It's disconcerting when they talk about big numbers in environmental reports. For instance, the number of refrigerators that is dumped each year. It was a major problem at the time we were trying to avoid eating away the whole of the ozone layer with CFCs released by aerosol sprays and leaking from those dumped cooling boxes. A quick "back-of-an-envelope", or Fermi, calculation reveals the truth.

Let's assume there are 30 million households in a small nation and 2 out of every three has a refrigerator, some might have a little desktop cooler for chilling the beer, others will have a double-barreled, giant US-style cold food store, with icemaker. Some households will have a standalone freezer unit too or any combination. For simplicity's sake. 20 million refrigerators. Next, let's assume that an average unit wears out in ten years despite ongoing pump replacements, new light bulbs and refilling the coolant system over its lifetime. So, that's 20 million units every ten years. 1 million every year being replaced and the old model dumped somewhere. So that's a lot of metal boxes with their various bits of pipe work and plastic.

Now, let's make some similar assumptions about other devices that most of those homes will have one of each, at least: washing machines and tumble dryers (5-year) televisions, similar, laptops and PCs (3 years), mobile phones (18 months), the list goes on. Moreover, we can assume that although it's usually simply a battery failure that pulls down the average lifespan of a portable electronic device, there is also the pressure on everyone who uses them and watches TV etc to upgrade, upgrade, upgrade. So millions of devices and machines every year, not forgetting cars.

This is not the end of the big numbers, our original assumption was for a single small nation, but there are many millions of households in the developed world with all of those gadgets many times over and many in the developing world where the gadgets are becoming increasingly available. Needless to say, there are millions of tons of metals, semiconductors, plastics and glass being used each year across the globe and dumped.

Hazardous  materials  such as cadmium, arsenic, copper, lead, lithium, mercury and hexavalent chromium, asbestos, polychlorinated  biphenyls (PCBs), phthalates, brominated flame retardants  and the chlorine-containing plastics that release other noxious chemicals when burned are present in varying amounts along with many other materials in one form or another in  e-waste, cathode ray tubes (CRTs), printed board assemblies, capacitors,  mercury  switches  and  relays,  batteries,  liquid  crystal  displays  (LCDs),  toner cartridges etc etc.

Of course, in some parts of the world, regulations and schemes are in place to force manufacturers and consumers to retrieve and recycle e-waste rather than it ending up in landfill sites. Decades of waste dumped before such regulations were in place might one day be future source of lost materials that we might mine. But, rules are commonly broken in some regions and in some regions, the infrastructure does not exist to allow the safe retrieval of toxic substances from e-waste. In addition, the generous western world currently frees itself from many of its obligations by donating obsolete and perhaps barely functioning devices via charitable organization on less developed nations. They thus simply displace the problem given that much of the donated equipment is worthless except as scrap.

Various observers, such as Adarsh Garg of Wipro Pvt. Ltd in Greater Noida, U.P. India, have noted this problem and have highlighted the issue that many of those attempting to make money from e-waste across India are less likely to recognize the hazards presented by toxic metals as they are to recognize the monetary value of copper wires and cable insulation.

The e-waste might follow a neat cycle of collection, separation and sorting, dismantling, recycling and debris disposal, but at each stage exposure of individuals, including countless children, and the environment to toxic metals, carcinogens, arsenic, dioxins etc etc, is often unknown or deliberately ignored. E-waste is a rapidly growing problem, every phone upgrades, every worn out refrigerator replaced, every new TV tuned, it is an endless numbers game. A game the rules for which few take care to note and many simply ignore.

David Bradley blogs at and tweets @sciencebase, he is author of the popular science book "Deceived Wisdom".