1
|
Héroux P, Belyaev I, Chamberlin K, Dasdag S, De Salles AAA, Rodriguez CEF, Hardell L, Kelley E, Kesari KK, Mallery-Blythe E, Melnick RL, Miller AB, Moskowitz JM. Cell Phone Radiation Exposure Limits and Engineering Solutions. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:5398. [PMID: 37048013 PMCID: PMC10094704 DOI: 10.3390/ijerph20075398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 03/17/2023] [Accepted: 03/31/2023] [Indexed: 06/19/2023]
Abstract
In the 1990s, the Institute of Electrical and Electronics Engineers (IEEE) restricted its risk assessment for human exposure to radiofrequency radiation (RFR) in seven ways: (1) Inappropriate focus on heat, ignoring sub-thermal effects. (2) Reliance on exposure experiments performed over very short times. (3) Overlooking time/amplitude characteristics of RFR signals. (4) Ignoring carcinogenicity, hypersensitivity, and other health conditions connected with RFR. (5) Measuring cellphone Specific Absorption Rates (SAR) at arbitrary distances from the head. (6) Averaging SAR doses at volumetric/mass scales irrelevant to health. (7) Using unrealistic simulations for cell phone SAR estimations. Low-cost software and hardware modifications are proposed here for cellular phone RFR exposure mitigation: (1) inhibiting RFR emissions in contact with the body, (2) use of antenna patterns reducing the Percent of Power absorbed in the Head (PPHead) and body and increasing the Percent of Power Radiated for communications (PPR), and (3) automated protocol-based reductions of the number of RFR emissions, their duration, or integrated dose. These inexpensive measures do not fundamentally alter cell phone functions or communications quality. A health threat is scientifically documented at many levels and acknowledged by industries. Yet mitigation of RFR exposures to users does not appear as a priority with most cell phone manufacturers.
Collapse
Affiliation(s)
- Paul Héroux
- Department of Epidemiology, Biostatistics and Occupational Health, Faculty of Medicine, McGill University, Montreal, QC H3A 1G1, Canada
| | - Igor Belyaev
- Cancer Research Institute, Biomedical Research Center, Slovak Academy of Sciences, 814 38 Bratislava, Slovakia
| | - Kent Chamberlin
- Department of Electrical and Computer Engineering, University of New Hampshire, Durham, NH 03824, USA
| | - Suleyman Dasdag
- Biophysics Department, Medical School, Istanbul Medeniyet University, Istanbul 34700, Turkey
| | - Alvaro Augusto Almeida De Salles
- Graduate Program on Electrical Engineering (PPGEE), Federal University of Rio Grande do Sul (UFRGS), Porto Alegre 90010-150, Brazil
| | | | - Lennart Hardell
- Department of Oncology, Orebro University Hospital, 701 85 Orebro, Sweden (Retired)
- The Environment and Cancer Research Foundation, 702 17 Orebro, Sweden
| | - Elizabeth Kelley
- ICBE-EMF and International EMF Scientist Appeal, and Electromagnetic Safety Alliance, Tempe, AZ 85282, USA
| | - Kavindra Kumar Kesari
- Department of Applied Physics, School of Science, Aalto University, 02150 Espoo, Finland
| | - Erica Mallery-Blythe
- Physicians’ Health Initiative for Radiation and Environment, East Sussex TN6, UK
- British Society of Ecological Medicine, London W1W 6DB, UK
- Oceania Radiofrequency Scientific Advisory Association, Scarborough, QLD 4020, Australia
| | - Ronald L. Melnick
- National Toxicology Program (Retired), National Institute of Environmental Health Sciences, Research Triangle Park, Durham, NC 27709, USA
- Ron Melnick Consulting LLC, North Logan, UT 84341, USA
| | - Anthony B. Miller
- Dalla Lana School of Public Health, University of Toronto, Toronto, ON M5T 3M7, Canada
| | - Joel M. Moskowitz
- School of Public Health, University of California, Berkeley, CA 94704, USA
| | | |
Collapse
|
2
|
Kim J, Woo KC, Kim KK, Kim SK. πσ*-Mediated Nonadiabatic Tunneling Dynamics of Thiophenols in S 1: The Semiclassical Approaches. J Phys Chem A 2022; 126:9594-9604. [PMID: 36534791 DOI: 10.1021/acs.jpca.2c05861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The S-H bond tunneling predissociation dynamics of thiophenol and its ortho-substituted derivatives (2-fluorothiophenol, 2-methoxythiophenol, and 2-chlorothiphenol) in S1 (ππ*) where the H atom tunneling is mediated by the nearby S2 (πσ*) state (which is repulsive along the S-H bond extension coordinate) have been investigated in a state-specific way using the picosecond time-resolved pump-probe spectroscopy for the jet-cooled molecules. The effects of the specific vibrational mode excitations and the SH/SD substitutions on the S-H(D) bond rupture tunneling dynamics have been interrogated, giving deep insights into the multidimensional aspects of the S1/S2 conical intersection, which also shapes the underlying adiabatic tunneling potential energy surfaces (PESs). The semiclassical tunneling rate calculations based on the Wentzel-Kramers-Brillouin (WKB) approximation or Zhu-Nakamura (ZN) theory have been carried out based on the ab initio PESs calculated in the (one, two, or three) reduced dimensions to be compared with the experiment. Though the quantitative experimental results could not be reproduced satisfactorily by the present calculations, the qualitative trends among different molecules in terms of the behavior of the tunneling rate versus the (adiabatic) barrier height or the number of PES dimensions could be rationalized. Most interestingly, the H/D kinetic isotope effect observed in the tunneling rate could be much better explained by the ZN theory compared to the WKB approximation, indicating that the nonadiabatic coupling matrix elements should be invoked for understanding the tunneling dynamics taking place in the proximity of the conical intersection.
