resistance and allowing further increased current flow. medical implants. artificial cardiac pacemakers or implantable cardioverter-defibrillators (icd) are sensitive to very small currents. pre-existing medical condition. age and sex. other issues affecting lethality are frequency, which is an issue in causing cardiac arrest or muscular spasms. very high frequency electric current causes tissue burning, but does not penetrate the body far enough to cause cardiac arrest (see electrosurgery). also important is the pathway: if the current passes through the chest or head, there is an increased chance of death. from a main circuit or power distribution panel the damage is more likely to be internal, leading to cardiac arrest. another factor is that cardiac tissue has a chronaxie (response time) of about 3 milliseconds, so electricity at frequencies of higher than about 333 hz requires more current to cause fibrillation than is required at lower frequencies. the comparison between the dangers of alternating current at typical power transmission frequences (i.e., 50 or 60 hz), and direct current has been a subject of debate ever since the war of the currents in the 1880s. animal experiments conducted during this time suggested that alternating current was about twice as dangerous as direct current per unit of current flow (or per unit of applied voltage). it is sometimes suggested that human lethality is most common with alternating current at 100–250 volts; however, death has occurred below this range, with supplies as low as 42 volts. assuming a steady current flow (as opposed to a shock from a capacitor or from static electricity), shocks above 2,700 volts are often fatal, with those above 11,000 volts being usually fatal, though exceptional cases have been noted. according to the guinness book of world records, seventeen-year-old brian latasa survived a 230,000 volt shock on the tower of an ultra-high voltage line in griffith park, los angeles on november 9, 1967. a news report of the event stated that he was "jolted through the air, and landed across the line", and though rescued by firemen, he sustained burns over 40% of his body and was completely paralyzed except for his eyelids. the shock with the highest voltage reported survived was that of harry f. mcgrew, who came in contact with a 340,000 volt transmission line in huntington canyon, utah. prevention grounding the electrical enclosure of high-voltage machinery. use of insulated gloves, insulated boots, mats and tools. protecting electrical circuit with a residual-current device (rcd). epidemiology there were 550 reported electrocutions in the us in 1993, 2.1 deaths per million inhabitants. at that time, the incidence of electrocutions was decreasing. electrocutions in the workplace make up the majority of these fatalities. from 1980–1992, an average of 411 workers were killed each year by electrocution. workplace deaths caused by exposure to electricity in the u.s. increased by nearly 24% between 2015 and 2019, from 134 to 166. however, workplace electrical injuries dropped 23% between 2015 and 2019 from 2,480 to 1,900. in 2019, the top 5 states with the most workplace electrical fatalities were: (1) texas (608); (2) california (451); (3) florida (306); (4) new york (273); and (5) georgia (207). a recent study conducted by the national coroners information system (ncis) in australia has revealed 321 closed case fatalities (and at least 39 case fatalities still under coronial investigation) that had been reported to australian coroners where a person died from electrocution between july 2000 and october 2011. in sweden, denmark, finland and norway the number of electric deaths per million inhabitants was 0.6, 0.3, 0.3 and 0.2, respectively, in the years 2007–2011. people who survive electrical trauma may develop a host of injuries including loss of consciousness, seizures, aphasia, visual disturbances, headaches, tinnitus, paresis, and memory disturbances. even without visible burns, electric shock survivors may be faced with long-term muscular pain and discomfort, exhaustion, headache, problems with peripheral nerve conduction and sensation, inadequate balance and coordination, among other symptoms. electrical injury can lead to problems with neurocognitive function, affecting speed of mental processing, attention, concentration, and memory. the high frequency of psychological problems is well established and may be multifactorial. as with any traumatic and life-threatening experience, electrical injury may result in post traumatic psychiatric disorders. there exist several non-profit research institutes that coordinate rehabilitation strategies for electrical injury survivors by connecting them with clinicians that specialize in diagnosis and treatment of various traumas that arise as a result of electrical injury. deliberate uses medical uses electric shock is also used as a medical therapy, under carefully controlled conditions: electroconvulsive therapy or ect, a psychiatric therapy for mental disorders as a surgical tool for cutting