Document gbkYYbybxdvbK7Jp258zpv0ge

e*1 * cA H- to @, T\ifts University TM ^ oy ! Diet & Nutrition Letter PCBs in fish: a cause for concern? Eating mnrt oily fiah, which ia the richest die tary aource of omega-3 fatty acids, ia a wise move to hedge your beta againat heart disease. But this advice, carried in last month's Special Report, has now been somewhat clouded by a study indicating that if fatty fish have high levels of the chemical PCB, the eating of such fish may pose problems for woman who are planning to become pregnant. A research team headed by the University of Maryland's Greta Bin, PhD, has just reported in the journal Dtvdopmental Psychology and in the Journal ofPodiatrist that women who have had a long history of oating fatty fiah contami nated with high levels of polychlorinated bi phenyls (PCBs) gave birth to babiea who exhibited sluggish behavior and other such "worriaoma" responses. Their babiea wore also born smallsr ana earlier than infante not ex posed to PCBs. Although this new finding is of scientific camera, Joseph Jecobeon, PhD, one of the researchers at Wayne State University in Michigan, urges that women should not overre act. Indeed, he points out, the differences ob served in PCB-exposed newborns ware small and "do not necessarily predict anything bad down the road" far these children. Moreover, the women under otudy were regularly sating fiah whose PCB levels were as much aa 6 to U times higher than those considered normal or accept able by the FDAi The problems with PCB earns to light in the 1970a when it was found that the chemical, widely used in such industrial products as elec trical transformers and plastics, could cause concern. As a result, the FDA banned their far ther use in 1979. However, PCBe remain in items made before that time, are found in waste-dispoeal sitae, and are sometimes produced aa an inadvertent by-product in the manufacture of certain products. PCBs leach bom these sources into the water, soil, and air. ultimately winding up in the food supply. Because further resesrch linking PCBs to tumors and reproductive problems in animals has been reported, the FDA just last month re duced the allowable level of PCBs in fish and shellfish from S parts per million (ppm) to 2 ppm. Up to 3 ppm are permitted in poultry fat. The main problem involves fresh-water fish caught in lakes and streams polluted by indus trial waste. Seefood generally poses a lesser problem, although there have been reports of PCB contamination, particularly in harbors and bays near industrial sites. Fish that (bed in such polluted water accumulate PCBs in fatty tissue, as do people who eat these fish. Oily fish, including lake trout, salmon, mackerel, catfish, smelt, and carp, are more susceptible to high levels. On the other hand, lean white fish, such as cod, haddock, and pike, do not usually con centrate as many PCBs. Fbr years the state of Michigan has advised young women to avoid eating certain Great Lakes fish because of exceedingly high PCB lev els. Nevertheless, Dr. Fbin and her colleagues were able to locate 242 child-bearing women who did not know of the warnings and, indeed, reported eating Lake Michigan salmon and lake trout 2 or 3 times a month for 16 years. In studying these women, the researchers com pared their newborns to babies born to mothers who ate no Lake Michigan fiah. They found that the more PCB-contaminated fish the mothers ate, the more their infanta showed abnormal re flexes, general weaknesa, slower response to stimuli, and more signs of depression. They weighed 7 to 9 ounces lass and their heads were slightly smaller even though their body sise was within normal range. They also were born 6 to 12 days earlier than non-PCB-exposed babies. Dr. Jacobson believes that the aflected infanta will outgrow their differences, but he will reex amine these children when they are 4 years old to see if there are any long-term consequences of prenatal PCB axpoaun HONS 003827 EDITORIAL ADVISORY BOARD Chairman: Joan Mijw, AD. DSe. Pnildnt,Tufti Univaratty Slaphan M. Baiky, rnu Annum rrataoaor. Phyateal and Nutritional Anthroyalafy JaffPoy B. Blambat|. PhD. Anwit Prodraaar, Tninhi;: Aaaiatant Dtrortor. USDA Human NiunUw Raatarth Cmltr an A|tnf WiUiui 4. Evan*. PhD. AaaiaUM PrtlttNf. Phyaiatogy: Chttf. Human Phyawtoa? Libwuwf, USDA Raoaarch Cantor an A|inf Stanky N. OtratwH'. PhD. PriRaaar. Nutritional Btorbamiitry Joann* P CoMban. MEd. Ltrturor Nutrition and Dtatallea. Rahin