Collapse
Affiliation(s)
- Junggil Kim
- Department of Chemistry, KAIST, Daejeon34141, Republic of Korea
| | - Kyung Chul Woo
- Department of Chemistry, KAIST, Daejeon34141, Republic of Korea
| | - Kuk Ki Kim
- Department of Chemistry, KAIST, Daejeon34141, Republic of Korea
| | - Sang Kyu Kim
- Department of Chemistry, KAIST, Daejeon34141, Republic of Korea
| |
Collapse
|
3
|
Dupuy L, Talotta F, Agostini F, Lauvergnat D, Poirier B, Scribano Y. Adiabatic and Nonadiabatic Dynamics with Interacting Quantum Trajectories. J Chem Theory Comput 2022; 18:6447-6462. [DOI: 10.1021/acs.jctc.2c00744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Lucien Dupuy
- Laboratoire Univers et Particules de Montpellier, UMR-CNRS 5299, Université de Montpellier, Place Eugène Bataillon, 34095Montpellier, France
| | - Francesco Talotta
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, UMR-CNRS 8000, 91405Orsay, France
| | - Federica Agostini
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, UMR-CNRS 8000, 91405Orsay, France
| | - David Lauvergnat
- Université Paris-Saclay, CNRS, Institut de Chimie Physique, UMR-CNRS 8000, 91405Orsay, France
| | - Bill Poirier
- Department of Chemistry and Biochemistry, and Department of Physics, Texas Tech University, Box 41061, 79409-1061Lubbock, Texas, United States
| | - Yohann Scribano
- Laboratoire Univers et Particules de Montpellier, UMR-CNRS 5299, Université de Montpellier, Place Eugène Bataillon, 34095Montpellier, France
| |
Collapse
|
4
|
Picconi D. Nonadiabatic quantum dynamics of the coherent excited state intramolecular proton transfer of 10-hydroxybenzo[h]quinoline. Photochem Photobiol Sci 2021; 20:1455-1473. [PMID: 34657277 DOI: 10.1007/s43630-021-00112-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 10/04/2021] [Indexed: 12/13/2022]
Abstract
The photoinduced nonadiabatic dynamics of the enol-keto isomerization of 10-hydroxybenzo[h]quinoline (HBQ) are studied computationally using high-dimensional quantum dynamics. The simulations are based on a diabatic vibronic coupling Hamiltonian, which includes the two lowest [Formula: see text] excited states and a [Formula: see text] state, which has high energy in the Franck-Condon zone, but significantly stabilizes upon excited state intramolecular proton transfer. A procedure, applicable to large classes of excited state proton transfer reactions, is presented to parametrize this model using potential energies, forces and force constants, which, in this case, are obtained by time-dependent density functional theory. The wave packet calculations predict a time scale of 10-15 fs for the photoreaction, and reproduce the time constants and the coherent oscillations observed in time-resolved spectroscopic studies performed on HBQ. In contrast to the interpretation given to the most recent experiments, it is found that the reaction initiated by [Formula: see text] photoexcitation proceeds essentially on a single potential energy surface, and the observed coherences bear signatures of Duschinsky mode-mixing along the reaction path. The dynamics after the [Formula: see text] excitation are instead nonadiabatic, and the [Formula: see text] state plays a major role in the relaxation process. The simulations suggest a mainly active role of the proton in the isomerization, rather than a passive migration assisted by the vibrations of the benzoquinoline backbone.
