Low Frequency Magnetic Field Exposure Research Articles

Up- and Down-Regulation of Enzyme Activity in Aggregates with Gold-Covered Magnetic Nanoparticles Triggered by Low-Frequency Magnetic Field.

The modern global trend toward sustainable processes that meet the requirements of "green chemistry" provides new opportunities for the broad application of highly active, selective, and specific enzymatic reactions. However, the effective application of enzymes in industrial processes requires the development of systems for the remote regulation of their activity triggered by external physical stimuli, one of which is a low-frequency magnetic field (LFMF). Magnetic nanoparticles (MNPs) transform the energy of an LFMF into mechanical forces and deformations applied to enzyme molecules on the surfaces of MNPs. Here, we demonstrate the up- and down-regulation of two biotechnologically important enzymes, yeast alcohol dehydrogenase (YADH) and soybean formate dehydrogenase (FDH), in aggregates with gold-covered magnetic nanoparticles (GCMNPs) triggered by an LFMF. Two types of aggregates, "dimeric" (with the enzyme attached to several GCMNPs simultaneously), with YADH or FDH, and "monomeric" (the enzyme attached to only one GCMNP), with FDH, were synthesized. Depending on the aggregate type ("dimeric" or "monomeric"), LFMF treatment led to a decrease (down-regulation) or an increase (up-regulation) in enzyme activity. For "dimeric" aggregates, we observed 67 ± 9% and 47 ± 7% decreases in enzyme activity under LFMF exposure for YADH and FDH, respectively. Moreover, in the case of YADH, varying the enzyme or the cross-linking agent concentration led to different magnitudes of the LFMF effect, which was more significant at lower enzyme and higher cross-linking agent concentrations. Different responses to LFMF exposure depending on cofactor presence were also demonstrated. This effect might result from a varying cofactor binding efficiency to enzymes. For the "monomeric" aggregates with FDH, the LFMF treatment caused a significant increase in enzyme activity; the magnitude of this effect depended on the cofactor type: we observed up to 40% enzyme up-regulation in the case of NADP+, while almost no effect was observed in the case of NAD+.

EXTREMELY LOW FREQUENCY (ELF) MAGNETIC FIELD RADIATION ANALYSIS OF TEMPE MATERIAL MATURITY

Electromagnetic waves in physics are waves composed of a magnetic field and an electric field whose propagation does not require an intermediary medium. Magnetic fields with Extremely Low Frequency (ELF) frequencies have a frequency range of 0 to 300 Hz. Electromagnetic waves can propagate without needing a medium, so they are called electromagnetic radiation with various types of electromagnetic waves which are differentiated based on their frequency. Electric fields are easily blocked, so their intensity will decrease if they are blocked by objects. Meanwhile, magnetic fields have characteristics that are not easily blocked so they can penetrate almost all materials. The aim of this conducted research is to examine the influence of Extremely Low Frequency (ELF) magnetic field exposure on pH in the tempe fermentation process. This research uses a Completely Randomized Design (CRD) research design to examine the effect of several treatments with a number of replications for several experiments. The research findings indicate that exposure to Extremely Low Frequency (ELF) magnetic fields affects the pH in the tempe fermentation process, as depicted by the variations in the tables presented in the research results. Tempe is one of the fermented products that generally uses soybeans as the main raw material that has been fermented and has excellent nutritional content. Fermentation in making tempe occurs due to the activity of the mold Rhyzopus oligosporus which is able to produce phytase enzymes that function to hydrolyze phytic acid into inositol and phosphate.

Study on the safety assessment and protection design of human exposure to low-frequency magnetic fields in electric vehicles.

