TWI Frequently asked questions
It is not possible to give a completely definitive answer when asked about the risks to a pacemaker user of being exposed to the electromagnetic fields associated with welding. Each pacemaker is programmed for its users specific needsand each case needs to be treated separately. Pacemakers vary as to their sensitivity from type to type, maker to maker and individual to individual. Defibrillators, for instance, are far more sensitive to electromagnetic radiationthan single chamber pulse rate control pacemakers. A pacemaker user who is 100% pacemaker dependant is also at greater risk than a user who only needs the pacemaker for short periods of time e.g. if suffering from a condition such aspostural hypotension.
If the pacemaker user has any doubts about his or her working environment this should be taken up with the hospital that fitted the unit. To confirm whether or not there is a problem, the hospital could be asked to fit the user witha Holter monitor. This is similar in size to a "Walkman" tape player and is a form of portable ECG machine. It is worn by the user for a period of 24 hours and will monitor and record the functioning of the heart. This would enable anyeffect of the environment on the operation of the pacemaker to be detected.
As a general rule, working close to sources of electromagnetic radiation from "conventional" welding equipment e.g. MMA (SMA), MIG/MAG (GMA) or TIG (GTA) equipment, is unlikely to present much of a risk to a pacemaker user althoughit is advisable to reduce the exposure as much as possible. Welding cables should not be wrapped around the arm or draped over the shoulder and should be kept as far away from the user as possible.
Working in the vicinity of equipment which produces very strong electro-magnetic fields such as resistance welders or power sources which produce pulsing magnetic fields, particularly where the pulsing rate matches or is close tothe pulse rate of the pacemaker user, can be a hazardous situation. In the presence of pulsing magnetic fields, the pacemaker can be fooled into thinking that the heart is beating normally and does not need assistance. In this case itwill switch off with the risk therefore of a cardiac arrest and collapse. Removal from the magnetic field will result in the pacemaker returning to its normal, programmed condition. Exposure to very strong magnetic fields can clear thememory of the pacemaker. With more modern pacemakers, it is likely that they will reset to a default condition and pulse continuously until reprogrammed.
Copyright by TWI, 1999
