ENVIRONMENTAL HEALTH
January 17, 2003
Bright Leaf State Nature Sanctuary
Austin, Texas
Bonnie New, a former trauma surgeon and public health researcher,
and currently an occupational health doctor, director of Beacon
Industrial Health Management and partner in Doctors for Clean
Air, (later broadened and redubbed Health Professionals for Clean Air) spoke on environmental health topics.
She first explained that she understood that Texas EGG members
were most interested in funding of implementation, such as
efforts to influence policy, educate the public, and help
with service delivery, not in supporting basic research. She
also understood that Texas EGG funders were more concerned
with issues where environmental health was a major central
factor: for instance, controversies that touched on lead's
critical effect on children's neurology, instead of climate
change's incidental effect of moving malaria northward. She
also assumed that TEGG members were more engaged with local
environmental health problems, such as ground-level ozone
in Texas cities, rather than schistosomiasis or other water-borne
diseases more common in Africa.
Ms. New suggested that funders would probably be well off
by starting with a good grasp of risk ranking, including factors
such as:
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the severity of the health impact,
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the population affected by the disease,
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the quality-of-life impact on this population,
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the strength of the evidence supporting the connection
between the disease and the suspected cause, and
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the proportion of the health risk attributable to the
environmental problem.
As an example, she said that the severity of the health impact
would hinge on decisions, in the extreme, like whether the
malady was an aorta rupture or a hangnail.
As for affected populations, the basic question is one of
how severe the health burden would be on the entire community.
Beyond that, the affected population issues might break down
-
by genetic predisposition (such as the connection between
breast cancer and the Bricken gene),
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by age (seniors might suffer respiratory problems from
ozone because of other cardiopulmonary burdens they already
carry, while children might suffer from ozone exposure due
to their faster metabolisms, greater time outdoors, etc.),
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by physiological condition (athletes might suffer from
ozone due to greater rates of respiration while running
in polluted areas), and
-
by occupation (migrant farm workers might be hurt by
pesticides due to their direct dousing from aerial spraying
and/or contact with sprayed plants).
Quality of life questions sometimes turn on rather subjective,
perceptual judgements, and sometimes on more definite epidemiological
statistics. Some of these issues arise in cases like asthma
- it's a disease that seldom kills, but widely upsets routine,
and so might be assigned a high quality of life impact. Some
quality of life questions also arise in diseases such as heart
disease or cancer, which tend to come later in life, sometimes
seem less immediate and critical to the general public, and
so might be seen as having a less major quality of life impact.
Decisions about the strength of evidence supporting an environmental
health concern could be made by considering the following:
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The source of the information - is it a reputable author
or institution?
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The methodology of the study - is it a double-blind study,
or only an anecdotal report?
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The frequency of the health problem - is it common enough
a disease to be caused by a variety of background factors,
or is it unusual enough to be ascribed to only one factor?
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The maturity of the study - is this a new, superficially-studied
concern, or something that has been studied thoroughly for
many years, such as second-hand tobacco smoke?
-
Dr. New then encouraged funders to consider risk proportion
as part of a risk assessment. In other words, is this environmental
factor a major, central cause or a minor, peripheral cause
of the problem? Taking antibiotic resistance as an example,
doctors' over-prescription of antibiotics likely holds a
greater proportion of the risk than overuse of subtherapeutic
antibiotics in factory farms.
Dr. New next asked funders to assess exposure:
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There needs to be a route of exposure linking the suspected
environmental health factor and the disease. Proximity,
without more, is not enough - sitting next to a smallpox
container or living next to a creosoting facility is not
sufficient to cause concern. There needs to be some route
of exposure - eating, drinking, touching, or breathing the
smallpox or creosote is necessary.
-
Given some exposure, there then needs to be an adequate
dose (was the concentration of smallpox in the cup or the
amount of phenols in the creosote vat enough to cause harm?),
and a sufficient internal dose (what concentration of smallpox
virus or phenol compounds were found in the blood?).
-
Finally, there needs to be a path effect (PCBs accumulate
in fat, and wouldn't have a path to affect a starving person
in Cameroon), and a functional effect (once present in the
person's body, the chemical would then have to have an effect
on the reproductive, or endocrine, or renal system, etc.).
With all these filters and rating approaches in mind, Dr.
New then reviewed several major environmental health topics.
She focused on several, including air quality, indoor air
quality, water quality, agriculture, genetically engineered
products, radiation and lead.
She feels that air quality is a "huge issue" for
all major Texas metropolitan issues: 100% of the public is
affected, there are numerous susceptibilities, the strength
of the evidence is high, and the risk of asthma, birth defects,
and stroke, from ozone alone, is high. She noted that it's
recently been shown that high levels of ground-level ozone
not only make asthma worse, but can actually cause asthma,
which is often a permanent condition.
Regarding indoor air quality, she saw little about radon
to be concerned about. Most radon problems are restricted
to New England and to a small belt of north Texas, where levels
of radon in the underlying subsoil and rock are unusually
high. However, Dr. New felt that second-hand tobacco smoke
was a significant concern, with strong medical research to
back up control efforts.
Considering water quality, Dr. New concedes that untreated
sewage in coastal areas can cause hepatitis A, but she argues
that this is a well-understood and diminishing problem, as
point-source treatment improves. On the other hand, she is
somewhat concerned about non-point pollution caused by surface
runoff, which is a major problem that is poorly regulated,
though she felt that there was little major health impact.
In agriculture, she recognizes the concerns over farmworker
exposure to pesticides, but believes that the exposure of
homeowners to RoundUp is less appreciated and protected against.
Dr. New then discussed genetic engineering, which did give
her pause for the possible crossovers among fields, and for
the toxicity of engineered crops to predators and pollinators.
On the other hand, she did not see a large risk for humans
to develop new allergies to engineered proteins - she believes
that our enzymes will break down these new proteins and render
them safe.
She believes that radiation of food is safe and has gotten
too much unearned concern and attention. She explained that
radiation kills bacteria on food, but does not make consumers
"hot".
She sees a more significant risk in bacteria from agriculture,
including e. coli strains, sludge from factory farm lagoon
overflows, and runoff from fields where biosolids are applied.
Likewise, she feels that lead in the environment, particularly
in old paint, is a major concern which can cause neurological,
cardiac and renal problems, particularly in children, and
often in poor and minority children in poorly maintained buildings.
She had less confidence in larger environmental justice claims,
believing that living next to a hazardous facility does not,
alone, make for an exposure, and also believing that many
health problems in minority communities may be due to causes
unrelated to industry, such as Hispanic women's dislike of
mammograms or poor people's lack of insurance or a vehicle
to get access to a clinic.
She concluded with a discussion about the risk of radiation
from a nuclear facility. She felt that a release from an accident
could cause severe impacts, but it was difficult to identify
the risk of a release.
Questions and Answers
Q: Are there useful websites to learn more about environmental
health? Dr. New said that there were, and later supplied
the following URLs:
Q: Please describe the group, Doctors for Clean Air.
Dr. New explained that it was an informal group under
the wing of Environmental Defense that was focusing on casting
Houston's air quality as a health problem and attempting to
organize presentations by doctors to the general public and
decisionmakers.
Q: Please explain the judgement on fluoride treatment
of water: whether it was a good or bad idea? Dr. New
felt that it was undoubtedly useful, and considered fluoridation
opponents to be like those who denied vaccinations for their
children. |
Discussions we have held
with experts in various Texas environmental areas:
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