During the development of new methods for the evaluation of 36 workers with well-defined chemical exposures resulting in a diagnosis of toxic encephalopathy, an observation was made that these patients have a high incidence of symptoms consistent with the new onset of an intolerance to odors (97%) and persistent fatigue (100%). A new type of brain scan, SPECT-SINGLE PHOTON EMISSION COMPUTERIZED TOMOGRAM, were positive in 84.2% of the cases and, in general, revealed decreased regional brain blood flow. The most frequently affected areas involved the frontal and temporal lobes and the basal ganglia. One patient without well-defined occupational exposure, but with a diagnosis of multiple chemical sensitivity and chronic fatigue was evaluated with the same methods and had similar results. One patient was scanned with a more sensitive device, PET (POSITRON EMISSION TOMOGRAM), by imaging regional brain glucose metabolism and had similar results to the SPECT, but additionally showed lesions of the amygdala, putamen, thalamus, and hippocampus. EEG, CT scans, and MRI of the head were negative in all but two cases and gave very little useful information.

These results suggest that the Multiple Chemical Sensitivity/Chronic Fatigue Syndromes could be variations of a neurological disorder involving the olfactory-frontal temporal lobe-limbic system and pons. Becuase of the symptoms produced by these lesions, this disorder would have the appearance of chronic fatigue, atypical allergies to any substance, multiple organ system symptoms, and would not fit into classical disease categories. Such an illness would most likely be misinterpreted as a psychological illness.

Quantum Field Theory predicts that a large number of particles (atoms and/or molecules) mutually coupled by the radiative electromagnetic field (e.m.f.), when a density threshold is exceeded, undergoes a phase transition. Particles move coherently, kept in tune by a resonating coherent e.m.f. trapped within a region (coherence domain) whose size is the wavelength of the e.m.f. The above coherent dynamics account for the dynamic properties of water.

It is possible to analyze the collective properties of biomolecules and water by using the same kind of dynamics. Some qualitative features of the dynamics of living matter are predicted.

Review of health hazards of radon. Enhancement of the exposure to radon as a consequence of smoking and passive smoking. Analysis of lung cancer death rates in industrial countries generated by occupational and environmental exposure for smokers and nonsmokers in connection with the radon exposure problem. Addressing the most important question: What is the cause of the almost complete lace of any public reaction and EPA regulation?

The dominant immunoglobulin, and the longevity of the hemagglutination inhibition (HI) antibodies against the eastern equinine encephalomyelitis (EEE) virus were studied by enzyme-linked immuno-sorbent assay (ELISA) and HI test, respectively.

Domestic chickens, ten weeks to eighteen months, were used as sentinels, immunized and hyperimmunized, of varied pedigrees and from different countries. Results (as observed in all chickens studied) show that the H1 antibody (IgG) is short-lived. It peaks and disappears below detectable levels within 30 days. IgM is the dominant immunoglobulin relatively long-lasting and constitutes the secondary response.

These results are contrary to classical expectations. If these responses are characteristic to avians, in general, then the present standard method of EEE virus seroepidemiological surveillance must be modified to be effective; these result also effect an opportunity to study the dominant immunoglobulin involve in human beings to specific micro-organisms and antigens.

Eye strain is a frequent complaint among visual display terminal (VDT) operators who worked 25-30 hrs per wk. We have investigated the effect of sustained accommodative stimulus on th tonic level of accommodation, pupil, and convergence. The results were compared with non-VDT operators. The near triad was definitely abnormal in VDT operators. Asymmetric response of the near triad in the right eye and the left eye was seen. The existence of a hysteresis of the response was also noted.

Various factors were considered to produce above phenomenon. An influence of electromagnetic wave would be considered.

The results will be shown by video.

An unexplained 1989 outbreak of EMS (elevated absolute eosinophil blood counts, myalgia, and a syndrome of disability unresponsive to treatment) brought prompt epidemiologic and basic science research response. The apparent culprit was the amino acid L-Tryptophan. To protect public health and safety, USFDA issued a voluntary recall of L-Tryptophan containing products. Most researchers developed hypotheses that directly linked a toxic effect or metabolite of L-Tryptophan to the syndrome. An alternate hypothesis was that a contaminant in L-Tryptophan preparations accounts for the EMS. To differentiate between these hypotheses, a clinical study was undertaken. The study made use of the similarity between EMS and allergic autoimmune vasculitis. The author will explain the outcome of the study.

