A Second Look at Methanol
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The optic nerve and eye are methanol targets. Scientists are now looking at other potential targets. |
Responding to the mandate of the amendments to the Clean Air Act, the federal government, the auto industry, and other groups are looking to develop cleaner fuels such as methanol. Although the risks to humans of blindness and death associated with ingestion of methanol (usually in the form of "wood alcohol") have been known for some time, the increasing interest in its development as an alternative fuel has prompted scientists to consider the potential health effects of methanol inhalation.
In the body, methanol is metabolized to formate, which becomes toxic at high concentrations. Formate is then detoxified to carbon dioxide. Preliminary studies conducted by scientists at the Chemical Industry Institute of Toxicology, which analyzed formate levels after methanol exposure, indicate the risk to most people would be minimal. In one study monkeys were exposed to concentrations of methanol from 200 ppm (the threshold limit value or TLV; the TLV is the maximum exposure recommended for humans in the workplace) to 2000 ppm for 6 hours. Results showed that formate levels in the blood were no greater than normal levels.
A subsequent study was conducted using radioactive methanol to distinguish between formate due to methanol exposure and formate normally found in the body. Preliminary results indicate that the maximum blood formate concentrations due to methanol exposure at or below the TLV were 100 to 1000 times lower than normal formate levels and 1000 to 10,000 times lower than toxic levels of formate. These data suggest that the body is efficient in removing formate resulting from inhalation of low levels of methanol. Consequently, exposure to methanol at the TLV should not pose an unacceptable risk in healthy individuals.
There is, however, evidence indicating that the developing fetus may be at a much greater risk for adverse health effects from maternal inhalation of methanol. A recent report in Teratology (volume 47) suggests that exposure to high levels of methanol may cause birth defects in pregnant rats. It is unclear whether the defects are a direct result of methanol, formate, or some other metabolite. If the defects are due to methanol directly, studies of formate levels may not provide an accurate measure of inhalation risk.
If, in fact, formate is found to be the culprit, its effects on pregnant women may be exacerbated by folic acid deficiencies in these women. Folic acid, found in foods such as broccoli and spinach, is a critical cofactor in detoxification of methanol. In the absence of folic acid or in cases of folic acid deficiency, formate accumulates in the blood, causing a pH imbalance which can cause toxicity. An article published in the New England Journal of Medicine (volume 327, December 1992) estimated that at least 15 to 30% of pregnant women in the United States and Europe, and as much as 50% of pregnant women in India, have some form of folic acid deficiency due to an increased rate of folic acid breakdown during pregnancy. Scientists at CIIT plan to study whether inhalation of methanol poses a health risk to these individuals. Says one CIIT scientist of methanol exposure, "We still need to examine the issue for potentially sensitive individuals so that we don't trade one form of risk for another."
Banking on Future Research
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A national human tissue specimen bank would be a resource for future studies. |
There is an increasing need for national monitoring and assessment of the actual amounts of environmental pollutants that human populations are carrying in their bodies--a need which may best be met through a national human tissue specimen bank. Such was the conclusion of a group of scientists who met in North Carolina recently to examine these issues.
Participants at the Human Tissue Monitoring and Specimen Banking Symposium, which brought together scientists and policy makers from agencies such as EPA, NIEHS, the National Cancer Institute, the National Center for Health Statistics, and the Centers for Disease Control, met to provide a state-of-the-art overview of human exposure assessment, biomonitoring techniques, and advances in human tissue specimen banking. Discussion at the symposium encompassed the need for monitoring and banking programs, sampling design and analysis, specimen collection and management, application of specimen data to biomarkers and risk assessment, and ethical considerations such as confidentiality, rights of human subjects, and regulation of uses of data.
A major portion of the conference was devoted to identifying and discussing the potential benefits and uses of a human tissue specimen banking program. Tissue specimens collected as part of national surveys or particular epidemiologic studies would allow scientists to measure amounts of known chemical contaminants in human tissues and help identify new or previously unrecognized hazards, identify population groups (e.g., by age, sex, or geographic location) that may be at increased risk due to high body burdens, and conduct research in related areas such as determination of body burdens, distribution of chemicals in various body tissues, and procurement, storage, and analysis of human tissues.
