Document ID: EPA-HQ-OPP-2009-0687-0015
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2009-11-30T05:00Z

Suggested References by Panel Members 

1.  Roberta L. Grant, Bernard J. Kadlubar, Neeraja K. Erraguntla,
Michael Honeycutt. 

Evaluation of acute inhalation toxicity for chemicals with limited
toxicity information

Regulatory Toxicology and Pharmacology 47 (2007) 261–273

Abstract

−5. For a chemical with limited toxicity information, this composite
factor is multiplied by a 4-hour LC50 value or other appropriate acute
lethality data. Both approaches can be used to produce an estimate of a
conservative threshold air concentration below which no appreciable risk
to the general population would be expected to occur after a one-hour
intermittent exposure.

2.  Honaganahalli, P. and J.N. Seiber.  Measured and predicted airshed
concentrations of methyl bromide in an agricultural valley and
application to exposure assessment.  Atmos. Environ.  34 (2000)
3511-3523

Abstract

A field study was conducted in September 1995 to measure the ambient
atmospheric concentrations of methyl bromide (MeBr) in the Salinas
Valley, California. Air concentrations of MeBr were measured at 11 sites
located on the adjacent mountains, valley floor and at the Pacific Ocean
coast over a 4-d period. The concentrations ranged up to 8.98 lg m-3.
Industrial Source Complex Short Term 3 (ISCST3) and CALPUFF dispersion
model simulations were performed with several fumigated fields serving
as sources, using two estimates of source strengths from published flux
values. CALPUFF was driven by 3D meteorology from CALMET. With the lower
of the two estimates, the ISCST3 model under predicted concentrations
for 76% of data and averaged 66% of measured, and the CALPUFF model also
under predicted concentrations for 67% of observations and averaged 84%
of measured. With the higher of the two estimates the ISCST3 over
predicted by a factor of two for 67% of data, and CALPUFF over predicted
concentrations by a factor of 1.6 for over 50% of data. Between the
model predicted and measured concentrations, the coeffcient of
determination, R2, was was approx. 0.7 for both source strengths with
ISCST3 model. The R2 with CALPUFF model was 0.55 and 0.82 with source
strength estimated from two prior flux studies. The margin of exposure
(MOE) for the population of the city of Salinas was calculated based on
the measured ambient concentrations and compared with the current
benchmark used by US-EPA and California Department of Pesticide
Regulation for acceptable human health risk. Based on the models
predicted worst-case exposure concentration, the MOE for acute effects
was approximately 10,000. For chronic effects it was approximately 100,
indicating a need for attention to exposure to MeBr in areas of intense
methyl bromide use.

3. Monique A.J. Rennen, Tialda Bouwman, Annette Wilschut, Jos G.M.
Bessems, and Cees De Heer.  Oral-to-inhalation route extrapolation in
occupational health risk assessment: a critical assessment. Regulatory
Toxicology and Pharmacology 39 (2004) 5–11

Abstract

Due to a lack of route-specific toxicity data, the health risks
resulting from occupational exposure are frequently assessed by
route-to-route (RtR) extrapolation based on oral toxicity data. Insight
into the conditions for and the uncertainties connected with the
application of RtR extrapolation has not been clearly described in a
systematic manner. In our opinion, for a reliable occupational health
risk assessment, it is necessary to have insight into the accuracy of
the routinely applied RtR extrapolation and, if possible, to give a
(semi-)quantitative estimate of the possible error introduced.
Therefore, experimentally established no-observed adverse-effect-levels
for inhalation studies were compared to no-adverse-effect-levels
predicted from oral toxicity studies by RtR extrapolation. From our
database analysis it can be concluded that the widely used RtR
extrapolation methodology based on correction for differences in
(estimates of) absorption is not generally reliable and certainly not
valid for substances inducing local effects. More experimental data are
required (from unpublished data or new experiments) to get insight into
the reliability of RtR extrapolation and the possibility to derive an
assessment factor to account for the uncertainties. Moreover, validated
screening methods to predict/exclude the occurrence of local effects
after repeated exposure are warranted. Especially, in cases where
chemical exposure by inhalation or skin contact cannot be excluded
route-specific toxicity studies should be considered to prevent from
inadequate estimates of human health risks.

4.  Martha E. Harnly, Asa Bradman, Marcia Nishioka, Thomas E. McKone,
Daniel Smith, Robert McLaughlin, Geri Kavanagh-Baird,
Rosemary Castorina, and Brenda Eskenazi.   HYPERLINK
"http://pubs.acs.org/doi/full/10.1021/es9020958?cookieSet=1" \l "afn2"  
 Pesticides in Dust from Homes in an Agricultural Community. Environ.
Sci. Technol., Article ASAP. DOI: 10.1021/es9020958. Publication Date
(Web): October 30, 2009.

  HYPERLINK "http://pubs.acs.org/doi/abs/10.1021/es9020958" \t "" 
http://pubs.acs.org/doi/abs/10.1021/es9020958 

Abstract

 49% increases, respectively, in dust concentrations for each kg applied
per day, near participant homes, in the month or season prior to sample
collection. However, agricultural use of diazinon, which was 2.2 times
that of chlorpyrifos, and of permethrin were not significantly
associated with dust levels. Other variables independently associated
with dust levels included temperature and rainfall, farmworkers storing
work shoes in the home, storing a diazinon product in the home, housing
density, having a home less clean, and having an air conditioner.
Permethrins, chlorpyrifos, DCPA, and iprodione have either a log
octanol−water partition coefficient (Kow) greater than 4.0, a very low
vapor pressure, or both. Health risk assessments for pesticides that
have these properties may need to include evaluation of exposures to
house dust.

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