March 24, 2010

Science Advisory Board Meeting Minutes
DEP, 2nd Floor
March 24, 2010

SAB Members present: David Williams (Chair), Larry Boise (Vice Chair), Hilary Hackbart, Veronica Vieira, Anne Marie Desmarais, Chris Swartz, Robin Dodson, Martha Mittelstaedt

Others present: Heather Tenney (TURI), Liz Harriman (TURI), John Raschko (OTA), Glenn Keith ( DEP), Sean Moynihan (MCTA)

Welcome

Program Updates
· TURI is still planning on moving to Wannalancit, probably in May.
· Liz updated and invited members to the 20th Anniversary Tour site visits happening this spring

Approve January Minutes
The January Minutes were approved with two abstentions.

Chromium
The question is whether we should we split the chromium category so that we can reflect differences in hazard of the different valence states. If that were the case then the thresholds would be 25,000 for each rather than combined. To start we went over the information that had been agreed upon last time:

Chromium 6
· IARC 1
· Mutagen
· Positive Developmental Toxin
· Renal Toxin

Chromium 3
· Doesn’t easily convert to +6
· Doesn’t Bioaccumulate
· Relatively low acute toxicity
· Naturally occurring in soil and rock

Questions remained regarding the likelihood of Chromium 3 converting to Chromium 6, the asthmagen status of each, and the Chromium 4 inhalation study

Chromium conversions:
Chromium 3 does convert to chromium 6 in the natural environment but not easily (2002 Lin)
In the presence of iron it converts back to chromium 3
It is a slow process: a small percent (2%-17% in the lab) converts over several months
The Southwest is a hot spot for conversion to hexavalent chromium. It could convert in a low iron aquifer.
Several percent in aquifer solids can result in lots of hexavalent chromium in the pore fluid [then it can convert back]
Manganese drives chromium 3 to chromium 6. Iron and organic matter drive chromium 6 back to chromium 3, likely faster. If there is much iron then conversion is unlikely.
Chromium 4 inhalation study
Not well cited (1-2 citations). Not significant.
Asthma Status
See below.

Motion: move chromium 6 out of chromium compounds: 6 in favor, 0 opposed

Motion: move chromium 6 for consideration as a Higher Hazard Substance, 6 in favor, 0 opposed
Concerns remain about the transfer of chromium 3 to chromium 6 and asthmagen status

Motion: chromium compounds including chromium 3 be placed in “uncategorized” category 6 in favor
Facilities could use engineering assumptions or lab tests to speciate chromium. Default to Chromium 6 unless shown otherwise.

Asthmagens
We began a discussion on Asthmagens and the AOEC (Association of Occupational and Environmental Clinics) Asthmagen list. To start AOEC’s listing of hexavalent and non hexavalent chromium were discussed along with the papers that AOEC evaluated to make the listing. Then the general AOEC listing process was discussed.

The studies AOEC used were discussed, in particular Park et al, 1994. Speciation is not common. These studies are rather old – next time we need to check for newer studies along with what AOEC used-have they been cited? The Methacholine challenge is controversial. Inhalation challenges are considered the “gold standard”. Irritant is consistent with nuisance- fine particulates.

The public sensor program works with DOL. The Board is interested in having Polly,Molly, or Elise coming to a meeting and explaining the types asthma, prevention, etc. Is the increase in prevalence due to a change in definition?

Decision Making Document
The version that Liz sent around was accepted with changes – 6 in favor. Liz will bring the revised version next time.

Next Meeting
Wednesday, May 19th, 2010 1PM