal
are often the sources of carcinogenic synthetic substances and so favors green
energy. Of course, petroleum is also the source of many synthetic chemicals
that improve health and make our lives safer and more convenient. The bigger
part of toxic chemical releases comes from coal-burning power plants and
emissions from vehicles. She notes that the death rate from cancer has actually
fallen and this is due primarily to the success of smoking cessation programs.
However, childhood cancer has slowly but steadily increased over the years. She
notes that certain industrial chemicals have been proven to cause cancer among
those who work with them so precautions are needed, including outright
banning in some cases.
Steingraber recounts her childhood in Central Illinois
prairieland/farmland where part of her family farmed. Illinois is 87% farmland.
It has been farmed for a long time and pesticide use is abundant, including the
use of atrazine. Atrazine in the environment is high during spring planting and
lower in winter. It and its byproducts are found in surface water, air, and
groundwater as well. A 1992 study found that one-quarter of private wells in
Central Illinois contained agricultural chemicals, typically in trace amounts.
How they get into groundwater and how much varies according to how much is used,
how much runs off, and the local geology and groundwater configurations are
important factors. Even long-banned DDT and PCBs are still found in the
environment due to their chemical stability. She notes that:
“Atrazine remains the most frequently detected pesticide [as
of publication 2010] in water throughout the United States, found in three of
every four American streams and rivers and 40% of all groundwater samples.”
She gives some info/data and anecdotes about DDT, PCBs, and
atrazine and introduces Rachel Carson, who succumbed to cancer and whose work
led to DDT being banned. Through the book, it can be seen that Steingraber
venerates Carson and follows in her footsteps. She recounts her visits to the
library at Yale University that houses Carson’s papers. She reproduces some of
Carson’s notes about her own cancer and impending death and through narrative
stories about Steingraber’s friend Jeannie who had an aggressive form of cancer
in her thirties and died from it. Carson’s famous 1962 book, Silent Spring, led
to the banning or restricted use of several dangerous pesticides, although the
chemical industry fought her. In a few isolated cases these pesticides can be
useful according to many – such as in very specific applications to prevent
malaria which kills many children around the world in tropical countries with
abundant mosquitos. Many say DDT could prevent those deaths but there is no
access since it is banned internationally. DDT, PCBs, and possibly atrazine
(which is not banned in the U.S. but is in Europe) are in some ways associated
with cancer although data and conclusions have been inconsistent. Thus, even
with these powerful poisons it is difficult to get incontrovertible
conclusions. This makes the much less powerful pesticides in use today like
glyphosate much more benign by comparison. Steingraber also recounts Carson’s
public appearances to fight the chemical/pesticide industry after Silent Spring
was published and her struggling cancer patient appearance as she defended her
work. Carson argued that pesticides and other chemicals caused cancer before it
was generally ceded that that was the case. Steingraber notes Carson’s ode to
citizen activists as helping her to speak out and sees herself in the same
light – as an activist as well as a scientist – Steingraber has been vocal in
recent years in opposition to oil and gas industry activity near Ithaca, NY
where she lives – although I think her focus may be misplaced since the
fracking revolution likely produces far more benefit than harm and the fears
about water contamination are overblown.
She recounts the experience of having cancer throughout the
book, the boredom, the anxiety, the fear, the frustration. She also notes
cancer trends and trying to tease out trends from the data that is available.
She pours through state and federal cancer registries and compares them to TRI
data. She looks at cancer incidence rates = number of new cancer cases per
100,000 people per year. Tracking changes in cancer incidence can lead to
discoveries that point to sources. Unfortunately, there are often multiple
possible sources so that the availability of many of them may correlate with
cancer incidence and yet not be related by cause. The adage “correlation does
not equal causation” is often relevant to these statistical epidemiological
approaches. Teasing out clear relationships from the data can be difficult. She
acknowledges these problems.
