The 1995 PBS Frontline documentary “Currents of Fear” (produced by Jon Palfreman) provides a balanced, in-depth examination of the heated public controversy over whether extremely low-frequency electromagnetic fields (EMFs) from power lines and electrical infrastructure cause cancer—particularly childhood leukemia. Airing amid growing citizen activism, inconclusive science, and multimillion-dollar research efforts, the episode contrasts the lived experiences of affected families and EMF advocates with the arguments of physicists, epidemiologists, and laboratory scientists. It underscores the challenges of proving (or disproving) subtle environmental risks in an electrically saturated society, the limits of epidemiology for weak associations, and the human and economic costs of unresolved fear.
The program opens with a vivid portrait of everyday exposure: over two million miles of U.S. power lines emitting invisible, odorless, silent 60 Hz magnetic fields to which virtually everyone is exposed at home, work, and play. It introduces the core tension—dozens of epidemiological studies have linked these fields to elevated cancer risks, yet authorities have taken little protective action. Residents in Omaha, Nebraska, personify the alarm. In 1992, Julie Alram’s son Kevin was diagnosed with acute lymphocytic leukemia. Distraught and fearing for her other children, she noticed an unusual cluster of cancers at Omaha Children’s Hospital and, while driving, spotted high-voltage transmission towers and a substation near her neighborhood. She connected with other mothers, including Adrian (who reported personal and family health issues: premophilia, Addison’s disease, multiple miscarriages, cancer, and hysterectomy; her parents lived 50 feet from a 160 kV tower). Together they mapped cases, identifying 11 children diagnosed with cancer within one mile of the substation over seven years. Frustrated by the health department’s initial response, they contacted authorities, plotted data themselves, and joined the national EMR Alliance, convinced of a cover-up after viewing a CBS Street Stories segment on a California school with high teacher cancer rates and the landmark Swedish study.
Activist voices amplify the concern. Journalist Paul Brodeur (longtime New Yorker writer who exposed asbestos hazards) argues the epidemiological evidence is unprecedented in volume and consistency for any environmental agent—dozens of peer-reviewed studies associate power-frequency fields with cancer at levels far below those causing obvious effects. He calls continued inaction “unforgivably stupid” public health policy. Dr. David Carpenter, Dean of the School of Public Health at SUNY Albany, agrees: magnetic fields are “dangerous,” potentially explaining up to 15% of childhood cancers, with consistent signals for leukemia and brain tumors in both residential and occupational settings. Families like Julie’s met President Clinton (Kevin appeared on a children’s town meeting; his brother Patrick asked about EMF standards), highlighting political sympathy but perceived industry influence tying policymakers’ hands. Congress had already allocated ~$65 million for research.
Skeptics—primarily physicists and some epidemiologists—counter that causation is biologically and physically implausible. Yale physicists Robert Adair and William Bennett demonstrate that power-line fields (typically a few milligauss in homes, up to tens under lines) are minuscule compared to the Earth’s ~500 milligauss static field, in which humans evolved. The 60 Hz oscillating fields induce currents and forces thousands of times weaker than the body’s own thermal molecular motion (“lost in the noise,” like a cat’s breath affecting a tree in a windstorm). They cannot break chemical bonds or ionize DNA (unlike X-rays, gamma rays, or cosmic rays higher on the electromagnetic spectrum). Even standing under a high-voltage line at night delivers far less energy than moonlight. The American Physical Society’s report echoed this, deeming cancer fears unfounded. Bennett’s measurements on Amtrak electric trains (peaks to 600 milligauss) found no leukemia epidemic among long-exposed commuters or workers.
Epidemiology, the main pillar of concern, is portrayed as suggestive yet deeply flawed for proving causation here. Occupational studies of electrical workers show weak associations (typical risk ratios 1.5–2 for leukemia or brain cancer), but results are inconsistent: some studies elevate leukemia but not brain cancer; others the reverse; several large recent ones found nothing. Exposure misclassification is rampant—home appliances (especially close-up), wiring, and intermittent use create ubiquitous background levels comparable to or exceeding workplace exposures. “Lay epidemiology” like the Omaha mothers’ ZIP-code mapping is dismissed even by sympathetic scientists as statistically invalid (random clustering occurs by chance; the “Texas sharpshooter” fallacy of drawing boundaries after seeing the data).
The flagship residential study—the 1992/1993 Swedish investigation by Maria Feychting and Anders Ahlbom—enrolled everyone living within 300 meters of high-voltage lines over 25 years, using calculated historical fields (superior to spot measurements). It reported up to a nearly 4-fold increased leukemia risk for the most exposed children, prompting Swedish government review (though later no major policy changes). However, the episode scrutinizes the full contractor’s report (~800 risk ratios calculated across timings, cutoffs, cancer types, and subgroups). Only the strongest positive findings were highlighted in the published paper; critics call this selective reporting and multiple-comparisons fallacy—by chance alone, ~5% of analyses would appear “significant” positive or negative. Other residential studies yielded mixed or null results with similarly low effect sizes.
