NYC 9/11 Public Portal Document
Predicting air levels if cleanup is inadequate
Air levels might also be predicted if the cleanup is inadequate. As discussed in my December 6 =
memorandum, the EPA determined that neither conventional nor HEPA vacuum's were capable
of removing significant amounts of asbestos from carpet. Only the wet-extraction HEPA
vacuums removed the asbestos particles which adhere to the carpeting a Even the wet-extraction
HEPA vacuums did not remove all of the asbestos, onlyabout 60%
Thus, the same or similar levels of asbestos could rerr a%n`in the carpets as their were before the . .
cleanup. After cleanup, the air levels. could remain as high as projected in Table 2. The dust in
both of the apartments in the Ground Zero Task Force study (Table 2) was not that thick, only a:'
fine dusting where you could still read the writing on papers on a'table even in the high exposure
building.. This small amount of dust could easily work its way, into the carpet and remain
4
h r (I have been informed that typically, in asbestos abatement, carpeting is removed and discarded
{
~£ z -because of the inability to remove all the asbestos: More documentation on recommendations
and this practice is requested. Information on actually testing or test methods for asbestos
contaminated carpeting is also solicited jenkins.cate@epa gov) a =tix
,{ ? , x ,` ", ,.z fV" `~
,.SAY S
r
CALCULATING TOTAL DOSE FROM ATSDR's a~ ,:
CUMULATIVE EXPOSURE INDEX
Cumulative, or total dose, found by ATSDR to be related to health effect; ' ~~ `
' ; '. _,
.', .. . - . .. .`.. A•A _..;:`~
, _ _..':, s ':ii..
.i yo- .
:.~ f . ..~. ~; r':.'
The Agency for Toxic Substances and Disease Registry (ATSDR) is part of the Centers for
: Disease Control. It develops toxicological profiles in response to the Comprehensives
Environmental Response 'Compensatican, and Liability Act (CERCI:A,'or Superfund) 'These
profiles are subjected to extensive review by the most prestigious scientists as well as being
reviewed and commented upon by affected industries and the public The ATSDR found that the '' .
'cumulative exposure," or total dose, was valid for predicting the probability of suffering health a
}
effects from asbestos. There was no "threshold" or safe level 9 ` t °1
A number of researchers have found that the occurrence of asbestosis and rung cancer correlates (
<. . F, with cumulative exposure (that is, the product of concentration 1PCM fibers/mL] multiplied by
-years of exposure). Therefore, human exposures are expressed below as PCM f-yr/mL ,.
[AJ number of other studies indicate that lung cancer risk is Imearly related to cumulative dose
without any obvious threshold
In other words, it does not matter whether or not you got the same total dose over L snort period -.
of time at higher levels, or a long peric,3 of time at lower levels. The health effects will be the
same. The ATSDR does explain that there is no absolute correlation of the total dose with health
effects, but uses it as a valid method to evaluate health risks.
Table 3 lists some of the "cumulative doses" found by the ATSDR to be associated with asbestos
health effects. The table also gives examples of what the air asbestos levels are required for
different time periods to achieve this dose.
FILE No. A74983669 EXHIBIT #
-7-
NYC-WTC 000125940
OCR can misread numbers and units. Confirm readings against the page image before using them.