Environmental ▼ News Making accurate beach water-quality determinations
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weekly measurements of three indicator bacteria—total coliforms, fecal coliforms, and enterococci— and daily standards and monthly geometric means for all three, says Steve Weisberg, executive director of the Southern California Coastal Water Research Project (SCCWRP), ALEXANDRIA BOEHM, STANFORD UNIVERSITY
wo recent studies are raising questions about the sampling techniques currently used for monitoring beach water quality, the results of which provide the basis for decisions on whether to close a public beach. Concentrations of fecal indicator bacteria can literally vary minute to minute, according to a 40-year retrospective study of bacteriological monitoring and rainfall data combined with several short-term, highfrequency sampling surveys. The data were collected at Huntington Beach, Calif., which is just south of Los Angeles, by researchers from the University of California–Irvine (UCI), Orange County Sanitation District, and Chapman University (Environ. Sci. Technol. 2002, 36, 3885–3892). The work calls into question the U.S. EPA’s proposed standard for monitoring recreational water quality. The other report, by researchers from Flinders University of South Australia, reveals that fecal indicator organisms can live much longer in sediments than the overlying water column, from where monitoring samples are typically drawn. The ES&T findings suggest that EPA’s recommended single-grab sample standard, which should be finalized this year, is fundamentally flawed, says Stanley Grant of UCI, one of the study’s authors. “Here’s a case where the intent is to capture a one-time event with a single sample standard that would prevent people from going in when the water is bad, but the reality is that because the water quality signal itself is of such a high frequency, that goal is impossible unless you sampled every minute and knew those results instantaneously,” he says. California’s beach monitoring standards, which are more stringent than EPA guidelines, require
A beach closure sign at Huntington Beach, Calif., is ignored by surfers in the background.
a collaboration of city, county, state, and federal agencies. On the basis of the Huntington Beach study, Grant and his colleagues recommend that California’s approach be used more broadly. EPA’s standard also recommends using a geometric mean, but only for enterococci in marine watersand enterococci or E. coli in fresh waters. Because current measurement methods for enumerating indicator bacteria require an 18- to 96-hour incubation period, contaminated beaches may already have recovered by the time warning signs are posted, Weisberg stresses. In fact, as many as 70% of contaminated beaches are clean 24 hours later, according to SCCWRP. As a result of the new study and others, California is sponsoring research toward more rapid bacterial measurement techniques, Weisberg adds.
ENVIRONMENTAL SCIENCE & TECHNOLOGY / OCTOBER 1, 2002
Grant and his colleagues also recommend that water samples be collected at the same time every day, ideally early in the morning. They found that concentrations of fecal indicator bacteria are typically at their highest levels in the middle of the night, falling to near or below detection limits at midday, which they say is probably due to sunlight killing the bacteria. According to the Australian study, these recommendations may not go far enough. Nancy Cromar and her colleagues suggest monitoring the level of fecal indicator concentrations in the water column alone may underestimate the exposure and infection risk. Measuring decay rates in various sediment cores and overlying water samples at various temperatures in both the lab and the field, Cromar’s group found that the organisms disappeared much more quickly from the water column than in any of the sediments. The organisms they studied included E. coli, enterococci, and coliphage, as well as the pathogens Salmonella typhimurium and S. derby. Their results suggest that sediments serve as reservoirs for indicator and pathogenic organisms, which, as they are resuspended through recreational or wave activity, could pose more of a risk to swimmers than previously thought, says Howard Fallowfield, one of the study’s coauthors. He presented the findings at the American Water Works Association conference in New Orleans in June. “In many cases, we were obtaining 1000 organisms per 100 grams in the clay sediments, while there were no organisms found in 100 milliliters of the overlying water,” Cromar says. “At the sandy sites, the differential was much smaller.” The researchers also found that higher © 2002 American Chemical Society
Fecal coliforms
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The concentration of fecal coliforms in the clay sediments at Port Adelaide River in Australia is often more than a 1000 times higher than those found in the overlying water column. The line represents Australia’s current median fecal coliform guideline concentration for primary contact recreation based on five samples.
