A meeting took place at EPA offices on May 8, 2008 between EPA staff and
members of the Policy Navigation Group and Duttko Worldwide relating to
potential regulation of perchlorate at the end of 2008.

Present at the meeting from EPA was:  

Pam Barr, Phil Oshida, Ann Johnson, Eric Burneson and Clifton Townsend

Present from PNG was: 

Jonathan Whitehill and James Rollins 

Present from Duttko Worlwide was:

Max Hamel 

On May 8, 2008 PNG and Duttko representatives met with EPA to determine
what the status was of the Perchlorate Preliminary FRN and to further
discuss their comments (sent via the Perchlorate Study Group) on
perchlorate in the May 1, 2007 Regulatory Determination 2 Preliminary
FRN. 

PNG wanted to know if EPA was still considering using the
Physiologically Based Pharmacokinetic (PBPK) modeling that was discuss
in an earlier meeting on August 16, 2007. Also, did EPA come up with a
Health Advisory (HA) for perchlorate. They reiterated that PBPK modeling
has shown perchlorate is not stored in the body and its behavior is
predictable and National Academy of Science (NAS) was aware of this. 
They continue to acknowledge that neonate and fetus are true sensitive
subpopulations affected by exposure to perchlorate. However, they
believe that children are the least sensitive sub-population exposed to
perchlorate.  PBPK modeling data showed children were less affected by
perchlorate and had only a 0.3% inhibition of iodine uptake. 

EPA stated that PBPK modeling was still an option for use in the
determination of perchlorate and acknowledged that HA’s are needed but
not mandatory. The Administrator can do a HA on any contaminant and that
there was not a rigid timeframe to adhere to. PNG stated that most
groups wanted to see a national standard MCL or at least a HA. If a MCL
is warranted, groups would be accepting however, a HA is
“preferred”.

The discussion then turn to Renal Clearance and/or the homeostasis of
iodine to perchlorate uptake. PNG cited Food and Drug Administration
(FDA) studies that looked at iodine data from infants 0-60 days old. It
was found that these infants were not significantly affected by
perchlorate. The”perfect” example of homeostasis shows that breast
milk that contain high iodine one would find high perchlorate. The
uptake of iodine and perchlorate essentially counteracts any negative
effects of perchlorate due to homeostasis. 

PNG again cited perchlorate exposure to children at 220 ppb having only
a 0.3% inhibition of iodine uptake. They followed this by stating that
FDA studies did not show a substance population with iodine deficiency
in regards to perchlorate exposure in food. PNG then cited a 2005
article by A. Kirk entitled “Perchlorate and iodide in dairy and
breast milk” and stated in the study the amount of perchlorate in
breast milk was inaccurate. When the correct value (amount of
perchlorate in breast milk) is used, it clearly shows the ratio of
perchlorate vs. iodine to be 1 to 1.

To conclude the meeting, EPA asked PNG if they had any studies and/or
textbooks on renal clearance and/or homeostasis to back up there claims.
EPA also stated that the use of PBPK modeling was still an option for
use in determining perchlorate and would be considered. EPA did however
mention that the Perchlorate Preliminary FRN would still come out before
the end of the 2008 calendar year as stated by the AA. 

PNG responded by stating that there were some studies available in
regards to renal clearance and that they would be happy to get EPA those
studies/books. Also, PNG and Duttko Worlwide felt that a National
Standard could be achieved based on the current info cited in meeting or
at best a MCL. However, they also asked could EPA have a “Real
Impact” with a MCL? PNG continued to keep their position from the last
meeting in August 2007 that it is not worth EPA to regulate and/or
create a MCL for perchlorate. It would be a waste of resources to write
a rule on/or regulate perchlorate with few at risk from exposure from
it. PNG again urged EPA to make their decision swiftly, and offered to
help in any way they could.

PNG, Duttko Worldwide, and EPA Meeting – May 8, 2008

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