- BOSTON -- My nose is clamped
and I'm trying not to choke on a tube a scientist at Harvard University
has stuffed in my mouth. I am blowing into a clear plastic bag, which is
sealed and later studied for what it contains.
- Sure, everyone suffers occasionally from a little bad
breath. But what they found in mine was enough to keep my wife away for
- Besides my breath, researchers at Harvard's School of
Public Health examined my blood, hair, urine, toenails and bones. It's
all in the name of the emerging science of body burden, a concept referring
to the amount of chemicals that accumulate in the human body.
- As it turns out, I am polluted. Everyone is to some degree.
But as the list of toxic chemicals identified in people continues to grow,
scientists are trying to figure out what the implications are for human
- "It is alarming," Professor John Spengler says.
"This is not meant to be settling information. I think if more people
wake up to this fact, the better we are going to be . . . and the more
demanding we're going to be of our governments and our industries."
- An estimated 35,000 chemicals are in commercial use in
Canada and more than twice as many in the United States. The national American
government registers an average of 2,000 newly synthesized chemicals each
- Cosmetics have at least 5,000 chemicals; more than 3,200
are added to food. As many as 1,010 chemicals are used in the production
of 11,700 consumer products, and about 500 chemicals are used as active
ingredients in pesticides, according to Environmental Protection Agency
data cited by the Environmental Working Group, based in Washington, D.C.
- Many chemicals end up in the environment, even thousands
of kilometres from industry.
- Despite being banned years ago, PCBs are still found
in Arctic wildlife. Biologists are also finding rising levels of polybrominated
diphenyl ethers (PBDEs), flame retardants used in foam, textiles and plastics,
as well as chlorinated paraffins, chemicals used in paints, sealants and
- Scotchgard, which is part of a family of chemicals used
to make clothes, carpets and furniture stain-resistant, has been found
in polar bears in Alaska and bald eagles around the Great Lakes.
- If chemicals are showing up in wildlife and the environment,
it's no surprise that many are being discovered in people.
- "Pretty much from the minute you wake up to the
moment you go to bed, you're exposed to hundreds and hundreds of chemicals,"
says Jane Houlihan, vice-president of research for the Environmental Working
Group. "...In most cases, they're in minuscule quantities. But that
fact is it's hundreds [of chemicals] and they're adding up."
- What's disturbing, Prof. Spengler says, is how the majority
of the chemicals have been approved for use without any research being
done on their potential impact on human health, except mainly for those
that end up in drugs or food.
- What's more, little is known about what our chemical
body burden truly is. "So measurements like we're doing on you, and
myself, and our research subjects are really part of a new frontier because
it's really trying to understand ... what effects these might have on disruption
of human function," Prof. Spengler says.
- No extensive study has considered the chemical body burden
of Canadians, although separate studies have reported the presence of individual
compounds -- for example, research documenting a dramatic rise of PBDEs
in breast milk.
- More wide-ranging studies have been done in the United
- In one, researchers found at an average of 91 "industrial
compounds, pollutants and chemicals" in the blood and urine of nine
volunteers and a total of 167 chemicals in the group. According to the
research, conducted by Mount Sinai School of Medicine in New York with
the Environmental Working Group, "76 cause cancer in humans or animals,
94 are toxic to the brain or nervous system, and 79 cause birth defects
or abnormal development." None of the people tested worked with chemicals
or lived near an industrial facility.
- "I expected to find many different chemicals,"
Ms. Houlihan says. "But to actually see the numbers roll out that
show that one person has 100 chemicals in their blood at one time. It's
- The most comprehensive research on body burden to date
was conducted by the U.S. Centers for Disease Control and Prevention and
released in 2003. As part of the $6.5-million (U.S.) report, the agency
tested the blood and urine of 2,500 volunteers for 116 compounds, including
PCBs, pesticides, dioxins, furans and metals.
