LF-EMF Compound Block Type Signal Activates Human Neutrophilic Granulocytes In Vivo.

This research aims to demonstrate in a randomized, placebo-controlled crossover design study that a nominal 5 µT low-frequency electromagnetic field (LF-EMF) signal for 30 min activates neutrophils in vivo in humans. Granularity of neutrophils was measured in blood samples of healthy human volunteers (n = 32) taken before and after exposure for both the exposure and control sessions. A significant decrease in the granularity, indicative of neutrophil activation, was observed both in the exposure measurements and the exposure minus control measurements. Earlier EMF publications show immune function increase in isolated cells and more effective immune responses in animals with infections. This result, therefore, supports the thesis that the exposure can activate the innate immune system in humans, speed up the innate immune response, and may have potential beneficial effects in infectious disease. © 2022 Bioelectromagnetics Society.

Retrospective estimation of the electric and magnetic field exposure conditions in in vitro experimental reports reveal considerable potential for uncertainty.

Experiments on cell cultures exposed to extremely low frequency (ELF, 3-300 Hz) magnetic fields are often subject to multiple sources of uncertainty associated with specific electric and magnetic field exposure conditions. Here we systemically quantify these uncertainties based on exposure conditions described in a group of bioelectromagnetic experimental reports for a representative sampling of the existing literature. The resulting uncertainties, stemming from insufficient, ambiguous, or erroneous description, design, implementation, or validation of the experimental methods and systems, were often substantial enough to potentially make any successful reproduction of the original experimental conditions difficult or impossible. Without making any assumption about the true biological relevance of ELF electric and magnetic fields, these findings suggest another contributing factor which may add to the overall variability and irreproducibility traditionally associated with experimental results of in vitro exposures to low-level ELF magnetic fields. Bioelectromagnetics. 39:231-243, 2018. © 2017 Wiley Periodicals, Inc.

A short-term extremely low frequency electromagnetic field exposure increases circulating leukocyte numbers and affects HPA-axis signaling in mice.

There is still uncertainty whether extremely low frequency electromagnetic fields (ELF-EMF) can induce health effects like immunomodulation. Despite evidence obtained in vitro, an unambiguous association has not yet been established in vivo. Here, mice were exposed to ELF-EMF for 1, 4, and 24 h/day in a short-term (1 week) and long-term (15 weeks) set-up to investigate whole body effects on the level of stress regulation and immune response. ELF-EMF signal contained multiple frequencies (20-5000 Hz) and a magnetic flux density of 10 µT. After exposure, blood was analyzed for leukocyte numbers (short-term and long-term) and adrenocorticotropic hormone concentration (short-term only). Furthermore, in the short-term experiment, stress-related parameters, corticotropin-releasing hormone, proopiomelanocortin (POMC) and CYP11A1 gene-expression, respectively, were determined in the hypothalamic paraventricular nucleus, pituitary, and adrenal glands. In the short-term but not long-term experiment, leukocyte counts were significantly higher in the 24 h-exposed group compared with controls, mainly represented by increased neutrophils and CD4 ± lymphocytes. POMC expression and plasma adrenocorticotropic hormone were significantly lower compared with unexposed control mice. In conclusion, short-term ELF-EMF exposure may affect hypothalamic-pituitary-adrenal axis activation in mice. Changes in stress hormone release may explain changes in circulating leukocyte numbers and composition. Bioelectromagnetics. 37:433-443, 2016. © 2016 The Authors. Bioelectromagnetics Published by Wiley Periodicals, Inc.

The Evolution of Functionally Redundant Species; Evidence from Beetles.

While species fulfill many different roles in ecosystems, it has been suggested that numerous species might actually share the same function in a near neutral way. So-far, however, it is unclear whether such functional redundancy really exists. We scrutinize this question using extensive data on the world's 4168 species of diving beetles. We show that across the globe these animals have evolved towards a small number of regularly-spaced body sizes, and that locally co-existing species are either very similar in size or differ by at least 35%. Surprisingly, intermediate size differences (10-20%) are rare. As body-size strongly reflects functional aspects such as the food that these generalist predators can eat, these beetles thus form relatively distinct groups of functional look-a-likes. The striking global regularity of these patterns support the idea that a self-organizing process drives such species-rich groups to self-organize evolutionary into clusters where functional redundancy ensures resilience through an insurance effect.

Calcium signalling in human neutrophil cell lines is not affected by low-frequency electromagnetic fields.