B Kanaaak. PhD. Awiitinl Proftater. Nutrition and Behavior Hobart B. MrOandy. MD, Profoaaor. Nutrition and Chroma Dlaoaaa Rahart M. Ruaaall. MD. Aaaoeiata ProRaaar. Qaatroantarekgy Marian Frank Ztallin. PhD. Aiaiatont Profeaaor. Nutritional Surve> Meihoda and Iniaraontmna I RESEARCH REPORT V What docs all this maan in practical tarma? First, don't panic and quit anting all fatty fish, ft* their oils may indeed offer your heart some protection. But because statistics show that more than 20 percent of the fish Americans eat is fish they've caught, you should take special precautions--especially if such fish is eaten by woman of Childbearing age. PCBs accumulate in the body and.can be transferred not only to the fetus but also tp the baby via breast milk. Second, heed adHsories to avoid eating flah from known PCB-contahnnated water sources. New York State, for example, has just recently issued an advisory to eat no iqore than one fish meal per week. As far as youk favorite fishing spot is concerned, chances are you don't need to worry. But to find out if it is known to be PCB-pol luted, you can try calling yofcr state department of puilbiic health or the divisioh^of fisheries and wildlife, lb be sure, they don' know the anewer, becauee there is no> wway t federal or stste fovammonts can monitor ifety of all waters and all fish. But one thhiing_ ifcfertain, be circumspect about fishing downstrea^ fVom in duatrial plants Finally; befora you cook fatty frssh-wats\flsh, clean the layers of fit off the backbone i stomach along with dark sections and tho skin. And rather than frying the flah, broil or gril\it. Up with calcium, up with salt? Could it bo that calcium ie mors ii salt in determining whether pertenskm? Indeed, sodium ei often implicated aa the villain i hypertension. But a report, iourinal Sciencei m-i_g-ht - - _. . lifetime of contsuurmniing pllaennttyyd^f calcium ie more likely to protect you from rising blood preeeuro than is regular curtaili 'fit o`f your salt intake. ling data from a hugs government survey celled the HANES Latumt David MeCarron, MD, and colleagues from Oregon Health Sci ences Univsrsity/Snalyssd the diets of more than 10,000 popple. The researchers assessed the rslationunp between the intake of 17 nu trients an&nigh blood pressure. Surprisiifgly, the results showed that people with hypertension tended to consume signifi- lees calcium than thoee with normal preeeuro. Fbr example, individuals with a dSUy intake of lass than 300 milligrams of cal cium were more likely to have hypertension than those with a 1,600-milligram daily intake. Perhaps even more interesting, diets low in so 9 dium were associated with hypertension. Ca verssly, high-sodium diets were aseociate&with the lowest risk for hypertension. Individuals who consumed less than 2,600 milligrams of sodium a day ran a greater risk of reeloping hypertension than did people consuming more than 4,800 milligrams. Also wmfn noting, peo ple with hypertension tended Ur take in less of vitamins A and C as well as less potassium. Does all this really mean tftat calcium is more important than sodium ut controlling blood pressure? Dr. McCarroort report emphasises that the study "does not prove causality" Ilia findings limply indkate possible associations between nutrients .and the regulation of blood pressure. Furthermore, as pointed out in the American Journal of Epidemiology by another group of researchers who studied the same HANES dataf the relationship between low salt intake and mgh blood pressures may be ex plained byvibe fact that older people, who had the lowetf salt intake, had the highest blood pressures. Younger people, on tho other hand, ate more sodium and had lower pressures. So the findings may be the result of an age differ* rather than a cause-snd-effect relationship in sodium and blood pressure. Several people have pointed out that the data /used by Dr. MeCarron do not take into conakfer* ation the amount of salt people added at the table or in the preparation of food. One of the critics of the study, Herbert Langford, MD, Chief of the Endocrine end Hypertension Divi sion at the Univereity of Mieaiaeippi, has been o specific mi 's and notes ive idsntiftsd n hypertension. such as milk, yogurt, cheese, or Jettons) Heart, lines foMr OhyMpSer- 0038^8 i restriction in Tufts University Diet and Nutrition Uttesrunre. Chairman it published monthly by Tufts University:Dhieotreport. Her- Letter. Box 34T, 322 Vfeat 