Today, if they are unable to get a Court injunction, the people of Holsworthy face the awful prospect of a Foot & Mouth Disease pyre starting up one mile from their beautiful town.

The main fuel for the pyres is coal, railway and sleepers (containing oil and bitumen). Combustion temperatures are low, especially in rainy weather, and this favours the formation of dioxins. The Government has admitted that the dioxins released from the pyres so far are equivalent to 3-6% of Britain's annual output of these chemicals. They will be concentrated in a much smaller area than usual. Dioxins are cancer causing agents. In addition, they depress the immune system, and have a hormone disrupting effect which interfere with sex hormones in the body. These "gender benders" are associated with lowered sperm count, testicular cancer, prostatic cancer, undescended testicles and conditions like hypospadias, where the penis of the young male embryo does not develop correctly.

Acidic gases such as sulphur dioxide and oxides of nitrogen will be formed. These are associated with bronchitis and other respiratory diseases.

Particulates in the smoke will cause asthmatics to get bouts of wheezing. Particulates are also associated with an increased incidence of heart problems.

There is a fear that some of the railway sleepers will have been imported from eastern Europe where apparently arsenic is used as a preservative, so the smoke may be laced with this poison also.

Using Government data, we can calculate that the burning of 100 beef cattle will produce between 6 and 30 lethal doses of BSE agent - the cause of "mad cow disease" and Creutzfeld-jacob disease in humans. The dose from dairy cattle would be between 24 and 120 per 100 dairy cattle burned, as the incidence is higher in dairy cattle. This is one of the reasons that the Government, with agonising slowness, is inching its way towards vaccinating dairy cattle.

Most of these will land on pasture land, effectively rendering the land unusable for grazing for an indefinite period of time. Doses landing on vegetables are liable to be eaten by people, and of course some may be unfortunate enough to take in BSE agent in with the smoke. Workers tending the pyres and anyone actually in the smoke will be at risk. Rain will increase the concentration of pollutants in the area near the fire.

MAFF allege that the risk of getting BSE is very low, but their official study made the elementary mistake of comparing distribution of smoke from a pyre with that from an incinerator chimney.

In 15 to 20 years time, a few unfortunate people will develop vCJD, the human form of mad cow disease. It is a horrible, slow way to die, and as it is incurable, we should clearly take every precaution to prevent people from catching it.

It is possible for Foot and Mouth virus to be caught up in the air surrounding the smoke without being heated sufficiently to kill it. So far as we have been able to establish, there has been no scientific testing of FMD pyre smoke to find whether viable FMD virus is present. On the other hand, there were three outbreaks in Derbyshire in 1967 which may have been caused by this route. The smoke is therefore a route of re-infection, leading to the danger of more outbreaks, more slaughter, more burning and more pollution and ill health.

There are other health risks to the smoke. Bacteria such as salmonella and E. coli 0157 may be sucked up in the smoke, causing diarrhoea and vomiting. Overload with bacteria and half burnt animal products can cause general ill health in exposed populations.

This catalogue of poisons and health challenges should also be as a cumulative threat. The various agents will multiply the effects they have on each other. For instance, one authority on vCJD believes that the agent is more infectious to people with sore throats. Smoke will cause people to get sore throats. The immune suppressant effects of dioxins may make people more likely to succumb to salmonella and E Coli 0157.

All of these physical health challenges come at a time when communities are in emotional turmoil, and this stress itself will make people more likely to suffer illness. The fear of illness itself may mimic real illness, making the job of the GP all the more difficult.

The whole country has been affected by the news. Several people have told me that they have broken down and wept at the spectacle of death and destruction. Rural communities will suffer economically and socially from this crisis. At the very time when they need social support from their friends and neighbours, farmers are isolated in their farms, afraid to meet in groups for fear of spreading the virus.

What can we do?
First, we must hope that a court injunction can be obtained to stop the pyre. If the court injunction fails, and the fire is started, there are laws governing air pollution. The local council can monitor the air quality, and serve abatement notices against MAFF if the levels measured exceed the set values. Finally, in Common Law, citizens are allowed to take reasonable action to defend themselves against an act that they believe will result in serious injury to themselves. That action, once carried out, would have to be tested in a court of law.

We should not be brainwashed into believing that mass slaughter is a necessary evil. Vaccination without mass slaughter is a viable, practical economic alternative.

