The Toxicologist - Society of Toxicology

elevant in vivo exposures to determine if WTC dusts caused adverse outcomes in
respiratory function & provide a tool hereafter for the generation of (and host exposure
to) larger particle fractions.
1260 SENSING OF THE CYANIDE METABOLITE 2, 4
AMINOTHIAZOLINE CARBOXYLIC ACID WITH
SURFACE ENHANCED RAMAN SPECTROSCOPY –
STEPS TOWARD A PORTABLE SENSOR.
D. E. Thompson 1 , A. Parbatani 1 , T. Tessema 2 , A. Meyers 1 and I. Petrikovics 1 .
1 Chemistry, Sam Houston State University, Huntsville, TX and 2 Chemistry, Villanova
University, Villanova, PA.
Portable field detectors of cyanide intoxication would be useful in triaging victims
of fires on location. We have assembled a surface enhanced Raman spectrometer
(SERS) that uses expanded beam sensing to monitor the presence of the cyanide
metabolite 2,4 aminothiazoline carboxylic acid (ATCA). This is a spectrometer that
is built on a laser table, but which has the potential to be miniaturized for portability.
The film-over-nanosphere and nanoprism array sensing surfaces on which
ATCA is detected were produced using evaporation induced self-assembly of polystyrene
spheres on glass followed by gold deposition. The detailed design of the
spectrometer is explained. Specific attention is given to the elements of the spectrometer
design that are targeted at achieving a detection limit for ATCA in the biologically
relevant nM range. Scanning electron and optical microscope images
characterize the SERS sensing surfaces on which ATCA is detected. Preliminary
SERS spectra of aqueous ATCA solutions, collected using a 785nm pump laser,
demonstrate promising proof-of-principle for the method.
1261 BTEX SERUM LEVELS IN THE GENERAL U.S.
POPULATION: AN ANALYSIS OF THE 2003-2004
NHANES DATASET.
J. D. Urban, L. Fitzgerald, B. Burkhalter, D. Staskal-Wikoff, M. Harris and L.
Haws. ToxStrategies, Inc., Austin, TX.
Benzene, toluene, ethylbenzene and xylenes (BTEX) are volatile organics compounds
that are commonly found in many solvents and petroleum products.
Although BTEX compounds are rapidly metabolized and eliminated in the human
body, persistent exposure can result in a measurable internal dose. The National
Health and Nutrition Evaluation Survey (NHANES) gathers data on a host of
chemicals found in the general public and, as such, are useful for interpreting data
gathered during exposure investigations designed to assess whether particular individuals
are being exposed to chemicals in their environment. The objective of this
investigation was to derive serum reference values for the national population using
BTEX serum concentration data (ng/ml) from the 2003-2004 NHANES dataset.
Weighted summary statistics were calculated for BTEX serum levels using
NHANES subset-specific 2-year weights. Data were evaluated by several demographic
variables including gender, age, and ethnicity, as well as by smoking status
based on two biomarkers for smoking [2,5-dimethylfuran (DMF) and cotinine].
Consistent with prior analyses of earlier NHANES datasets, data distributions for
all compounds were right-skewed. m/p-Xylene (median: 0.13, range: 0.02-5.6) and
toluene (0.1, 0.02-9.0) had the highest serum levels, followed by benzene (0.03,
0.02-1.4), o-xylene (0.03, 0.02-1.5), and ethylbenzene (0.03, 0.02-1.6). No significant
trends were noted when serum concentrations were evaluated by demographic
variables. However, smokers had elevated mean and median serum levels for all
compounds except o-xylene regardless of the smoking biomarker. While historically
cotinine has been the standard smoking biomarker, DMF is now believed to be a
better measure of smoking because it is a direct by-product of tobacco smoke. We
found serum BTEX levels in smokers were higher when using DMF as the biomarker
for smoking activity regardless of statistic (mean, median, 95th percentile).
In conclusion, these summary statistics are useful reference values for investigators
assessing exposures to BTEX compounds.
1262 PROFILING THE INTERNAL DOSE OF REACTIVE
AGENTS AND THEIR METABOLITES USING N-
TERMINAL VALINE ADDUCTS.
S. Goel, N. I. Georgieva, M. Thompson and G. Boysen. Environmental and
Occupational Health, University of Arkansas for Medical Sciences, Little Rock, AR.
Humans are constantly exposed to various mixtures, such as tobacco smoke, auto
exhaust, and other environmental and occupational pollutants, containing several
thousand compounds, including many known carcinogens. DNA and protein
270 SOT 2011 ANNUAL MEETING
adducts are well established biomarkers for the internal effective dose and are an integral
part of science-based risk assessment. Technical limitations, however, have
prevented comprehensive assessment of a broad spectrum of different adducts simultaneously.