Molecular regulation of brain metabolism and function can now be measured selectively. Patients with mood and thought disorders can often be classified based on this information. Clinical management can often be improved by therapeutic interventions based on advanced chemical and immunologic testing techniques. The relevant information is distributed over various medical, laboratory, and research disciplines and, thus, is not easily accessible by practicing psychiatrists. This lesson seeks to bridge this gap. This lesson focuses on a molecular and cell biology look at the diagnosis and clinical management of the depressions and the schizophrenias.

It is well-known that chemically sensitive patients have the symptoms of autonomic nervous system dysfunction after they are exposed to pesticides or chemical solvents. However, no objective studies have been done to address the change of the autonomic nervous system in chemically sensitive patients. We evaluated the autonomic nerve function using open loop pupillography in 43 chemically sensitive patients, proven either by intradermal or inhaled challenge under environmentally controlled conditions and 18 controls. Of 43 patients, 20 had orgaochlorine pesticides in their blood and 23 had chemical solvents (aliphatic and aromatic) in their blood. The significant differences of autonomic nervous nervous system function were seen in velocity of constriction and dilation time in the chemical solvents patients group, compared to the control group. In the pesticide patients group, the significant differences were seen, not only in the velocity of constriction and dilation time, but also pupil area and velocity of dilation. These results showed that the patients with chemical sensitivity usually had deregulation of their autonomic nervous system. The pupillary abnormalities that were the result of autonomic nerve disturbances were seen in 33 out of 43 chemically sensitive patients by pupillographical examination as compared to a control group. When analyzing the type of autonomic nerve disturbance in the patients, the inhibitory (sympatholytic) type of ANS function was seen in 21 of 33 patients while cholinergic changes were seen in nine patients. This present pupillographical study suggests that there is autonomic nervous system dysfunction in chemically sensitive patients, and their dysfunction can be accurately measured under environmentally controlled conditions.

Epidemiological studies suggest that chronic exposure to electromagnetic fields (EMFs) increases the risk for disease, particularly cancer. Clinical observations suggest that acute exposure to EMFs produces a broad range of symptoms. Our hypothesis is that EMF effects are post-translational with respect ot the EMF-detecting cell (PDC): Fields are detected by a neural electrogenic protein that mediates subthreshold changes in membrane potential, which modify ongoing oscillatory behavior. The resulting efferent CNS signals initiate nonspecific adaptive responses to the EMF, which may trigger reactions in sensitive individuals. Chronic activation of the adaptive system adversely affects immunosurveillance by natural killer cells, thereby increasing the occurrence of disease. The portion of the theory dealing with the prediction of altered brain-wave activity was tested by exposing subjects to EMFs and comparing the brain waves (in the form of their Fourier transform) with those obtained from the same subject when the EMF was not applied, using the Wilcoxon signed-ranks test. Sham exposure (no field applied) was used as a negative control, light was used as the positive control. The results were (N, # of subjects; ND, # of subjects that detected the stimulus.

It is clear that EEG sensitivity to weak magnetic fields is a general characteristic of human subjects, as predicted by the PDC theory.

The firing of action potentials recorded intracellularly from somata of adult mouse sensory neurons in cell culture was decreased reversibly by a static 10 milli Tesla (mT) field produced by an array of four permanent magnets of alternating polarity. Resting membrane potential and input resistance were not affected significantly. A 13.7 mT field produced by two magnets of alternating biological effects of static magnetic fields produced by arrays of permanent magnets may be determined by the configuration of the field or its gradient.

A number of biological processes are characterized by the rapid polymerization of cytoplasmic monomer to form a functional structure which, after the function is completed, rapidly dissolves. These structures have a high degree of spatial organization, which is reproducible from cell to cell. Examples include the polymerization of tubulin monomers to form the spindle apparatus in mitosis, and the polymerization of actin to form the cytoskeletal structure of the pseudopod in the direction of the chemotactic gradient in chemotaxis. A number of observations suggest that electric fields are involved in these phenomena:

We propose that the mechanism by which internal electric fields determine the spatial organization of labile cellular structures is the switching-on of an internal electric field that interacts with the electric dipole moment of cytoplasmic monomers to orient them in the direction of the electric field. The resultant enhancement of the polymerization rate is calculated and found to grow exponentially with chain length, making this an excellent mechanism to explain the rapid switching observed. Polymers will form parallel to the field lines in the model, so simple charge distributions will determine complex structures. This approach allows the calculation of intracellular structures by postulating charge distributions. In the case of mitosis, assuming a dipole field with foci at the spindle poles allows the calculation of the spindle apparatus at metaphase, and excellent agreement with light and electron microscopy data is obtained. Excellent agreement is also obtained with many aspects of chemotaxis.