As the power performance of electric vehicles continues to improve, the human body may be exposed to electromagnetic threats in the cabin. This study tested an electric vehicle to analyze the low-frequency magnetic field distribution in the cabin and to assess the safety of human low-frequency magnetic field exposure. A simulation analysis of human electromagnetic exposure was carried out to obtain the magnetic flux density, induced electric field strength and induced current density, and the test results were much lower than the limits specified in GB8702-2014 and the International Commission on Non-Ionizing Radiation Protection, and the relative error between the simulation results and the test results was <15%. This paper investigates the frequency, driving current, vehicle body material and cable layout to explore the law of human body induced electromagnetic field changing with power cable current, and provides theoretical reference for the design of human body low-frequency magnetic field protection.

Extremely Low Frequency Electric and Magnetic Fields Exposure: Survey of Recent Findings

Extremely Low Frequency Electric and Magnetic Fields Exposure: Survey of Recent Findings

EFFECT OF EXTREMELY LOW FREQUENCY (ELF) MAGNETIC FIELD EXPOSURE OF 700µT AND 1200µT INTENSITIES ON THE DEGREE OF ACIDITY (pH) AND MASS OF LEMURU FISH (Sardinella lemuru)

The Extremely Low Frequency (ELF) magnetic field is included in electromagnetic waves which have a frequency range of 0-300 Hz. In foodstuffs, the use of magnetic fields can be used for food security. Lemuru fish is a fish that is consumed by many people. In general, lemuru fish will last approximately 8 hours after arriving from capture. The purpose of this study was to examine the effect of exposure to the ELF magnetic field on the degree of acidity (pH) and density in lemuru fish. The research design used was Completely Randomized Design (CRD). Extremely Low Frequency (ELF) magnetic field exposure treatment is used to increase lemuru fish resistance by inhibiting pathogenic bacteria. The research sample was 110 lemuru fish and divided into 5 groups. One group served as a control, 2 experimental groups were exposed to an ELF magnetic field intensity of 700µT for 60 minutes and 120 minutes, and the other 2 groups were exposed to an ELF magnetic field with an intensity of 1200µT for 60 minutes and 120 minutes. The variables studied included the pH value and the density of lemuru fish. Measurements of pH and density were carried out at the 8th and 20th hours after exposure to the ELF magnetic field. The research data were analyzed using statistical analysis, namely the Kruskall Wallis Test. The results of this study indicated that the intensity of 1200µT for 60 minutes was effective for maintaining the pH value of lemuru fish, while the intensity which was effective for maintaining the density value was 1200µT for 60 minutes and 120 minutes until the 20th hour.

The effects of extremely low-frequency magnetic field exposure on apoptosis, neurodegeneration and trace element levels in the rat brain

Aim: The aim of this study was to investigate the effects of 1mT, 1.5 mT, and 2 mT extremely low-frequency magnetic fields, which were within the limits for public environmental and occupational magnetic field exposure guidelines, on apoptosis, neurodegeneration and trace elements in rat brain cells.&#x0D; Material and Method: A total of 35 adult male Wistar rats were allocated into four main groups: Group 1 (n=8) was healthy controls; Group 2 (n=9) was exposed to 1 mT extremely low-frequency magnetic field; Group 3 (n=9) was exposed to 1.5 mT extremely low-frequency magnetic field and Group 4 (n=9) was exposed to 2 mT extremely low-frequency magnetic field. All the rats in the exposure groups were exposed to 50 Hz extremely low-frequency magnetic field for 4 hours per day, 5 days per week for 30 days in the Helmholtz coils. After the exposure, rats were sacrificed and rat brains were evaluated for histopathological and immunohistochemical changes as well as about the trace element levels in the brain.&#x0D; Results: Different levels of exposure to extremely low-frequency magnetic field doses caused increases in Ca levels and increased apoptosis in the rat brain. As the applied extremely low-frequency magnetic field levels increased, so did the apoptosis and Ca levels in the brain tissues. &#x0D; Conclusion: Extremely low-frequency magnetic field exposure caused neurodegeneration in rat brain tissue, increased apoptosis, and increased Ca concentration. These changes may cause various biological damage, especially cancer in healthy tissues and measures should be taken to minimize extremely low-frequency magnetic field exposure in daily life in terms of protecting public health.