Dr Richard Lawson
Green Party F&MD Campaign Co-ordinator

RISK DUE TO BSE INFECTIVITY FROM BURNING CATTLE

Dr Richard Lawson, Green Party FMD Co-ordinator

12.4.01

The document "Assessment of Risk due to BSE Infectivity from Burning Cattle" was prepared for the Ministry of Agriculture, Fisheries and Food by "DNV Consulting" on 28th February 2001. It can be obtained from MAFF Animal Health (BSE and Scrapie) Page St, London SW1P 4PQ tel 02079046256

METHODOLOGY

The DNV paper starts with an estimate of infectivity in cattle, that is, the amount of BSE infective tissue in a given number of the present herd. It finds that 7.2 per thousand of dairy cattle and 1.7 per thousand of beef cattle would be expected to carry the BSE infective agent. It estimates that 0.1 gram of brain tissue from an infected cow could cause vCJD infection in a human. The conclusion is that the brain and spinal cord of an infective carcass would give 700 ID50 infectious unit doses. ID50 is the dose necessary to cause BSE in 50% of cows who ingested that dose. The brain and spinal cord of one contaminated cow, spread uniformly through the human population could cause 350 new cases of vCJD in humans.

The paper then looks at the event tree for burning cattle. The main routes are direct inhalation of smoke particles, consumption of unprocessed crops, and consumption of water supply from ground and surface water. They then assume that a proportion of the infectivity is destroyed in the fire. They accept that the fire will not be hot enough to destroy the BSE infective agent (which is very heat stable) and that the fire will draw up light ash particles into the plume for later deposition as fall-out.

They assert, "with a hot fire the particles will tend to be lifted away from the immediate area and people close to the fire should not be exposed." This is quite clearly not the case. Smoke from the fires drags along the ground and those exposed to the smoke will get a high dose. This is the key point: they base their assumptions on incinerators, which give wide dispersal. There can be no justification for extrapolating from incinerators to pyres in terms of fallout plumes.

The conclusion of DNV is that from a fire in which 100 cattle are burned, the infective ID50 dose from 100 cattle released and returned to the population is 0.00017 to 0.00071, that is, that a dose thousands of times too small to cause a single case of vCJD in an exposed human.

Using the DNV assumptions,

• 1 bovine burned gives a 0.000000535 chance of creating one 100% probability of creating a human case (=half of the 0.0000017 ID50).
  
• 1,869,159 beef cattle burned would therefore produce the probability of creating a single case of human vCJD if ingested (0.000000535 x 1869159 = 1.0).

The number of dairy cattle needed to cause this single case will be about 467,000 due to the higher infective load in this type of cattle. A new upsurge in Foot & Mouth numbers is predicted at the beginning of May, when dairy cattle will be turned out onto infected grass.

The DNV paper concludes that "the individual risk of exposure would be low"

An alternative analysis is, unfortunately, not so reassuring.

CRITIQUE

The DNV paper frankly acknowledges the extent to which assumptions have been used throughout.

In the annexe containing the input data, the fraction of infectivity entrained in the smoke, a factor of 0.1 and the fraction of ash spilled before burial at a value of 0.01 is, with refreshing candour for a government document, sourced as a "Guess".

More seriously, the estimates for fractions of particulates falling on a populated area, unprocessed crops etc., eight parameters in all, are sourced as from an incinerator. Incinerators operate at very high temperatures, and are not at all comparable to pyres. The smoke plume from an incinerator is completely different as it is expelled at high temperature from a tall chimney. The use of incinerator data in this case invalidates the assumptions and conclusions of the MAFF paper.

It is claimed by Maff that only animals under 5 years old are committed to the pyres. In the chaotic circumstances that prevail in the field it is difficult to believe that these guidelines are strictly adhered to, but even if they are scrupulously observed, BSE is still present. The older the cattle, the greater the statistical risk that they will release BSE agent when burnt..

The DNV assumptions are spread out for the population as a whole and there is no analysis for targeted, at risk groups. It is normal in epidemiology to consider a group with high exposure such as people living close to pyres and the workers and managers who are tending the fire itself.