temperatures resulted in higher decay rates in the overlying water than in the surface sediments. “We’re presuming that being attached to sediment particles confers all sorts of benefits on them, allowing them refuge from sunlight and potential predators, as well as perhaps providing a buffering effect from pH extremes,” Cromar says. Likewise, more nutrients such as nitrogen and
phosphorus arrive in sediments than in water, which could also be enhancing the organisms’ survival. The Flinders University researchers are now developing a quantitative microbial risk assessment framework for resuspension to help better determine how many days a beach should be closed following a storm event, Fallowfield says. —KRIS CHRISTEN
California greenhouse gas law could change U.S. auto fleet The first law in North America to regulate greenhouse gas emissions from cars and trucks, which was enacted in California on July 22, has inspired a flurry of legal and legislative action. A host of other states are considering adopting the legislation, which is expected to trigger changes in auto industry standards for the entire United States. But first the new legislation must overcome a court challenge claiming that it is an illegal attempt to boost federal fuel economy standards. California Assembly Bill 1493 directs the California Air Resources Board (CARB) to develop, by 2005, regulations that achieve the maximum feasible reduction of greenhouse gases emitted by cars and light-duty trucks, including sport utility vehicles (SUVs). The regulations
would apply only to vehicle models designed for 2009 and beyond. CARB is likely to set specific emission standards after working with auto companies to determine what is achievable, says Jerry Martin, spokesperson for CARB. The standards will probably be met by new devices that are already on the market. For instance, the 42volt battery currently found in hybrid electric cars can be used with standard combustion engines to cut CO2 emissions by 10% by eliminating idling. Other approaches currently used by companies such as Honda, Audi, and General Motors (GM) include increasing the number of valves per cylinder from two to four to improve performance while cutting CO2 releases by 2–5%. In addition,
News Briefs The hybrid electric buses that are transporting people through New York City get up to 22% better fuel economy than their standard diesel counterparts, according to the U.S. National Renewable Energy Laboratory (NREL). The Orion VI hybrid buses “easily” met the emissions reduction goals established by New York City Transit (NYCT), cutting CO by 98%, NOx by 44%, particulate matter by at least 99%, and CO2 by 33% during the “Manhattan” dynamometer tests that have a slow average speed, which is closest to how the buses are actually operated according to NREL. All hybrid buses use diesel gas because they rely upon heavyduty diesel engines, according to GM, a manufacturer of hybrid buses. Drivers reported that the hybrid buses performed as well or better than the standard diesel buses, and NYCT expects more than 300 buses to be added to its fleet by 2005. To see a copy of NYCT Diesel Hybrid Electric Buses: Final Results, go to www.ott.doe.gov/otu/field_ ops/pdfs/nyct_final_results.pdf. In August, the U.S. Internal Revenue Service announced that owners of Toyota Prius automobiles were entitled to a $2000 tax deduction for the first year the car was in service, beginning retroactively in 2001. The Prius is the first hybrid gas–electric automobile to be eligible for a clean-burning fuel deduction, in accordance with federal law that allows individuals to claim a deduction for the incremental cost of buying a motor vehicle propelled by a clean-burning fuel. The Prius uses a 70-horsepower engine supplemented by a 44-horsepower electric drive motor, and the U.S. EPA estimates that it gets 52 miles per gallon (mpg) in the city and 45 mpg on the highway. For more information, go to www.irs.gov/pub/ irs-news/ir-02-93.pdf.