Incidence rates can change when new detection technologies
appear such as mammography for breast cancer. She explores the trends in breast
cancer, noting that breast cancer has been dropping irregularly since it peaked
in the 1990’s. There are several possible reasons: decline in women taking
hormone-replacement drugs, decline in women getting mammograms, disproportional
under-reporting, and declining exposure to causative agents. She notes that
breast cancer kills 41,000 women in the U.S. yearly. Another reason cancer
trends are hard to track is that it is a slow disease and people move to
different localities making cancer by region difficult to calculate evenly. She
notes that the overall cancer incidence rate is 463 per 100,000. This is more
than twice the cancer mortality rate so more people are surviving cancer. Over
11 million people in the U.S. have cancer, are in remission, or are cured. The
cancers that are rising are leukemia, non-Hodgkin lymphoma, soft tissue
cancers, kidney cancer, and brain and nervous system tumors. Childhood cancers
are rising as well, which suggests environmental factors. She notes that
children do receive a higher proportion of any poisons in air and water due to
body weight and they don’t have lifestyle factors as adults do. She notes that
cigarette smoking causes 85-90% of lung cancer with a very high fatality rate
and is thus the largest preventable form of cancer.
Steingraber lauds calls to fund more cancer incidence
research as well as research of more potential chemical carcinogens. She notes
cancer studies that have grouped people by birth year, by racial/ethnic
background, gender, or all of the above. She focuses in on the data about
non-Hodgkin lymphomas and notes that people of certain occupations tend to get
it such as farm workers and dry cleaning workers. Solvents, PCBs, and certain
pesticides (phenoxy herbicides) are suspected sources or triggers. She studies
cancer distributions across space and time. One might find cancer clusters and
compare them to nearby potential sources of toxins, although one would have to
prove that those toxins are there and know something about their toxicological
effects. She notes throughout the book that cancer study results are often
unclear and inconclusive and can only suggest where and what to study further.
She thinks there is a general correlation between industrialization and rising
cancer rates. She suggests that increased coal-burning in China and living near
a Soviet petrochemical complex in Ajerbaijan correlate well to increasing
cancer rates in those places. She implicates coal and petroleum in particular –
many synthetic chemicals derive from petroleum. However, it is hard to know how
much cancer or cancer influence is derived from petroleum chemicals. We also
know that the UV light from the sun causes cancer in those susceptible and that
plant substances can be carcinogenic. Lifestyle factors may also stack the deck
for or against cancers. Household chemicals, cosmetics, cleaning chemicals,
paints, and solvents may be factors. It is hard to know how much with each of
these without large, long-lasting, and well-planned studies. More people die of
heart disease than cancer (especially now as more and more cancers become
treatable) and lifestyle is also a large factor in heart disease. Toxin
exposure could be a contributing factor as well. She notes that increasing
cancer rates among migrants to a new place certainly suggests an environmental
influence.
She calls for a nationwide cancer registry. The National
Cancer Institute keeps an atlas of cancer mortality but not incidence (cancer
mortality has dropped due to better treatment and sooner detection). She notes
a good correlation between cancer mortality and industrial areas. However, she
also notes that quality of treatment is a factor and that cancer diagnoses do
not seem to correlate as well to industrial activity. She does say that cancer
rates seem to match industry more than any other health problems match it. She
mentions a study in the UK that correlated leukemia very well to industrial
facilities, particularly to those involving chemical solvents at high
temperatures. Cancer rates among certain occupations have long been studied:
farmers, chemists, dental workers, barbers, hairdressers, firefighters,
painters, welders, asbestos workers, miners, printers, fabric and dye workers,
certain electronics workers, and plastics manufacturers. Being somehow exposed
to dumped chemicals and wastes is also considered, particularly the many
Superfund sites. She does also consider methodology and the difficulty of
getting from correlation to causation. Here she mentions ecological fallacy as
a term meaning to falsely attribute causation to correlation. She complains
that uncertainty has been used to delay corrective action for reducing
environmental pollution. That can work both ways as those who favor strong
regulation of potential toxins often use uncertainty to argue their position –
the basis of the Precautionary Principle. It is basically a ‘prove it safe’ vs.
a ‘prove it harmful’ debate. I would argue that since many of the toxins are or
derive from substances that do much good in the world, including making people
healthier and enabling many things – that the burden should be on those to
‘prove it harmful’ for most things – that usefulness to society, cost, and
disruption also need to be taken into account.
