TOWARDS the end of “Toy Story 3”, with Andy having left for college, his much-loved toys from childhood mistakenly face destruction in the maw of a moving-grate garbage incinerator. If, in real life, the plant had been built prior to 1989, the plastic toys would have produced a nasty dose of dioxins and furans—toxic emissions from combustion taking place in the presence of chlorine—as well as heavy metals and dubious organic compounds. Until then, few people were aware that such chemicals presented a serious health hazard, capable of upsetting the immune system, damaging the liver and causing cancer. Unwittingly, municipal incinerators were among the worst offenders.

Industry subsequently spent billions retrofitting incinerators with activated-carbon injectors and particle traps to capture the dioxins and furans, as well as volatile metals like cadmium and mercury. Thanks to new regulations, the emission of such toxic chemicals from waste processing has been reduced a thousandfold. Today, the total emission of dioxins and furans produced by all the incinerators in America is less than ten grams a year, according to the Environmental Protection Agency (EPA). By contrast, homeowners burning rubbish in their backyards are reckoned to contribute up to 500 grams a year. Some of the worst emitters are the fireworks used to celebrate the Fourth of July.

Even so, municipal incinerators—especially the new waste-to-energy (WTE) plants that use rubbish as a fuel for generating electricity and heat for local distribution—continue to have an image problem. In America, most communities prefer their waste to be composted—provided, of course, the landfills are nowhere near their own backyards. Yet, without costly plumbing, landfills produce copious quantities of methane from their decomposing waste. As a greenhouse gas, methane does more than 20 times the damage to the environment as comparable emissions of carbon dioxide.

At some of the larger municipal landfills, the methane produced by anaerobic decomposition is captured and used to generate electricity. The mountain of rubbish at the Puente Hills Landfill in Los Angeles, the largest of the 1,900 municipal landfills in America, is over 500-feet high—taller than most of the skyscrapers in the city's downtown area to the west. With 60 years' worth of decomposing rubbish, Puente Hills produces enough methane to generate electricity for 70,000 homes.

Not all local authorities can afford such luxuries. New York City transports much of its garbage by truck and train to landfills hundreds of miles out of state. It is not the only one. More and more places are even shipping their rubbish abroad to countries willing to process it at a price. While China exports computers, mobile phones and other manufactured goods to America, the largest export from the United States to China (as measured by the number of cargo containers) is now trash, reports the Journal of Commerce.

The problem is exacerbated by the growing shortage of landfill space everywhere. As the rubbish piles up, officials are having to reconsider the sensitive issue of incineration. Modern incinerators are not your grandfather's dirty burners. Almost all nowadays capture the energy in the solid waste as well as the emissions from the combustion. Such WTE plants burn garbage at temperatures high enough (over 850°C) to break the molecular bonds in dioxin and other toxic chemicals and thus render them harmless. The flue gases are then cooled in heat exchangers that raise steam to drive the electricity-generating turbines.

The flue gases are then passed to a cleaning system that filters fine particles from the flow and scrubs the gas to remove sulphur dioxide as well as various acids and heavy metals. As in a car exhaust, the flue gases next pass through a catalytic converter, where the nitrogen oxides are chemically reduced with ammonia or urea. Finally, volatile heavy metals remaining in the flue are absorbed on activated-carbon powder.

The volume of the ash left after combustion amounts to around 5% of the waste ingested. The ash at the bottom of the combustion chamber is either buried in municipal landfills or recycled as aggregate for the construction industry. The fly ash that rises up the flue needs further processing to remove any remaining toxic particles that might be clinging to its surface. The result is a remarkably clean and efficient process for disposing of garbage.

As much municipal rubbish (eg, paper, cardboard, wood, cloth, food scraps) has a biological origin, the electricity and heat produced by WTE plants is considered renewable energy, useful for offsetting greenhouse gases from fossil-fuel plants. Meanwhile, for every tonne of municipal waste that avoids being buried in a landfill—and is burned instead in a WTE plant—the amount of methane entering the atmosphere is reduced by the equivalent of almost a tonne of carbon dioxide, calculates the EPA. So, what's not to like about processing trash this way?

Nimbyism aside, the main objection to WTE incineration is not that it is so bad, but that better WTE technologies are waiting in the wings. Another complaint is that municipal waste is still seen as a social nuisance needing to be disposed of at a cost. Instead, it should be viewed as a valuable resource. In other words, rather than burn it, recycle as much of it as possible.

That means sorting the trash mechanically beforehand into recyclable metals, plastics, glass and paper, and then using anaerobic microorganisms to breakdown the biological residue into biogas and compost. The biogas (primarily methane, carbon dioxide and hydrogen sulphide) can then be used to generate electricity, or even cleaned and compressed to form a fuel for motor cars.

Others suggest replacing the biological step above with some form of heat-treatment, such as high-pressure superheated steam in an autoclave, or gasification using a plasma arc that vaporises the garbage in the absence of oxygen—so few of the noxious products of combustion are produced. Either way, the result is a biofuel for generating electricity. Though still experimental, such technologies could one day prove more attractive than today's waste-to-energy incineration.

To which, your correspondent says all in good time. Right now, there are lower-hanging fruit to pick. Simple changes in the law could reduce the amount of rubbish produced dramatically. In his book “Garbology: Our Dirty Love Affair With Trash”, the Pulitzer prize-winning author Edward Humes notes that other wealthy countries with high living standards have rejected the disposable products that make up much of America's rubbish.

According to the OECD, the average person creates 3.3lb (1.5kg) of rubbish a day in France, 2.7lb in Canada and no more than 2.3lb in Japan. By the OECD's reckoning, the average American tosses 4.5lb a day, though more recent accounting puts the figure over 7lb a day, with less than a quarter being recycled. As a result, communities in America spend more on waste management than on fire protection, parks and recreation, libraries or schoolbooks, says Mr Humes.

The main difference is that in Europe and elsewhere manufacturers, rather than consumers, are held responsible for the cost of processing the packaging used to wrap their goods. Thus, a tube of toothpaste comes without a cardboard box; a TV set without all the polystyrene packing.

Having lived for many years in Tokyo before moving to Los Angeles, your correspondent finds it ironic that in high-price Japan, where the government has long ridden roughshod over consumers so that producers may prosper, it is the manufacturers who have been held accountable for the waste they dump on society. By contrast, in consumer-driven America, the cost of cleaning up the mess has been dumped at the consumer's door. That is what needs to be changed.