Tasers, created to save lives by subduing criminals and others without shooting them, are now the target of health papers. They are used by over 16,000 police forces in 107 countries and use compressed nitrogen to fire two barbed electrical probes that deliver a pulsed 50,000 volt shock, causing intense skeletal muscle contractions and pain.
Writing in BMJ, journalist Owen Dyer says the health risks are greater than previously thought. Of recent concern is the police use of Tasers against mentally ill patients, which has prompted the UK home secretary, Theresa May, to order a review of police use of force against mentally distressed people.
The most commonly used Taser (the X26) also has a "drive-stun" mode, in which two electrodes at the front of the weapon are held against the body, causing pain but not muscle contractions. A pull of the trigger delivers five seconds of current, more if the trigger is held down. In the United Kingdom, use of Tasers tripled between 2009 (when police officers not trained in firearms were first allowed to carry them) and 2013. Police drew tasers on 10,380 UK civilians aged 14-85 years in 2013 and fired them in 20% of those cases. A similar number of police officers received shocks while training.
Their use has been linked to eye injuries, seizures, collapsed lung (pneumothorax), skin burns, and muscle, joint, and tendon injuries. The most dangerous risk is head injury from uncontrolled falls and there is still much debate about whether Tasers affect the heart, in particular the potential to induce lasting heart rhythm problems (arrhythmias).
As is the case in the US, safety is on the onus of the manufacturer, so they have to pay for and provide study results, but in the modern world activists and some academics question whether or not anyone but them can be ethically neutral. In one small study (n=8, even less than Andrew Wakefield's autism-vaccine study) it was claimed that Tasers had caused irregular heart rhythm (ventricular fibrillation). A US National Institute of Justice review concluded that direct inducement of cardiac arrhythmias in "a confluence of unlikely circumstances" was a "plausible but unproven" outcome, which means not impossible even if it had not been shown yet.
Regardless of the data, BMJ has offered the chance to promote fear and doubt about the technology, making it more likely police will have to consider more violent means in the future.