- It found many of the contaminants in at least half of
the people they tested. As well, researchers discovered elevated levels
of lead in the blood of children and the ubiquitous presence of phthalates,
chemicals widely used in plastics that are linked to cancer and reproductive
problems in studies on rats.
- Meanwhile, they also discovered that chemicals such as
DDT and PCBs, which are banned or restricted, appear to be going down.
- "Just because they can [detect it] doesn't mean
it's at a dangerous level or a level that causes health effects. It mostly
reflects the fact that we've improved our ability to measure," says
Jim Pirkle, deputy director of science for the CDC, referring to new technology
that allows scientists to identify compounds in amounts that would have
gone unnoticed a decade earlier.
- Dr. Pirkle notes that most of the chemicals being found
are in infinitesimally small amounts of parts per million and parts per
billion, equivalent to a grain of rice in an Olympic-sized swimming pool.
- "There are going to be small levels of many things
in people. That's because they're dispersed in low levels all over the
environment. What you really have to do is stop and look at them one by
one and go through them and say, 'Is that a level that's likely to cause
disease? Is that a level that's so trivially small, we have good instruments
that can measure it, but it's so small it's not of any concern?' You have
to do that one chemical at a time."
- All this brings us back to Harvard and my own results.
- After bombarding my knee for half an hour with a small
amount of radiation, the technician in the bone lab gives me the news:
My skeleton is contaminated with lead.
- Lead is an acute toxin. It's poisonous at higher levels.
But even at low concentrations, research has linked it to an increased
risk of hypertension, kidney disease, impaired neurological development
in children, even cataracts.
- The good news is my lead levels place me well within
the average range for someone my age with no appreciable health risk, says
Howard Hu, a professor of occupational and health medicine at Harvard's
School of Public Health.
- Others are less fortunate. Dr. Hu has measured lead amounts
five to 10 times higher in many women, posing potential harm to their unborn
- "There's so many different exposure routes that
just living and breathing can provide exposures today," he says. "Lead
is in many different consumer products. It was in gasoline. ... It was
in food cans, pipes and solder. ... It was in toys and plastics."
- In another lab across the street, scientists have clipped
a lock of my hair and are analyzing it. It will tell them how much mercury
my body contains.
- Although it occurs naturally in the environment, mercury
is also a byproduct of coal-fired power plants and waste incinerators.
When it enters the water and reacts with bacteria, it is transformed into
methyl mercury and it accumulates in fish, and people when they eat it.
- It's a neurotoxin and the human fetus is particularly
vulnerable. At low doses, it can cause subtle changes to the developing
brain; at larger doses, it can cause blindness and other birth defects.
At high levels, it can kill nerve cells, causing blurred vision, lack of
co-ordination and slurred speech.
- Fortunately, my mercury level is .411 parts per million,
about half the EPA guideline of 1 ppm.
- Next came my blood results. As it turns out, my blood
contains PCBs and pesticides, including DDT, an insecticide banned in North
America decades ago. But for many people my age, my results are considered
well within the low-to-average range.
- Unfortunately, as Russ Hauser of Harvard's School of
Public Health points out, his research is finding that men exposed to similar
doses have problems with semen quality, which is associated with infertility.
- "PCBs and DDT were banned decades ago, but they're
still present in the environment," Dr. Hauser says. "You're exposed
primarily through intake of food because they accumulate as we move up
the food chain. ... So consuming fish, dairy products, meats, that's primarily
how you're exposed."
- Although the Harvard scientists were looking for arsenic,
a highly poisonous metal, in my toenails, they found virtually none. Prof.
Spengler wasn't surprised, saying it's something they typically find in
people who drink water from a well and mine comes from a lake.
- But he was amazed by something in my breath, the content
of which is an indicator of relatively recent exposure to chemicals in
the air. It wasn't the list of solvents, such as benzene, that are often
associated with vehicle exhaust. It was MTBE, a fuel additive that is not
supposed to be widely used in Canada (less than 2 per cent of gas in this
country contains it, according to Environment Canada). Prof. Spengler speculates
I breathed in MTBE on the way to Harvard in a taxi.