Perhaps the greatest potential benefit of a national specimen bank, however, may be as a resource for future environmental and toxicological studies. Data from future studies might be used to establish trends in body burdens of chemicals that result from changes in manufacture, use, and disposal patterns, thus enabling regulators to monitor programs to control specific chemical hazards. Future studies might also include measurement of toxins not originally studied, baseline measurements for chemicals not currently considered toxic or not yet invented, and measurements using new or more sensitive analytic techniques yet to be developed. These new techniques may frequently involve the characterization of biomarkers, which could be more predictive of disease outcomes.
A working group of selected conference participants estimated that the cost of properly conducting and maintaining such a specimen bank would be between $20 and $50 million a year. However, they also estimated that the costs of not having a bank would likely be far greater because public health threats from chemical exposures would not be detected until significant disease outcomes become evident.
EPA Elevation Slow
The proposal by the Clinton Administration and some Members of Congress to elevate the Environmental Protection Agency from a federal executive agency to the departmental level is not moving as quickly as anticipated. This proposal would give EPA cabinet status and has broad support in Congress, but considerable debate has arisen concerning how the new Department of Environment would carry out its responsibilities.
The Clinton Administration supports bills introduced in the House and the Senate that would elevate EPA to cabinet level and abolish the White House Council on Environmental Quality. Almost all of the duties of CEQ would be transferred to the new department. These bills have generated concern in many federal agencies and in some environmental groups about transferring responsibility from CEQ for final decisions on disputes related to Environmental Impact Statements involving federal construction projects. The White House restated its position and agreed to continue to resolve such disputes. Environmentalists voiced fears that if CEQ were abolished, they would be denied access to the White House on critical issues. The establishment and staffing of a new environmental office in the White House has mollified some but not all of this opposition.
The simplest proposal, known as a "clean bill," would redefine the EPA in existing legislation as a department. Such a bill has been introduced and has the support of key Republicans in the House of Representatives. This approach would replace all references to EPA with the term "department" in the laws that created the EPA and describe its responsibilities. This bill does not address the perceived need to correct shortcomings in the existing structure and mode of operation of EPA. Some members of Congress who want to take advantage of this opportunity to redress these problems in the legislation that elevates EPA. These members are drafting such a bill, which will certainly be controversial.
Representative John Dingell (D-Michigan), chair of the House Committee on Energy and Commerce, which has jurisdiction over EPA, is reported as being opposed to the proposed elevation. He has been a persistent critic of EPA and has stated he does not believe that elevation to cabinet status is warranted. Dingell has been careful not to rule out passage of some version of an EPA elevation bill, but his personal concerns cast further doubt on hopes for rapid elevation of the agency.
A bill passed in the Senate on May 4, introduced by John Glenn (D-Ohio), reflects the desires of the Clinton Administration. The Senate approved the elevation of EPA by a vote of 79 to 15. The bill does not change the basic structure or function of EPA. It does shift the duties of CEQ to EPA and allows an expanded role for protection of the global environment.
Agencies May Merge on Environment
Congressmen Bob Walker (R-Pennsylvania) and George Brown (D-California) have introduced a bill in Congress that would merge the Department of Energy, the Environmental Protection Agency, and the National Aeronautics and Space Administration. In addition, the proposed legislation would transfer the National Institute of Standards and Technology and the National Oceanographic and Atmospheric Administration from the Department of Commerce to the new agency.
Such a reorganization of federal energy, environment, space research, and regulatory programs would radically change the structure of the federal Executive Branch and the Committees of the Senate and House of Representatives. A similar bill was introduced in the last session of Congress but was not enacted. The reintroduction is given little chance of approval and is sure to generate significant opposition. Its sponsors are senior members of Congress and the ranking members of the House Science, Space, and Technology Committee. Brown is highly regarded as an expert on federal research and development policy and has recently made provocative presentations on the subject of reorganization at meetings of scientists.