Consequently, most studies have focused on determination of abundant
individual or a selected few adducts. These studies have produced valuable insights
into metabolism of individual carcinogens, but they are insufficient in
providing accurate data needed for assessment of the risk posed by exposure to mixtures.
To overcome this limitation we present herein a sensitive and specific method
for quantitative profiling of a broad spectrum of reactive compounds or their
metabolites using hemoglobin adducts as surrogate biomarkers. The reported
method is based on our previously established immunoaffinity liquid chromatography–tandem
mass spectrometry (LC-MS/MS) method. To enable simultaneous
quantitation of a broad spectrum of N-terminal valine adducts the immunoaffinity
chromatography was modified and adduct profiles were obtained by full scan mass
spectrometry. The method has been validated with in vitro treated human and
mouse globin. Subsequently the method was applied to generate exposure profiles
from various rodent inhalation studies. This novel concept enables determination
of the internal doses of several carcinogens simultaneously to better understand the
behavior of individual compounds in mixtures, identify novel, uncharacterized
alkylating agents, elucidate potential compound–mixture interactions, and generate
more comprehensive exposure data needed for accurate risk assessment of exposure
to mixtures.
1263 EVALUATION OF AIRBORNE TOXICANT
CONCENTRATIONS FROM THE DEEPWATER
HORIZON OIL SPILL.
J. Keenan 1 , H. Avens 2 , K. Unice 3 and D. Paustenbach 1 . 1 ChemRisk, San
Francisco, CA, 2 ChemRisk, Boulder, CO and 3 ChemRisk, Pittsburgh, PA.
The Deepwater Horizon oil spill in the Gulf of Mexico has surpassed the Exxon-
Valdez oil spill as being the largest in U.S. history. Oil recovery and remediation
workers are potentially exposed to volatile toxicants while on boats on or near oil
spills. These volatile toxicants include, but are not limited to, benzene, ethyl benzene,
toluene, and xylene. British Petroleum (BP) has made tens of thousands of IH
samples available for review. Each measurement had an associated job/task/location
descriptor assigned by BP which were not consistent in their terminology and were
not readily useful for doing an analysis. In order to analyze this large dataset and to
determine if specific jobs, tasks, or locations were associated with higher chemical
concentrations, the available BP data was grouped into 35 new task categories that
described approximately 25% of the data. The task categories include actions such
as deploying boom, applying dispersants, taking water samples, and performing
skimming operations. Task categories were grouped into a lower, middle, and upper
exposure level for each chemical. The vast majority of the data were in the middle
group which comprised the task categories whose geometric means were within half
to two-fold the geometric mean for all the data. The analysis revealed that measurements
did not vary significantly from task to task and most measurements were low.
The geometric means for the middle level exposure group were 7.7 (+/- 1.6), 26
(+/- 2), 26 (+/- 2), and 63 (+/- 2) ppb for benzene, ethylbenzene, toluene, and xylene,
respectively. These data will be used to evaluate a simple model for characterizing
airborne toxicant concentrations resulting from a continuous deepwater release
of oil.
1264 IDENTIFYING AND COMMUNICATING EXPOSURES
AND HEALTH RISKS FROM MICROCONSTITUENTS
AT BIOSOLIDS LAND APPLICATION SITES.
V. B. Mylavarapu 1 and P. V. Cline 2 . 1 EE&S, CH2M Hill, Orlando, FL and 2 EE&S,
CH2M Hill, Gainesville, FL.
Land application of biosolids is a technology considered by EPA as the option that
promotes beneficial reuse while causing least harm to the environment. Public
health concerns are raised about exposures to residual microconstituents in soil,
groundwater and surface water. This case study addressed concerns of nearby residents
where biosolids were land farmed for over 25 years. The biosolids were from
domestic wastewater, hospitals and a large university. The residents attributed occurrence
of thyroid cancer and reproductive abnormalities of farm animals to exposures
to dust and groundwater contaminated with pharmaceuticals/endocrine disrupting
chemicals land applied biosolids. In response, a sampling strategy was
developed to identify and analyze chemical residues in biosolids. A commercial laboratory
with validated protocols was selected for analyzing hormones, pharmaceuticals,
and industrial endocrine disruptors. The results were compared against concentrations
at other sites and toxicity data. Majority of the chemicals analyzed did
not have toxicity factors from EPA or other published sources. For example only 5
out of 35 chemicals selected for analysis had peer reviewed toxicity factors. A subset
of the 35 chemicals was selected to allow sample numbers within budget, accom-