She goes through a type of epidemiology known as “ecological
studies,” which attempt to discern disease trends in large groups. One might
study populations where exposure to toxins is likely vs. populations where it
is unlikely. Investigation of cancer clusters can be tricky or legitimate
requests for such studies can be dismissed by health workers. We are all
exposed to various levels of ‘probable carcinogens’ such as metal degreaser
trichlorethylene (TCE) as it is in most water supplies. In such cases it is
difficult to find a comparison population with no exposure to the toxin. Cancer
is more difficult to study because it may take a long time after exposure (to
certain toxins) for cancer to develop. People move between exposure and onset.
Also, cancer may have numerous causes so that pinpointing it to one cause is
not easy. She notes that GIS (geographic information systems) can be very
helpful. Environmental epidemiology is wrought with difficulties as well as
being amenable to inconclusive results that may suggest causation that is not
causation and vice versa.
Steingraber focuses on synthetic organic chemicals as
potential sources of cancer although she does not mention that there are
natural sources of cancer as well and that some of the synthesized chemicals
also do occur in nature, although often in different forms. Crude oil is a
natural substance that is toxic if ingested. She notes that:
“Synthetic organic 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.”
This is problematic she says. Many organic chemicals are
inert in their final forms but active in their intermediate forms during
manufacture. If enough of some chemicals get in our systems they may mimic
natural body chemicals as is thought to be the way endocrine disruptors act.
She also mentions chloroform, considered a probable carcinogen. It is used in
many chemical processes and appears in wastewater. It also appears as a
byproduct of chlorinated water so removing it may be impossible. Later in the
book she does mention favoring alternatives to chlorine use but water companies
still prefer chlorine based on cost and feasibility. She laments the
ineffectiveness of the 1976 Toxic Substances Control Act (TSCA) which does not
require testing for the vast majority of new chemicals on the market. Of
course, massive new studies on every new chemical would mean massive animal
testing and such tests often involve giving animals massive lethal doses. She
notes that barely a handful of chemicals have ever been taken off the market
and none for the last nineteen years. Pesticides are regulated differently –
Federal Food, Drug, and Cosmetic Act (FFDCA) and Federal Insecticide,
Fungicide, and Rodenticide Act (FIFRA). In 1986 the Emergency Planning and
Community Right-to-Know Act (EPCRA) passed Congress over massive opposition by
industry. It spurred the Toxics Release Inventory (TRI) which requires
companies to report the total amount of about 650 toxic chemicals released as
waste, by-products, and spills every year. TRI was scaled back in 2008 and 2009
citing homeland security concerns since knowledge of where toxins were stored
could be used by those wishing to unleash them for terroristic reasons.
However, in order to explore whether environmental toxins are influencing
cancer incidence one would need to know what is actual in the environment from
day to day or at least on avg.
Toxics and pollutants may be concentrated at places like
landfills, particularly at those that accept toxic waste such as heavy metals
that have been implicated as carcinogens. Steingraber does her own
investigative analysis of industrial toxics released into her childhood area of
Tazewell County, Illinois.
She goes back again to endocrine disruptors, mainly those
that mimic the hormone estrogen. While this is true of several industrial
chemicals just today I read an article about naturally-occurring chemicals in
the essential oils used in many soaps, shampoos, and lotions also doing the
same thing. The substances in the oils are also known to bioaccumulate rather
than fully metabolize. Apparently, there are several ways substances (both
synthetic and natural) interfere with hormones. Phthalates used in PVC plastic
and added to perfumes and lotions are known disruptors as are a rather toxic
chemical group known as organochlorines which includes PCBs, TCE, DDT, dioxin,
and several others. Organochlorines tend to persist in the environment. Burning
plastic produces dioxin and other organochlorines. She mentions the UN
Stockholm Convention on Persistent Organic Pollutants (POPs) as inspiring since
it seeks to eliminate the use of the most toxic POPs. Several of the worst
organochlorines are on the list.
