From: "\"Doc\" Bruce K. Melson" <email@example.com>
New List of Carcinogens May Include Viruses
Inclusion would be a first for government report
By Adam Marcus
MONDAY, July 30 (HealthScoutNews) -- Three viruses are among the list of
nominees for inclusion in the latest list of potential sources of human
The 16 nominations for the Eleventh Report on Carcinogens, due out in 2004,
include two strains of hepatitis -- B and C, which have been linked to liver
cancer -- and human papillomavirus (HPV), which is a leading source of
cervical cancer in women. It's the first time viruses have been proposed for
the report, which comes out every two years.
The report, which Congress established in the 1970s, initially covered only
well-defined chemicals or chemical mixtures. But a mid-1990s review of the
statute creating the report encouraged cancer researchers to open its
membership to other substances or exposures, says Bill Jameson, who oversees
the document for the National Toxicology Program (NTP), a division of the
National Institute of Environmental Health Sciences. The ninth report, for
example, included exposure to sunlight as a known cause of skin tumors.
"The data appears to be very strong that there is an association between
[the proposed viruses] and cancer in man," Jameson says. "I'm sure in the
future there will be others."
Most of the items on the latest list were put there by government
researchers, whose review of the scientific literature turned up at least
the potential for concern. They include: cobalt sulfate, a substance used in
ceramics and electroplating; naphthalene, found chiefly in mothballs and
toilet bowl deodorizers; X-ray radiation and neutrons. Exposure to these
atomic particles is typically trivial, but patients undergoing neutron
radiotherapy and possibly also aircraft travelers and crew may be at
increased risk of cancer.
Also among the nominees this round are occupational exposure to lead and
lead compounds, such as those churned out by smelting facilities, battery
works, steel welding and even firing ranges. Recent evidence suggests that
exposure to high levels of lead may up the risk of brain, lung, kidney and
A private group, the United Auto Workers, has proposed that diethanolamine,
or DEA, make the list. DEA belongs to a group of molecules called
surfactants. These chemicals reduce surface tension of liquids and are used
in a wide range of applications, from detergents and cosmetics to neonatal
intensive care, where they help babies with under-formed lungs breathe. Work
in rodents has shown "clear evidence" that DEA, which the auto industry uses
in metalworking applications, can cause cancer in some mice, the NTP says.
Franklin Mirer, the UAW's director of health and safety and a noted
toxicologist, says, "The data available are from the rodent [test]; however,
there is some indication of increased liver toxicity and liver cancer in
humans" from skin exposure to the substance.
"Metalworking fluids are at the top of our list of health hazards associated
with work for our membership," says Mirer, adding that "thousands" of union
members are probably exposed to DEA on the job. The chemical "is probably
one of five carcinogens that are routinely found in metalworking fluids. In
this case, it's there as something that can be substituted for, or as an
Jameson says suggestions from non-governmental sources are treated the same
as those coming from within the federal envelope. "When we receive a
nomination from outside the NTP, we take it very seriously and usually go
through the effort of putting together a background document to see all the
relevant information," he says. On the other hand, Jameson adds, the
substances and exposures ultimately reviewed are far fewer than the catalog
of chemicals the public proposes.
The list of nominees will now undergo a period of public comment along with
a review by government toxicologists, who will determine the cancer risks,
if any, of each. Those with clear evidence of their harm to humans are
labeled "known" carcinogens, while those with less-certain risks may be
considered "reasonably anticipated" to cause cancer.
The initial conclusions will then become part of a draft report, which gets
circulated throughout other federal agencies. A final version is due to
Congress in 2004.
What To Do
For a complete list of the nominated substances and exposures, visit the
National Institute of Environmental Health Sciences.
To learn more about the toxicology report, check out the National Toxicology
"When the way comes to an end, then change - having changed, you pass through."
Bruce "Doc". Melson