Cancer Prevention Coalition Critiques Risk Proposals

[Patricia Dines <73652.1202@CompuServe.COM>]

Hello all - 

This forwarded email might especially interest people who:
- are interested in the work being done to shift the conversation from "risk
assessment" (RA) to risk prevention, and want to participate in it;
- want to understand more about the issues/problems that can occur with RA;
- see RA as very subject to bias, logic flaws, and scientific unknowns, yet
relied on to set policy;
- are concerned about cancer and the ongoing policy definitions of carcinogens
(if there's a "safe" level or not of one; if non-human data is predictive on
humans; etc.)
- are looking for tangible things to do to improve policy regarding toxics (i.e.
you might want to consider joining the opposition to this draft report).

If you can read past the techno-speak, some important points are made here
regarding the RA mechanisms that allow us to be poisoned at the level we are.
Remember, polluters use their version of "science" to continue polluting - and
to discourage our participation.  Let's not let that work.  Let's learn how to
challenge them on a scientific/logical basis, because there's plenty of flaws
there to point out.

Includes discussion of harm done by incineration pollution.  I like paragraph
toward end that starts "The Commission pays lip service to environmental
justice..." and last paragraph.  Would like to see them bring these points to
the front, to highlight why the rest of their conversation is so important.

If you're interested in this, you can contact their group for more info on what
Commission this is, etc.

P. Dines

-- FORWARD---
From: Rich Winkel, INTERNET:rich%pencil@PSUVM.PSU.EDU
Sender: o-imap@chumbly.math.missouri.edu
To: Patricia Dines, 73652,1202
Date: Thu, Nov 14, 1996, 4:20 PM
Subject: Cancer Prevention Coalition Critiques Risk Proposals

/** headlines: 109.0 **/
** Written 11:29 PM  Nov 10, 1996 by econet in cdp:headlines **
/* Written 10:54 PM  Nov  8, 1996 by cpc@igc.apc.org in env.justice */

Please read the following document.  The Cancer Prevention Coalition (520
North Michigan Avenue, Suite 410, Chicago, IL, 60611, fax: 312-467-0599,
phone: 312-467-0600, email: cpc@igc.apc.org) is organizing community
groups in opposition to the June 16, 1996 Draft Report of the Commission
on Risk Assessment and Risk Management.  The Draft Report is located at
http://www.riskworld.org if anyone is interested.  The critique that
follows is of critical importance so please sign on and return your
organizations name, contact and address information.

Sincerely,

Melissa Troester
Program Director

August 8, 1996

Commission on Risk Assessment and Risk Management
529 14th Street, N.W., Suite 452
Washington, D.C. 20045

                    Response to the June 13th
Draft Report of the Commission on Risk Assessment and Risk Management

We express grave concerns over the June 13, 1996 draft report of the
"Commission on Risk Assessment and Risk Management," which presents "a
unique risk management perspective to guide investments of precious --
resources in -- risk assessment, risk characterization, and risk
reduction."  The Commission's elaborate managerial proposals are fixated
on the assessment and management of risk due to avoidable carcinogenic and
other toxic exposures with minimal recognition of the critical and overdue
need for risk prevention by toxic use reduction.

Of particular concern is the Commission's redefinition of fundamental
principles of carcinogenesis, along lines long advocated by special
interests, as follows: challenging the validity and human relevance of
routine "high dose" carcinogenicity test data; disqualifying the human
relevance of a wide range of carcinogens, many involving large scale human
exposure, on grounds including non-specific experimental "overload"
effects and mechanism differences between rodents and humans; and
classifying carcinogens into "non-threshold" and "threshold." These and
other Commission proposals are scientifically and conceptually flawed:

***The Commission fails to recognize the scientific consensus on the
predictive value of experimental carcinogenicity data to human risk,
irrespective of mechanistic or genetic evidence.  All 23 recognized human
carcinogens are also carcinogenic in experimental animals. For many of
these carcinogens the animal data preceded epidemiological data, in some
instances by decades; for 18/23 of these carcinogens, one or more sites in
humans were predicted experimentally [Rall, D., Ann. NYAS, 534:78-83,1989].

