Incinerating unrecyclable waste plastic is environmentally the most benign way of disposing of it, new experiments show (New Scientist, Vol 143, No 1932).

Europe's Association of Plastic Manufacturers incinerated municipal waste containing 3 different proportions of plastics -- without added plastic, with 7.5 per cent extra plastic and with 15 per cent extra plastic. It found that the greater the proportion of plastics in the waste, the greater the heat produced -- which could be used to generate electricity -- and the lesser the amount of airborne pollutants produced.

Though plastics normally account for 7 per cent by weight of municipal solid wastes, they store up to 30 per cent of the energy content of garbage.