When it comes to items discarded rather than recycled one huge problem is there no safe way to dispose of them.
Computers and electronic devices contain many toxic metals and materials including but not limited to nickel, mercury, lead and barium. These materials can have an impact not only on the environment but also human health.
If placed in landfills these materials can seep through the soil and into the groundwater impacting not just crops, wildlife and livestock but also toxicity levels in the sea when the water eventually flows into it. If electronics are incinerated the chemicals are released into the atmosphere causing damage and pollution.
Whilst recycling is of course preferable it is not without its own risks, particularly depending on how it is undertaken. Studies from the Chinese City of Guiyu, home of the largest e-waste recycling plant on Earth, show substantially increased levels of neurological, digestive and respiratory problems amongst its residents.
Aside from health and pollution issues there is also another side to the environmental impact- the cost of making new items. This can be the costs of manufacture and transportation of new products but also the cost of their raw materials. There are large quantities of gold and other metals used in electronics production, some of course can come from recycling but the rest must be mined. Mining is a hugely energy intensive process and some metals used like neodymium are incredibly rare.