An epidemiological screening study of 6,000 office workers in Northern Sweden has been conducted. The workers were selected in a proportional stratified manner from all office employees from workplaces with more than ten office employees. A questionnaire, tested and validated in a prestudy, was used to gather data on the perceived indoor climate and psycho-social work load, demographic data and reported symptoms, work characteristics and building data at work and at home.

The study is the first part in a study of sick building syndrome (SBS) and video display terminal (VDT)-related skin symptoms in office workers. It is followed by two case-referent studies and a complementary study on 15 buildings with high and 15 buildings with low prevalences of SBS.

The data from the questionnaire confirmed that women, more than men, suffer from SBS symptoms and from negative physical climate factors. SBS cases are more prevalent among workers with a personal history of atopy and among VDT users. Two-thirds of the office workers used VDTs on a daily basis; 30% less than 1 hr, 20% more than 4 hrs/day. The skin symptoms from the questionnaire showed a clear dose response increase with the time spent in front of the VDT, reaching an odds ratio of about two for the group with the highest exposure compared with the lowest.

Cell demodulated electronically targeted analgesia treatment device is described. This unique equipment, which has been on trial at the Breakspear Hospital, has been found to be effective in two studies for dental treatments, including fillings and teeth removal and the replacement of epidural anesthesia in labor in a study of 500 patients.

In our evaluation, we have used it for patients with a variety of medical complaints, including arachnoiditis, rheumatoid arthritis, herpes zoster with peripheral neuritis, and others. The theoretical background to this equipment and its eficacy will be discussed.

In recent years, it has become clear that a syndrome of depression during the winter months is quite common. Various causes have been suggested, but the consensus is that it is hormonally controlled. It is usually associated with longer periods of sleep during the winter months and often an increase in weight associated with carbohydrate craving.

It has been described in blind patients and is, therefore, not normally associated with light perception variations with the seasons. It is possible to treat relatively simply, and there is good response to this treatment in most patient. It is also clear that, where the seasonal variations are relatively slight, benefit can still be gained from treatment.

A questionnaire has been devised for patients and a survey undertaken. An analysis of these results will be undertaken and discussed.

NeuroElectric Therapy (NET) is a ten-day treatment for all drugs of dependence, including alcohol and tranquilizers (four days for cigarettes) by a transistorized, pre-programmed electric stimulator, which rapidly reduces both acute and chronic withdrawal symptomatology of all substances of abuse, without administering drugs, and without any negative side-effects.

It is hypothesized the NET acts by specific electrical frequency stimulation of endorphin production that has been decreased due to chronic substance abuse. There is possibly a chain effect on other neurotransmitters, since both craving and anxiety are demonstrably diminished.

NET used in our rat models has shown that cortisol, serotonin, and hepatic enzyme activity were significantly altered. The findings of other scientists will also be reported.

The latest follow-up of NET-treated patients over seven years showed that 98% were successfully detoxified and that, between 1 and 8 years later, 80% were free of their substance of abuse.

It will be demonstrated that the frequency and shape of the wave are of critical importance.

In this paper, we briefly present our research on biological effects of specific frequencies and waveforms of magnetic and electromagnetic field emissions. We have conducted extensive experimentation involving field effects on such physiological parameters as EEG, EKG, and GSR, by externally generated, low-frequency, low-intensity, magnetic, and electromagnetic fields. We have also developed a theoretical model that describes some aspects of the process of information processing in the human body. This work has been conducted over the last eleven years and may give new insights into central and peripheral nervous system functioning as well as cardiac physiology.

The reason we believe these fields can have effect on biological processes in humans, as well as canines (which we have also studied) is that they match some of the natural electromagnetic signals used in transfer of information associated with life processes, i.e., biocybernetics.

