Dioxin emissions from the steel and cement industries and major ozone – depleting emissions from a Teeside chemicals plant – are identified in the latest round of data published in the Environment Agency’s pollution inventory website.  The Agency has improved the quality of data and removed irregularities since the inventory’s launch last year.

The idea of the inventory emerged in the late 1980’s and was inspired by the US Toxics Release Inventory.  The Agency’s version was launched on its website in May 1999 and received more than 2,700 visits in its first week (ENDS Report 292 pp24-27)

The Agency says the inventory continues to be a success – but surprisingly it could not provide information on the number of visitors.  It says the site is widely used by students, residents and environmental groups interested in local emissions.

In July, the Agency added data relating to emissions in 1999, but there is nothing on the website to advertise the fact.  Indeed the inventory is constantly changing and the site gives no indication of how long some of the data have been available.

According to the Agency’s Charlie Corbishley, the range of data reported for 1999 is broadly the same as that for the launch year 1998.  However it has allowed corrections to previous years data and in some cases it is claiming details on the inventory at the time of launch were incorrect.

Some major new dioxin sources have been added including Corus (formerly British Steel) sites at Rotherham and Sheffield.  The two sites both enter the top ten sources, increasing the company’s domination of the league.  Corus now accounts for six of the ten largest dioxin sources with the remaining four being other metal industrial sites.

One significant dioxin source, which may previously have been overlooked, is the cement industry.  According to the 1999 data, the top 30 emission sources consist almost entirely of metals, power station and cement manufacturing sites – the single exception being Sheffield’s troubled municipal waste incinerator.

Castle Cement’s Buckley Works and Rugby Cement’s Ferriby works appear at positions 11 and 12 in the dioxin league – each emitting about 1.5g of dioxin a year, measured as an equivalence (TEQ) of the most toxic dioxin 2,3,7,8 – TCDD. Three other cement works appear in the top 30; Rugby’s Southam Works, Blue Circle’s Hope Works and Castle’s Ribblesdale Works.

Total emissions from the ten largest dioxin emitters declined significantly between 1998 and 1999, but it would be premature to read too much into figures, which still seem likely to change.

In the chemicals sector, meanwhile, Du Pont has achieved a massive reduction in its emissions of nitrous oxide – a significant greenhouse gas- since 1998.  Releases from nylon manufacture at its Teeside works declined from 49,473 tonnes in 1998 to 3,240 tonnes in 1999.  The reduction is equivalent to a 3% cut in the UK’s total greenhouse emissions according to the Agency.

However Du Pont is now under the spotlight relating to another significant release identified in the inventory – methyl bromide, an ozone depleting substance regulated under the Montreal Protocol.  Du Pont’s Sabanci Polyester’s Teeside plant released some 95 tonnes in 1999 – equivalent to a fifth of the UK’s emission from horticulture, where the compound is used as a soil sterilant.

Du Pont pointed to an improvement in the environmental performance of the plant sine 1994 when the business was owned by ICI.  Methyl bromide emissions have declined from 211 tonnes and the company has agreed to a long-term strategy with the Agency to reduce emissions further.

Other information on the ozone –depleting HCFCs is hard to find because of a long-standing error on the database.  Efforts to retrieve data on these compounds fail – despite the fact that ICI continues to be a significant source.  In 1999 ICI released 57 tonnes of HFCs – a three-fold reduction on the previous year - and 2.5 tonnes of HCFCs.  The company is installing an incinerator to stem these releases.

The Agency appears to have resolved inconsistencies in the reporting of releases of traces of toxic compounds such as PCBs, DDT and pesticides.  In 1998 many paper companies appeared to be significant sources of such compounds because they had extrapolated discharge levels from the limits of analytical detection – thereby calculating apparently significant discharges (ENDS Report 292 p.26).

Mr Corbishley said that the situation arose because companies did not follow reporting guidance agreed with the Paper Federation.  Pesticides and trace organics only need to be reported if there is evidence that they are in discharges, he explained.
Companies can use raw material mass balances or emission factors to derive estimates of releases.

The Agency also clarified some issues relating to commercial confidentiality.  Where sites claimed confidentiality last year all data were withheld.  This year only data on particular substances are excluded and viewers are alerted by a warning message.

For a few sites the Agency has also publishes notes which seek to put emissions data in context.  For example data on Sita’s Edmonton waste incinerator are prefixed by a paragraph explaining that £15 million was invested in 1996/97 to upgrade abatement equipment – resulting in large reductions in emissions of dioxins and hydrogen chloride.  The statement will no doubt be appreciated by Sita, which in planning to extend the plant is sensitive to public opinion.

Changes to the scope of the inventory to be announced in the autumn, may go some way to answering criticism from Friends of the Earth, which has said that the inventory is ‘meaningless to everyone except a few boffins’.  It cites the lack of league tables and the absence of health information.  In its own league table FoE highlighted emissions of ‘cancer causing chemicals’ – based on pollution inventory data for compounds, which have been identified as carcinogenic.  Overall FoE’s data show a 25% reduction in such releases from a list of major sites since 1998.