Habitability of the Love Canal Area: An Analysis of the Technical Basis for the Decision of the Habitability of the Emergency Declaration Area: A Technical Memorandum Page: 44
vii, 58 p. : ill. ; 28 cm.View a full description of this report.
Extracted Text
The following text was automatically extracted from the image on this page using optical character recognition software:
of the target substances. Were the detection limits for
each compound sufficiently low and were actual lab
oratory performances sufficiently high to allow a con
clusion that those chemicals not detected would be
present in such low levels as not to pose a threat to
human health? Is the range of variability for MDLs
sufficiently low to be certain that estimates of variance
for absolute concentrations are not within hazardous
concentrations for all target substances? Until MDL
values are reported with estimates of variances for
each, uncertainties about the meaning of none detected
and trace, remain.
What If EPA's Numbers Are Wrong?
Most of the samples in which EPA detected meas
urable amounts of chemicals revealed concentrations
in the ppb range. If those numbers are accurate, the
assumption can be made that the samples in which
only traces of chemicals were detected or in which not
even traces were detected contain even lower concen
trations of chemicals. Looking at the data reported
later in tables C 5 and C 6, it can be seen that if the
trace measurements are in the ppb range, the levels
of chemicals in the EDA are indeed so low as to pose
an acceptable health risk (except for hexachloroben
zene and dioxin).
NBS was asked to comment on the amount of chem
icals that might have gone undetected in EPA's mon
itoring program at Love Canal. NBS was not con
vinced that the absence of detectable levels of chem
icals in the EPA analysis was consistent with concen
trations as low as parts per billion."Instead, it is con
fident that the concentration of a chemical reported
to be below detection is no more than 1 part per mil
lion.
OTA asked officials of DHHS who participated in
making the habitability decision if they would persist
in their conclusion that the declaration area was hab
itable if many chemicals were present in the near 1 ppm
range. The response was that they would stick by their
earlier decision with a demur about certain chemicals.
OTA would not be so sanguine about the safety of
the EDA if the concentration of all or most of the 150
chemicals approached 1 ppm. If the NBS estimate that
the "no detectable limit" might be as high as 1 ppm
is applied to monitoring of drinking water, then every
limit shown on table C 5 would be exceeded in the
EDA. If the conservative NBS estimate is not applied
to drinking water because it is to be expected that
drinking water would be cleaner than other waters and
soils, finding concentrations in the 1 ppm range in"Krammer, op. cit.
other media would still show that contamination of
the EDA was widespread. In that case, the chance of
human exposure would have to be reckoned as sub
stantial.
Some toxic chemicals exhibit "synergism," i.e., the
toxic effect of simultaneous or sequential exposure to
two (or more) chemicals greatly exceeds the toxic ef-
fects predicted from adding together the effects of the
individual chemicals. Without consideration of syn
ergism and with consideration of only additive effects
of chemicals, OTA would not consider the EDA hab
itable if many of the 150 chemicals were present at con
centrations near 1 ppm. For instance, if 10 carcinogens
are present in concentrations such that each one poses
a 1 in 100,000 chance of a person developing cancer,
then the 10 together may pose a 1 in 10,000 risk, which
may well be so high as to be unacceptable. For the very
reason that so little is known about carcinogenic poten
tials and other toxic potentials, OTA would come to
the conclusion that the uncertainties about health ef-
fects from many chemicals being present at near 1 ppm
each would preclude considering the declaration area
to be habitable.
However, it is impossible to interpret the NBS opin
ion as supporting the idea that all chemicals for which
MDLs were reported might be present in concentra
tions near 1 ppm. First, the ability of laboratories to
detect chemicals varies from substance to substance.
The basis of the NBS conclusion, that no concentra
tions higher than 1 ppm would have gone undetected
must be based on consideration of the properties of
the chemicals most difficult to detect and measure.
Therefore, the MDLs for chemicals that are more easily
detectable must be lower, perhaps in the low ppb range
claimed by EPA. The second reason is that there is little
reason to believe that all 150 chemicals monitored by
EPA were actually present in significant amounts in
the Love Canal dump. Therefore, to assume that all
the 150 chemicals could be present at concentrations
of up to 1 ppm poses an immediate question about the
origin of all these chemicals. OTA's concentration on
a subset of chemicals known to be present in the land
fill eliminates the problems associated with assigning
a possible concentration to chemicals that are not pres
ent.
It would be a tedious task for EPA to supply esti
mates of variance to support the contention that all
MDLs were in the low ppb range. However, it might
be a manageable job for EPA to examine the records
for the 16 or so chemicals known to be in the landfill
in significant amounts. Because the argument about
possible health effects hangs on knowing the absolute
concentrations of chemicals in the EDA, further anal
ysis of the EPA data seems worthwhile.
Upcoming Pages
Here’s what’s next.
Search Inside
This report can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Report.
United States. Congress. Office of Technology Assessment. Habitability of the Love Canal Area: An Analysis of the Technical Basis for the Decision of the Habitability of the Emergency Declaration Area: A Technical Memorandum, report, June 1983; [Washington D.C.]. (https://digital.library.unt.edu/ark:/67531/metadc39508/m1/48/: accessed April 23, 2024), University of North Texas Libraries, UNT Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.