Memorandum on asbestos wipe sampling and cancer risk estimation, December

NYC 9/11 Public Portal Document

Predicting air levels if cleanup is inadequate j-,.?;;.. J

Air levels might also be predicted if the cleanup is inadequate. As discussed in my December- fi- memorandum, the ERA determined that neither conventional norHEPA vacuums were capable - ■J'

of removing significant amounts of asbestos from carpet Only the wet-extraction HEPA vacuums removed the asbestos particles which adhere to the carpeting.’ Even the wet-extraction HEPA vacuums did not remoye all of the ^bestos, only about 60%.; g ;

Thus, the same or similar levels of asbestos could ferr,am in the c^ets as their were before the cleanup. After cleanup, the air levels could remain as high .as projected in Table 2. The dust in ’ X gwis ( both of the apartments in the Ground Zero Task Force study (Table 2) was not that thick, only Y -XX;; ."fine dusting where you could still read me writing oii pap^ on a table even in the hi^ expojs^e ^W^-'^' # V.-7;. r ■ building.. This small amount of dust could easily work its way into the carpet and remain.yf<if5V,

(I have been informed that typically, in asbestos abatement, carpeting is removj^ and discarded because of the inability to remove all the asbestosJ' Moredocumentation on rec6mmeridatibnsX:^<*^J^-« and this practice is requested. Information on actually testing or test methods for asbestos :,

fex 5 contaminated carpeting is also solicited. [email protected]) X.*'.v : ' l ;

;■ CALCULATING TOTAL DOSE FROM h

' CUMULATIVE EXPOSURE INDEX 1 Cnmnlaitive. or total dose, found by ATSDR to be related to health effectsS

, The Agency for Toxic Substances and Disease Registry'(ATSDR) is part of the Centers for- j Disease Control. It develops toxicological profiles in rehouse to the Comprehensives - ‘ Environmental Response, Compensation, and Liability Act (CERCLA, or Superfimd). These •/I?’' profiles are subjected to extensive review by the most prestigious scientists as -well as beings ; reviewed and corrunented upon by affected industries and the; public. The ATSDR found that the

[k. Z1 / “cumulative exposure/’ or total dose, was valid for predicting the probability of suffering health •

; effects from a^estos. There was no “threshold’’ or safe level?.?^-;:;S/:vt^?<Ttn3‘

• A number of researchers have found that the occurrence of asbestosis arid lung cancer correlates' ■ with cumulative exposure (that is, the product of concentration [PCM fibers/mL] multiplied by- - £ ■ • years of exposure).therefore, human exposures are expressed below as PCM f-yr/mL/t ;r ’

[Al number of other studies indicate that king cancer risk is linearly related to cumulative dose withoutany obvious threshold ,•t ' : ■ '

In other words, it does not matter whether or not you got the same total dose over a short period ' - of time at higher levels, or a long period of time at lower levels. The health effects will be the same. The ATSDR does explain that there is no absolute con-elation 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 EXH I BIT # -7-

NYC-WTC_000151641