Sooner or later we all have to get rid of an old computer and many people just trash ’em.

But consider this: inside those computers are lead, mercury, and chromium. They’re toxic. Dangerous chemicals cause all types of health problems. So, if you shouldn’t trash them, what do you do?

E-Waste recycling centers are opening up across the country. Non-profits remove the parts that can be used again. Most won’t charge you anything.

Best Buy has a great recycling policy. While the retailer doesn’t take big-screen TVs or refrigerators, it will take computers, routers, printers, cellphones, old hard drives, and small appliances.

You’ll get a discount on a replacement item and if it works, you might be able to trade it in for a gift card.

The best way to limit the number of computers in landfills is to make yours last longer. Rather than tossing a laptop because the battery doesn’t last long, replace the battery.

Replace the spinning hard drive with a solid-state hard drive with no moving parts. Clean out the dust with canned air.

Keep up with updates from Apple and Microsoft. Use an anti-virus and anti-malware program.

And the age-old question: is it best to turn off the computer when you’re not using it?

Leaving it on overnight will use a small amount of electricity but turning it off and on every day will limit its lifespan. Every time you turn it on, all those parts start turning again. And most computer issues happen when it starts up. So put it to sleep overnight. Turn it off about once a week to reboot everything and install any updates.

Today’s computers should last eight years or more. Extending their life, even for a year, is going to save you a lot of money as prices will drop.