Why should we be worried ABOUT AN INCINERATOR?
1. Governments and environmentalists have been telling us for years that burning carbon-based fuels produces carbon dioxide, CO2 - thought to be a major contributor to global warming and disastrous world climate changes.
ALL domestic and much industrial waste contains carbon - in paper, cardboard, plastic, waxes, oils, paints, thinners, textiles, detergents and even in vegetable and meat scraps.

2. burning plastics, paper and cardboard also release both sulphur and chlorine.

Sulphur is released as sulphur dioxide, SO2 - a smelly, noxious gas which reacts with rainwater to form sulphurous and sulphuric acids. This is `acid rain" which so merrily kills trees, damages plants and eats away at building materials. Sulphur dioxide can also affect the linings of lungs and may contribute to conditions such as asthma.

Chlorine is another nasty ... combined with the plastics - many of which contain chlorine - and other carbon-based wastes being burned, it can form a range of compounds known as trichlorophenols and pentachlorophenols - smelling much like TCP - and another called dioxins. Both families of compounds can have serious effects on the health of people who are continuously exposed to them - even at relatively low levels.

These products are destroyed when flue temperatures are kept above 800C - about 4 times hotter than the hottest domestic oven and 100C hotter than than the flame of a laboratory Bunsen Burner.

Very few large-scale incinerators operate with flue temperatures this high.

WHAT DO THESE CHEMICALS DO?
Trichloro and pentachlorophenols: Trichlorophenols are ant-bacterial agents - but breathing them in isn't a good idea. (TCP stings when in a cut - think what it does to sensitive lung linings.)
Pentachlorophenols were used as wood preservatives - in USA telegraph poles used to be treated with this compound. Workers who came in regular contact with "penta" suffered a painful skin irritation called chloracne - so breathing in this stuff wouldn't be a good idea either. Pentachlorophenols have been banned from use in the USA as materials for animal feed bins, paints, dyes, cosmetics and domestic cleaning agents.

Dioxins: Now we come to the more dangerous of the products : DIOXINS
Dioxins came to public notice during and after the Vietnam War. Low concentrations of dioxins were found in "Agent Orange" and "2,4,5-T" defoliants sprayed on the jungles by US Army and Air Force. Levels of dioxin in Agent Orange were found to be between 1 part and 60 parts per million. Yet returning servicemen who had been exposed to Agent Orange reported strange health problems - including a statistically significant increase in cancers and liver diseases. Their children suffered birth defects, ranging from spina-bifida to lukaemia and malformation of limbs and were statistically more prone to other childhood cancers. In the USA and Europe, low temperature combustion of domestic wastes have proven to be sources of dioxin-family compounds and the health of people living nearby is thought to be "at risk".

Where do dioxins go? Dioxins dissolve very little in water - they are better at dispersing into fatty and oily substances - the fat of animals, humans and the oils of fish.
Fish and animals absorb dioxins largely through eating plants contaminated with dusts and rain-washed fall-out. We absorb them by eating plants, animals and fish that have been exposed to them.

Other sources of dioxins: There is a natural or background level of these compounds in the soils and water supplies. It has been shown that very low concentrations of dioxins are present in smoke from burning plants and wood - so forest and grassland fires probably account for this. Coal and oil fired power stations' flue gasses have proven to have little or no traces - but their flue temperatures are in the higher ranges.

The jury is still out on badly tuned auto engines and domestic heating boilers. When not maintained properly, both will produce black smoke and unburned hydrocarbons and these fumes are detrimental to the health of people who breath them in. If the exhaust or flue temperatures are not hot enough, low levels of dioxins may also be present.

E.J.A. BSc (Chemistry) 1999