We are increasingly exposed to low-frequency electromagnetic fields (LF EMFs) by electrical devices and power lines, but if and how these fields interact with living cells remains a matter of debate. This study aimed to investigate the potential effect of LF EMF exposure on calcium signalling in neutrophils. In neutrophilic granulocytes, activation of G-protein coupled receptors leads to efflux of calcium from calcium stores and influx of extracellular calcium via specialised calcium channels. The cytoplasmic rise of calcium induces cytoskeleton rearrangements, modified gene expression patterns, and cell migration. If LF EMF modulates intracellular calcium signalling, this will influence cellular behaviour and may eventually lead to health problems. We found that calcium mobilisation upon chemotactic stimulation was not altered after a short 30 min or long-term LF EMF exposure in human neutrophil-like cell lines HL-60 or PLB-985. Neither of the two investigated wave forms (Immunent and 50 Hz sine wave) at three magnetic flux densities (5 µT, 300 µT, and 500 µT) altered calcium signalling in vitro. Gene-expression patterns of calcium-signalling related genes also did not show any significant changes after exposure. Furthermore, analysis of the phenotypical appearance of microvilli by scanning electron microscopy revealed no alterations induced by LF EMF exposure. The findings above indicate that exposure to 50 Hz sinusoidal or Immunent LF EMF will not affect calcium signalling in neutrophils in vitro.

Low-Frequency Electromagnetic Field Exposure Enhances Extracellular Trap Formation by Human Neutrophils through the NADPH Pathway.

Low-frequency (LF) electromagnetic fields (EMFs) are abundantly present in modern society, and the potential biological consequences of exposure to these fields are under intense debate. Immune cells are suggested as possible target cells, though a clear mechanism is lacking. Considering their crucial role in innate immune activation, we selected an ex vivo exposure set-up with human neutrophils to investigate a possible correlation between neutrophil extracellular trap (NET) formation and LF EMF exposure. Our study shows that formation of NETs is enhanced by LF EMF exposure. Enhanced NET formation leads to increased antimicrobial properties as well as damage to surrounding cells. We found that LF-EMF-induced NET formation is dependent on the NADPH oxidase pathway and production of reactive oxygen species. Additionally, LF EMF exposure does not influence autophagy and PAD4 activity. Our study provides a mechanism by which exposure to LF EMFs could influence the innate immune system.

Low-frequency electromagnetic fields do not alter responses of inflammatory genes and proteins in human monocytes and immune cell lines.

The effects of low frequency electromagnetic fields (LF EMF) on human health are the subject of on-going research and serious public concern. These fields potentially elicit small effects that have been proposed to have consequences, either positive or negative, for biological systems. To reveal potentially weak but biologically relevant effects, we chose to extensively examine exposure of immune cells to two different signals, namely a complex multiple waveform field, and a 50 Hz sine wave. These immune cells are highly responsive and, in vivo, modulation of cytokine expression responses can result in systemic health effects. Using time course experiments, we determined kinetics of cytokine and other inflammation-related genes in a human monocytic leukemia cell line, THP-1, and primary monocytes and macrophages. Moreover, cytokine protein levels in THP-1 monocytes were determined. Exposure to either of the two signals did not result in a significant effect on gene and protein expression in the studied immune cells. Also, additional experiments using non-immune cells showed no effects of the signals on cytokine gene expression. We therefore conclude that these LF EMF exposure conditions are not expected to significantly modulate innate immune signaling.

Extremely low frequency electromagnetic field exposure does not modulate toll-like receptor signaling in human peripheral blood mononuclear cells.

The effects of extremely low frequency electromagnetic fields (ELF-EMF) on human health remain unclear. It has been reported that ELF-EMF may modulate the innate immune response to microorganisms in animal models and mammalian cell-lines. With the recently gained insight in innate immune signaling and the discovery of pattern recognition, we aim to study whether ELF-EMF modulates innate inflammatory signaling pathways. We used human peripheral blood mononuclear cells (PBMCs), isolated from blood from healthy volunteers, which we stimulated with specific TLR2 and TLR4 ligands, and with several microorganisms. The cells were subsequently exposed in B(dc)=3 µT to a highly controlled and standardized ELF-EMF signal (20-5000Hz, B(ac)=5 µT, 30 min) and cytokine production was measured at different time points after stimulation. No significant difference in immune response, as reflected by IL-1ß, IL-6, TNFα, IL-8 and IL-10 production, could be detected after stimulation with LPS (TLR4 ligand), Pam3Cys (TLR2 ligand) or a panel of heat killed microorganisms: Mycobacterium tuberculosis, Salmonella typhimurium, Candida albicans, Aspergillus fumigatus and Staphylococcus aureus (multiple TLR ligands). We therefore conclude that under our experimental conditions, ELF-EMF does not modulate the innate immune response of human primary cells after TLR stimulation in vitro.

Macroinvertebrate responses to insecticide application between sprayed and adjacent nonsprayed ditch sections of different sizes.