***While repeatedly insisting that many carcinogens "elicit tumors only
at very high doses that are unlikely to be relevant to human exposures,"
the Commission fails to recognize the inherent insensitivity of
carcinogenicity testing.  This reflects the following considerations:
Statistical limitations due to the very small number of animals tested
in relation to the many million humans at risk; the short life span of
experimental animals relative to prenatal and lifetime human exposure;
and the possibility that humans are more sensitive to particular
carcinogens than animals.  In an attempt to reduce such gross
insensitivity, National Toxicology Program bioassays are routinely
conducted at maximally tolerated doses (MTD) and MTD/4.  For those few
carcinogens, dimethylnitrosamine, vinyl chloride and
acetylaminofluorene, whose testing has been extended downwards below
MTD/4, carcinogenic effects have persisted at the lowest levels tested.
Contrary to the Commission, such levels are of environmental relevance.
Furthermore, while challenging the human relevance of "high dose"
routine carcinogenicity tests, the Commission fails to recommend that
dose-response tests on profitable chemicals be conducted by industry at
levels extending down to the environmental.  It may further be noted
that industry routinely relies on "high dose" testing as evidence of
safety for chemicals found to be non-carcinogenic.  << PD NOTE:  GOOD POINT!!
i.e. the tests are fine when they prove we're safe, just not when they say we're
unsafe.... Bad science/logic!!

***The Commission challenges low dose linearity as "inconsistent with a
variety of secondary mechanisms of carcinogenesis. -- Dose response
relationships are chemical-specific and depend on modes of action. --
However, the Commission fails to support its challenge to linearity by
reference to any data on no-effect levels of "threshold carcinogens."
Furthermore, the remarkable advances in our understanding of molecular
mechanisms of carcinogenesis over the last few decades are fully
consistent with linear dose-response extrapolation for all classes of
carcinogens.

***The Commission's emphasis on mechanistic data as prerequisite to the
human relevance of experimental carcinogenicity data excludes a wide
range of carcinogenic industrial chemicals, although these are
recognized as "possible" or "probable" human carcinogens by the World
Health Organization's International Agency on Research on Cancer, and
the National Toxicology Program.  Among these are nitrilotriacetic acid
(NTA) and saccharin, whose carcinogenicity is attributed to non-specific
irritant effects in the bladder; EBDC fungicides such as ethylene
thiourea (ETU), whose carcinogenicity is attributed to excessive
hormonal stimulation of the thyroid; and chlorinated organic solvents
(such as trichloroethylene, perchloroethylene, chloroform and carbon
tetrachloride), whose carcinogenicity is challenged in view of "vexing
problems" in the interpretation of the mouse liver tumors they induce.
Contrary to the Commission, these carcinogens also induce tumors at
other sites besides those alleged to be non-specific.  Illustratively,
NTA induces kidney cancers in rats and mice and adrenal tumors in rats,
saccharin induces thyroid tumors in mice; and trichloroethylene induces
lung and testicular tumors and lymphomas in mice following inhalation
exposure, and kidney tumors in rats following oral administration.
Furthermore, in insisting on the importance of mechanistic data, the
Commission fails to recognize that we still do not know the mechanism of
action of any single carcinogen.

***While stressing the need to recognize multiple and multimedia toxic
exposures, the Commission dismisses the likelihood of synergistic
interaction except at "high dose" occupational exposures.  Growing
evidence indicates the contrary. Illustrative is a recent report that
two pesticides induce effects some 1000 times greater than those
resulting from exposures to either alone (Arnold et al, Science,
272:1489-1492, 1996).