The incredible sensitivity of biological systems to extremely low intensity magnetic fields of highly complex combinations of waveform, different frequencies, and intensities is of interest not only because it may help physicians in the clinical setting but to help scientists better understand information processing in living systems.

The public and the scientific community are in a controversy over the possible harmful or beneficial biological effects of weak electromagnetic and magnetic fields. This controversy can only be resolved by careful scientific research. The issues involved are:

The two major phases of the research conducted, which is described briefly in this report, were the following:

The main emphasis in our laboratory has been to characterize natural and manmade fields in various parts of the United States and Canada as to their frequency content, waveform shape, intensity, possible source location, frequency of occurrence, and degree of variability over time.

In this presentation, we will present a brief, but detailed account of our environmental monitoring on an almost daily basis from 1979.

Seventy-three patients with electromagnetic sensitivity were treated on a regimen of rotary diet, nutrition, with injection for metals, biolgical inhalants, foods, and chemicals. They also were placed on an avoidance program for electromagnetic generating substances. The length of the follow-up was 1 to 20 months. Twenty-five patients (34.2%) improved, 46 patients (63.1%) stayed the same, and 2 patients (2.7%) got worse.

The human pineal gland, a neuroendocrine organ near the center of the brain, produces an important hormone, melatonin, which has a number of effects on both endocrine and nonendocrine tissues. Melatonin is synthesized by the pineal in a circadian manner with low levels being produced during the day and high levels at night. Melatonin is rapidly released into the blood vascular system; melatonin concentrations during the day are 10-20 pg/ml while at night they are 40-70 pg/ml. The circadian rhythm of melatonin production is normally regulated by visible radiation (light), which is detected by the retina and transferred to the pineal over a series of neurons in the central nervous system. The exposure of humans to light at night is followed by a precipitous drop in both the synthesis and secretion of melatonin. In humans, there is a fluence-response relationship between the intensity (or irradiance) of light and the degree of melatonin suppression. The wavelengths that are most capable of inhibiting melatonin synthesis are 500-525 nm light, i.e., blue light; thus, preliminary data suggest that rhodopsin, which is activated by blue light, is the retinal chemical mediator of the inhibitory effects of light on the pineal gland. Besides visible radiation, extremely low frequency (ELF) electromagnetic (EM) radiation also suppresses nocturnal pineal melatonin production. Thus, in experimental animals (including nonhuman primates and presumably humans), combined 60 Hz electric and magnetic field exposure prevents the nocturnal rise in pineal melatonin synthesis. Also, the exposure of animals to pulsed, static MF is severely detrimental to pineal melatonin synthesis. The pulsed magnetic fields seem to produce their effects by inducing electric currents (eddy currents) in the animals; these currents cause the formation of phosphenes (visual impressions of light), which, like light, suppresses pineal and blood melatonin levels. Since melatonin is a natural anticancer agent, these observations have implications for cancer incidence. The inhibitory effects on these wavelengths on melatonin also relate to immunodeficiency, reproductive dysfunction, cardiovascular problems, and depression.

Patients who claimed that exposure to common xenobiotics exacerbated their varied symptoms were asked to evaluate a modified macrobiotic diet. It is a demanding diet requiring total restructuring of the kitchen, diet, household, and life, putting new demands not only on the patient, but on friends and family as well. Many choose not to make this commitment.

To 160 patients who were asked to evaluate the diet, a questionnaire was sent. Many chose not even to try the diet. Forty-eight responded. Of these, 17 questionnaires were disregarded as they had not answered every question on the form. The 31 (13%) remaining responders rated their degress of strictness with the diet on an average of 71% (range 20 to 100%). The average length of time on the diet was 11 months (range 1.5-36). They rated themselves as 67% (10-100%) chemically less sensitive and felt that their overall improvement in total health problems was 76% (30-100).

This overall improvement included other modalities such as injections, nutrient corrections, Candida programs, and a reduction in stress. They felt that 51% (10-100) of their reduction in chemical sensitivity was directly due to the modified macrobiotic diet. Specific case examples will demonstrate dramatic improvement in documented cases of rheumatoid arthritis, acute myelogenous leukemia, chemical, food, mold and electromagnetic sensitivity, Stage IV lymphoma, and multiple sclerosis. The possible mechanisms will be explored.