Steingraber favors so-called green chemistry over petroleum
chemistry but it is quite difficult to compete with petroleum (or natural gas
liquids and derivatives) as feedstocks. She mentions as one green chemistry
success story – the development of a soy-based adhesive that replaces
formaldehyde in plywood. She argues that green chemistry should be mandated
like smoking cessation and exercise – as health-promoting. However, she doesn’t
acknowledge that some of nature’s own chemicals, when concentrated and exposed
to creatures can cause health problems too. I think she overly focuses on the
synthetics. Too many wood ashes concentrated in one spot can contain
carcinogenic heavy metals. Wood smoke is highly toxic. An USDA-organic approved
fungicide like copper sulfate can be more toxic than commonly used pesticides
as can other highly concentrated natural substances. She does acknowledge that
pre-synthetic substances like celluloid and castor oil are also environmentally
harmful and so does not advocate for banning all synthetic chemicals, only the
most harmful ones. While that may seem reasonable some are difficult to
replace. However, her activism to ban fracking and an underground propane
storage facility suggest that she does advocate bans.
She goes through some case studies of possible relationships
between certain pesticides and breast cancer. She also explains why assays –
evaluations of biological or chemical substances – can be expensive, messy, and
complex. In assays for potential carcinogens animal studies need to involve
large amounts of animals who need to be evaluated for years as cancer often
takes a long time to appear. For complete understanding such long complex
assays would be needed for each potential chemical carcinogen, ideally. Some
researchers have advocated for new chemical screening tools since the time
constraints and inconclusiveness of animal assays keep a huge backlog of
chemicals for which toxicity is unknown. Better knowledge of the interactions
of networks of genes, proteins, and receptors has shown that certain chemicals
and classes of chemicals disrupt the pathways of these cell functions.
She discovers that her own cancer, a type of bladder cancer
called transitional cell carcinoma, also occurs among beluga whales from the
St. Lawrence estuary in Canada. Many workers from a nearby aluminum smelting
operation also got that particular type of cancer. PCBs, DDT, chlordane, and
other toxins are found in the waters and sediment of the estuary. There is also
benzo-[a]-pyrene, product of combustion classed as a polycyclic aromatic
hydrocarbon (PAH). Liver cancer in fish has also been linked to toxics.
She laments the change from large numbers of small family
farms to less farms but bigger more industrialized ones. Using pesticides
reduced the need for crop rotation. She recounts her childhood farm experiences
in Illinois. While Illinois corn and soybeans are sold for export, most goes to
feed livestock. A significant amount also becomes snacks and corn sugar. She
also advocates taxing foods of lower nutritional value, like soda to deal with
the obesity epidemic. Obesity and weight gain are risk factors for cancer,
probably related to hormones and inflammation. She sees the farm belt as
overproducing the two – corn and soy – but they make the best animal feed,
snacks, and best grain nutrition for export. Also, larger more industrialized
farms are way more efficient and reduce overall land use quite significantly.
Corn and soy also account for the largest share of herbicide use. Of course ,
there is also organic, which uses organically approved pesticides, not
synthetic, but which may also have some ill effects. Weeds used to be removed
by plowing, hoeing, and disking but these were time and labor intensive. They
also released more carbon from soils. Modern no-till methods are better for
soil health and retain more carbon. Herbicide-resistant varieties developed
through genetic engineering. Though she laments that by 2004 a third of
Illinois corn was GMO (probably much more now), this is now widely seen as a
good thing since overall pesticide use is down. She does not mention this. She
invokes herbicide-resistant weeds which can be problematic but have yet to be a
huge problem, especially as herbicides are more targeted in place and time to
reduce runoff. She laments the continued use of atrazine, banned in the EU,
because of its water solubility and ability to spread all over the environment.