Cleaner Air May Mean Worse Health
The 1990 Clean Air Act requires reformulation of gasoline sold in areas of the country that do not meet the EPA's ambient air standard for carbon monoxide. Last winter some petroleum manufacturers, in an attempt to comply with the act, added 15% methyl tertiary butyl ether (MTBE) to gasoline sold in 39 nonattainment areas cited by the law. Although preliminary data showed a drop in carbon monoxide levels below levels for the previous year, the news was not all good. Soon after the introduction of gasoline containing MTBE, public health officials and the EPA in Alaska, Montana, Colorado, and New Jersey began receiving complaints of nausea, headaches, and dizziness in workers and commuters exposed to exhaust or gasoline fumes containing MTBE.
MTBE increases the oxygen content of fuel, thereby reducing carbon monoxide emissions. On March 11, EPA officials reported data showing a 95% reduction above the standard carbon monoxide levels in 20 areas, implying that the oxygenation program was effective in meeting EPA goals. However, complaints of adverse health effects prompted an investigation by state health departments and the Centers for Disease Control.
On March 10, William Roper, director of CDC, reported to Congress the findings of investigations in Alaska by a team of CDC scientists. Roper noted that CDC found measurably higher levels of MTBE in the blood of people exposed to gasoline or vehicle exhaust containing MTBE. Roper stated that MTBE is listed in the Clean Air Act as an air toxic and was once used by physicians to dissolve gall stones; however, this use was discontinued, in part, because of symptoms and side effects similar to those seen in the persons CDC studied in Alaska. According to Roper, the evidence of health effects is sufficient to suggest that MTBE may present a serious public health threat. Industry officials, on the other hand, support the safety and efficacy of MTBE and have stressed that no current studies have clearly implicated MTBE as a risk to human health. Meanwhile, EPA and CDC have agreed to collaborate on further research to characterize the risk of MTBE.
NIH Renewal Has High Priority
The legal authority permitting the National Institutes of Health to award research and training grants and to conduct its intra-mural research studies was given highest priority by Congress when it reconvened in January. The first bill introduced in the Senate and the fourth bill in the House provide for the reauthorization of the NIH programs. This year, the bills have not produced the same bitter controversy that created an impasse preventing reauthorization in the last session of Congress.
Perhaps the most important factor contributing to the new attitude toward the NIH reauthorization is the change in administration. The White House is no longer opposed to the use of fetal tissue in research conducted and supported by NIH. Another compelling factor is that the bill provides new authority and emphasis on research into diseases and conditions affecting women and minorities. Important among these are requirements for increasing the participation of women and minorities in clinical research. The bill also emphasizes research into hormonally related cancers such as cancer of the breast, prostate, and uterus.
Environmental health sciences research is also prominent in the bill. If the bill passes as it is now written in the House, the National Cancer Institute and NIEHS will be required to study the incidence of breast cancer on Long Island, New York. In addition, NIEHS will be specifically mandated to increase research into the developing alternatives to whole animals for use in product testing, toxicologic research, and biomedical science.
National Biological Survey
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Bruce Babbitt |
In an effort to coordinate his department's scientific research priorities, Interior Secretary Bruce Babbitt has proposed a new scientific agency and has named Thomas Lovejoy, a Smithsonian Institution official and ardent conservationist, as his scientific advisor.
The National Biological Survey would coordinate the often competitive scientific activities of agencies such as the Fish and Wildlife Service and the Bureau of Land Management. Babbitt's proposal models the agency on the United States Geological Survey, founded through a joint effort of the Smithsonian Institution and the National Academy of Sciences. A priority of the agency would be to prepare a biological survey using an ecosystem mapping approach, as opposed to the traditional single-species approach, for use in protecting endangered species.
