will not increase, Marshall stated, citing reports from Midwestern growers who applied the herbicide only once instead of the typical three or four times annually. "I think environmentalists are confusing the issues and using semantics to make problems," she said. Another concern of environmentalists is that the gene producing the resistance will "hop" to nearby weeds in the same genetic family, again creating weeds resistant to Roundup. Because there are few if any weedy soybean relatives in the United States, genetic "hopping" is not expected to be a problem here. But Roundup-resistant soybean plants exported to Asia and Australia could crossbreed with wild soybean species and other weeds Fitzgerald said Marshall asserted that it is highly unlikely that gene-hopping will occur because the soybean plant self-pollinates Farmers apparently have not been swayed by the environmentalists' concerns. Transgenic seeds were planted on 9.2 million of the 250 million acres of food commodities grown this year, said Terry Francl of the American Farm Bureau Federation (AFBF). Of that, 5 million acres were planted with Roundup Ready soybean seeds. But commodity watchers and seed brokers expect purchases of Roundup Ready soybeans to double or even triple in 1997. Not all genetically engineered plants met similar success this year. Monsanto's pest-resistant cotton plant, Bollgard Bt, did not control the cotton bollworm in some cases in the Southeast, causing growers to use pesticides. This prompted the Union of Concerned Scientists and the Environmental Defense Fund in October to ask EPA to suspend the plant's registration. The two groups also asked EPA to delay approvals of other Br crops. Bt plants are injected with a naturally occurring microorganism, Bacillus thuringiensis {Bt)) which causes the plant to create a toxin the bollworm cannot digest. Widespread use of transgenic Bt crops will lead to a loss of nongenetically engineered Bt, an insecticide popular among organic farmers. CATHERINE M. COONEY
NEWS GOVERNMENT Dioxin assessment revisions unlikely to change conclusions Clearer documentation, greater transparency, more detail, but little substantive change are expected in the conclusions of the EPA dioxin risk reassessment currently undergoing revisions. According to interviews with EPA and other scientists in and out of the federal government who are on the rewriting team, many of the conclusions in the original risk assessment remain: Dioxin is a probable human carcinogen, and some rsnrpr and noncancer effects being seen at or near current body burden levels in humans The team is preparing a clearer, better referenced document that is expected to be released in February to the EPA Science Advisory Board (SAB), the body whose criticism triggered the current effort to revise parts of the 2000-page, nine-chapter assessment. Last year, SAB called for EPA to rewrite sections on dose-response and risk characterization. If EPA makes the February date, it will mark a milestone in the five-year review (ES&T, August 1995 p 338A) As of early November, the dose-response revisions were complete, but the writing team had bogged down on key risk characterization sections on cancer, toxic equivalency factors, and immunotoxicology. The team has reached agreement on these sections, but team members who are responsible for writing them have been stretched too thin to complete the job, scientists said. Generally, the revised sections include new and better data supporting the use of toxic equivalent factors and body burden levels rather than daily intake as a dose metric. The revised sections will also reflect more studies showing a very small margin of exposure for dioxin. Regulators usually seek a difference of at least 100-fold between exposure and observable effects, EPA officials said, but studies and other data are turning up no margin for sfime subtle effects from dioxin.