OCTOBER 1, 2002 / ENVIRONMENTAL SCIENCE & TECHNOLOGY
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DUNCAN CRAIG, FLINDERS UNIVERSITY OF SOUTH AUSTRALIA
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COURTESY OF FORD MOTOR CO.
variable valve timing and continumy,” counters Barton “Buzz” needed to meet the new California ously variable transmissions imThompson, natural resources law emission limits because the state prove transmission efficiency and professor at Stanford University. constitutes 10% of the U.S. car marreduce CO2 output by up to 3% and Under the Clean Air Act, California ket, asserts Roland Hwang, com8%, respectively. Taken together, is allowed to set its own standards bustion engineer with the Natural such existing devices Resources Defense could slash CO2 emisCouncil. In addition, sions by nearly 30%, several other states, Martin says. notably New York, have However, because the signaled their intention only way to cut CO2 to adopt California’s legemissions from cars is to islation, Hwang says. improve fuel efficiency, California’s action folthe Alliance of Automolows in the footsteps of bile Manufacturers, an a European Union law industry group, claims requiring vehicle emisthe new California statute sions of greenhouse violates the federal Corgases to be cut 25% from porate Average Fuel 1998 levels by 2008. Economy law, which In a related move, the forbids states to set fuel attorneys general from economy standards. Eron This Ford Explorer SUV could emit 30% less CO2 if it were equipped 11 states, led by Massawith affordable devices already on the market, according to the Shosteck, spokesperson chusetts Attorney California Air Resources Board. for the alliance, says his General Thomas Reilly, group intends to sue the state of for vehicle emissions, and the new have asked President Bush to take California. greenhouse gas law falls under this steps to curb greenhouse gas emis“Congress never intended to provision, he says. sions. Their July 17 letter warns that prevent California from setting air If the California law’s legality is the absence of federal leadership pollution standards simply because upheld, automakers are likely to will result in a hodgepodge of state they also might affect fuel econostandardize nationwide the devices regulations. —JANET PELLEY
World’s greenest PC goes global NEC Solutions America began selling a new computer it is billing as “the first environmentally friendly PC” in the United States this month. The tiny PowerMate eco is notable for being designed for recyclability, containing lead-free solder, and incorporating two innovative alternatives to traditional flame retardants. The PowerMate eco is the first computer specifically designed to have the least negative impact possible on the environment, according to NEC. The product capitalizes on technical breakthroughs that the company has made in the past two years, including the creation of its patented NuCycle plastic, which incorporates a silicone-based flame retardant material, says Larry Miller, vice president and general manager for the Mobile Solutions division of NEC Solutions America. Many of the flame retardants in current electronic products—including PCs—contain bromine, and 370 A
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these brominated flame retardants have been banned in Europe because of their suspected toxicity and their persistence in the environment (Environ. Sci. Technol. 2002, 36, 50A– 52A; 188A–192A). Researchers in Sweden have documented that flame retardants can enter the bloodstream of workers when electronic products are recycled (Environ. Sci. Technol. 2001, 35, 58A–59A). The alternative flame-retardant material used in the eco PC’s plastic casing is the first to contain neither phosphorus nor a halogen element such as bromine, according to NEC. This silicone-based flame retardant is dispersed throughout the polycarbonate resin in the NuCycle plastic, unlike the plastic used in other computer cases, which are rendered fireproof by a coating of a flame-retardant material. NuCycle is also 100% recyclable, Miller says, adding that NEC has already set up facilities for recycling and regener-
ENVIRONMENTAL SCIENCE & TECHNOLOGY / OCTOBER 1, 2002
ating the plastic in Japan where the company has a 60% market share. The integrated circuits inside the PowerMate eco are protected by a flame retardant-free mold resin, which, when exposed to fire, forms a foam that blocks oxygen and heat. Typically, such chips are flame-proofed with a brominated flame-retardant coating, so NEC’s alternative approach makes the motherboard upon which the chips are embedded easily recyclable, Miller says. Åke Bergman of Sweden’s Stockholm University, who was one of the first researchers to raise awareness about the environmental problems caused by brominated flame retardants, praises NEC’s new PC for using flame retardants that contain neither bromine nor phosphorus. “It certainly sounds promising,” he says, stressing that he needs to know the exact chemical composition of the replacement flame retardant to be more certain. “Silicone products have been PCB