or coagulation in electrosurgery. an electrosurgical unit (esu) uses high currents (e.g. 10 amperes) at high frequency (e.g. 500 khz) with various schemes of amplitude modulation to cut or coagulate as a treatment for fibrillation or irregular heart rhythms: see defibrillation and cardioversion as a method of pain relief: see transcutaneous electrical nerve stimulation (tens) as a treatment for excessive sweating with a process called iontophoresis electrodiagnosis, for example nerve conduction studies and electromyography electroporation for gene delivery entertainment electrifying machine at musée mécanique that actually works with vibration mild electric shocks are also used for entertainment, especially as a practical joke for example in such devices as a shocking pen or a shocking gum. however devices such as a joy buzzer and most other machines in amusement parks today only use vibration that feels somewhat like an electric shock to someone not expecting it. it is also used entertainingly for sex stimulation. this is usually done via the use of an erotic electrostimulator which induces erotic electrostimulation. these devices may include a violet wand, transcutaneous electrical nerve stimulation, electrical muscle stimulation, and made-for-play units. policing and personal defense electroshock weapons are incapacitant weapons used for subduing a person by administering electric shock to disrupt superficial muscle functions. one type is a conductive energy device (ced), an electroshock gun popularly known by the brand name "taser", which fires projectiles that administer the shock through a thin, flexible wire. although they are illegal for personal use in many jurisdictions, tasers have been marketed to the general public. other electroshock weapons such as stun guns, stun batons ("cattle prods"), and electroshock belts administer an electric shock by direct contact. electric fences are barriers that use electric shocks to deter animals or people from crossing a boundary. the voltage of the shock may have effects ranging from uncomfortable, to painful or even lethal. most electric fencing is used today for agricultural fencing and other forms of animal control purposes, though it is frequently used to enhance security of restricted areas, and there exist places where lethal voltages are used. torture electric shocks are used as a method of torture, since the received voltage and current can be controlled with precision and used to cause pain and fear without always visibly harming the victim's body. electrical torture has been used in war and by repressive regimes since the 1930s. the united states army is known to have used electrical torture during world war ii. during the algerian war electrical torture was used by french military forces. amnesty international published a statement that russian military forces in chechnya tortured local women with electric shocks by attaching wires onto their breasts. the parrilla (spanish for 'grill') is a method of torture whereby the victim is strapped to a metal frame and subjected to electric shock. it has been used in a number of contexts in south america. the parrilla was commonly used at villa grimaldi, a prison complex maintained by dirección de inteligencia nacional, a part of the pinochet regime. in the 1970s, during the dirty war, the parrilla was used in argentina. francisco tenório júnior (known as tenorinho), a brazilian piano player, was subjected to the parrilla during the military dictatorship in brazil. advocates for the mentally ill and some psychiatrists such as thomas szasz have asserted that electroconvulsive therapy (ect) is torture when used without a bona fide medical benefit against recalcitrant or non-responsive patients. the judge rotenberg center in canton, massachusetts has been condemned for torture by the united nations special rapporteur on torture for its use of electric shocks as punishment as part of its behavior modification program. japanese serial killer futoshi matsunaga used electric shocks to control his victims. capital punishment electric chair in sing sing electric shock delivered by an electric chair is sometimes used as an official means of capital punishment in the united states, although its use has become rare from the 1990s onward due to the adoption of lethal injection. although some original proponents of the electric chair considered it to be a more humane execution method than hanging, shooting, poison gassing, etc., it has now generally been replaced by lethal injections in states that practice capital punishment. modern reporting has claimed that it sometimes takes several shocks to be lethal, and that the condemned person may actually catch fire before death. other than in parts of the united states, only the philippines reportedly has used this method, from 1926 to 1976. it was intermittently replaced by the firing squad, until the death penalty was abolished in that country. electrocution remains legal in at least 4 states (florida, alabama, north carolina and kentucky) of the united states.