In the US, over 75 million units a year are sold.  The rapid expansion of the personal computer industry carries enormous implications for energy use, hazardous waste issues, and human health.
Pre- and post-manufacturing e-waste
The production of computer parts such as microchips, for example, requires higher quantities of water, fossil fuels, energy, toxic chemicals, and elemental gases than any other industry. This manufacturing process creates exorbitant amounts of waste, as well as the use of potentially toxic materials. Monitors with cathode ray tubes (not flat paneled) contain between four to eight pounds of lead each. Flat paneled monitors contain less lead, but greater amounts of mercury. The toxic qualities of lead have been well documented and it is already banned from many uses. The toxicity of mercury is well known as well, and it is potent in acute quantities. Just 1/70th of a teaspoon of mercury can pollute and contaminate a 20 acre lake, rendering its fish unsuitable for consumption.
Further, once these computers become obsolete and are thrown away or replaced by newer versions, they create an additional source of waste; electronic waste (e-waste) is the fastest growing portion of the US waste stream, rising at rates around eight per year. According to the US Environmental Protection Agency (EPA), by 2005, 250 million computers in the US became obsolete. The waste generated by these computers will include one billion pounds of lead, about two million pounds of cadmium, 1.2 million pounds of chromium, more than 4 billion pounds of plastic, and almost 400,000 pounds of mercury.
However, fewer than ten percent of these outdated electronics are updated or recycled. The rest end up in landfills or incinerators where they can then enter the water or air supply and cause harm to human and ecosystem health.
Computers and energy
The average American is responsible for almost 22 tons of carbon dioxide emissions per year, the largest source being electricity generation, representing approximately 30 percent of emissions. Home office equipment and electronics account for about 20 percent of this electricity use.
Most computers are left on for 24 hours per day. To power a conventional computer all day costs between $115 and $160 in electricity per year, releasing 1,500 pounds of carbon dioxide into the air. Given that a tree absorbs between 3 to 15 pounds of carbon dioxide per year, it would take between 100 and 500 trees to offset these emissions for just a year.
Of the total electricity used for computers, at least 65 percent is wasted, while only 35 percent is used for actual computing. More energy efficient computers have entered the market, with ENERGY STAR qualified computers promising up to 70 percent reductions in energy usage.
And the energy use doesn't stop with individual computers. Websites, data storage, and Internet servers live in giant data centers which consume double the energy they consumed in 2000—no small amount, considering it's 1.5 percent of total US electricity.
Related health issues
The toxic chemicals in computers are linked to many health problems. When computers are improperly discarded, these substances can enter groundwater supplies through landfills or the air if they are incinerated, causing possible risks to human health.
Lead and mercury, both heavy metals, can cause permanent brain damage, reproductive and developmental harm, and potentially cancer. Cadmium, also a metal, is known to cause cancer. Brominated flame retardants have been shown to cause brain damage and possible cancer.
People who work with computers, either in the production process or in recycling, are at the greatest risk for toxic exposure to heavy metals lead, chromium, cadmium and mercury. There is no evidence that computer users are exposed to these chemicals.
Some manufacturers are significantly reducing the use of hazardous substances in their products, including lead, mercury, cadmium, arsenic, and brominated flame retardants. Programs like EPEAT (Electronic Product Environmental Assessment Tool) give manufacturers set of eco-goals for which to strive in producing less toxic machines.
- cadmium: Found in chip resistors, infrared detectors, and semiconductors. Toxic and bio-accumulative, this chemical can affect your kidneys.
- lead: Used in the soldering of circuit boards, and it can cause damage to your nervous system, your kidneys, and your blood system. It is estimated that consumer electronics are responsible for 40 percent of the lead in landfills. From there, it can seep into our drinking water and then accumulate in the environment, affecting plants, animals, and humans.
- mercury: Found in batteries and circuit boards, can seep into waterways. This chemical travels through the food chain and can cause brain damage.
- brominated flame retardants (BFRs): Used on printed circuit boards and components like plastic covers and cables. Once released into the environment through leaching and incineration, BFRs travel through the food chain and can increase cancer risk.
- The Northwest Product Stewardship Council guide to computers
- Green Electronics Council: Nonprofit group working to encourage the design and manufacturer of greener electronics products.
- EPEAT (Electronic Product Environmental Assessment Tool): US EPA-funded effort offered by the Green Electronics Council, this tool helps consumers (both public and private) evaluate and compare desktop PCs, notebooks and monitors based on environmental criteria, including use of dangerous chemicals, energy efficiency, and packaging.
- Financial Times Article -Strong mobile sales boost global PC shipments
- The Green Guide - Product Report: Computers
- Computer Take Back Campaign Informational Website
- The Computer Take Back Campaign
- The Green Guide - Product Report: Computers
- Tufts University Brochure on Computers
- Rocky Mountain Institute Home Energy Brief on Electronics
- ENERGY STAR - Computers
- Worldwatch Institute - Efficiency Measures Could Cut Data Center, Server Energy Use by Half