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THE US has a big waste problem and, officially at least, recycling is
seen as one of the best solutions. Twenty-five states now have laws mandating
some type of recycling. Eight of these aim to reduce the flow of domestic
waste by between 15 and 30 per cent within a few years. Connecticut, most
ambitious of all, will forbid the incineration or disposal by landfill of
any recyclable item from 1991. ‘Reverse vending’ machines swallow used
cans and bottles and automatically credit the manufacturer with a return.
But one archaeologist thinks that the US may be recycling some of its discarded
materials for the wrong reasons.

William Rathje of the University of Arizona specialises in rubbish tips,
rather than the sites of ancient civilisations. His team of archaeologists,
microbiologists and chemists has so far dug into seven sites across the
US. They apply established archaeological techniques of ‘layered’ excavation
to cut a cross-section into a landfill, then sort the refuse taken from
the cross-section into categories. They can tell how old each layer of refuse
is by its depth in the landfill and from changes in the design of, for example,
Coca-Cola bottles. ‘Sell-by’ dates and newspapers give more accurate information
and are still legible even when they are 40 or 50 years old.

Waste disposal and recycling authorities commissioned the digs to find
out precisely what people in the US throw away and what then happens to
the refuse. ‘Much of the information used to formulate solid waste policies
– what we think is in landfills and what happens to it over time – may be
based more on fantasies than on fact,’ says Rathje.

His most controversial conclusions are that plastic and foam are not
a growing landfill problem, that bans on the use of expanded polystyrene
foam – already in force in some areas of the US – are a waste of time, and
that resources currently devoted to reducing the amount of plastic waste
would be better spent elsewhere.

Rathje says that one unfairly labelled villain is the plastic drinks
bottle. The popularity of light, shatterproof, disposable bottles made from
PET (polyethylene terephthalate) has shot up since they were introduced
in 1977. Now, about 95 per cent of large soft-drink bottles in the US are
made from this plastic. But although ecology-conscious Americans may be
haunted by images of immortal Coke bottles and Big Mac foam ‘clamshells’
outliving their landfill graves, Rathje argues that the problems these materials
cause in litter do not apply to refuse in landfill sites.

Since it is inert and compactable, plastic is the perfect throwaway
material, he says, and the least likely to release toxins into the environment.
‘It’s commonly estimated that 30 per cent of our landfills are taken up
with plastics. That may be true of litter, but not garbage. In seven digs
over two years we exhumed 16 000 pounds of garbage, weighing every item
we found and sorting them into 27 basic categories and then into 162 sub-groupings.
The entire category of things made from plastic accounted for less than
5 per cent of the landfills’ contents by weight and for only 12 per cent
by volume.’

If Rathje is right, recycling PET bottles would seem to be a waste of
resources unless selling the recycled bottles makes it economically worthwhile.
But there are technological problems with recycling PET, because of its
tendency to absorb other chemicals or toxins before remelting. There is
concern that potentially carcinogenic chemicals could leach into food or
drink stored in recycled containers. Plastics manufacturers in the US have
imposed a voluntary ban on remaking PET into new food or drink containers
until they can work out and agree on the best solution.

Rathje thinks that attempts to deal with what people perceive to be
the plastic problem by means of biodegradable materials are equally misguided.
Biodegradable plastic bottles usually use corn starch as a degenerative
bonding agent, and they degrade to small pieces of plastic – a pointless
exercise when refuse compactors crush the bottles completely flat, he says.
In fact, such containers use more plastic because they need to be thicker
to compensate for the weakening effect of the degenerating agent.

The real culprit, according to Rathje, is paper. He says that paper
accounts for 40 to 50 per cent of everything we throw away, both by weight
and by volume. Newspapers take up betweeen 10 and 28 per cent of landfill
volume, while phone books are almost as prominent. And rather than biodegrading,
most paper appears to retain its original weight, volume and form.