Collapse
Affiliation(s)
- David Picconi
- Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Potsdam-Golm, Germany.
| |
Collapse
|
5
|
Offenbacher AR, Sharma A, Doan PE, Klinman JP, Hoffman BM. The Soybean Lipoxygenase-Substrate Complex: Correlation between the Properties of Tunneling-Ready States and ENDOR-Detected Structures of Ground States. Biochemistry 2020; 59:901-910. [PMID: 32022556 PMCID: PMC7188194 DOI: 10.1021/acs.biochem.9b00861] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Hydrogen tunneling in enzymatic C-H activation requires a dynamical sampling among ground-state enzyme-substrate (E-S) conformations, which transiently generates a tunneling-ready state (TRS). The TRS is characterized by a hydrogen donor-acceptor distance (DAD) of 2.7 Å, ∼0.5 Å shorter than the dominant DAD of optimized ground states. Recently, a high-resolution, 13C electron-nuclear double-resonance (ENDOR) approach was developed to characterize the ground-state structure of the complex of the linoleic acid (LA) substrate with soybean lipoxygenase (SLO). The resulting enzyme-substrate model revealed two ground-state conformers with different distances between the target C11 of LA and the catalytically active cofactor [Fe(III)-OH]: the active conformer "a", with a van der Waals DAD of 3.1 Å between C11 and metal-bound hydroxide, and an inactive conformer "b", with a distance that is almost 1 Å longer. Herein, the structure of the E-S complex is examined for a series of six variants in which subtle structural modifications of SLO have been introduced either at a hydrophobic side chain near the bound substrate or at a remote residue within a protein network whose flexibility influences hydrogen transfer. A remarkable correlation is found between the ENDOR-derived population of the active ground-state conformer a and the kinetically derived differential enthalpic barrier for D versus H transfer, ΔEa, with the latter increasing as the fraction of conformer a decreases. As proposed, ΔEa provides a "ruler" for the DAD within the TRS. ENDOR measurements further corroborate the previous identification of a dynamical network coupling the buried active site of SLO to the surface. This study shows that subtle imperfections within the initial ground-state structures of E-S complexes are accompanied by compromised geometries at the TRS.
Collapse
Affiliation(s)
- Adam R. Offenbacher
- Department of Chemistry, East Carolina University, Greenville, North Carolina 27858
- Department of Chemistry and California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, California 94720
| | - Ajay Sharma
- Department of Chemistry, Northwestern University, Evanston, Illinois 602084
| | - Peter E. Doan
- Department of Chemistry, Northwestern University, Evanston, Illinois 602084
| | - Judith P. Klinman
- Department of Chemistry and California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, California 94720
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720
| | - Brian M. Hoffman
- Department of Chemistry, Northwestern University, Evanston, Illinois 602084
| |
Collapse
|
6
|
Soudackov AV, Hammes-Schiffer S. Proton-coupled electron transfer reactions: analytical rate constants and case study of kinetic isotope effects in lipoxygenase. Faraday Discuss 2018; 195:171-189. [PMID: 27735009 DOI: 10.1039/c6fd00122j] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A general theory has been developed for proton-coupled electron transfer (PCET), which is vital to a wide range of chemical and biological processes. This theory describes PCET reactions in terms of nonadiabatic transitions between reactant and product electron-proton vibronic states and includes the effects of thermal fluctuations of the solvent or protein environment, as well as the proton donor-acceptor motion. Within the framework of this general PCET theory, a series of analytical rate constant expressions has been derived for PCET reactions in well-defined regimes. Herein, the application of this theory to PCET in the enzyme soybean lipoxygenase illustrates the regimes of validity for the various rate constant expressions and elucidates the fundamental physical principles dictating PCET reactions. Such theoretical studies provide significant physical insights that guide the interpretation of experimental data and lead to experimentally testable predictions. A combination of theoretical treatments with atomic-level simulations is essential to understanding PCET.