Proof of Concept of an ELF Magnetic Field Exposure System with Biphasic Magnetic Pulses: Effects on Human Dermal Fibroblast Proliferation

The aim of this work was to validate the usefulness of an Extremely Low Frequency (ELF) magnetic field exposure system with a magnetotherapy device of common use in clinical practice that generates Biphasic Magnetic Pulses (BMP), in order to study the effects of the BMP on the proliferation of Human Dermal Fibroblasts (HDF). In that regard, HDF were exposed 2h in the morning and 2h in the afternoon for 2 days to BMP of 1.41mT peak value at 5, 10, 25Hz continuous and 50Hz intermittent (2s on/ 1.5s off). MTT assay was performed to assess proliferation. The 10Hz BMP showed a significant decrease in proliferation of 6.6% (p = 0.001) with respect to controls, but no significant changes in proliferation were seen with the other BMP. In order to analyze whether these results could be related to the exposure protocol, a 50Hz power line intermittent signal (1s on/ 1s off) was generated and tested but exposure time was increased to 48h to cover the complete cells doubling time. A significant increase in proliferation of 9% (p < 0.001) was found in this case. The results validate the in vitro exposure system for its use with the BMP. Though the MTT proliferation assay alone is not enough to make definitive claims, the results might indicate that exposure time plays a key role in the outcome of the experiments. Therefore, special attention should be paid to the exposure time on in vitro protocols and how they relate to in vivo experiments and current treatments.

Improving the Understanding of Low Frequency Magnetic Field Exposure with Augmented Reality.

Low frequency magnetic fields are often present in our everyday life due to the multitude of electronic devices. High magnetic fields can occur in the workplace from a wide variety of machines and systems, which must be measured and evaluated from the point of view of occupational safety. To facilitate the understanding of magnetic fields by supervisors and employees in the workplace, an augmented reality (AR) application was developed to visualize the measured flux densities and the resulting safety distances. The application was deployed on two smartphones, allowing for the simultaneous viewing of the same scene without the use of additional markers. Whether the application creates a better understanding of the exposure situation was evaluated with the help of an online survey. In this survey, participants received either a classic measurement report or a report enhanced by augmented images. The evaluation shows that it subjectively felt less difficult for participants with the augmented report to answer questions about the exposure situation. Furthermore, they also objectively performed better in answering the questions than did the group with the classic report. Therefore, this work shows that AR enhanced images can improve the understanding of an exposure situation, and it describes how such images and videos can be created.

Effect of high- intensity extremely low frequency magnetic field on the intermediate stage atherosclerotic plaque remodeling: Monitored by histopathology and color doppler ultrasonography

Background and Aims : The aim of this study was to generate an experimental rabbit common carotid artery model of intermediate stage atherosclerosis and the subsequent, investigating the effect of Extremely Low Frequency (ELF) magnetic field exposure on the foam cells- rich plaque structure in this model.

Extremely Low Frequency Magnetic Fields Induce mTOR and Hsa_Circ_100338 Expression Changes in Gastric Cancer and Normal Fibroblast Cell Lines.

Objective Extremely low-frequency magnetic field (ELF-MF) exposure, as a targeted tumor therapy, presents several potential advantages. In this research, we investigated effects of different ELF-MF intensities on cell viability and expression levels of the mammalian target of rapamycin (mTOR) and hsa_circ_100338 in the normal fibroblast (Hu02) and human gastric adenocarcinoma (AGS) cell lines. Materials and MethodsIn this experimental study, cell lines of AGS and Hu02, were cultured under the exposure of ELF- MF with magnetic flux densities (MFDs) of 0.25, 0.5, 1 and 2 millitesla (mT) for 18 hours. The 3-(4, 5-dimethylthiazoyl-2- yl)-2, 5-diphenyltetrazolium bromide (MTT) assay was used to evaluate the cell viability. Relative expression of mTOR and hsa_circ_100338 RNAs was estimated by quantitative real-time polymerase chain reaction (qRT-PCR) technique.Results Viability of the normal cells was significantly increased at MFDs of 0.5, 1 and 2 mT, while viability of the tumor cells was significantly decreased at MFD of 0.25 and increased at MFD of 2 mT. Expression level of mTOR was significantly increased at the all applied MFDs in the normal cells, while it was significantly decreased at MFDs of 0.25 and 0.5mT in the tumor cells. MFDs of 1 and 2 mT in tumor cells inversely led to the increase in mTOR expression. hsa_circ_100338 was downregulated in MFD of 0.25 mT and then it was increased parallel to the increase of MFD in the normal and tumor cells. ConclusionResults of the present study indicated that ELF-MF at MFDs of 0.25 and 0.5 mT can lead to decrease in the both mTOR and hsa_circ_100338 expression levels. Given the role of mTOR in cell growth, proliferation and differentiation, in addition to the potential role of hsa_circ_100338 in metastasis, expression inhibition of these two genes could be a therapeutic target in cancer treatment.

