BUFFALO, N.Y. -- Scientists at the University at Buffalo and the
Chinese University of Mining and Technology/Beijing are tracing a
toxic trajectory of excess fluorine, which may be crippling
millions of people with skeletal fluorosis in a poor, remote
Chinese province.
The disease causes chronic joint pain and leads to muscle
wasting and crippling spine and major joint deformities. Most
often, the source is excess fluorine in polluted water, but in
certain areas in China it comes from coal.
The UB and CUMTB research, focused on Guizhou province in
southwest China, uses an advanced chemical analysis technique, a
specialty of the team, to pinpoint the origin of the excess
fluorine in order to develop ways to minimize exposure. The
technique is being performed using state-of-the-art chemical
instrumentation facilities in the UB Department of Chemistry.
"We need to better understand the chemistry and mechanism of
this exposure," says Joseph A. Gardella Jr, PhD, Larkin Professor
of Chemistry in the UB College of Arts and Sciences. "When the coal
is burned, is excess fluorine released into particulates that are
then deposited on food that people eat, or is it released into the
smoke that people then breathe? And are there other chemicals that
combine with the fluorine to make it even more toxic?"
Several million people are believed to be afflicted with
skeletal fluorosis in China, with as many as a million of them in
Guizhou, which has a population of 14 million. The disease can be
so devastating that it leaves its victims unable to walk; many of
Guizhou's residents also have dental fluorosis, which badly
discolors teeth and which, in some cases, can be a precursor to the
skeletal form of the disease.
Gardella traveled to Guizhou province last year to obtain
samples and to collaborate with scientists at the CUMTB.
He notes that the Chinese government has been proactive in
trying to protect residents, providing villagers with new stoves
with high chimneys in order to improve ventilation. But important
scientific questions remain unanswered.
"The subsurface coal that is mined in Guizhou and sold to power
plants doesn't contain such high fluorine levels," says Gardella.
"It's the coal that the poorest villagers pick up along the road,
which gets mixed with clay and soil that has the high levels.
That's what they use to cook, to heat their homes and to dry
vegetables."
So, with funding from a National Science Foundation Award for
Special Creativity, a special grant award encouraging "high-risk"
research for which scientists do not apply, Gardella has been
working to figure out exactly how fluorine is released from these
chunks of coal.
In 2008, Gardella, one of the world's foremost experts in a
sophisticated chemical analysis method called Time-of-Flight
Secondary Ion Mass Spectrometry (ToF-SIMS), was contacted by
Hangdong Liang, PhD, of CUMTB, who studies fluorosis exposure in
China, and who consults with the Chinese government on resources
and the environment.
Liang, well-versed in earlier versions of the technique, was
interested in learning from Gardella how the power of the newest
ToF-SIMS instrument can be harnessed to discover how the fluorine
is being released from the coal.
ToF-SIMS is well-suited to the research, according to the UB
scientists.
"While other techniques give primarily information about the
elements present in the sample, ToF-SIMS, coupled with scanning
transmission X-ray microscopy, allows us to determine, at the
molecular level, the chemical structure of fluorine-containing
species in the coal," explains Brett Yatzor, a doctoral candidate
in the UB Department of Chemistry, who is working in Gardella's
lab.
"Before we can develop ideas about how the fluorine is released
once it is combusted, and what it might be bound to once it's
released, it's important to first understand the types of fluorine
in its native state," says Gardella.
He notes that imaging techniques, such as scanning electron
microscopy, previously revealed that the fluorine is found in the
clay used as an additive in the mining process and which villagers
add to the coal to make briquettes for burning.
That's why he and Yatzor are using ToF-SIMS to study
cross-sections of coal and coal-clay mixtures, examining its
organic and inorganic composition and its sulfur content and
searching for other contaminants that may be synergistic, making
the fluorine more toxic when it is released.
They also are studying pieces of corn and chili peppers that
villagers have hung to dry over their stoves in order to determine
if they might be a source of the fluorine exposure.
"Our goal is to gather basic information about the chemistry of
the fluorine, what happens to it during combustion and what
chemical structure and reactions lead to the exposure," says
Gardella.
Since beginning the joint research with Liang, Gardella has
traveled to Guizhou, China to obtain samples; he also has given
presentations on the research both in China and in the US and he
has chaired international meetings on secondary ion mass
spectrometry in Canada and China.
This research is the second project for which Gardella has
received an NSF Special Creativity Award; he received the first
such award in 1991, which he used to study and develop new methods
to determine chemical reaction rates at the surfaces of polymer
materials, resulting in the awarding of several patents.
The University at Buffalo is a premier research-intensive public
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York system and its largest and most comprehensive campus. UB's
more than 28,000 students pursue their academic interests through
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the Association of American Universities.