From pmadden@igc.apc.orgThu Mar 14 12:28:27 1996 Date: Tue, 12 Mar 1996 06:07:00 -0800 From: Patrick Madden To: sanet-mg@amani.ces.ncsu.edu Subject: farming under power lines Every major city, including Los Angeles where I live, has substantial acreage under power lines not available for many uses. Areas such as this are often used for "urban agriculture." High value horticultural crops, very close to markets, are often grown. Recently I was asked whether there is any scientific validity to the claim that living and working under high voltage power lines is harmful to human health -- physical, emotional, mental. I recall hearing apocryphal conclusions of long term ill effects, both on people and on the crops and livestock. I'd like to be able to reply to these inquiries with scientific data. If you are aware of any good references, please let me know. If there are omionous effects, then farming under the power lines is not "sustainable." Thanks. Patrick Madden, World Sustainable Agriculture Association (WSAA is a private non-profit organization.) From VERHEY@wsuvm1.csc.wsu.eduThu Mar 14 12:30:39 1996 Date: Tue, 12 Mar 96 12:55:22 PST From: Steve Verhey To: pmadden@igc.apc.org, sanet-mg@amani.ces.ncsu.edu Subject: Farming under power lines Hello, Re your question on sanet about the effects of electromagnetic fields (EMF) on people and crops. As you may be aware, EMF issues are in the news most recently because of a paper in the International Journal of Radiation Biology (mid-February 1996 issue). In the paper, the authors speculate about a link between radon daughters influenced by electric fields and certain cancers. However, they also state in their abstract "at present, there still remains no persuasive biological evidence that power frequency electromagentic fields can influence any of the accepted stages in carcinogenesis." There is a news item in the 15 February issue of Nature from which I took most of the above information. As far as I can tell, the issue of EMF's effect, if any, on cancer (I haven't heard about mental or emotional effects) is still very much up in the air. A paper in last year's Nature (Vol 375, p 23) reported a failure to reproduce one of the most highly publicized possible links, an increase in transcription of a gene involved with carcinogenesis, but there have been several reports of the connection. The Nature paper contains a number of references, and might be a useful place to start your research, but even the experts seem confused at the moment. Of relevance to the issue of growing and working on crops under power lines, most or all of the effects that have been reported are seen at the limits of detection. It may be that the level of exposure of a person who works in the fields (both agronomic and electromagnetic) seasonally and sleeps away from the field is low enough to be of little concern. As for the crops, I have always wondered why no one seems to have looked at the effects of EMF on plants such as trees that live for extended lengths of time and many generations under very high voltage long distance power transmission lines. As far as I know, this is still an open study area. Back to the radon issue: the title of the Int. J. Rad. Biol. paper is "Enhanced deposition of radon daughter nuclei in the vicinity of power frequency magnetic fields." Apparently it has long been known that EMF causes radon daughters to stick to surfaces. So there may be a chance that, _in areas of high levels of soil radon_, radon decay products might be deposited on crop plant surfaces. In areas of low radon levels this would not be a concern, of course. Hope this helps, Steve Verhey Department of Crop and Soil Science Washington State University Pullman WA 99164-6420 From mross1@uic.eduThu Mar 14 12:31:09 1996 Date: Wed, 13 Mar 1996 12:13:39 -0600 From: Mary Ross To: sanet-mg@amani.ces.ncsu.edu Subject: farming under power lines I reviewed the EMF issue last year, and thought I'd briefly outline my findings. Regarding cancer, there have been studies that go both ways, some finding associations between increased cancer rates and electromagnetic field exposure and some not. Where increased rates are found, the cancers have been lymphomas, leukemia and nervous system cancers. The gist of the review is no conclusive evidence for either effects or no effects. A new study was published just a month or so ago, I believe in Amer. J. Epidemiology, which also found no increase in cancer rates. The same is true of the concern about increased miscarriage rates. Chernoff et al (Toxicology. 1992. 74:91-126) reviewed animal studies and came to no conclusion. Shaw and Croen (Environ Health Perspectives. 1993. 101(suppl 4): 107-119) reviewed the human studies and also came to no conclusion. What I found interesting were the few studies on depression and suicide. The earliest report was by Reichmanis et al (Physiol Chem Physics. 1979. 11:395-403) in which suicide deaths in England were plotted along with the location of electric transmission lines, and there was a positive association with this measure of EMF exposure. In a series of studies, Perry et al (Public Health. 1989. 103:177-180; Public Health. 1988. 102:11-18; Health Physics. 1981. 41:267-277) found that people living closer to power cables had higher rates of depressive illness or suicide; Dowson et al (The Practioner. 1988. 232:435-436) did a similar study with similar results. The most recent studies give conflicting results. Poole et al (Am J Epidemiol. 1993. 137:318-330) conducted a telephone survey of residents and divided them into "near" and "far" groups based on proximity to power lines. A significant positive association was found between depressive symptoms and being near a power line. In contrast, McMahan et al (Am J Epidemiol. 1994. 139:58-63) made measurements of magnetic fields in study participants' homes, and found no significant association between depressive symptomology and proximity to power lines. The proposed biological mechanism is based on the neuro-endocrine function of the pineal gland. Wilson (Bioelectromagnetics. 1988. 9:195-205) provides the best summary. In the wee hours of the morning the pineal gland kicks in on melatonin production, and animal studies have found that EMF exposure can reduce melatonin production, as has an interesting study of humans using electric blankets. It is believed that a low-melatonin syndrome may disrupt not only circadium rhythms, but may interfere with the serotonin and catecholamine balance that is believed to be important in causing clinical depression. I found this interesting, but I must note that the big problem with all of these studies is measuring exposure to EMF. Proximity to power lines is a very crude measure, and doesn't take into account length of residence, workplace exposures, or differences in home wiring. It would be expensive to design a more accurate study, and time-consuming, too. From brateaver@aol.com Sat Mar 16 10:40:27 EST 1996 Article: 11382 of alt.sustainable.agriculture Path: newz.oit.unc.edu!concert!news-server.ncren.net!taco.cc.ncsu.edu!lll-winken.llnl.gov!news.larc.nasa.gov!lerc.nasa.gov!magnus.acs.ohio-state.edu!math.ohio-state.edu!howland.reston.ans.net!newsjunkie.ans.net!newsfeeds.ans.net!newstf01.news.aol.com!newsbf02.news.aol.com!not-for-mail From: brateaver@aol.com (BRateaver) Newsgroups: alt.sustainable.agriculture Subject: Re: farming under power lines Date: 15 Mar 1996 06:37:17 -0500 Organization: America Online, Inc. (1-800-827-6364) Lines: 4 Sender: root@newsbf02.news.aol.com Message-ID: <4ibkpd$9l9@newsbf02.news.aol.com> References: <199603121407.GAA00922@igc2.igc.apc.org> NNTP-Posting-Host: newsbf02.mail.aol.com X-Newsreader: AOL Offline Reader Dr. Madden, would you not wish to ask Dr. Philip Callahan, recently retired from U. Florida? B. Rateaver