Fermentation Process of Dry Cocoa Beans through Extremely Low Frequency (ELF) Magnetic Field Exposure

Several studies have found and proved that exposure to Extremely Low Frequency (ELF) magnetic fields can cause the proliferation of cells or bacteria. Meanwhile, bacteria play an essential part in the fermentation process. Thus, this study aims to examine the fermentation process of non-fermented dry cocoa beans using Extremely Low Frequency (ELF) magnetic field exposure. The sample of this study was 30 kg of non-fermented dry cocoa beans divided into 10 sample bags of 3kg each and grouped into 4. The control group (K) consisted of 1 bag while the rest bags were divided into 3 sample bags exposed to an ELF magnetic field with intensities of 100 μT (E-100), 200 μT (E-200), and 300 μT (E-300). ELF magnetic field exposure was carried out at the beginning of the fermentation process with variation in the exposure time of 15 , 45 , and 75 minutes. During the fermentation process, temperature measurements were conducted. Moreover, moisture content measurements were also conducted during the drying process in the sun for up to 3 days. At last, measurements of pH and alcohol content were carried out on dried cocoa beans. The findings showed that there was no significant temperature change (p &gt; 0.05) during the fermentation process. A decrease in the moisture content of cocoa beans during the drying process was proven to be faster in the sample group exposed to the ELF magnetic field compared to those in the control group. The alcohol and pH of dried cocoa beans from the sample group exposed to the ELF magnetic field were significantly higher than those in control (p &lt;0.05). The highest alcohol content was found in the sample group which was exposed to the intensity of the ELF of 200 μT for 45 minutes. Conclusion: Exposure to ELF magnetic fields can increase the fermentation activity of dry cocoa beans. This indicates that exposure to ELF magnetic fields in the fermentation process of cocoa beans might improve the quality of non-fermented dry cocoa beans.

Extremely Low Frequency Electromagnetic Fields Alter Expression of C-Myc and circ-CCDC66 in Gastric Cancer Cell Line

: The biological effects of electromagnetic fields (EMF), in particular their beneficial or adverse impacts on the promotion and progression of cancer, have attracted considerable attention. C-Myc has a critical regulatory role in cell transformation and causes metabolic changes, that accompany malignant transformation. Observations have shown that c-Myc expression can be altered by circular RNAs (circRNA). In this study, the changes in the expression of c-Myc and circ-CCDC66 in the AGS cell line after the extremely low-frequency magnetic fields (ELF-MF) exposure were investigated. The AGS cells were exposed to different magnetic flux densities for 18 h, continuously and discontinuously (2h on/2h off). To evaluate the expression changes of c-Myc and circ-CCDC66 real-time PCR was used. The results showed that discontinuous magnetic fields could reduce c-Myc expression. Continuous exposure of 0.25 mT could reduce the c-Myc expression, but with increasing the magnetic flux density c-Myc was upregulated. The expression level of circ-CCDC66 decreased under exposure to continuous and discontinuous ELF-MFs. The difference between the results of c-Myc under the influence of magnetic fields may be described by the hypothesis of the window effect of the fields. Our results indicated that ELF-MFs can induce changes in c-Myc and circ-CCDC66 expression.