She also laments the dead zones caused by nitrogen and phosphorus fertilizer
runoff overload. She notes that manure is way less used than it used to be
(although she doesn’t mention that manure runoff also contributes significantly
to the runoff that creates dead zones). Synthetic nitrogen fertilizers are made
from natural gas in fertilizer plants. Although she sees that as a problem it
is really the basis for improved yields and preventing more global hunger as
well as allowing farmers to make a profit and food to be plentiful and cheap.
Fertilizer can also be targeted in place and time to reduce runoff, which also
can save farmers money. She goes on to advocate organic farming and
agroecology. These are of course good things but in terms of yields and
reducing land use for agriculture they are still way behind modern mechanized
agriculture utilizing synthetic fertilizer. She seems to think organic farming
reduced carbon footprints but more recent analysis suggests it’s the other way
around, mainly due to less land required for comparable yields = less
deforestation/more reforestation. More modern scientific analysis suggests that
organic “methods” combined with efficient and smart use of synthetic
fertilizers, and genetic engineering will be the best overall solution. More
recently there is CRISPR gene-editing that may make GMOs more versatile. Her
call to go back to the old ways of farming on a large scale seems rather
anachronistic and naive in light of the massive success of modern methods.
Next, she considers airborne toxins that follow the weather
to distribute themselves across the globe, even in remote parts of the world
such as the Arctic. She mentions that in 2007 one-third of toxins released into
the environment were released into the air. However, much of it probably ends
up not heavily concentrated. There are chemical reactions that can combine to
make new air contaminants from combusted material like how nitrous oxides and
volatile organic compounds (VOCs) contribute to photochemical smog/ground-level
ozone. This is a well-known pollutant in many urban areas and is considered to
shorten life if one lives in an area of chronic smog. She thinks the increase
of lung cancer among non-smokers may be attributed to particulates and smog. Oncologists
and pathologists have also suggested that air pollutants like nitrogen dioxide
may also help cancer spread from other areas to the lungs where it is difficult
to treat.
Next, she considers water pollution, noting that it may be
responsible for habitat destruction for many riverine species including water
fowl. As in many place, she notes that water quality improved in the Illinois
rivers due to the requirements of the 1972 Clean Air Act. The 1974 Safe
Drinking Water Act set limits of certain chemicals allowable in drinking water.
She notes the concept of “enforceable limits” of a few parts per billion of
some substances like benzene and TCE where any amount is considered dangerous
but water can only be “cleaned” to those enforceable limits. Most limits are in
single-digit parts per billion. She notes that as of 2009 there were only
enforceable limits established for 90 contaminants. Any device that heats water
(showers, dishwashers, washers) can also release VOCs from the water so that
water can also contribute to airborne toxics. Some studies have suggested that
showers can be more toxic than drinking toxins in water. Again she considers
chlorinated water, noting that chlorine combines with contaminants in water to
make toxic by-products, some of which are organo-chlorines. She notes that
about 600 of those by-products have been discovered with few tested for
carcinogenicity. A few are monitored and regulated – trihalomethanes and
haloacetic acids – and chloroform being the most common. She favors alternative water disinfection
strategies although chlorine has proven to be quite effective and removing
chlorine has proved deadly in a few cases. She favors activated charcoal and
ozonation but it is unclear how they compare to chlorine in effectiveness and
cost. Manure from farms (which she laments the loss of) is the most widely
implicated source of water contamination – so protection of source water can be
key to preventing contamination. She does mention that using activated
charcoal, then aeration, then using chlorine as the final (rather than the
first) stage can reduce trihalomethanes – although aeration can make them
airborne. She also considers groundwater
contamination through time and in different parts of aquifers (groundwater
moves slow in some aquifers, faster in others). She notes that contamination in
groundwater recharge areas, typically upland is more problematic than in
discharge areas, typically lowland. Thus, protection of recharge areas is
emphasized. Contaminated groundwater is difficult to remedy.
