The great diversity of molecular processes in chemistry, physics, and biology exhibits universal property: they are controlled by powerful factor, angular momentum. Conservation of angular momentum (electron spin) is a fundamental and universal principle: all molecular processes are spin selective, they are allowed only for those spin states of reactants whose total spin is identical to that of products. Magnetic catalysis induced by magnetic interactions is a powerful and universal means to overcome spin prohibition and to control physical, chemical and biochemical processes. Contributing almost nothing in total energy, being negligibly small, magnetic interactions are the only ones which are able to change electron spin of reactants and switch over the processes between spin-allowed and spin-forbidden channels, controlling pathways and chemical reactivity in molecular processes. The main source of magnetic and electromagnetic effects in biological systems is now generally accepted and demonstrated in this paper to be radical pair mechanism which implies pairwise generation of radicals in biochemical reactions. This mechanism was convincingly established for enzymatic adenosine triphosphate (ATP) and desoxynucleic acid (DNA) synthesis by using catalyzing metal ions with magnetic nuclei (²⁵Mg, ⁴³Ca, ⁶⁷Zn) and supported by magnetic field effects on these reactions. The mechanism, is shown to function in medicine as a medical remedy or technology (trans-cranial magnetic stimulation, nuclear magnetic control of the ATP synthesis in heart muscle, the killing of cancer cells by suppression of DNA synthesis). However, the majority of magnetic effects in biology remain to be irreproducible, contradictory, and enigmatic. Three sources of such a state are shown in this paper to be: the presence of paramagnetic metal ions as a component of enzymatic site or as an impurity in an uncontrollable amount; the property of the radical pair mechanism to function at a rather high concentration of catalyzing metal ions, when at least two ions enter into the catalytic site; and the kinetic restrictions, which imply compatibility of chemical and spin dynamics in radical pair. The purpose of the paper is to analyze the reliable sources of magnetic effects, to elucidate the reasons of their inconsistency, to show how and at what conditions magnetic effects exhibit themselves and how they may be controlled, switched on and off, taking into account not only biological and madical but some geophysical and environmental aspects as well.

化学，物理和生物学中分子过程的巨大多样性表现出普遍的特性：它们受强大的因素，角动量控制。角动量守恒（电子自旋）是一个基本且通用的原理：所有分子过程都是自旋选择性的，它们仅适用于总自旋与产物相同的反应物的自旋态。磁相互作用引起的磁催化是克服自旋禁止并控制物理，化学和生化过程的强大而通用的手段。磁场相互作用几乎不贡献总能量，几乎可以忽略不计。能够改变反应物的电子自旋并在自旋允许和自旋禁止的通道之间切换过程，控制分子过程中的途径和化学反应性。现在，生物系统中电磁效应的主要来源已被普遍接受，并在本文中被证明是自由基对机理，这意味着在生化反应中成对产生自由基。通过使用具有磁性核（²⁵ Mg，⁴³ Ca，^67的金属离子）催化，令人信服地确立了该机制用于酶促三磷酸腺苷三磷酸（ATP）和脱氧核酸（DNA）的合成。Zn）并受磁场影响而对这些反应产生影响。该机制在医学上已作为医学疗法或技术发挥作用（经颅磁刺激，心肌中ATP合成的核磁控制，通过抑制DNA合成杀死癌细胞）。但是，生物学中的大多数磁效应仍然是不可再现，矛盾和神秘的。本文显示了这种状态的三个来源：顺磁性金属离子的存在作为酶促位点的成分或作为不可控制量的杂质；当至少两个离子进入催化位时，自由基对机理的性质在较高浓度的催化金属离子下起作用；以及动力学上的限制 这意味着自由基对中化学和自旋动力学的相容性。本文的目的是分析磁效应的可靠来源，阐明其不一致的原因，以显示磁效应如何以及在什么条件下表现出来，以及如何控制，开启和关闭磁效应，而不考虑到仅在生物学和医学上，但在地球物理和环境方面也是如此。