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Researchers said the new risk characterization section will be a more transparent document with clearer references to supporting sections in the main risk assessment and will be easier for risk managers to use—a chief SAB criticism. However, they also noted that the long delays caused by reviewing and rewriting mean that the report's underlying data are becoming dated; risk assessment chapters ^ygj-g first peer re~ viewed in 1992. Meanwhile the has moved ahead to pose new dioxin control regulations for incinerators which are a major dioxin source without a final assessment of health impacts JEFF JOHNSON
Enforcement spurs pollution alternatives, EPA report says The threat of enforcement actions is among the most important factors in motivating business managers to consider pollution reduction techniques, according to a new EPA survey. "A Study of Industry Motivation for Pollution Prevention" is based on an anonymous survey of 1000 executives, evenly split between small printers and production managers at large manufacturing companies that report to the Toxics Release Inventory (TRI). The survey was authored by the EPA Pollution Prevention Policy Staff (EPA Report No. 100-R96-005). It showed that enforcement may be an important motivator for reducing toxic releases, but contact with technical support programs will significantly increase awareness and implementation of pollution prevention approaches at industrial sites. The survey's purpose was to determine whether and how environmental issues influence core business decisions. And according
to Natalie Roy, National Pollution Prevention Roundtable director, one of the significant results was the report's conclusion that regulatory programs are almost unrivaled in focusing the attention of business managers on environmental obligations. Bob Kerr, a pollution prevention consultant and principal of Kerr and Associates, pointed out, however, that the survey does not determine whether enforcement encourages installation of pollution controls or pollution prevention alternatives. Agreeing, Kathy Barwick, senior scientist, California Department of Toxic Substances Control, said the results indicate the need to integrate pollution prevention into the regulatory system. But how that integration takes place is important said Nikki Roy EPA Pollution Prevention Staff director who noted that industry officials ranked government advice quite low The survey concluded that most production managers and printers, when contacted by technical assistance programs, tended to implement pollution prevention. Also, production managers contacted by technical assistance programs were more likely to say that pollution control or compliance costs were a strong influence in their choice of equipment and operations. The influence of technical assistance surprised Gary Miller, assistant director of the Illinois Hazardous Waste Research and Information Center. He noted that some state programs are considering shifting environmental technical assistance duties to business assistance organizations; but the results, he said, show that environmental technical assistance programs are effective and should not be replaced. One of the more equivocal results of the survey was the impact of government-required pollution prevention planning. The number of companies doing such plans was high—half the printers and two-thirds of the production managers—but, Miller noted, states with the most stringent planning requirements, whose industries gave the highest marks to planning efficacy, did not achieve greater TRI reductions. —JANET PELLEY
NEWS SOCIETY States tackle animal waste problem to improve water quality In some areas of the United States, animal farms have become so concentrated that they produce the same volume of waste as a large city. Traditionally spread untreated on fields, the waste releases heavy loads of nutrients into the environment, resulting in fish kills and groundwater contamination. Because it has been taboo to regulate the farming community, states are using a variety of creative solutions to tackle this problem. Recent trends in agribusiness have led to large concentrations of animal production facilities, according to Mark Risse, agricultural pollution prevention specialist with the University of Georgia Cooperative Extension Service. These facilities produce huge quantities of animal manure: All the livestock produced in Pennsylvania, from chickens to swine, generate 25 million tons of manure annually, or five times the waste of New York City's human
population Hot spots include Maryland's southeastern shore and West Virginia for poultry North Carolina's infamous hog megalopolis; and Florida and Virginia dairy production areas For years this manure has been spread, untreated, on fields or stored in open pits. Both methods release significant amounts of nutrients and bacteria to the environment. From 5090% of the nitrogen in hog ma-
nure lagoons is released to the air as ammonia and deposited within a 50-100-mile radius of the lagoon, said North Carolina Environmental Defense Fund scientist Joe Rudek. When lagoons leak or flood, receiving water bodies experience algal blooms, anoxic water, and fish kills, and rainwater carries pollutants into groundwater and streams. The state of Pennsylvania has responded by focusing on nutrient management planning. Passed in 1993, Pennsylvania's Nutrient Management Act calls for farms with more than 1000 pounds of animals (two cows) per acre to draft a plan that will identify best management practices (BMPs), such as fencing cattle out of streams, that prevent nutrient releases to the environment The plans must meet a performance requirement that no
nitrogen will be applied to the land than absorb But implementation of the act met strong opposition from the farmers' lobby It has taken nearly four years for the Nutrient Management Advisorv Board to draft rules for the plan which will hecome effective sometime next vear said Bill Fhel a board member Meanwhile, Pennsylvania banks, faced with astronomical liability costs for manure spills into waterways, have taken steps to protect their investments by continued on page 530A
Despite the power of the farming lobby, a number of states have enacted laws to control animal waste, and others experiment with innovative reuse and biotechnology solutions. VOL. 30, NO. 12, 1996 / ENVIRONMENTAL SCIENCE & TECHNOLOGY / NEWS • 5 2 9 A