Collapse
Affiliation(s)
- Alexander V Soudackov
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
| | - Sharon Hammes-Schiffer
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
| |
Collapse
|
7
|
Salna B, Benabbas A, Russo D, Champion PM. Tunneling Kinetics and Nonadiabatic Proton-Coupled Electron Transfer in Proteins: The Effect of Electric Fields and Anharmonic Donor–Acceptor Interactions. J Phys Chem B 2017. [DOI: 10.1021/acs.jpcb.7b05570] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Bridget Salna
- Department of Physics and Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, Massachusetts 02115, United States
| | - Abdelkrim Benabbas
- Department of Physics and Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, Massachusetts 02115, United States
| | - Douglas Russo
- Department of Physics and Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, Massachusetts 02115, United States
| | - Paul M. Champion
- Department of Physics and Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, Massachusetts 02115, United States
| |
Collapse
|
8
|
Salna B, Benabbas A, Champion PM. Proton-Coupled Electron Transfer and the “Linear Approximation” for Coupling to the Donor–Acceptor Distance Fluctuations. J Phys Chem A 2017; 121:2199-2207. [DOI: 10.1021/acs.jpca.7b00539] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Bridget Salna
- Department of Physics and
Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, Massachusetts 02115, United States
| | - Abdelkrim Benabbas
- Department of Physics and
Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, Massachusetts 02115, United States
| | - Paul M. Champion
- Department of Physics and
Center for Interdisciplinary Research on Complex Systems, Northeastern University, Boston, Massachusetts 02115, United States
| |
Collapse
|
9
|
Soudackov AV, Hammes-Schiffer S. Nonadiabatic rate constants for proton transfer and proton-coupled electron transfer reactions in solution: Effects of quadratic term in the vibronic coupling expansion. J Chem Phys 2016; 143:194101. [PMID: 26590521 DOI: 10.1063/1.4935045] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Rate constant expressions for vibronically nonadiabatic proton transfer and proton-coupled electron transfer reactions are presented and analyzed. The regimes covered include electronically adiabatic and nonadiabatic reactions, as well as high-frequency and low-frequency proton donor-acceptor vibrational modes. These rate constants differ from previous rate constants derived with the cumulant expansion approach in that the logarithmic expansion of the vibronic coupling in terms of the proton donor-acceptor distance includes a quadratic as well as a linear term. The analysis illustrates that inclusion of this quadratic term in the framework of the cumulant expansion framework may significantly impact the rate constants at high temperatures for proton transfer interfaces with soft proton donor-acceptor modes that are associated with small force constants and weak hydrogen bonds. The effects of the quadratic term may also become significant in these regimes when using the vibronic coupling expansion in conjunction with a thermal averaging procedure for calculating the rate constant. In this case, however, the expansion of the coupling can be avoided entirely by calculating the couplings explicitly for the range of proton donor-acceptor distances sampled. The effects of the quadratic term for weak hydrogen-bonding systems are less significant for more physically realistic models that prevent the sampling of unphysical short proton donor-acceptor distances. Additionally, the rigorous relation between the cumulant expansion and thermal averaging approaches is clarified. In particular, the cumulant expansion rate constant includes effects from dynamical interference between the proton donor-acceptor and solvent motions and becomes equivalent to the thermally averaged rate constant when these dynamical effects are neglected. This analysis identifies the regimes in which each rate constant expression is valid and thus will be important for future applications to proton transfer and proton-coupled electron transfer in chemical and biological processes.
Collapse
Affiliation(s)
- Alexander V Soudackov
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Ave., Urbana, Illinois 61801, USA
| | - Sharon Hammes-Schiffer
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Ave., Urbana, Illinois 61801, USA
| |
Collapse
|
10
|
Wide-dynamic-range kinetic investigations of deep proton tunnelling in proteins. Nat Chem 2016; 8:874-80. [PMID: 27554414 DOI: 10.1038/nchem.2527] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 04/14/2016] [Indexed: 11/08/2022]
Abstract
Directional proton transport along 'wires' that feed biochemical reactions in proteins is poorly understood. Amino-acid residues with high pKa are seldom considered as active transport elements in such wires because of their large classical barrier for proton dissociation. Here, we use the light-triggered proton wire of the green fluorescent protein to study its ground-electronic-state proton-transport kinetics, revealing a large temperature-dependent kinetic isotope effect. We show that 'deep' proton tunnelling between hydrogen-bonded oxygen atoms with a typical donor-acceptor distance of 2.7-2.8 Å fully accounts for the rates at all temperatures, including the unexpectedly large value (2.5 × 10(9) s(-1)) found at room temperature. The rate-limiting step in green fluorescent protein is assigned to tunnelling of the ionization-resistant serine hydroxyl proton. This suggests how high-pKa residues within a proton wire can act as a 'tunnel diode' to kinetically trap protons and control the direction of proton flow.
Collapse
|