Next, she considers the effects of garbage incinerators,
mainly on airborne contamination. These waste-to-energy plants vary in effect
based on how the waste-stream is sorted and how effective are the pollution
control systems. In modern times some systems claim 99% of contaminants are
removed (although the 1% remaining still worries nearby residents). Places like
Sweden use their WTE plants as a source of pride in the use of renewable energy
while places in the U.S. may consider them sources of industrial toxicity.
Perhaps it depends on how they are marketed and the propaganda. There is a
long-standing debate about whether landfilling or WTE plants are better for the
environment. Her analysis here is a few decades old so I won’t dwell on it. The
bottom line today is how much pollution-control is implemented or in the case
of landfills how sophisticated are the leachate collection systems, the
groundwater monitoring wells, and the methane collection and pumping systems.
Each project should be evaluated separately. Dioxin is one major toxin produced
and clearly those who live nearest are the most affected. She documents studies
on dioxin and how it may work to lead to cancer but the jury is still out on
its effects and what an acceptable level should be. Burning most things
produces some dioxins, including burning wood. She favors recycling but that
too has costs and it is difficult for recyclers to make money and to get people
to do it on a large scale. Zero waste is a nice concept but in reality it is
far from achievable without massive changes in social habits.
Next, she considers ‘body burden,’ the sum total of all the
effects of ingesting, inhaling, and absorption through skin of contaminants to
get an idea of ‘cumulative exposure.’ We can measure the amounts of different
contaminants in different parts of the body. The highest amounts of DDT, PCBs,
and chlordane were found when those chemicals were most in production and use.
Measuring levels of pollutants in people is known as “biomonitoring.” When lead
was phased out of gasoline, blood levels of lead in children began to decrease
and they ended up decreasing more than the models predicted so we know that
changing the levels of some chemicals in the environment can lead to less of
them in our bodies in a reasonable amount of time. Biomonitoring has also shown
that banning smoking in public places has resulted in less “smoke” in our
bodies. In 1999, the CDC began monitoring a group of 5000 people in 15
geographic locations for up to 148 chemicals. One surprise was the amount of
flame-retardants we have in our bodies – these are potentially dangerous
endocrine-disrupting POPs that we have way more in our bodies than Europeans.
She notes that advances in chemistry have made biomonitoring more effective and
cheaper. California was the first state to embrace biomonitoring but most
states have followed suit.
She knows how cancer works:
“Destroying healthy tissue and clogging vital passageways,
metastases are what make cancer deadly”
“… tumors are not just homogenous balls of bad cells.
Rather, they are composite tissues, with cancerous and normal cells coexisting
in a complex society. But the malignant cells are the ones running the casino.”
“They are Cells Gone Wild. They are defiant, disobedient,
unstable, chaotic, and in the view of many cancer biologists, almost purposeful
in the ways they disrupt cellular biochemistry.”
She goes through the stages of cancer development in detail,
noting the three overlapping stages: initiation, promotion, and progression and
how contaminants may affect each stage. More recently two processes: chronic
inflammation and abnormal epigenetic regulation have been implicated in
transforming cells. Obesity can increase chronic inflammation. Genes affect
one’s ability to get cancer and so too does the environment. It is not one or
the other but how the two interact. Environmental epigenetics is a new avenue
of research investigating how contaminants affect epigenetics, the switches
that turn genes off and on or otherwise code them. Oddly, she notes that the
Inuit people of Greenland, via their own food chain and the way airborne
contaminants have fallen on their region due to weather patterns (called global
distillation in terms of contaminant transport) have the highest levels/body
burdens of POPs -persistent organic pollutants.
