Saturday 30 May 2009

NANOPARTICLES

Nanoparticles…….New Incinerators, New waste streams, New Problems. The changing face of waste, more metals, more electricals and more plastics.

When you put metals into a furnace they are usually lumps, large or small and relatively safe, you can’t breathe a lump of lead in, for example. After you have heated them up, and made them go through chimney reactions they become very tiny particles and become very much more dangerous, mercury and cadmium being particularly serious examples. You will be surprised to hear that there are no laws regulating heavy metal discharge levels in air, apart from lead, so that councils can get away with not monitoring them. The levels of metals emitted by incinerators is very high, and much higher than found in emissions from cars. You may well hear of PM 10’s or even PM2.5’s….these particles are PM0.18’s! Filters designed for bigger particles won’t be able to cope…..even now cyclists masks do not protect them from traffic particulates. There is evidence from Mexico city that these can pass directly into the brain, via the nose, as well as being small enough to get into the blood via the lungs.

Another very real problem is the plastic packaging that everybody has got used to, as well as the plastics in bottles etc. PVC doors and windows are more than 90% organic chlorine, and will become more of the waste stream in future. The chlorine atoms in plastic are related to the formation of dioxins, directly. The more plastic in the burn the more dioxins are produced, to enter the merry-go-round of afterburning, flue gas washing and filter capture (or not!).

Many electrical goods contain PBDEs, polybrominated diphenyl ethers, and are finding their way into incinerator waste streams. They are also the flame retardants in furniture, now a legal requirement.

The face of incineration has changed in more ways than one. There are no easy reassurances, and no easy way to check what was on that lorry that just went in the depot. You can guess the number of wrongly declared lorry loads in the world history of incineration, but, by the time they got discovered, it was all too late.

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