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substitutes without causing, to my knowledge, any major (potential) environmental problems,” he adds. One of the reasons the PowerMate eco contains such environmentally advanced features is because it is based on a design for the more environmentally conscious Japanese market, Miller says. NEC is one of the 2700 manufacturers that are part of Japan’s green purchasing network, which stipulates that consumer products make a “big contribution to environmental protection.” The July introduction of the first national U.S. legislation aimed at regulating computer recycling, the Computer Hazardous Waste Infrastructure Act, is just one indication that the U.S. market is ripe for greener PCs, Miller says. An estimated 41 million PCs will be entering the U.S. waste stream in 2002, Miller says, noting the rising tide of legislation controlling the disposal of computer products and growing U.S. awareness about whether this electronic waste ends up in the developing world (Environ. Sci. Technol. 2002, 36, 52A–53A). The Silicon Valley Toxics Coalition, an industry watchdog, says that the average desktop PC contains at least 36 chemicals, including compounds with lead, barium, boron, and cobalt. The PowerMate eco does not contain any of these chemicals, nor are they used in manufacturing the products, Miller says, but he acknowledges that the PC’s thin-film transistor flat-panel screen does contain mercury.
While Ted Smith of the Silicon Valley Toxics Coalition agrees that lead and flame retardants are the computer chemicals of greatest concern and lauds NEC’s new computer, he says it is “disappointing” that it contains mercury. “Mercury continues to be a major issue of concern. Even though it’s small amounts of mercury, it doesn’t take much mercury to pollute a whole lake or river,” he comments. Mercury also poses problems in the recycling arena because there’s an increasing move toward shredding end-of-life products, and “if you end up shredding a monitor that has mercury in it, it’s going to end up contaminating the whole ‘kit and caboodle’,” he adds. In addition to the lead-free solder containing copper, tin, and selenium that NEC has been using in its computers for over two years, the eco PC avoids the use of lead by using a flat-panel screen rather than a cathode ray tube (CRT). Moreover, the PowerMate eco is designed to use very little power (31 Watts), which Miller says is onethird the energy of a typical desktop computing system. The PowerMate eco’s use of power-saving computer chips allows it to operate without a fan, making it very quiet. How well the computer will sell is an open question, given that critics say that its pricing, which starts at $1599, is higher than most desktop computers and more on a par with that of other laptop computers on the U.S. market. —KELLYN S. BETTS
The use of geographic information systems is central to achieving a successful transition from traditional environmental and resource management practices to sustainable development, says a draft report by the U.S. National Research Council that focuses on the technology’s prognosis in Africa. The report points out that geographic data are useful for monitoring soil erosion and biodiversity and can inform land-use decisions and water-resource allocations. Although the technology’s popularity is growing throughout the continent thanks in part to partnerships with organizations, including the U.S. National Oceanic and Atmospheric Administration and the United Nation’s Food and Agricultural Organization, barriers remain, particularly a lack of data format standards. Down to Earth: Geographic Information for Sustainable Development in Africa is available at www.nap.edu. Increasing consumer demand for minivans, light trucks, and sport utility vehicles caused a dramatic increase in CO2 emissions from 1990 to 2000, claims a report by Environmental Defense, a nonprofit environmental organization. The report calculates the automakers’ “carbon burden”—their annual emissions of CO2—by multiplying the number of sales of a particular model by the model’s annual CO2 emissions in million metric tons of carbon (MMTc). General Motors had the highest overall carbon burden at 6.7 MMTc, while Honda, with its emphasis on fuel economy, yielded the smallest at 1.3 MMTc. The carbon burden concept offers policy makers a new approach to address the climatic consequences of global warming. Automakers’ Corporate Carbon Burdens: Reframing Public Policy on Automobiles, Oil and Climate can be found at www. environmentaldefense.org.
OCTOBER 1, 2002 / ENVIRONMENTAL SCIENCE & TECHNOLOGY
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