esm223_03_Other_Reading_PPCPs-NYT-3Apr07

esm223_03_Other_Reading_PPCPs-NYT-3Apr07 - m 86% 8 88.380...

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Unformatted text preview: m 86% 8 88.380 -::2 8:: .383 20:88: 8888: :o :2: 0:: 0: 28588888 888 88 88:0 .8288 8:8 88 :o 88:88: 8 :82: .82 28:88: 82888888: :3 98:8 88 2:8 .83 2:: 85:: :o 2:888 80:: B828: 28 88:: 28:8 .2888: .88 888:: 8:88:82: 8:88 28: 3:838 2:: 8:88 88:82 88 88:: :o 8:88 8 cm .88: :88: 8 8888 E82: 2: .8: 8:3 :88 8:838 8:83 8 8:8: 08 2:8 Sm 83:8 2:: 8 838 88: :83 :o 82:: 8888 282.: 8:3 883 3:5 85:3 8:: 8:8 8.8888 8:: £88 :88 E .88: -8 :8 98: 8:: : 88 a: :8 8:: 88:3 .268 8:: 3o: .88: 888 8:: 08:3 :8 8:2: .:88:o::>8 8:: 8 88888 :88 2:888: £85888 2:: 8328 28 0:888 o: 283 32: w828: :8 888mm 882:: 88 :88:8>om 888m 8 82:8 :8 :88: a 3. :88 3:83 0: 88:2: :38 .88 2 o8:: 8:: 8.8888: :23 22:2: .8 82:88 8:: 28: 8:: 8:: 88888: 2888: :o :8: 8888 8:: 28: 8:8: -88 88:: :::3 :8: 83 222:8 cm .88 8:: 888:: 88:: :o 808 9:8 :8 88:88:: 88288 38888:: 28 wfiwm 82 .38 8 85mm: 328: 8 8 88 8388883: man: 88 :8: 0:: .838: -8: :8 82:88:88 8 38888 .888: -88 82:: c: 85898 88:: 8 82888 -88 88 888 8:: 888: 2 8:: :8: E :2885: o: :2: 2:: o: 8 :88: -828 2 885: .8888 88-8 8 8 :: :8: 288888: 88 8:88: 8 8:8 98 -88 8:: :o :28N 8m 8 .:::m .88 88: 4:8 8 :88 mm amaze—88: 8:88 8:8: 8928: 82,82: :85 :8 38:8 :82 82:: 8: 8:8: 28: 8:: 88:35:88 :888 ...m::8888::8 w8 8888: 8:8 £88888 88:: :85: 28: w8:o:88: .888: 82:88:: 8:888: .35: 8:: o: w8:88< 2:888 288 88: 88388:» 0:: 8:88: :o 88:: :88 .88: 8838 88: 82:: 9:28: 8:: 88 8:8: 88: v8 .m..m.o.m.n: :o .8888 88 8:88: 28. 828888.88 8:. 48:: 88.2 o: 8:88 888 E83 2 .28: 8:8 8:: :0 .888: 88:: o: 8:88: 28 8: 8 2:8: 28:88 8:: :o 88:: 8:: 8888 o: m: 88:: .28: 28 8:: :0 .8888 3:88:38: 8 8 2:8 2:8 8:888:88 88 8:8: 28:: 28: 8:: :8 £83883 9:28: 8:: 0:8 83 :8:: 888: 88 88888 8:8 8 :8: a :8 82888 88:88:: 88888: 2:8 8:8 8:88 8:: :o 8883: 28: 882:8 8 . 22.82 : 80D .883 2.: E 8< Ewan: 8E: Fwd _ There Are Drugs in the Water. But Does That Matter? Continued From First Science Page over paint or insecticides, periodical- ly collected for safe disposal, often by incineration. For example, Clark County, Wash, has a program in which residents with unwanted or expired drugs can take so-called controlled substances, like prescription narcotics, to police stations or sheriffs’ offices for dis- posal. They can drop noncontrolled drugs at participating pharmacies, and 80 percent of the pharmacies in the county participate. In guidelines issued in February, three federal agencies, including the E.P.A., advised people with leftover medicines to flush them down the drain “only if the accompanying pa- tient information specifically in- structs it is safe to do so.” Otherwise, the guidelines say, they should dis- pose of them in the trash (mixed with “an undesirable substance” like kitty litter to discourage drug-seeking Dumpster divers) or by taking them to designated take-back locations. Worries about water-borne chem- icals flared last summer when re- searchers at the United States Geo- logical Survey said they had discov- ered “intersex fish" in the Potomac River and its tributaries. The fish, smallmouth and largemouth bass, were male but nevertheless carried immature eggs. Scientists who worked on the project said they did not know what was causing the situation, or even if it was a new phenomenon. But the discovery renewed fears that hor- mone residues or chemicals that mimic them might be affecting crea- tures that live in the water. In a survey begun in 1999, the agency surveyed 139 streams around the country and found that 80 percent of samples contained residues of drugs like painkillers, hormones, blood pressure medicines or antibiot- ics. The agency said the findings sug- gested that the compounds were more prevalent and more persistent than had been thought. Meanwhile, the Food and Drug Ad- ministration started looking into the effects of residues of antibiotics and antiseptics in water, not just to see if they might affect people but also to assess their potential to encourage the development of drug-resistant bacteria. Reports of contamination with pharmaceutical residues can be alarming, even when there is no evi- dence that anyone has been