A 36-year-old female software engineer presents with a history of fatigue, headaches, inhalant allergies, memory loss, poor concentration, and short attention span for about one year, which was considerably worse after being at work for one hour. She reported widespread chemical sensitivities and other somatic complaints, and stated that she could not read and comprehend well. She had worked as a software engineer for five years, writing actuarial programs, using two computer monitors all day. She was also a part-time graduage student in computer science at a local university. The electromagnetic milieu of her place of work, the university setting, and how it affected her will be described. The patient was tested using the Iriscorder, which is a computerized assessment of autonomic nerve function. A series of double-blind EMF exposures was conducted to see if there would be specific frequencies that would provoke symptoms or that induced changes in the computerized pupillographic testing. The results of a screening challenge of multiple frequencies will be shown, along with the results of a specific double-blind, placebo-controlled challenge of 1.0 Hz. The changes induced in the autonomic nerve function were statistically significant. The implication of this confirmed electromagnetic sensitivity will be discussed in the context of the overall treatment of the patient.

All-trans retinoic acid (RA) and dexamethasone (DEX) are teratogens in mice. A 2x2 factorial design experiment was undertaken using RA and DEX to determine whether RA and DEX interact on post-natal murine development. Forty timed pregnant mice [x2] (bred 08:00-09:00) were divided into four groups. RA was given orally (200 or 50 mg/Kg) on day 10.5 (plug date day=0) in 10 ml/kg corn oil. DEX was diluted in sterile saline and given ip (1.25 mg/Kg) on days 10, 11, 12, and 13 at a volume of 10 ml/kg. RA and DEX reduced maternal hepatic and splenic weights (p<0.05). Maternal weight, feed consumption, implantations, sex of the fetuses and duration of pregnancy did not differ among treatment groups; however, survival and growth were affected. RA (200 and 50 mg/kg) and DEX caused synergistic loss of pups within the first 24 hrs (RA p<0.01; DEX p<0.01; interaction p<0.05). Mice treated with DEX had pups which, on day 21, were heavier than the other groups (p<0.01); interaction with RA (p<0.05) can be explained as removal of the DEX effect. Crown-rump length was initially shorter in RA and DEX groups (p<0.05), but rapidly became longer than the control and RA/DEX groups (p<0.05). No differences were noted in time for developmental milestones to occur (eyes and ears open, hair growth, and independent feeding). RA and DEX increased activity and decreased balance at 14 days. It was concluded that RA and DEX produced synergistic decreased post-natal survival, but minimal interactive effects on postnatal development.

(Support: NSERC OGP0036697)

Subclinical toxicology, by definition, is a field in which application of the scientific method is difficult. Subclinical toxicity implies lack of overt clinical manifestations of disease following toxic insult; therefore, sensitive methods of detecting subtle changes must be used to determine these toxic effects. This presentation aims to first alert the audience to the problem of toxicity testing, and how a few individuals are going to slip through the safety net. Later suggested methods of research to solve the problem of subclinical toxicity will be put forward. The presentation will firstly outline the methods presently used for toxicity testing, risk assessment, and regulation of compounds. Next a glance at the balance of how the risk assessment process tries to achieve a best results for most individuals will be given. The field of subclinical toxicology will then be outlined, and some of the methods used to determine the subtle endpoints of such toxicity given. Research methods detailed will then be organized in a reductionist method to show how basic questions of toxicity may be evaluated.

(Support: NSERC OGP0036697)

The author will discuss the chemistry of the omega three and omega six polyunsaturated essential fatty acids. The metabolic interrelationships and biochemical pathways will be delineated as well as the ability of man to dietarily manipulate the prostaglandins formed from these metabolically significant fatty acids. The relationships between allergic and inflammatory disorders and the dietary fatty acid composition will be covered in an attempt to demonstrate how these dietary manipulations can augment the therapeutic regimes used in the environmentally ill patient.

Skin symptoms among VDT-workers have been reported frequently in the last years. The cause for the symptoms has not yet been established. VDT-factors such as electric and magnetic fields, electrostatic charge, indoor climate factors, and psychological factors have been suggested. From a screening study of 6,000 office workers, a group of 150 VDT-workers were selected for a case-referent study. Cases were defined as VDT-workers with sensory and visual facial skin symptoms. Referents were VDT-workers free from such symptoms and matched for age, sex, and living area.