Laboratory science, intended to resolve the impasse, largely failed to support a mechanism or effect. The U.S.-funded large-scale rodent program at the Illinois Institute of Technology’s state-of-the-art non-metallic facility (exposing up to 3,000 animals simultaneously under tightly controlled conditions, fields from 20 to 10,000 milligauss) completed key studies by spring 1995: no increase in fetal abnormalities or birth defects (full skeletal/visceral exams on 3,000 animals); no reproductive or developmental effects across three generations; no promotion of lymphoma in cancer-prone mouse strains; and no immune-system alterations. A two-year chronic exposure study was still underway. Attempts to confirm earlier claims that EMFs subtly activate the MYC oncogene (a potential cancer pathway without breaking DNA) also failed. Molecular biologist Jeff Saffer (and a Cambridge team) rigorously replicated the experiments—including using the original investigators’ cells, vessels, and equipment—finding no effect on gene expression. Their negative results appeared in Nature (May 1995 Scientific Correspondence) alongside the Cambridge work. Additional negative findings included no EMF effect on human melatonin levels (a hormone hypothetically linked to breast cancer) and no adverse outcomes in a large study of pregnant women using electric blankets.
The episode acknowledges genuine scientific uncertainty and the precautionary dilemma. Even proponents like Carpenter admit proof is not 100%, yet see “too much smoke” for inaction. Skeptics like physicist Bennett and risk assessor Peter Volberg note that any true risk must be very small (hard to detect amid noise), making extreme measures (e.g., moving schools) potentially riskier than the hypothetical hazard (bus travel injuries/deaths are concrete and quantifiable). Society already pays an estimated $1 billion annually in anxiety-driven costs—litigation, property devaluation, unnecessary mitigation—potentially diverting resources from proven dangers like smoking or automobiles. Physicists’ past errors (e.g., downplaying radioactive fallout risks) are noted, but so is epidemiology’s history of eventually identifying real hazards (asbestos, smoking) through persistent signals.
In closing, the documentary leaves the issue unresolved but leans toward skepticism: negative lab data, physical implausibility, weak/inconsistent epidemiology, and failed replications outweigh the “smoke.” Yet families remain 100% convinced, cancers like Kevin’s and Jonathan Hendricks’ entered remission thanks to medical advances (nearly two-thirds of childhood cancers are now curable), and the public fears what it cannot control or fully understand. The program calls for rigorous science over panic or dismissal, noting that true environmental carcinogens have historically been identified through careful epidemiology plus supporting biology—not either alone.
Studies and Reports Discussed (with full citations and links where available)
- Feychting, M., & Ahlbom, A. (1993). Magnetic fields and cancer in children residing near Swedish high-voltage power lines. American Journal of Epidemiology, 138(7), 467–481. https://pubmed.ncbi.nlm.nih.gov/8213751/ (The landmark residential study; full 1992 contractor’s report with extensive analyses: Feychting, M., & Ahlbom, A. (1992). Magnetic fields and cancer in people residing near Swedish high voltage power lines (IMM-rapport 6/92). Karolinska Institutet. Available via https://www.nrc.gov/docs/ML0735/ML073510360.pdf.)
- Saffer, J. D., & Thurston, S. J. (1995). Short exposures to 60 Hz magnetic fields do not alter MYC expression in HL60 or Daudi cells. Radiation Research, 144(1), 18–25. https://pubmed.ncbi.nlm.nih.gov/7568767/ (Failed replication of claimed EMF effects on the MYC oncogene; also published as letter in Nature, 375(6526), 22–23 (1995): https://pubmed.ncbi.nlm.nih.gov/7723837/.)
- Large-scale rodent bioassays at Illinois Institute of Technology (IIT), Chicago (EMF RAPID/DOE-funded program, ~1993–1995). Multiple studies (developmental toxicity, multi-generation reproduction, cancer promotion in susceptible strains, immunology) using a facility exposing thousands of rodents to controlled 60 Hz fields up to 10,000 milligauss; all completed studies negative. (Specific papers emerged later from IIT/IITRI collaborators; episode references results reported spring 1995, with chronic study pending.)
- Norwegian study of electric railway workers (~1994). Found no effect on leukemia or cancer incidence despite high exposures. (Contextual reference; related work includes Tynes, T., et al., studies on railway/EMF exposure in Norway, e.g., updates in American Journal of Epidemiology.)
- Additional referenced studies (generic or partial details in transcript):
- Multiple occupational epidemiological studies of electrical workers (dozens published by mid-1990s; typical weak/inconsistent RR 1.5–2; e.g., misleading telephone linemen male breast cancer report with only two cases, not actual linemen).
- Human melatonin-level study (negative; no EMF effect).
- Large study of pregnant women using electric blankets (negative for adverse reproductive outcomes).
- Bill Bennett’s Amtrak/electric railroad field measurements and exposure analysis (high peaks observed; no corresponding leukemia epidemic).
These represent the core scientific references featured or critiqued in the episode. The debate continued post-broadcast, with later pooled analyses (e.g., Ahlbom et al. 2000) refining but not resolving the weak-association picture.
