There’s the oft-repeated factoid that the Indians used every part of a buffalo when they killed it. The Danes are learning from their example:

But in one area, greenery might be taken to excess. Denmark’s crematorium association has revealed its profitable sideline in recycling metal parts salvaged from the dead. Burnt bodies leave knee or hip replacements that can be recycled as scrap metal, says Allan Vest, the association’s chairman. Since 2006 the country’s 31 crematoriums have earned DKr 77,762 ($15,000) from 4,810kg of salvaged metal sold to a Dutch recycler.

When the ecclesiastical ministry changed the law to allow such recycling in 2005, it barred the reuse of such spare parts in works of art. But it did not say anything about telling relatives about the fate of a deceased. This is not a problem, says Mr Vest; recycling is good for the environment.

That principle underlies a second practice: recycling crematorium heat. Earlier this year, 15 crematoriums said they favoured sending waste heat into district-heating systems. This is because new regulations, due to come into force in 2011, will require crematoriums to filter out toxic substances such as dioxins and mercury from waste gases. To do this the crematoriums must use water to cool chimney gases from around 800°C to 180°C. It is the excess energy from the cooling process that crematoriums want to capture.