***In its emphatic downgrading of the significance and predictive value
of experimental carcinogenicity data, the Commission fails to recognize
that most carcinogens also induce other chronic toxic effects, such as
reproductive, immunologic, and neurotoxic.  Unlike cancer, in the
absence of a national incidence data base, such effects are poorly
quantifiable, thus masking their causal relation to avoidable toxic exposures.

***The Commission's emphasis on the greater weight of human over animal
data is misplaced and unrealistic.  Epidemiological studies are
generally unavailable for most industrial chemicals in commercial use.
Furthermore, such relatively few available studies are commonly
confounded by inadequate exposure data, sample size and follow-up,
besides other limitations.

***The Commission fails to recognize industry's responsibility in risk
assessment.  While active involvement in cost analysis is encouraged,
scientific participation is ignored.  Industry should be required to
routinely develop microbiological and genetic data as early warning
signals for chemicals in use that are still untested for
carcinogenicity.  Industry should further be required to defray the
costs of carcinogenicity screening of its profitable chemicals, now
unreasonably undertaken by the National Toxicology program at the
taxpayer's expense.  For those carcinogens detected at relatively high
dose levels, MTD and MTD/4, and under challenge for these reasons,
concerned industry should be required to conduct appropriate
dose-response tests at levels extending down to the environmental.
Industry should further be required to conduct valid epidemiological
studies, with detailed exposure data.

***The Commission pays lip service to environmental justice in
recognizing "the disproportionately high (toxic) exposures and adverse
human health effects -- in minority groups and low-income populations."
A revealing Commission solution is "education" of sensitive subgroups
eating contaminated Great Lakes fish, rather than developing strategies
to prevent such pollution at its sources, particularly incinerator and
industry smokestack emissions. In further elaboration of this "blame the
victim" position, the Commission concludes: "Recognition of subgroup
susceptibility does not necessarily result in more stringent regulation.
For example, people allergic to particular chemicals or pet-animal
proteins might modify their exposures or modify their responses (with
medication)."

***A recurrent theme in the Commission's report is the high cost and
"investment of precious public-sector and private-sector resources" in
risk management.  The Commission further insists that the public
"stakeholders" share the burden of pollution abatement with polluting
industries.  Couched as "willingness-to-pay," public tax dollars will be
used as the limiting factor for protection and pollution prevention.  In
contrast, the much higher, but poorly quantifiable, delayed health and
environmental costs of failure to regulate receive minimal emphasis.

***The Commission does well to insist that: "Potential peer reviewers
with clear conflicts of financial interest should be disqualified from
service on peer-review panels that could influence regulatory decisions
related to the products or interest of the organizations."  Such
criticisms also appear relevant to Dr. Gilbert Omenn, Chairman of the
Commission, and to the heavy representation of industry consultants in
the Commission, itself.

***The Commission endorses EPA's April 23, 1996 "Proposed Guidelines for
Cancer Risk Assessment" and further downgrades its public health and
environmental regulatory standards.  The criticisms of EPA's Guidelines
by some 80 public interest, social justice, women's and labor groups,
representing some 10 million citizens nationwide, are even more
applicable to the more radical Commission proposals.

At a time when cancer rates have escalated to epidemic proportions, now
striking more than one in three and killing more than one in four, it is
singularly inopportune for the Commission to seek to roll back
regulation of avoidable exposures to carcinogenic and other toxic
exposures.  It is equally inopportune to focus on promoting risk
management policies, rather than risk prevention based on toxic use
reduction strategies.  The Commission appears unresponsive to the
groundswell of national concern on the losing war against cancer.  Its
report should be unequivocally rejected.

=========================================================
The Cancer Prevention Coalition (CPC)
520 N. Michigan Ave, Suite 410
Chicago, IL 60611
312-467-0600 (p)
312-467-0599 (f)

internet: cpc@igc.apc.org

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
"Working to prevent cancer in our communities"

** End of text from cdp:headlines **

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