5? Street. NewIttohrok.ugh calcium S18 per yeor. Second class postal* paid atnNwowsvidsnes is additional mailinf offices. fotmaoter S*nrdlayddirmesps liestad. to Tufts University Diet and Nutrition Utter, PO. ~ BoukWr. CO 00322 t advics to fei nt have high y toward its dt- o meet the RDA of 800 milligrams for calciun FYI: D. R. Bishop J. H. Craddock J. C. Nassif L. J. O'Keill 10-12-33 EPA, Utilities Grapple with PCB Problems PCB's in transformers may be a thing of the past sooner than expected The Environmental Protection Afency (EPA) and a few utility companies teem ready (o accede to demands that Heps b taken quickly to replace electrical equip* meat containing polychlorinated biphen yl* or PCB's. This appears to be a rever sal, at least on the part ofEPA. ofa long standing view that PCB's in electrical equipment post no tignidrant health hasard. The utility companiit, however, have responded aa a result of recent PCB accident* and the lawsuit* that followed. In 1976. when Congress banned the manofecturinc of PCB's. It presumably thoufht that problems with this perva sive and tonic chemical were fee the most pert solved. But a loophole in the law allowed the continued use of PCB's In electrical transformers and capacitors as insulation. A year ago, the utility industry successfully argued before EPA that transformer* MM with PCB's should oaly ht replaced u the equip ment wore out. At this rate, transformers would be replaced ta 2B years. The cost to pioceed any fester would be prohibi tive. the industry contended. Now EPA is moving to close the loop hole. Because accidents involving the release of PCB's are occurring much more frequently than previously be lieved, BPA is considering a costly pro posal that would ban PCB transformers tat public buildings. But in the past 6 months, two utility companies say they have daddad to spaed up the replacemeat program not because they believe there me serious health hazards linked with PCB's hut because they say they an weary of trying to counter the public perception that PCS'* are extremely tox ic. Public concerns were heightened af ter transformer accidents m Bingham ton, New York, and Sen Francisco re sulted hi the contamination of commer cial budding*, costing mMNons of dollars to chan up. Other companits art campiigniag to calm public fears about PCB's. General Electric and Monsanto, for example, have bean active In onasminating infor mation claiming that the health effects of PCB's have been overblown. Although there is good evidence that PCB's we toxk at high dose levels, the companies maintain that the data on low-dose ef fects are hr less claar cut. Last May. tht Pacific Gas and Electric Company daddad to replace its large transformers shortly alter one of them science, vol ::: HONS 003829 1 exploded and contaminated a high-rise office building ki San Francisco. The episode, and (tie subsequent lawsuits, prompted the company to allocate $60 mttHoa over the next $ yean to replace about 1000 FCB transformer*. "We |ot tired of battling public perception," said company spokesman Tony Ledwell. Re* cemty. the Florida Power and Light Company, which services half of Flori* da, look the tame step and will spend $15 million over the next 5 years. Althoueh it has not had a major PCB accident with its Irensformers, "we're gening ahead of the game before a problem occurs," sold company spokeswomen Stacey Shew, citing the accident in San Francisco and a similar one in Binghamton that oc* curved in 1912. "The public's concerns bout FCB'i have been severely exag* rated." she said. The cause for concern can be largely attributed to the feet that FCB's ere pervasive in the environment. According to EFA. (here art 750 million pounds of FCB's either in storage or in use in the United State*. In a national health study. EFA found that almost everyone has a detectable amount of FCB's in adipose tissue, although the number affected has dropped since Congress banned the pro* ductioa of PCB's in 1976. About I per* cam of the U.S. population in 1961 hod 1977. The meaning of these low levels in not clear. But many studies show that heavy PCB exposure is toxic, according to data presented at a recent meeting on FCB's held at the National Institute for Envi* ronmemal Health Sciences at Research Triangle Fark, North Carolina. FCB's are in a class of compounds related to dibenzodioxittt end dibenzoforans. Ac cording to Ernest McConnell, chief of the chemical pathology branch at the National