- The National Toxicology Program, headquartered
at the National Institute of Environmental Health Sciences, has announced
the addition of 14 substances,including several diesel combustion products,
to the 184 already included in the federal governmentís official
list of known or "anticipated" human carcinogens. The 14 new
substances, as well as one reclassified substance, will appear in the Eighth
Report on Carcinogens, a Congressionally mandated report to Congress.
- Kenneth Olden, Ph.D., Director of NTP
and NIEHS, said, "The report identifies public health hazards but
does not in-and-of-itself restrict substances. Never-the-less, regulatory
agencies and Congress take note and may take action in cases where the
substances are not already regulated.
- "The report," he continued,
"is not necessarily a condemnation, in that some substances such as
the newly listed transplant drug cyclosporin have health benefits, when
properly used, that can far exceed their potential risk."
- Cyclosporin's labeling already calls
attention to studies indicating a potential cancer risk. The drug is used
to help prevent rejection of a transplanted kidney or other organ by its
- A second prescription drug for a life-threatening
condition, thiotepa, is also newly listed as a known human carcinogen.
It was previously listed as an anticipated human carcinogen.
- The Report on Carcinogens is prepared
by the National Toxicology Program, which is headquartered at the National
Institute of Environmental Health Sciences in Research Triangle Park, N.C.
The reports are prepared with the help of NIEHS and NTP-participating
agenciesóthe National Cancer Institute, the Food and Drug Administration,
the National Institute for Occupational Safety and Health, the Environmental
Protection Agency, the Agency for Toxic Substances and Disease Registry,
the Consumer Product Safety Commission and the Occupational Safety and
Health Administration, as well as the NTP's Board of Scientific Counselors.
- Newly listed as KNOWN human carcinogens:
- CYCLOSPORIN, an immunosuppressive drug.
- THIOTEPA, a drug used to treat lymphomas
and tumors of the breast and ovary. It has also been used at high doses
in combination chemotherapy with cyclophosphamide in patients with refractory
malignancies treated with autologous bone transplantation.
- Newly listed as Reasonably ANTICIPATED
to be Human Carcinogens:
- AZACITIDINE, a drug used to treat acute
- p-CHLORO-o-TOLUIDINE and its HC1 salt,
used to produce azo dyes for cotton, silk acetate and nylon and as intermediate
in production of Pigment Red 7 and Pigment Yellow 49. Also an impurity
in and metabolite of the pesticide chlordimeform.
- CHLOROZOTOCIN, a drug used to treat cancers
of the stomach, large intestine, pancreas and lung; melanoma; and multiple
- DANTHRON, or dantron, a laxative removed
from the market several years ago when tests were published indicating
it caused cancer in laboratory animals. It is also an intermediate in
the manufacture of dyes.
- 1,6-DINITROPYRENE. No commercial uses
but is detected in ambient atmospheric samples and as a constituent of
- 1,8-DINITROPYRENE. Also in diesel exhaust
and air samples.
- DISPERSE BLUE 1, used as an anthraquinone-based
dyestuff in several semi-permanent hair dyes and also in coloring fabrics
- FURAN, used as a chemical intermediate
in the synthesis and production of other organic compounds.
- O-NITROANISOLE, used as a precursor in
the synthesis of o-anisidine which is used in the manufacture of more than
100 azo dyes.
- 6-NITROCHRYSENE. Not used commercially,
but detected in ambient atmospheric samples.
- 1-NITROPYRENE. Not used commercially,
detected in ambient atmospheric samples and as a constituent of diesel
- 4-NITROPYRENE. Not used commercially,
detected in ambient atmospheric samples.
- 1,2,3-TRICHLOROPROPANE, used as a polymer
crosslinking agent, paint and varnish remover, solvent and degreasing agent.
It has also been detected in drinking and ground water in various parts
of the United States.
- The newly listed substances have been
through three scientific peer reviews, one of which was by a subcommittee
of the NTP Board of Scientific Counselors in an open meeting with comment
provided from industry and public interest groups and there was a period
for public review and comment.
- George Lucier, Ph.D., director of the
Environmental Toxicology Program at NIEHS, said, "A great many scientists
have worked on the studies and reviews that produced this document, which
is an important part of our national effort to protect the public from
potentially dangerous exposures."
- The Report on Carcinogens Summary is
accessible now from the NIEHS Environmental Health Information Service
at: http://ehis.niehs.nih.gov/ or from the NTP Home Page at http://ntp-server.niehs.nih.gov/
- Printed copies of the report in full,
or the summary (which contains the same information except for information
on related regulations by regulatory health agencies) will be available
later. Either can be ordered by contacting the NIEHS Environmental Health
Information Service (EHIS) 1-800 315-3010, Attn: Order Processing, P.O.
Box 12510, Research Triangle Park, NC 27709-2510, fax number (919) 541-0763,