Effect of extremely low frequency magnetic fields on oxidative balance in rat brains subjected to an experimental model of chronic unpredictable mild stress

BackgroundThere has been an increasing interest in researching on the effects of extremely low-frequency magnetic fields on living systems. The mechanism of action of extremely low-frequency magnetic fields on organisms has not been established. One of the hypotheses is related to induce changes in oxidative balance. In this study, we measured the effects of chronic unpredictable mild stress induced-oxidative balance of rat’s brain exposed to extremely low-frequency magnetic fields.Methods A first experiment was conducted to find out if 14 days of chronic unpredictable mild stress caused oxidative unbalance in male Wistar rat’s brain. Catalase activity, reduced glutathione concentration, and lipoperoxidation were measured in cerebrum and cerebellum. In the second experiment, we investigate the effects of 7 days extremely low-frequency magnetic fields exposure on animals stressed and unstressed.ResultsThe main results obtained were a significant increase in the catalase activity and reduced glutathione concentration on the cerebrum of animals where the chronic unpredictable mild stress were suspended at day 14 and then exposed 7 days to extremely low-frequency magnetic fields. Interestingly, the same treatment decreases the lipoperoxidation in the cerebrum. The stressed animals that received concomitant extremely low frequency magnetic fields exposure showed an oxidative status like stressed animals by 21 days. Thus, no changes were observed on the chronic unpredictable mild stress induced-oxidative damage in the rat’s cerebrum by the extremely low-frequency magnetic field exposure together with chronic unpredictable mild stress.ConclusionsThe extremely low-frequency electromagnetic field exposure can partially restore the cerebrum antioxidant system of previously stressed animals.

Exposure To Extremely Low-Frequency Magnetic Fields In Low- And Middle-Income Countries: An Overview.

To compare extremely low-frequency magnetic field (ELF-MF) exposure in the general population in low- and middle-income countries (LMICs) with high-income countries (HIC), we carried out a systematic literature search resulting in 1483 potentially eligible articles; however, only 25 studies could be included in the qualitative synthesis. Studies showed large heterogeneity in design, exposure environment and exposure assessment. Exposure assessed by outdoor spot measurements ranged from 0.03 to 4μT. Average exposure by indoor spot measurements in homes ranged from 0.02 to 0.4μT. Proportions of homes exposed to a threshold of ≥0.3μT were many times higher in LMICs compared to HIC. Based on the limited data available, exposure to ELF-MF in LMICs appeared higher than in HIC, but a direct comparison is hampered by a lack of representative and systematic monitoring studies. Representative measurement studies on residential exposure to ELF-MF are needed in LMICs together with better standardisation in the reporting.

Extremely Low-Frequency Magnetic Fields Exposure Measurement during Lessons in Elementary Schools.

Schools are an important place for children’s exposure to electromagnetic fields, which may cause adverse health effects. To better understand environmental extremely low-frequency magnetic fields (ELF-MFs) exposure among elementary school students, we measured numeric values of ELF-MFs in five classrooms at four schools during digital learning class hours. The measurement of ELF-MFs was taken with an EMDEX II field analyzer. Specifically, we examined the level of exposure to ELF-MFs for each student’s seating position in the classroom. The results showed that ELF-MFs exposure levels were lower than those in the International Commission on Non-Ionizing Radiation Protection guidelines; however, there were significant differences in the level of magnetic field exposure at each school and at each student’s seat. The exposure to ELF-MFs at students’ seat positions was mostly caused by electrical appliances, electronic wiring, and distribution boxes, but the exposure level decreased as the distance increased. Therefore, it is important to design safe and appropriate environments for digital learning in schools, such as proper seating arrangements, to avoid ELF-MFs exposure to students as much as possible. Future studies should measure ELF-MFs levels in other areas and investigate the effects of exposure to ELF-MFs during school hours on children’s health.