ALTERNATIVE ANALYSIS

Using the data supplied in the DNV document,

1 Take a pyre of size 100 cattle.
2 There is a 0.17 chance that one of them will be infected.
3 Each infected animal holds 350 lethal doses of BSE/vCJD
4 Therefore 59.5 lethal doses go into the fire. (350x0.17)
5 CNV assume that one tenth of this infective load will escape destruction in the fire
6 Therefore 5.95 lethal doses are released into the smoke from 100 cattle.
7 If the fire reduction is only 50%, nearly 30 lethal doses are released from the fire.

The animals have a hole in their heads made by the bolt gun or bullet that killed them

As they heat up, the brain fluids will boil, sending a jet of potentially infective tissue into the rising plume of smoke. This material will certainly not be destroyed by heat, so the 50% assumption above may be an underestimate.

As at 5.4.01, 1,152,000 animals have been killed under MAFF’s stamp out policy.

1 Of these 233,678 are cattle – nearly all beef cattle.
2 Using the low figure of 5.95 per 100, the total release is 13,904 (233,678 / 100 x 5.95)
3 Using the high figure of 30 doses per 100, the total release to date is 70,103 (233,678 /100 x30)
4 The total number of lethal doses released if the cull-only policy will continue to rise in proportion to the number of cattle slaughtered. The majority of these doses will be concentrated on a relatively small population around the pyres. Using standard environmental modelling, it would be possible to calculate the real risk to the target population.
5 Clearly not all of these doses will be directly ingested by humans. Most will fall out onto pastureland, (where they may re-infect the next cattle that graze there), and also onto vegetables, roads, and roofs. The doses will be distributed in concentrations that diminish with distance from the fires. Concentrations will be greater in calm weather conditions, and less in windy conditions.

Some of the doses will be ingested by humans breathing the smoke from the pyres. The Maff document assumes a widespread distribution, similar to that resulting from an incinerator with a tall chimney. This assumption is completely invalid. Smoke from the pyres drags along the ground, giving a high deposition and air concentration of particles.

DNV consulting neglected to examine the exposure to high risk, target populations, of whom the most obvious are workers tending the fires, and residents whose homes lie on the vicinity of the pyres, and who may be exposed to the smoke day and night.

It is therefore possible that anyone living downwind of a pyre, or a worker tending the pyre may have a significant risk of contracting new variant CJD.

It is imperative that field trials be carried out to find empirical evidence of BSE/vCJD infectivity by sampling the smoke, and by sampling fallout areas around the fires. An indicative test would cost a few pounds, and take a few days. The definitive test would come take 300+ days to give an answer.

RECOMMENDATIONS

1. It is recommended that cows be burned in a head down position so that the jet of boiling brain tissue is directed into the fire, and not upwards or sideways.

2. It is recommended that slaughterers should wear protective face masks to avoid being splashed with brain material at the moment that they fire their bolt guns.

3. It is recommended that people exposed to the smoke should be issued with respirators capable of trapping particles onto which the BSE infective agent might be bound and that people living downwind of fires whose homes are enveloped in smoke should be either evacuated or be advised to stay indoors with the doors and windows closed.

4. It is recommended that there should be immediate sampling of the smoke from the fires by scientists independent of MAFF and the Government. The smoke samples should be tested the presence of viable BSE particles. Vegetation and soil samples should be checked also.

5. At the same time, an analysis should be made for the presence of viable Foot & Mouth disease picorna virus in the smoke.

6. Pyres should not be used at all because of their risks of spreading FMD and the risk from the carcinogens and infective agents. The alternative, burial, is also environmentally disastrous since it will contaminate the ground and surface waters with high BOD and disinfectant, but it is the lesser of the two evils.

7. In the light of the Purdey hypothesis, especially stringent precautions should be applied in those areas where there is high manganese level in the soil.

8. Due to the environmental effects of the disposal problem, it is recommended that the slaughter policy should be abandoned, and vaccination firebreaks should be used instead.

Dr Richard Lawson

Green Party FMD Co-ordinator

Commentary by Dr Richard Lawson, Green Party Foot & Mouth Disease Campaign Co-ordinator, prefixed by RL-

SEAC: Public Summary of meeting on 30 March 2001

The Spongiform Encephalopathy Advisory Committee (SEAC) met in London on 30 March to consider the BSE aspects of various disposal options for cattle carcasses in the present emergency arising from Foot and Mouth disease (Thin).

