Magnets are fascinating for both children and adults. They also have a variety of uses, from the industrial to the mundane. Large magnets can lift cars and trucks while small magnets can hold pictures to the refrigerator. However, the unique properties of magnets also mean that they have some downsides. Magnets can be harmful to certain types of objects and even dangerous in certain situations.
Items with strong magnetic fields can harm a pacemaker. Some items that can react with pacemakers are slot machines, electric speakers and radio transmitters. People with pacemakers should also not have an MRI, because the machines contain very strong magnets. If you have a pacemaker, you should also store your cell phone in the pocket on the opposite side of your body from the pacemaker and hold your phone to the ear opposite your pacemaker.
Although typical magnets will not harm most modern electronics and hard drives, they can be harmful to older electronics. A household magnet will stick to a 3.5-inch floppy disk and erase any data that it contains. Modern memory cards are less susceptible to data loss, but older Cathode Ray Tube monitors and television sets are sometimes permanently affected by magnets. Electronics manufacturers like Apple and Microsoft recommend against storing their products near magnetic wallet clips or other magnets.
One thing that magnets do damage with some frequency is credit cards. After prolonged exposure, even a weak magnet will erase the data on a magnetic credit card strip. Some magnets that can cause this kind of damage include those in MRI machines, purse and wallet magnets and store security tag deactivators. In the case of purse and wallet magnets, the chances of damage are relatively small, as long as you keep the magnet at least an inch or so from your credit card.
Children are often fascinated by the physical properties of magnets. When turned one way, they stick together, when turned the other way they push each other apart. Unfortunately while magnets are fun for children to play with, they can be dangerous to young children. Many magnets are small enough for children to swallow. If a child swallows more than one magnet, they can stick together through different loops of intestine and cause intestinal pain and blockages. Children who have swallowed multiple magnets should be brought for immediate medical attention.