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Diesel Technology Forum Statement on EPA Science Panel Review

12 October 2000

Diesel Technology Forum Statement on EPA Science Panel Review Of Diesel Health Assessment Document

    WASHINGTON, Oct. 12 The Diesel Technology Forum today
issued the following statement on the Clean Air Science Advisory Committee's
(CASAC) deliberations on the EPA staff report on the health assessment
document for diesel exhaust emissions.
    "This is a debate about diesel power systems as they performed in the
past, not the clean diesel of today," said Allen Schaeffer, spokesperson for
the Forum.  "The document under review by CASAC is an assessment of studies of
the health effects of exposure to diesel exhaust primarily during the 1950s,
'60s and '70s."
    During the 10 years of this EPA review, diesel technology has progressed
rapidly.  The sharp reductions in diesel emissions achieved in the 1990s call
into question any conclusions based on data from thirty, forty or fifty years
ago.
    The draft Health Assessment Document, considered by CASAC, finds that the
human evidence is not sufficient to support a definitive conclusion that
exposure to diesel exhaust is causally associated with cancer.  The document
concludes -- based largely on studies of workers in jobs with exposure to
diesel exhaust 20 to 40 years ago -- that diesel exhaust is "likely" to be
carcinogenic to humans.
    The EPA's draft document also develops an estimate of the level of diesel
exhaust to which humans may be exposed throughout their lifetime without
experiencing any adverse non-cancer health effects.  "That estimate is more
than three times higher than the actual levels of diesel exhaust typically
found in urban areas," said Schaeffer.
    "The direction of diesel for the future is far more important than this
debate," said Schaeffer.
    The EPA and industry together have been working to reduce diesel emissions
for decades, including more stringent engine standards and cleaner diesel
fuels since 1993, along with increasingly advanced diesel technology engines.
Engine manufacturers and fuel refiners already have cut emissions of new on-
highway engines by reducing fuel sulfur and adopting a range of new
technologies.  Particulate matter has been reduced by 83% and nitrogen oxides
(NOx) by 63% since 1988.  (NOx will be reduced another 38% by 2004.)  A
rulemaking is underway to achieve an additional round of massive reductions to
take effect in 2007.
    EPA and industry also are working together to reduce the emissions of
older, in-service engines through advanced technology.  EPA has announced a
program to retrofit older engines to improve emissions performance.  The
Diesel Technology Forum is playing a central role in this effort, assisting
EPA in identifying good candidates for retrofit and working through the
technical challenges that retrofit entails.