Under typical agricultural use of an insecticide, it is likely that only part of an edge-of-field drainage ditch will be directly contaminated by spray drift. The response, including recovery, of aquatic macroinvertebrates in sprayed ditch sections may be affected by immigration of organisms from adjacent nonsprayed ditch sections, but also the population dynamics in nonsprayed sections (refuges) may be affected by nearby contaminated patches (known as action at a distance). Experimental ditches were used to study the influence of the presence of nearby refuges on the responses of macroinvertebrates in ditch sections directly sprayed with the insecticide lufenuron, and vice versa. The treatment regimes differed in the proportion of the ditch (0, 33, 67, and 100% of surface area) that was sprayed to reach a lufenuron concentration of 3 microg/L in the water column of the sprayed ditch section. In sprayed ditch sections, clear treatment-related effects were observed for adult midges in the emergence traps and for aquatic arthropods (mainly juveniles) in the artificial substrate/sweep net samples. The extent in magnitude and duration of effects in sprayed ditch sections was overall larger when a larger proportion of the ditch was sprayed and/or the distance to the refuge was larger. In nonsprayed ditch sections of partially treated ditches, treatment-related effects were absent or minor for macroinvertebrates that predominantly dwell on or in the sediment compartment, particularly at a larger distance from the sprayed ditch sections. More mobile arthropods that predominantly dwell in the water column showed clear treatment-related effects in the nonsprayed ditch sections as well, but action at a distance was smaller if a smaller proportion of ditch was treated.

Effects of a herbicide-insecticide mixture in freshwater microcosms: risk assessment and ecological effect chain.

Effects of chronic application of a mixture of the herbicide atrazine and the insecticide lindane were studied in indoor freshwater plankton-dominated microcosms. The macroinvertebrate community was seriously affected at all but the lowest treatment levels, the zooplankton community at the three highest treatment levels, with crustaceans, caddisflies and dipterans being the most sensitive groups. Increased abundance of the phytoplankton taxa Cyclotella sp. was found at the highest treatment level. Threshold levels for lindane, both at population and community level, corresponded well with those reported in the literature. Atrazine produced fewer effects than expected, probably due to decreased grazer stress on the algae as a result of the lindane application. The safety factors set by the Uniform Principles for individual compounds were also found to ensure protection against chronic exposure to a mixture of a herbicide and insecticide at community level, though not always at the population level.

Aquatic risk assessment of a realistic exposure to pesticides used in bulb crops: a microcosm study.

The fungicide fluazinam, the insecticide lambda-cyhalothrin, and the herbicides asulam and metamitron were applied to indoor freshwater microcosms (water volume approximately 0.6 m3). The treatment regime was based on a realistic application scenario in tulip cultivation. Concentrations of each pesticide were equal to 0%, 0.2%, 0.5%, 2%, and 5% spray drift emission of label-recommended rates. Contribution of compounds to the toxicity of the pesticide package was established by expressing their concentrations as fractions of toxic units. The fate of the compounds in the water, and responses of phytoplankton, zooplankton, periphyton, macroinvertebrates, macrophytes, decomposition, and water quality were followed for 13 weeks. The half-lives of lambda-cyhalothrin, metamitron, and fluazinam were 1 to 2 d; that of asulam was >30 d. No consistent effects could be demonstrated for the 0.2% treatment regime that was therefore considered the no-observed-effect concentration community (NOEC). The macroinvertebrate populations of Gammarus pulex, Asellus aquaticus, and Proasellus meridianus were the most sensitive end points, followed by species of copepods and cladocerans. Responses mainly were due to lambda-cyhalothrin. The 0.5% treatment regime resulted in short-term effects. Pronounced effects were observed at the 2% and 5% treatment levels. At the end of the experiment, the macrophyte biomass that consisted of Elodea nuttallii, showed a decline at the two highest treatment levels, asulam being the causal factor (NOEC: 0.5% treatment level). Primary production was reduced at the 5% treatment level only. In our experiment, the first-tier risk assessment procedure for individual compounds was adequate for protecting sensitive populations exposed to realistic combinations of pesticides. Spray drift reduction measures seem to be efficient in protecting aquatic ecosystems in agricultural areas.

Effects of a mixture of two insecticides in freshwater microcosms: I. Fate of chlorpyrifos and lindane and responses of macroinvertebrates.

Effects of chronic application of a mixture of the insecticides chlorpyrifos and lindane were studied in indoor freshwater microcosms. The exposure concentrations (based on 0, 0.005, 0.01, 0.05, 0.1 and 0.5 times the LC50 of the most sensitive standard test organism for each compound) were kept at a constant level for four weeks. The calculated mean concentrations for chlorpyrifos were found to be almost at their corresponding nominal level during the treatment period. The mean calculated lindane concentrations, however, were found to be 15-40% higher than intended. In the post treatment period both insecticides dissipated fast (t 1/2: chlorpyrifos 9 days, lindane 22 days) from the water phase. The concentrations of the mixture at the highest treatment level corresponded to 0.53 toxic units (TU) for Daphnia magna and 0.61 TU for the most sensitive fish. The decomposition of Populus leaves in litter bags was significantly lower at the three highest insecticide concentrations. The macroinvertebrate community was seriously affected at the three highest treatment levels, with Crustacea and the Chironomidae Corynoneura proving to be the most sensitive groups. Gastropoda and Oligochaeta were relatively insensitive and some taxa (e.g. Valvata piscinalis, juvenile Physa fontinalis, Nemertea and Stylaria lacustris) increased in numbers. The observed effects could be explained from the individual toxicity of the insecticides to the invertebrates, and did not indicate synergistic effects. A second paper (Van den Brink et al., 2002) addresses the effects on other endpoints, as well as the overall risk assessment of the insecticide mixture.