harmed. In 2004, for example, the British gov- ernment reported that eight com- monly used drugs had been detected in rivers receiving effluent from sewage treatment plants. A spokes- woman for the Department for Envi- ronment, Food and Rural Affairs said it was “extremely unlikely" that the residues threatened people, be- cause they were present in very low concentrations. Nevertheless, news reports portrayed a nation of inad- vertent drug users — “a case of hid- den mass medication of the unsus- pecting public,” as one member of Parliament was quoted as saying. Christopher Daughton, a scientist at the Environmental Protection Agency and one of the first scientists to draw attention to the issue, said P.P.C.P. concentrations in municipal water supplies were even lower than they were in water generally be- cause treatments like chlorination and filtration with activated char- coal alter or remove many chem- icals. Dr. Daughton, who works at the agency’s National Exposure Re- search Laboratory in Las Vegas, said he believed that if any living be- ing suffered ill effects from these compounds, it would be fish and oth- er creatures that live in rivers and streams. Dr. Daughton and Thomas A. Ternes of the ESWE-Institute for Water Research and Water Technol- No evidence of harm to humans from trace chemicals, but some states are taking precautions anyway. ogy in Germany brought the issue to scientific prominence in 1999, in a pa- per in the journal Environmental Health Perspectives. They noted that pollution research efforts had fo- cused almost exclusively on “conven- tional” pollutants — substances that were known or suspected to be carci- nogenic or immediately toxic. They urged researchers to pay more at- tention to pharmaceuticals and in- gredients in personal care products — not only prescription drugs and biologics, but also diagnostic agents, fragrances, sunscreen compounds and many other substances. They theorized that chronic ex- posure to low levels of these com- pounds could produce effects in wa- ter-dwelling creatures that would ac- cumulate so slowly that they would be “undetectable or unnoticed” until it was too late to reverse them. The effects might be so insidious, they wrote, that they would be attributed to some slow-moving force like evo- lution or ecological change. Initial efforts concentrate on measuring what is getting into the nation’s surface and groundwater. The discharge of pharmaceutical residues from manufacturing plants is well documented and controlled, according to the EPA, but the con- tribution from individuals in sewage or septic systems “has been largely overlooked.” And unlike pesticides, which are intentionally released in measured applications, or industrial dis- charges in air and water, whose ef- fects have also been studied in rela- tive detail, the environmental agency says, pharmaceutical residues pass unmeasured through wastewater 5' William Duke treatment facilities that have not been designed to deal with them. Many of the compounds in ques- tion break down quickly in the envi- ronment. In theory, that would lessen their potential to make trouble, were it not for the fact that many are in such wide use that they are constant- ly replenished in the water. And researchers suspect that the volume of P.P.C.P.’s excreted into the nation’s surface water and groundwater is increasing. For one thing, per capita drug use is on the rise, not only with the introduction of new drugs but also with the use of ex- isting drugs for new purposes and among new or expanding groups of patients, like children and aging baby boomers. Also, more localities are introduc- ing treated sewage into drinking wa- ter supplies. Researchers who have studied the issue say there is no sign that pharmaceutical residues accu- mulate as water is recycled. On the other hand, the FDA. said in its re- view, many contaminants “survive wastewater treatment and biodegra- dation, and can be detected at low levels in the environment.” Some say the spread of these sub- stances in the environment is an ex- ample of how the products of science and technology can have unintended and unpredictable effects. In their view, when the knowledge about these effects is sketchy, it is best to act to