Institute of Environmental Health Setencei, FCB's rank third be hind dioxins and ferans when the most toxic isomer ofeach group is considered. Although Ocncrai Electric has stated that "the question of whether FCB's cause cancer in animaie is unresolved," there h Httle. if any, doubt in the aca demic sdcntHIc community that FCB's art animal carcinogens at high dost lev els. According to separate studies by Diane Nocbacfc. a pathologist at the Uni vanity of Wisconsin Medical School, and Renate Kimbrough, a medical officer at the Centers for Disease Control, FCB's cause Aver tumors in rats whan the animals are fed a heavy dose of 100 pens per million over period of 2 years. In animal studies, large doses of t ocroeex ini FCB's are also known to cause e drop in body weight, enlarge the liver, damage kidneys, and change skin pigmentation. They cause reproductive disorders in minks and monkeys. According to one study, minks fed a diet of Ash contam inated with FCB's showed a severe de crease in their reproductive rate. Mon keys exposed to FCB's became infertile. If, however, the monkeys were taken off the diet with FCB's, their fertility re turned. It is not clear whether FCB's are mutagenic. Several accidents with FCB's have provided some clinical data, but Kim brough OfCDC said at the institute meet ing that "k is difficult to sort out the toxicity'' because some of the accidents occurring in other countries may involve different mixtures of PCB isomers. An other problem is how to test for the Wortttrt eftm *p qfftr i PCB trmntfbrmtrfirt in Jen fren etic* luf May. The crMrnf prompted PUrfgr Gu end Cfrcirtr te spend M mHWen tc repfore elf IAe compenlei ferff trmmiformtrt with PCB't. presence of FCB's and how to best de termine adverse health effects. The con sensus seemed to be that fatty tissue provides the mow sensitive sample for FCB'i. Some scientists advocated serum samples, however, as a spaadier and less invasive teat. The drawback it that se rum does not bind FCB's as much as adipose tissue. Several studies do reveal some toxici ty of FCB's. In 1968. about 1300 Japa nese became HI after eating riee oO eonlaminated with FCB's that had leaked from a boat exchanger. With PCB con centrations exceeding 100 ppm, many developed chloracne, a disfiguring acne like disorder. According to a literature search by Robert MMer. chief of the epidemiology branch of the National Cancer Institute, nine pregnant Japanese women who had eaten fee rice oil gave birth to children with various abnormali ties. Some of fee babies showed dark pigmentation, which disappeared several months later. At least two children de veloped overgrown gums. The babies were also underweight. Kimbrough sag* getted that more extensive study of re productive effects in humans is needed. A number of Taiwanese were also poisoned in 1979 by rice otl that had been contaminated with FCB's. Shu-ying Tang, a physician and biochemist at Na tional Taiwan University, reported that researchers in her group have correlated neurological damage with PCB exposure among the Taiwanese who consumed the oil. Other scientists also noted molecular changes in Hver ceils from patients who have been exposed to FCB's. It is un clear. they say, what these changes mean because the patients have not as yet shown any clinical symptoms of dis ease. Arnold Schecter. professor of preven tive medicine at the State University of New York at Binghamton who has been studying the AreAghters and others in volved in the accident there, suggests that FCB's in transformers may even be more hazardous than currently believed because ferans are formed when FCB's are subjected to the intense heat ofa Are. Soot taken from the contaminated state building contained from 270 to 1206 pans per million of dibenzoforans. According to Martin Halper. chief of the exposure evaluation division at EFA. Ares involving transformers and capaci tor* containing FCB's are much more common than once thought. "It's no longer a one in a million chance. It's much more prevalent." By contacting Are departmenu, for example. EFA has discovered that "there have been s cou ple hundred Ares involving iramformen. Now the whole picture has changed " Halper estimates that there are 20.000 to 30,000 transformers with FCB's. Whether other utility compunies will fol low the lead of those in California and Florida is unclear, but Halper speculates that the majority "will have to be forced to replace the old equipment." HONS 003030