NEWS OF THE WEEK
TOXIC AIR EMISSIONS Tough EPA rule will hit 112 chemicals
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In the worst case, EPA calcu he Environmental Pro lates chemical price increases tection Agency has is EPA's chemical plant rule slashes of less than 3%. sued a final rule requir air toxics dramatically The rule should result in no ing chemical manufacturers to plant closures and have "little cut their toxic air emissions Health effectsRule protects against: or no impact on U.S. compet nearly 90% from 1990 levels. • Cancer itiveness because other coun Existing chemical plants have • Birth defects tries are moving in this direc three years to comply; new • Organ damage tion," Brenner says. "Trade plants must comply when they ra» Airborne Ecological effects— impacts will be negligible." begin operation. rhomiralc Rule results in: • Fewer fish kills Where they've been done, in "This is one of the most • Less concentration η dustry calculations differ. The sweeping air pollution rules of air toxins up the Chemical Manufacturers Asso EPA has ever issued," one that food chain ciation "estimates capital costs is highly protective of public to comply at more than $1 bil health, says EPA Administra Smog reductionlion, but has no estimates for tor Carol M. Browner. The rule Rule yields: • Improved visibility annual operating costs," says will reduce emissions of 112 • Less lung damage Karen K. Fidler, CMA director hazardous organic air pollut • Minimized crop damage for air and water issues. CMA ants a total of more than • Less building corrosion has not assessed the impact on 500,000 tons a year, by agency prices or on balance of trade. estimates. These 112 pollutants "We've prepared ourselves to comply account for a major portion of the 189 control achieved by the best performing toxic air pollutants whose emissions 12% of existing facilities. According to with the rule, but we have not taken is must beregulatedby 2003, under a 1990 Robert D. Brenner, director of EPA's Of sue with EPA concerning its associated Congressional mandate. fice of Air Policy Analysis & Review, costs," Fidler notes. "We knew the rule An added benefit of this standard, "Many of the bat performing facilities was coming. We knew it would be an which EPA calls the Chemical Manufac are in Texas." New sources must meet expensive rule. If government writes the turing Rule, is reduction in emissions of limits achieved by the best controlled right kind of rule, then the costs are what come along with it. EPA deserves smog-producing volatile organic com similar source anywhere in the U.S. pounds of 1 million tons per year. This is To avoid excessive control costs and a lot of credit for issuing this major equivalent to removing 38 million gaso to allow for flexibility, a chemical maker rule." line-powered vehicles from the road, can use so-called emissions averaging to Environmental and health groups also EPA says. comply. For example, if control of emis applaud EPA for issuing the standard, To meet the standard, 370 chemical fa sionsfromone process vent is too costly, but fault it for not covering all sources of cilities in 38 states will have to upgrade the company can install more stringent toxic air emissions from the organic their control technology to prevent evap controls on another vent. The chemicals chemical manufacturing sector. For ex oration and leaks from such sources as controlled need not be the same so long ample, batch processing vents are ex process vents, wastewater and transfer as the two vents are in the same facility. empted, meaning the rule likely will not But to use this option, the company have much impact on small firms. operations, storage tanks, and equip ment. However, Browner contends that must reduce total toxic emissions from Health and environmental groups more than 10% of the emission reduction the plant 10% more than it would if it also are unhappy about the rule's aver can be achieved through pollution pre did not employ the option. It also must aging option, which they claim does not vention. Most of the affected facilities are get approvalfromthe state in which the fully protect public health. As American located in Texas, Louisiana, and New plant is located to use this option, and Lung Association president Alfred Munmust conduct a risk assessment to en zer explains: The option "allows compa Jersey. Chemical producers must use maxi sure that final emission levels protect nies to average pollution emissions across different emission points in a facility con mum achievable control technology, as public health. EPA estimates that the new rule will taining vastly different mixes of chemi defined by the 1990 Clean Air Act, to meet the rule's emission limits. Emission generate total capital costs to the chem cals, which can potentially result in an in sources in existing facilities must meet ical industry of $450 million, and total creased health risk to the surrounding limits as strict as the average emission annual operating costs of $230 million. public." 4
MARCH 7,1994 C&EN