- In total, the scientists found 76 chemicals in my body,
including PCBs, pesticides, solvents and metals. Even though my body contains
extremely small amounts of them, I can't help but ask Prof. Spengler whether
I should be worried.
- "I would say you're not very toxic compared to people
we've measured all over the world, even compared to me," he says.
- He points out that his own DDT levels place him in the
top fifth of Americans. I'm in the bottom fifth.
- "On the one hand, you might say, 'Well, I'm normal.
I might be a little high on one thing and low on another.' But that's not
the way we should look at it."
- Prof. Spengler says the issue is not whether one has
an average amount of chemicals in his body. Rather, it's why the average
person is carrying around so many chemicals in the first place.
- There has been little scientific inquiry into the net
effect of being exposed to many chemicals at the same time, the so-called
"toxic soup effect."
- Complicating the toxicology is the counterintuitive concept
of hormesis, a phenomenon in which a small dose of an otherwise toxic substance
can be helpful. Studies on plants and animals have documented it in alcohol,
antibiotics, hydrocarbons and pesticides.
- Nevertheless, Prof. Spengler and many other scientists
believe that exposure to a range of chemicals in the environment may be
behind a host of emerging health problems in addition to those already
well documented. "We're concerned about the growing rates of cancer
in our society, the growing rates of autism," he says. "In most
developed countries, asthma has grown substantially over the past 20 years,
particularly in children"
- As for myself, Prof. Spengler says there's very little
I can do to reduce the contamination that is already in my body. Aside
from eating different types of fish to lower my mercury level, the PCBs
and pesticides are there for the long haul while the solvents will continue
to show up in my breath as long as I'm exposed to cars and trucks, which
are kind of difficult to avoid.
- Prof. Spengler says the solution is targeting chemicals
we don't want in our bodies in the first place. He points to PBDEs, which
has been referred to as the "PCBs of the 21st century."
- Research commissioned by The Globe and Mail and CTV News
found that many everyday foods consumed by Canadians -- such as salmon,
ground beef, cheese and butter -- are laced with PBDEs.
- In Sweden, the flame retardants were banned after rising
levels were noticed in the breast milk of women. "They said to the
industry, 'We don't want them in our plastics. We don't what them in our
materials' -- and they started to see the levels come down," Prof.
- "Now, you see the similar data out of North American
women. . . . The levels are already 50 times higher in our populations
and nobody is saying, 'Ban that product.' ... So I think this really has
to do with how we've come to judge what is beneficial to the population,"
he says. "[But] at what point do we invoke some precaution?"
- - Mark Stevenson is an independent producer and a regular
contributor to the Discovery Channel's Daily Planet. A version of this
feature has aired on the show.
- MARK'S BODY
- Test results show low levels of 76 chemicals.
Metals in blood*
metal Normal levels (ppb): Mark's levels (ppb):
Lead <100 19.13
Manganese 4.2-16.5 969
Cadmium <5 0.06
Mercury in hair
EPA reference level: 1.0 ppm
Mark's level: 0.411 ppm
Arsenic in toenails
Normal level: below 0.2 ppm
Mark's level: 0.032 ppm
Solvents in breath (nanogram/litre)
- Pesticides in blood
- Mark has 0.879 ppb of DDT (low to average)
- PCBs in blood
- Mark has 0.82 ppb (low to average)
- Lead content in bone
- Mark has 4.67 ppm (average)
- *Lead, cadmium and mercury are not considered "natural"
elements in the body. Manganese, on the other hand, is an essential element
at very trace amounts.
- **MTBE, a fuel additive to improve emissions, could have
been inhaled in the United States where it is much more common than in
- ***The high limonene level could be attributed to orange
juice or air freshener.
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