She mentions studies of adoptees and ‘epigenetic drift among
twins (the notion that as twins separate geographically that their epigenetic
factors change). She is an adoptee and wishes she had access to her genetic
history. She thinks the reverse may happen among adoptees – that their
epigenetic factors converge with non-adopted siblings due to similar
environmental factors. One study among identical twins in Scandinavia suggested
that the chance of developing the same cancer as one twin by the other was 11-18%,
which shows that genetics is a factor but not as strong a factor as expected, A
recent Johns Hopkins study has suggested that cancer is so complex that
determining the primary “cause” of most cancers is simply not possible. While
cancer may be initiated by accumulations of genetic errors it seems more
recently that abnormal regulations of genes by epigenetic factors is the
reason. She notes that the Human Genome Study has revealed that we have less
genes than thought before the mapping was done but more of those genes are
implicated in cancer development than previously thought. She cites the Swedish
Family-Cancer Database – the largest dataset of that kind in the world,
suggests that family history of cancer plays a modest role in cancer
development. She talks about oncogenes and adductors and an enzyme-based
chemical detoxification process called acetylation as being factors in the
likelihood one would develop cancer – if exposed to carcinogens, particularly
early in life. People that are “slow acetylators” are more susceptible and that
includes more than half of Europeans and Americans.
She compares a U.S Dept of Health and Human Services
brochure to a Genetics textbook regarding the environmental factors of cancer
development. The textbook considers environmental factors including smoking,
lifestyle habits, and obesity, to be responsible for most (as much as 90%)
cancers. Is it mainly a problem of behavior or exposure? We now know that one
dietary factor – eating more fruits and vegetables – deceases cancer incidence.
She thinks focus on behavioral and lifestyle factors tends to hide the environmental
roots of cancer. We do know that occupational exposures, typically more than
exposures among the general population to certain contaminants has led to
increased cancer rates. She asks whether the obesity factor is also related to
greater retention of pollutants, presumably along with greater levels of
chronic inflammation. Epidemiologists have cautioned against attributing
cancers to single causes and biomonitoring studies and how toxins interact in
the body do suggest that complex causes involving many factors could be at play
in most cancers.
She calls for green chemistry and the Precautionary
Principle but in several cases the Precationary Principle has proven more
harmful than beneficial. For instance, in genetic engineering, biotech, and
gene editing, the banning of such process in Europe has led to the banning of
them in parts of Africa where people could directly benefit from them through
less hunger, better nutrition, and more successful and cheaper farming and
food. Synthetic chemicals have done a lot of good in the world. Green chemistry
is a good idea but may only be marginally applicable. Natural chemicals can
also lead to cancer. There are trade-offs and no easy answers. There are
extreme costs to re-organizing society on greener principles and there are
unknowns. Its easy to say let’s have green energy now but there are toxins
associated with these sources as well and tremendous costs and logistical
problems. She favors “alternatives assessments” and I can agree – that we
should explore alternatives to toxic solutions when possible. She also favors
“full-cost accounting” where the health costs of toxic solutions are added in.
Apparently, judging from her recent activism, she favors the Precautionary
Principle in banning fracking as well. Fracking has resulted in massive
decreases of particulate pollution and carbon emissions and better air quality
as well as cheaper energy – all due to replacing coal with natural gas in power
plants. That would not have occurred if the Precautionary Principle would have
reigned as it has in areas where the process is banned. Most things that
involve risk also have benefit and these need to be evaluated intently. There
is also what is called “risk perception” which among humans has a very strong
emotional component due to our evolutionary neurological development.
Perception of risk versus real statistical risk can vary considerably.
Uncertainty is often exploited by those who favor avoiding risks and those who
favor taking risks. Studies have shown, however, that people are more willing
to exploit uncertainty and emotionality to promote avoiding risks. Heart
disease is bigger problem than cancer and yet people worry more about cancer,
seeing it as more of a risk, perhaps because it is thought that we can reverse
heart disease with lifestyle changes more than we can reverse cancer the same
way.
Overall, this is a very good book: detailed and honestly
written. She has worked hard to understand the issue of the environmental
factors in the development of cancers. She is no fool. While I disagree with
her anti-fracking activism I do understand and agree with her advocacy for
better evaluation of chemicals and her call for more studies of environmental
factors in cancer as well as getting rid of the most dangerous of chemicals.