reduce risk, even if the extent of the risk is unknown, an approach known as the precautionary princi- ple. Joel A. Tickner, an environmental scientist at the University of Mas- sachusetts, Lowell, saysthat it is a mistake to consider all of these com- pounds safe “by default,” and that more must be done to assess their cumulative effects, individually or in combination, even at low doses. In his view, the nation’s experience with lead additives, asbestos and oth- er substances shows it can be costly — in lives, health and dollars — to de- fer action until evidence of harm is overwhelming. ' Others say the benefits of action — banning some compounds, say, or re- quiring widespread testing or treat- ment for others — should at least equal and if possible outweigh their costs. “You have to somehow estimate as well as possible what the likely harms are and the likely benefits,” said James K. Hammitt, a professor of economics and decision sciences at the Harvard Center for Risk Anal- ysis. And while it is possible that some of the tens of thousands of chemicals that might find their way into water supplies are more dangerous in com- bination than they are separately, Dr. Hammitt said in an interview, “it’s perfectly possible that they counteract each other." Anyway, he said, assessing their risk in combination is a mathemat- ical problem of impossible complex- ity. “The combinatorics of this are truly hopeless.” Given all this uncertainty, policy makers find it difficult to know what to do, other than continuing their re- search. Studies of “the fate and transport and persistence” of the P.P.C.P.’s will allow scientists to make better estimates of people’s exposure to them, Dr. Zenick said, and “to assess the potential for hu- man health effects.” But even that normally anodyne approach comes under question be- cause of something scientists call “the nocebo effect” — real, adverse physiological reactions people some- times develop when they learn they have been exposed to something — even if there is no evidence it may be harmful. “The nocebo effect could play a key role in the development of ad- verse health consequences from ex- posure even to trace elements of con- taminants simply by the power of suggestion,” Dr. Daughton wrote re- cently in a paper in a special issue of Ground Water Monitoring and Re- mediation, a publication of the Na- tional Ground Water Association, an organization of scientists, engineers and businesses related to the use of groundwater. In fact, the idea that there are un- wanted chemicals in the water sup- ply has many characteristics that re- searchers who study risk perception say particularly provoke dread, re- gardless of their real power to harm. The phenomenon is new (or newly known), and the compounds are in— visible and artificial rather than nat- urally occurring. But scientists at agencies like the Geological Survey say it is important to understand the prevalence and ac- tions of these compounds, even at low levels. If more is known about them, agency scientists say, re- searchers will be better able to pre- dict their behavior, especially if they should start turning up at higher con- centrations. Also, the Geological Sur- vey says, tracking them at low levels is crucial to determining whether they have additive effects when they occur together in the environment. Comprehensive chemical analysis of water supplies “is costly, extraor- dinarily time-consuming, and viewed by risk managers as prompting yet additional onerous and largely unan- swerable questions,” Dr. Daughton wrote in his paper last year. But it should be done anyway, he said, because it is a useful way of maintaining public confidence in the water supply. “My work is really categorized as anticipatory research,” he added. “You are trying to flesh out a new topic, develop it further and see where it leads you. You don’t really know where it leads.” ...
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This note was uploaded on 08/06/2008 for the course ESM 235 taught by Professor Dunne during the Winter '08 term at UCSB.

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esm223_03_Other_Reading_PPCPs-NYT-3Apr07 - m 86% 8 88.380...

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