Insights in the biology of extremely low-frequency magnetic fields exposure on human health.

The extremely low-frequency magnetic fields (ELF-EMF) are generated by electrical devices and power systems (1 to 300Hz). In recent decades, exposure to ELF-EMF has emerged potential concerns on public health. Here, we discuss recent progress in the understanding of ELF-EMF biology with a focus on mechanisms of ELF-EMF-mediated disease and summarize the results of more recent experimental and epidemiological studies of ELF-EMF exposure effects on cancer, neurological, cardiovascular, and reproductive disorders. Current views on genomic instability effects, as well as scientific evidence about ELF-EMF therapy, are put forth. According to our literature review, exposure to ELF-EMF has an adverse biological effect depending on the current intensity, strength of the magnetic field, and duration of exposure. Accumulated epidemiologic evidence indicates a correlation between exposure to ELF-EMF and childhood cancer incidence, Alzheimer's disease (AD), and miscarriage. However, adult cancer does not show augmented risk caused by the ELF-EMF. Also, no consistent evidence exists in cardiovascular disease mortality due to ELF-EMF exposure. There is a lack of comprehensive mechanisms for explaining the biological effect of ELF-EMF. Eventually, more studies are needed to clarify the mechanisms of these magnetic fields.

Long-Term Monitoring of Extremely Low Frequency Magnetic Fields in Electric Vehicles

Extremely low frequency (ELF) magnetic field (MF) exposure in electric vehicles (EVs) has raised public concern for human health. There have been many studies evaluating magnetic field values in these vehicles. However, there has been no report on the temporal variation of the magnetic field in the cabin. This is the first study on the long-term monitoring of actual MFs in EVs. In the study, we measured the magnetic flux density (B) in three shared vehicles over a period of two years. The measurements were performed at the front and rear seats during acceleration and constant-speed driving modes. We found that the B amplitudes and the spectral components could be modified by replacing the components and the hubs, while regular checks or maintenance did not influence the B values in the vehicle. This observation highlights the necessity of regularly monitoring ELF MF in EVs, especially after major repairs or accidents, to protect car users from potentially excessive ELF MF exposure. These results should be considered in updates of the measurement standards. The ELF MF effect should also be taken into consideration in relevant epidemiological studies.

Extremely low frequency magnetic field induces human neuronal differentiation through NMDA receptor activation.

Magnetic fields with different frequency and intensity parameters exhibit a wide range of effects on different biological models. Extremely low frequency magnetic field (ELF MF) exposure is known to augment or even initiate neuronal differentiation in several in vitro and in vivo models. This effect holds potential for clinical translation into treatment of neurodegenerative conditions such as autism, Parkinson's disease and dementia by promoting neurogenesis, non-invasively. However, the lack of information on underlying mechanisms hinders further investigation into this phenomenon. Here, we examine involvement of glutamatergic Ca2+ channel, N-methyl-D-aspartate (NMDA) receptors in the process of human neuronal differentiation under ELF MF exposure. We show that human neural progenitor cells (hNPCs) differentiate more efficiently under ELF MF exposure in vitro, as demonstrated by the abundance of neuronal markers. Furthermore, they exhibit higher intracellular Ca2+ levels as evidenced by c-fos expression and more elongated mature neurites. We were able to neutralize these effects by blocking NMDA receptors with memantine. As a result, we hypothesize that the effects of ELF MF exposure on neuronal differentiation originate from the effects on NMDA receptors, which sequentially triggers Ca2+-dependent cascades that lead to differentiation. Our findings identify NMDA receptors as a new key player in this field that will aid further research in the pursuit of effect mechanisms of ELF MFs.

