Spicy solution

Cloves can stop hazardous asbestos fibres from escaping into the air

 
Last Updated: Saturday 04 July 2015

 Small yet strong (Credit: Preeti Singh / CSE) cloves are very popular for their medicinal powers. Now, scientists have discovered the spice has other potentials also -- they can play a crucial role in removing asbestos fibres from the atmosphere (New Scientist , Vol 172, No 2316, November 10, 2001, p25). Italian chemists have neutralised the lethal fibres using an extract of cloves. When the liquid extract touches the surface of asbestos, the material instantly hardens into a polymer similar to lignin, which gives wood its strength. Thereafter, all the potentially hazardous fibres are harmlessly embedded in the polymer and can't float off into the air.

Asbestos is used for manufacturing floor tiles, ceiling tiles and roofing materials among other things. But for decades now studies have shown that asbestos is "destructive" to human health (see 'Death Inside the Factory gates', Down To Earth, Vol 9, No 09, September 30, 2000). Between 1967-1997, there were 171,500 cancer deaths from asbestos fibres in the us. In western Europe, according to some estimates, it has been responsible for half-a-million cancer victims. Worse, in the next 29 years, it could claim another one million lives mostly in the developing world, according to a study conducted by usa Today.

Usually, buildings are sealed while they are being demolished, with air pressure differentials imposed to stop the deadly fibres from escaping into the air. Even the workers have to wear protective clothing to avoid breathing in the lethal fibres. But despite these precautions, fibres escape and linger in the air for more than four years, according to research by the us Environmental Protection Agency. However, now the Italian scientists have a remedy for this.

During their experiment, Bice Fubini and her colleagues in the department of inorganic chemistry at the University of Turin, Italy, used a combination of hydrogen peroxide and eugenol, a phenol-like chemical found in cloves -- Eugenia caryophyllata. Working with colleagues Ivana Fenoglio and Maura Tomatis, Fubini proved that the treatment works on blue asbestos or crocidolite, one of the most dangerous forms of the mineral. "We knew already that eugenol would polymerise on various silicates, so we thought we would try it on asbestos, which is a similar silicate," says Fubini. They are confident it will also work on the white (chrysotile) and brown (amosite) forms. "Asbestos could probably be buried without much danger to people," adds Fubini.

As an added bonus, the polymer also mopped up the "free radical" chemical complexes that can lurk on fibres and damage dna, potentially turning cells cancerous. The polymer has stayed stable since the experiment, the team reported.

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