Marcus Bleasdale knows more about what goes into your smartphone than you'd ever want to hear about it. The British photographer has been documenting unthinkable violence in the eastern Democratic Republic of the Congo (DRC) since 1999.

During that time, tens of thousands of child soldiers have been a part of conflict that has led to more than 5 million deaths. At the heart of this violence are what are called "conflict minerals," including gold and diamonds. More recently, three other conflict minerals — tantalum, tungsten and tin — have come into focus because they are used to produced smartphones, laptops, tablets, cameras and other electronic devices.

See also: How to Follow Social Good Summit Online

We caught up with Bleasdale Sunday morning before he took the stage at Social Good Summit.

"Anyone in today's world is using a significant amount of electronics products," he told Mashable. "All of these consumable products have, at some time, had conflict minerals from Congo in them. We as consumers should be appalled by that."

Bleasdale said the violence really hits home when he sees an 11-year-old child, the same age as his niece, forced to tote an assault riffle. He also called sexual violence "the weapon of choice" by warlords in the DRC. About 40,000 women were raped in the DRC during a 12-month period in 2006-2007, according to a report published in the American Journal of Public Health.

The solution, Bleasdale argues, is not to refrain from buying electronic products.

"I'm probably the worst user of conflict minerals on the planet; I'm a photographer with five camera bodies and two computers and phones," he said. "I walk around with half a Congolese mine in my bag everyday."

Instead, Bleasdale said consumers should demand that technology companies produce products that are free of conflict minerals. As part of the 2010 Dodd-Frank financial reform bill, American companies now have to audit their supply chains and disclose whether their minerals come from mines run by armed groups in the DRC.

The Enough Project releases an annual report, rating how companies are progressing toward remove these minerals from their supply chains. Bleasdale said that 10% of mines in the DRC are now conflict mineral free.

"We have a long way to go, but I do see that there's an opportunity for change," he said. "Three years ago there were none, so slowly the industry can see that it needs to change."

Bleasdale's photographs will accompany a story on conflict minerals in the DRC in the October 125th anniversary issue of National Geographic magazine, which focuses on the power of photography to impact change. The gallery below contains a sample of the images that will appear in the article.

Marcus Bleasdale's Photography

About Social Good Summit

The Social Good Summit is where big ideas meet new media to create innovative solutions and is brought to you by Mashable, The 92nd Street Y, The United Nations Foundation, The United Nations Development Programme, The Bill and Melinda Gates Foundation and Ericsson. Held during U.N. Week, the Social Good Summit unites a dynamic community of global leaders to discuss a big idea: the power of innovative thinking and technology to solve our greatest challenges.

Date: Sept. 22 through Sept. 24 Time: 12 to 6 p.m. each day Location: 92nd Street Y, 1395 Lexington Ave., New York, N.Y. Tickets are sold-out, but tune into the Livestream.

About Ericsson

BONUS: 10 Empowering Apps for Social Good

Social Good Apps

Image: Marcus Bleasdale/National Geographic