Dosimetric issues with simplified homogeneous body models in low frequency magnetic field exposure assessment

A simplified procedure, using circular disk models with homogeneous electric conductivity as representations for different body parts, has been proposed recently by product standard IEC 62822-3 for the assessment of magnetic field exposure in proximity to current-carrying conductors of welding equipment. Based on such simplified models, worst case coupling coefficients CCEi(I), i.e. maximum induced electric field strength, normalised for current and frequency, for body parts at different distances d to straight single and double wire arrangements, as well as rectangular loop-shaped current paths are tabulated in the standard. In this work we compared CCEi(I) values obtained by numerical computations with detailed anatomical models of the hand/forearm with the corresponding values given in IEC 62822-3 for current-carrying single wire conductors along the forearm at distances d = 30, 50 and 100 mm, respectively. Our results clearly indicated that the CCEi(I) given in the standard may substantially underestimate the actual exposure. Using average values for tissue conductivities the observed extent of underestimation was up to 8.9 dB (factor 2.79) and may be even higher for worst case combinations of tissue conductivities. The reasons for this substantial underestimation are the oversimplified geometry, i.e. the circular disk does not reflect anatomical constrictions of the induction area present in realistic hand/forearm geometries, as well as the missing conductivity contrast between different tissues in the homogeneous disk models. Results of exposure assessment and corresponding minimum distances to components of welding equipment obtained by the simplified disk model approach suggested by IEC 62822-3 should therefore be considered with caution.

LF-MF suppresses the colon cancer via regulating the function of MDSCs

The biological effect of magnetic field is a hot topic in biomedical engineering. The influence of magnetic fields on human health has caused the widespread concern, involving the study of magnetic field in central nervous system, blood and immune system, vascular and endocrine system, among which the most attractive application is usage of low frequency magnetic fields (LF-MF) in the tumor treatment. Our previous studies showed that LF-MF significantly inhibited the proliferation of liver cancer, lung cancer and melanoma cells, and regulated the immune cells to exert anti-tumor effect. We have found that LF-MF exposure was associated with activation of macrophages and dendritic cells, enhanced profiles of CD4+ T and CD8+ T lymphocytes, the balance of Th17/Treg in tumor-bearing mice. In cancer, myeloid-derived suppressor cells (MDSCs) demonstrating one of the key players engaged in tumor immunosuppression. This study will further explore the role of LF-MF in the growth of colon cancer and function of myeloid-derived suppressor cells (MDSCs). In this study, mouse colon cancer xenografts models were established and the tumor-bearing mice were exposed to a LF-MF (0.4 T, 7.5 Hz) for 35 days. The tumor growth and tumor weight were measured. Immunohistochemical staining for Ki-67 in tumor tissue was performed. Flow cytometry analyzed the proportion of MDSCs in the bone marrow, spleen, tumor, and peripheral blood of mice. Magnetic beads separated MDSCs from tumor tissues and MDSCs suppression assays were performed. Q-PCR was performed to detect the mRNA expression of Arg-1 , iNOS-2 , Gp91 phox , P47phox , and S100A8/A9 in MDSCs from tumor tissues. The reactive oxygen species(ROS)level in MDSCs was analyzed by flow cytometry. Western blot was used to detect the protein level of Gp91phox, P47phox and GAPDH. Results showed that LF-MF inhibited the tumor growth in the CT26 colon cancer xenograft model, and decreased the number of Ki-67 positive cells in the tumor tissues. LF-MF reduced the proportion of MDSCs in tumor tissues and attenuated the inhibitory function of MDSCs. In vitro , LF-MF had no effect on cell viability and cell apoptosis of MDSCs. In addition, LF-MF reduced the production of reactive oxygen species in MDSCs by inhibiting the expression of Gp91phox and P47phox. With the reduced the production of reactive oxygen species, the inhibitory function of MDSCs was attenuated by LF-MF. Together, our present study demonstrated that LF-MF obviously suppressed the development of colon cancer via regulating the expansion and function of MDSCs. LF-MF suppressed the inhibitory function of MDSCs by reducing the production of reactive oxygen species with the decreased expression of Gp91phox and P47phox. Our studies reveal a novel mechanism behind the anti-tumor effect of LF-MFs on colon cancer and provide a potentially useful adjunct therapy for treatment of colon cancer.