The investigated parameters can be divided into four sections; environmental physical factors as temperature, humidity, and personal charge; background 50 Hz electric and magnetic fields; VDT-related fields both in the line frequency range and the refresh rate range; and other VDT-related factors such as line frequency. The methods used for these measurements will be described.

A comparison between number of cases and referents regarding most of these various parameters showed no difference due to exposure. However, more cases than referents were found among VDT-workers with a high background 50 Hz electric field. Comparing the lowest exposed group with the highest exposed the odds ratio (OR) was a 3.0 (95% CI:1.2-7.2). An increased OR was also found among VDT workers with a high magnetic field in the refresh rate range. The same comparison gave in this case an OR of 2.5 (95%) CI:1.0-6.4).

The role of electromagnetic fields in the development, function, and homeostasis of the healthy human organism is discussed with particular reference to the electromagnetic properties of water. Electromagnetic fields provide yet another environmental stressor that man must succeed in coping with in order to retain health.

Disease in the human organism is considered as the failure of one of the endogenous regulatory systems intended to maintain homeostasis. The extent to which there may be an electromagnetic component to the processes constituting the disease state as well as the possiblity of the electromagnetic environment contributing to the disease condition is considered.

A description will be given of the mechanisms through which static magnetic fields interact with living systems. These mechanisms include electrodynamic interactions with moving ionic charges (blood flow and nerve impulse conduction), magnetomechanical interactions (orientation and magnetomechanical interactions (orientation and translation of molecular structures), and interactions with electronic spin states in charge transfer reactions (photo-induced electron tranfer in photosynthesis). A general summary of biological effects of static magnetic fields will also be presented, including experimental evidence for magnetoreception mechanisms in several classes of organisms. In many species of animals, there is no evidence that the interactions of static magnetic fields with flux densities up to 2 Tesla (20,000 Gauss) produce significant behavioral or physiological alterations. Although large electrical potentials are induced in the central circulatory system of animals exposed to high-intensity magnetic fields, there is no indication from extensive laboratory studies with rodents, dogs, or subhuman primates that these electrical stimuli produce alterations in cardiovascular functions. These conclusions, based on controlled studies with laboratory mammals, are supported by epidemiolgical surveys on human populations exposed occupationally to static magnetic fields.

Research support received from the U.S. Dept. Of Energy under Contract DE-AC06-76-RLO 1830 with the Pacific Northwest Laboratory. The Pacific Northwest Laboratory is operated from the U.S. Dept. of Energy by the Battelle Memorial Institute.

In contrast to the well-characterized, time-varying electric and magnetic fields associated with action potentials in nerve and muscle tissue, other biological systems produce a variety of steady or slowly-varying electric and magnetic fields that are poorly understood. For technical reasons, the electric fields are difficult to study. The elctrodes used for measuring biologically-produced potentials generate electrochemical potentials at the tissue-electrode interface that are affected by local ionic concentrations, pressure, and movement, and, as a result, produce slowly varying voltage artifacts. The vibrating microprobe, developed by Jaffe and his colleagues, affords measurement of steady potentials in cellular systems, but with this technique, the measurements must be made in a saline bath surrounding the specimen, which prohibits the study of steady currents deep within solid tissue. Magnetic techniques may overcome some of these limitations, since a high-sensitivity Superconducting Quantum Interference Device (SQUID) magnetometer can noninvasively detect a steady magnetic field emanating from within living tissue, and matematical models can be used to discern the strength and location of the currents that produce this field. Magnetic particle contamination must be avoided, and the measurements must be made in a magnetic shield. Steady field measurements conducted in several laboratories worldwide include observations of transient injury currents associated with myocardial ischemia, and 1-10 pT steady fields from the scalp, abdomen, and limbs. Magnetic measurements of the intact human brain and exposed or isolated animal preparations demonstrate the presence of steady magnetic fields associated with epileptic seizures, migraine, and spreading depression. Developmental currents have been recorded from chicken embryos after only 18 hrs of incubation. The role of steady currents in the development and function of complex biological organisms may have a yet unappreciated significance. While there is a possibility that in certain cases these currents are epiphenomena of little physiological significance, it is as yet premature to dismiss the currents as having no role in either development of homeostasis. If they have a role in physiology, they could as well provide a mechanism for interactions between biological systems and externally-applied magnetic fields. SQUID magnetometers may provide the requisite means for studying these currents.