David M. Driesen, an attorney with the Natural Resources Defense Council (NRDC), criticizes the averaging option "for allowing different baskets of pollutants to be traded. These different pollutants are not fungible." He also argues that "risk assessment is not far enough advanced to facilitate interpollutant trading." Industry, on the other hand, is pleased the option is in the rule. Both NRDC and CMA say it is pre-
mature to talk about potential lawsuits. But given the checkered legal history of the Chemical Manufacturing Rule— formerly called the HON rule for Hazardous Organic NESHAP (National Emissions Standard for Hazardous Air Pollutants)—future legal action can't be ruled out. "As far-reaching as this rule is, it would not be surprising if some sort of suit is brought," Brenner says. hois Ember
Amphibian population losstiedtoozone thinning Oregon State University scientists have UV-B radiation in sunlight (wavelengths found strong evidence for a biological 290 to 320 nm). UV-B causes some DNA effect of thinning in the stratospheric in amphibian eggs to form abnormal ringozone layer: A global drop occurring in like structures, but photolyase can return amphibian populations may be caused the DNA to its normal structure. by exposure to rising levels of ultraviolet Blaustein and coworkers find that phoradiation in sunlight resulting from the tolyase repair activity varies about 80-fold ozone depletion. among the 10 species: Those laying eggs Population numbers are declining for in shallow water exposed to sunlight have many species of frogs, toads, and sala- high levels of photolyase activity; those manders on every continent—ranging laying eggs in shady protected areas, such from the natterjack toad in Britain to as under leaves, show low activity. salamanders in Mexico and the CasBlaustein compares photolyase activcades frog and Western toad in Oregon. ity in the three Cascade species that lay Work published by the Oregon team last eggs in exposed areas. An amphibian week in the Proceedings of the Nationalwhose numbers are not dropping, the Academy of Sciences [91,1791 (1994)] indi-Pacific treefrog, shows the highest level cates that the UV radiation kills eggs of of photolyase activity. But two species amphibians that do not produce enough experiencing population declines, the of an enzyme, photolyase, that repairs Western toad and Cascades frog, show UV-damaged DNA. much lower photolyase activity. Currently, only about 45 to 65% of Zoologist Andrew R. Blaustein and colleagues at Oregon State studied 10 am- Western toad and Cascades frog eggs phibian species in the Oregon Cascade hatch, but nearly all Pacific tree frog Mountains. The species vary widely in eggs do. To test the hypothesis that ability to repair DNA damage caused by UV-B is depressing the hatching rate of
amphibian eggs, Blaustein shielded Western toad and Cascades frog eggs from UV-B with a Mylar sheet. About 20 to 25% more eggs hatched. "The bottom line is that current levels of UV-B radiation in sunlight are killing the eggs," Blaustein concludes. UV-B radiation levels have not been monitored in Oregon. However, UV-B levels in Toronto, Canada, at the same latitude, increased substantially over the past four years—7% per year in winter and 35% per year in summer (C&EN, Nov. 15, 1993, page 54). Stratospheric ozone levels depend on latitude, so a similar increase in UV-B has probably taken place in Oregon, experts say. Blaustein does not believe rising exposure to UV-B is the sole cause of worldwide decline in amphibian populations. Habitat destruction is probably the largest factor, he notes. Acid rain and chemical pollution also are creating problems in some areas. But the habitat is still largely intact in the part of the Cascades where he studies amphibians. He adds that "many other types of animals and plants would be vulnerable to rising levels of UV-B radiation," especially phytoplankton and larval fish (C&EN, May 24,1993, page 12). Bette Hileman
Fires emit significant methyl bromide levels
Smoke from forest and grass fires is a significant source of methyl bromide— CH3Br, the chemical that is the largest single source of ozone-depleting bromine atoms in the stratosphere. This finding, published in Science [263,1255 (1994)], raises questions as to whether restrictions now scheduled on synthetic methyl bromide, a widely used fumigant, will prove as important as assumed in halting ozone depletion. Although much of the methyl bromide emitted from both natural and human sources is oxidized in the lower atmosphere, a sizable fraction reaches the stratosphere where bromine reacts even more voraciously with ozone than does chlorine. A 1991 United Nations Environment Program (UNEP) report estimates that most methyl bromide emissions stem from marine organisms, but that 25% ±10% of the total Blaustein studies hatching of amphibian eggs in Oregon Cascade Mountains. Mylarcomes sheets from fumigation with the synthetic chemical. shield some eggs from ultraviolet light; other eggs are hatched in direct sunlight MARCH 7,1994 C&EN 5
