New controls on chemicals used in the sheep industry will try to prevent pollution and the death of tiny creatures living in streams and rivers.
Agreement has been reached with the farming industry on reducing the amount of organophosphate (OP) and synthetic pyrethroid (SP) chemicals which reach rivers from sheep dipping and wool processing. SPs are now thought to be 100-fold more toxic than OPs for aquatic life.
‘We have accepted that there should be a three month voluntary withdrawal period between dipping sheep and shearing them,’ said Ian Hartley, managing director of the British Wool Marketing Board.
‘We have discussed this with the farming unions, and the message will go out in a letter to producers in April this year.’ The Wool Board’s decision follows a recommendation from a working group set up last year to look at the effects of sheep dip chemicals on the textile industry.
Report findings
In its report, the working group said that chemical dips and pour-ons should not be used for at least three months before shearing or slaughter; sheep farmers should include details of chemicals used and the date of the last treatment in existing documents supplied to textile processors; and a review should consider the environmental case for introducing a set time for treating sheep with chemicals which is accepted by the industry.
Behind the Board’s thinking is the recognition that sheep dip chemicals can be toxic to anyone handling fleeces, especially shearers. They can be difficult to remove for the companies which clean and scour wool – and they can be detected in minute amounts by the Environment Agency which has to enforce environmental quality standards (EQS) on rivers. Synthetic pyrethroid chemicals are particularly toxic to tiny invertebrates which are essential for any thriving river.
As long ago as 1985, one of the companies which sold sheep dip – Coopers Animal Health – pointed out
the dangers of sheep dip for shearers. Coopers did not define freshly dipped sheep because, the company said, sheep will have about 6000 parts per million of OP insecticide in their wool for several weeks.
Shearers exposed
‘This constitutes a significant and unacceptable hazard to anyone shearing recently dipped sheep, particularly because the shearers will be hot and sweating whilst being stripped bare to the waist and very lightly clothed anyway,’ a Coopers manager wrote.
Raw wool is scoured to remove impurities such as grease, dirt and sweat, but the process also takes most of the sheep dip chemical out of the wool. Skins from slaughtered sheep and lambs are processed by fellmongers, who separate the wool from the skin and produce effluent containing sheep dip chemicals.
Effluent from scourers and fellmongers is treated to extract pollutants before it is discharged to sewage works for more treatment. When there is a lot of sheep dip in the effluent, the technology for removing chemical residues is efficient: when there isn’t much dip there – but still enough to damage river ecology – the technology is less efficient.
Company investment
When the Environment Agency gives wool scouring companies and water companies discharge consents, these technical shortcoming are picked up – and mean the companies have to invest in better equipment to clean up their effluent. W and J Whitehead (Laisterdyke) Ltd are top makers and worsted spinners on the River Aire in West Yorkshire – one of the rivers where the Environment Agency is trying to reduce pollution. The company treats the wool to remove grease, washes it and eventually it ends up in a cotton-wool shaped ball called a top. Stanley Robertson, the company’s chief engineer, said talks were progressing with the Agency about spending almost £400,000 on new plant to treat the effluent and reduce the chemical content by another ten per cent. ‘We would still have to treat the effluent because of the wool grease, which is the biggest contaminant.’
On the River Dart in Devon, the Buckfast Spinning Company will probably have to spend about £1 million on a new wool scouring machine which will concentrate the chemical part of the effluent into the components of land-fill. Buckfast is a subsidiary of Axminster Carpets, and has a policy of using British wool. Andrew Duffield, Buckfast’s technical director, said the chemical companies and the regulatory authorities should invest in research – such as genetic breeding – which would prevent sheep attracting the ticks and flies which the chemicals are supposed to prevent.
‘There is very little thinking going on,’ said Mr Duffield. ‘We have no control over the wool that we use. I would like someone to consider the idea of marketing pesticide-free wool – and we have put that to the Wool Marketing Board.’ Four years ago, Buckfast published a plea in the Wool Manufacturers Journal pointing out that if the farming industry did not take more care with chemicals, then the textile companies would be legislated out of business1. Mr Duffield said that little has changed – except that the plea had concentrated on OPs and levels of SP pollution have subsequently increased.
Pyrethroid pollution
Dr Andy Croxford, the Environment Agency’s pesticides manager who chaired the working party on sheep dip chemicals and the textile industry, confirmed that SP chemical pollution is rising. The agency’s report on pesticides in the aquatic environment for 1997 is due, and will show many more environmental quality standard failures for SPs. ‘It may be that we found more because we were looking harder – particularly in Wales where we did some intensive studies of rivers and found lots of SPs,’ said Dr Croxford. For 1996, the agency analysed 357,000 pieces of data: for 1997, that number has gone up to 370,000. ‘We have to monitor SPs down to very low levels, and there is an analytical issue there which I think we have overcome.’
The number of sheep dip pollution incidents – which may be reported by the public and are distinct from the agency’s own monitoring of EQS – are also up for 1997, and Dr Croxford said they appeared to be at about the same level for 1998.
There are about 80,000 sheep producers in the UK, and Ian Hartley from the Wool Board said that only about 10% of their wool was a potential pollutant. But it is very hard to find that 10%: the farms are small, the wool is graded and then put into a sale lot which may be an amalgam of farmers’ cuts.
About 65% of UK wool is made into carpets, and most of the rest is used for upholstery and blankets.
Mr Hartley said the Board is working with a company to devise a cheap test which will detect small residues of sheep dip chemical in wool. The existing test used in Australia and New Zealand costs between £110 and £120, and takes ten days. ‘We have commissioned some research to see if a cheap form of pesticide testing can be found,’ said Mr Hartley. That might prove to be just the solution which Buckfast Spinning and the other wool scouring companies are looking for.
References
Effects of organophosphate pesticide residues on wool textile manufacturers, Wool Manufacturers Journal, June 1996.
[This article first appeared in Pesticides News No. 47, March 2000, page 15]