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- [Voiceover] Arsenic has been known
to be acutely toxic for millennia.
If you take it at 700 parts per million in the water
then it will certainly kill you moderately quickly.
But what was not known until fairly recently
is continuous use at very low doses can be very bad,
and that means continuous, daily ingestion.
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You know, arsenic's a very common element
in the Earth's crust, it's number 20 or something like that.
And the question is how do you get it inside,
and it's coming mostly through water.
- The reason that's important for example, in New England,
is maybe one quarter of all the peoples wells
in New England have levels of arsenic
that we might think of as not being safe.
- We have estimated that about 2.3 million people
in New England use private wells
as their source of drinking water,
and in some states like Maine and New Hampshire,
that's about 40 percent of the population.
- New Hampshire law does not require water testing
at private homes nor quantity requirements at private wells.
- Low dose arsenic exposure has been associated with
skin cancer, bladder cancer, particularly in smokers
and possibly lung cancer.
- That's why it's particularly important
for private homeowners with wells
to test their wells periodically
and to take action to protect their family.
- [Jane] In 2001 EPA revised their drinking water standard
for arsenic to ten parts per billion,
and that was done after many months and years
of extensive testing and research.
- The drinking water standard in the United States,
for the levels that we used to
think were safe was 50 parts per billion.
Which sounds like a really tiny number and it is.
It's 50 micrograms which is one millionth of a gram
for every litter of water,
so it's a really, really tiny amount.
And yet, we now know from epidemiology studies
that that level is not safe, that if you drink that level
for a lifetime your disease risk is pretty substantial.
- With the previous arsenic drinking water standard
of 50 parts per billion, it was thought that
the cancer risk was as high as 1 in 100.
Meaning 1 in 100 people drinking arsenic at
50 parts per billion would develop cancer.
- Normally for man-made contaminates,
the acceptable risk rate for pesticides, herbicides,
fuels, industrial solvents is one in a million.
- We now have laboratory studies
and some emerging epidemiology studies that suggest
that ten is not safe either,
that we're seeing health effects
at as low at ten parts per billion.
- So we're really interested in looking at these low levels
and what's happening so sort of asking the question
of how low is low enough for an
appropriate drinking water standard.
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- Overwhelmingly the evidence that we have suggests that
the arsenic we see in ground water originates
from natural sources in the minerals
and the rocks of the region.
Apparently there's two main factors that control
whether arsenic ends up in your ground water
and that's having some arsenic in the rocks as a source
but also having the right geochemical conditions,
and in New Hampshire that equates
to having water that's relatively high PH
and water with relatively little dissolved oxygen.
Those two factors together result in
high arsenic concentrations in water.
- [Ben] In the world today, in Asia alone
about 100 to 120 million people suffer from
arsenic related illnesses.
- [Joshua] How arsenic causes disease is the
big 64 thousand dollar question.
Nobody really knows the answer to this.
What we do know is that arsenic
doesn't behave like any other chemical we know.
- My research focuses on the effects
of low dose arsenic exposure on the immune system,
particularly the immune system within the lung.
What we've done is we've developed a mice model
in which we've exposed mice to arsenic
in their drinking water at 100 parts per billion
for five weeks.
100 parts per billion is not an uncommon
level of arsenic to find in areas of New England
such as New Hampshire and Maine.
Following that exposure we infected the mice
with a sublethal dose of Influenza A,
an H1N1 strain of flu,
and what we found was that the mice
exposed to arsenic had an increased susceptibility
to infection and they also had an increased
severity of infection,
resulting in a severe morbidity observed
in those arsenic-exposed mice.
In theory there would be a dose threshold
in which we would expect no effects for arsenic exposure.
The problem is is that we don't
really understand what that dose would be.
We've certainly seen effects following arsenic exposure
at 10 pbb or even lower.
- In my laboratory we've seen effects
on endocrine disruption and some other endpoints
that we measure at below one part per billion.
So now we're talking about parts per trillion,
which is a hard number to even think about.
- The question remains as to whether or not
these effects are biological effects
or toxicological effects,
meaning do they have an adverse effect
on human health or not.
- And so the issue is one to educate the homeowner on
in terms of the importance of having
a comprehensive water quality test.
- I go to the state, I get a little decanter, free,
and the tests cost 10 to 15 dollars.
- The liquid is sprayed into the instrument and it goes
into the inductively coupled plasma,
which is a hot ionized gas.
It's 7,000 degrees which is hotter
than the surface of the sun.
So the sample basically is desolvated,
you loose all the water.
The molecules are broken up into the chemical elements.
Those elements are extracted into the mass spectrometer.
Then the mass spectrometer basically
counts the atoms of any particular element.
So we determine the element by its unique mass
and we count the number of atoms in that sample,
and that's how they determine concentration.
- It takes maybe two weeks to get the results back.
It's a pretty easy process, in and out.
There are various ways to remediate arsenic
and they're pretty inexpensive for a household like ours.
- [Bernie] There are two different sizes
of water treatment devices.
One is called whole house and would deal
with approximately 200 gallons of water each day.
The other is called point of use, and would only deal
with water that one would consume each day.
- It's not thought that dermal exposure,
such as you would get in the shower is such an
immediate concern when compared
to ingestion through the drinking water.
- We actually got ours at Sears,
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and had a plumber come and put it in underneath the sinks.
I think you can put them in yourself though.
- At the USGS in New Hampshire our primary responsibility
is to provide impartial science information
on the nations water resources.
We know from our studies that certain parts of the state
have 30 percent of wells where
we see arsenic concentrations exceeding 10.
By zooming in and looking more closely at specific geology
we see some places where every other well
has arsenic greater than 10.
- If arsenic is in a city water supply,
the city takes care of it, generally, and at least
tells you if there's a problem.
If you have your own water in your own well,
the city doesn't have to do that.
In fact, it's your own responsibility to take care of
and figure out what that arsenic concentration is.
- So really the bottom line is that
everybody has to test their well.
There's no predictive power.
It doesn't matter whether your neighbor
does or doesn't have arsenic, each well is individual
and has to be tested individually.
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