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Thomas Lovejoy |
The Endangered Species Act, which is administered largely by the Fish and Wildlife Service, has come under attack recently for failing to protect rare plant and animal species. An article in the March issue of the journal
Conservation Biology charged that some species are not listed for protection until extinction is imminent, and efforts at preservation and restoration are difficult and expensive. Babbitt has said that "The biological survey could be the best insurance policy against environmental and economic train wrecks," like the conflicts between loggers and environmentalists.
The official named to advise Babbitt on such matters is extremely well-versed in conservation issues. Lovejoy, assistant secretary for external affairs at the Smithsonian, is a former executive vice president of the World Wildlife Fund and president of the Society for Conservation of Biology. He is also a member of numerous scientific and conservation boards including the Environmental Defense Fund, World Resources Institute, and Wildlife Preservation Trust.
Lovejoy's experience and philosophy should complement Babbitt's own preservation agenda for the department. Babbitt, former president of the nonpartisan, nonprofit League of Conservation Voters, sees the mission of the Department of the Interior as teaching society to "live more lightly on the land." He has already announced several proposals designed to fulfill this goal. In addition to introducing an ecosystem approach to the Endangered Species Act, Babbitt also advocates market pricing of water in the West and market pricing for grazing cattle on federal lands, as well as an end to subsidization of timber sales by the Forest Service.
Clinton Economics May Boost Environmental Protection
President Clinton's original $16-million economic stimulus program highlighted childhood immunization and summer jobs but it also contains funding for environmental protection programs. The entire proposal met with stiff Republican resistance in the Senate on the grounds that it would contribute to the federal budget deficit and would have minimal impact on the overall American economy. The deadlock in the Senate was assured when a Republican filabuster prevented a vote on either the original proposal or a scaled-down version with $4 million in programs removed.
Environmental programs slated for acceleration under the stimulus package included wastewater treatment plant construction, watershed management projects, and improved energy efficiency. Nearly $1 billion would be appropriated immediately for these efforts if Congress approves the package. In the case of the wastewater treatment construction, some of the local cost-sharing requirements would be lifted so that work could begin quickly.
Republicans targeted these environmental projects in their opposition to the president's proposal. They say that the number of jobs created by these programs is much smaller than claimed by the administration. The reaction of environmentalists was mixed. There was support for the concept linking environmental protection, job creation, and economic stimulus; however, the plan was criticized for being too small. Environmentalists were also put off by the president's proposal to help reduce the deficit by cutting staff at EPA and reducing expenditures from the Superfund trust fund.
Assessing Risk Assessment
A report that evaluates federal research programs in risk assessment methodology was submitted to Congress in May. The report, prepared by the Office of Technology Assessment, will provide lawmakers with vital information and suggestions for future legislative actions and funding decisions in this area. Congressman George Brown, chair of the Committee on Science, Space, and Technology, and Congressman John Dingell, chair of the Committee on Energy and Commerce, requested the report.
According to Dalton Paxman, project director of the Biological and Behavioral Sciences Program of the OTA, the office, aided by a 15-member panel of scientific experts from around the country, was given a "nonpartisan, objective mandate" by Congress to survey federal research activities in risk assessment. Paxman added that although the OTA staff has talked to many agencies, "up to 11 are defined as having programs." Some of the agencies include EPA, FDA, NIEHS, CDC, National Cancer Institute, Department of Energy, Department of Defense, Department of Agriculture, and the Occupational Safety and Health Administration/National Institute for Occupational Safety and Health.
The survey, which describes the federal programs, also attempts to identify the programs' priorities and the ways in which their research has helped to improve risk assessment. An initial draft of the report was sent in December to 100 individuals both inside and outside of the agencies for review. Paxman said that neither congressional requestors nor OTA staff anticipated that the research would be controversial but found that it was. "People claimed that the report was biased towards industry and [some] towards environmentalists." The panel has made an attempt to incorporate the reviewers' comments into the report that went to the Technology Assessment Board, a group of 12 members of Congress who oversee the OTA. If approved, the report, which Paxman hopes will "create an atmosphere for collaboration," is expected to be published by the end of the summer.
Last Update: September 4, 1998