In particular, SEAC's advice was sought on

(a) the assumptions underlying the DNV's risk assessment on burning in pyres, and the Environment Agency's (EA) comments on that risk assessment and on burial;
RL- There is no reassessment of the criticisms re extrapolation from incinerators, and application to special at-risk target populations made in my paper "RISK DUE TO BSE INFECTIVITY FROM BURNING CATTLE" obtainable from Dr Lawson (rlawson@gn.apc.org)

(b) how the level of' risk would be affected by the age of the cattle, and whether they were beef or dairy
animals.

DNV Risk Assessment

SEAC considered an independent genetic risk assessment on BSE infectivity by DNV Consulting
which concluded that a pyre of 100 dairy cattle aged ever 5 years old could result in a total of 7 x 10 ~ infectious units being subsequently ingested by those people exposed. (An infectious unit is equivalent to the amount of BSE infected brain material, in grams, that would be required to induce disease in 50% of' those each exposed to that amount when ingested by the oral route).
DNV noted, that the amount of infectivity would be spread over a fairly wide population, and so the risk to an individual from this exposure would be lower. For example, if the infectious units were spread over 1000 people, the individual exposure would be 7 x 10-7 infectious units per person .
RL-It is important to understand that the infectious unit is indivisible: it is the risk of encountering the unit that is expressed in this figure. The figure is based on invalid assumption that pyre smoke is distributed in the same way as smoke from an incinerator chimney. I believe (the methodology was not made explicit in the DNV paper) that the method of analysis used by DNV indicates the risk returned to the individual, and therefore on their (flawed) analysis, there is a 50% chance that one of 10,000,000 persons exposed to the smoke will develop vCJD.
In the EA's view this was at the borderline of the widely accepted upper threshold of acceptable excess individual risk of 1 x 10 -6 per annum.
RL-Therefore the higher risk from consideration of pyre smoke/target group exposure will be above the acceptable excess individual excess.

SEAC discussed the main BSE - related assumptions made in the model: these related to the assumed level of BSE infectivity in the cattle population and the infectious dose for cattle and humans. Although SEAC did not consider the assumed parameters to be unreasonable, indeed they were largely ones that it had endorsed in previous meetings, the Committee considered that it would be preferable to base the calculation on, a range of plausible values to reflect the uncertainties underlying many of the assumptions, rather than to use point estimates.

SEAC accepted that DNV's assumption that 10% of infectivity remained after pyre burning was a reasonable, if unsupported, value to assume.
This meant that the exposure risk from leakage from a burial site into water sources, compared with burying the ash after burning, would be roughly 10 times higher.

In the light of this advice, and taking account of advice from the Environment Agency on hydrogeological aspects, DNV has since produced the following revised estimate of the total infectious units that might be ingested following the disposal of 100 cattle over 5 years old:

Results Summary
Median 2.5% 97.5%
1 Burning 9xl0-5 5x10-7 2x10-2
Dairy Cattle

2.Burning 2x10-5 lxl0-7 4xl0-3
Beef Cattle

3.Burial 6x104 3x106 lxl0-1
Dairy Cattle

4.Burial lxl0-4 6x10-7 3xl0-2
Beef Cattle

RL-The wide variation indicates great uncertainty, and the 95% levels indicate very real risk. Note that burial is considered more risky, although they have grossly underestimated the risk from pyres

Variability of level of risk

SEAC had before it an estimate that, assuming 10% maternal transmission of BSE in cattle in the last 6 months of the incubation period and an effective feed ban in August 1996, only 90 of the roughly 7 million animals currently alive that have been born since mid-l996 are BSE infected. The Committee thought that, based on the number of BSE cases seen so far in animals born after 1 August 1996, (just one, compared to 8 expected in 1999 and 2000 in modelling, assuming 10% maternal transmission) the true incidence of maternal transmission is likely to be lower than 10%. Nevertheless they considered it to be a reasonable working assumption. On this basis, the risk from burning or burying cattle born before August 1996 would be at least 400 times higher than the risk from burning or burying a similar number of cattle born after this date (i.e. under 5 years old).
RL- It is vital that cattle over 5 years are rendered, and the proceeds of rendering be incinerated. This is normal practice, but in the pressured and chaotic circumstances in the field it is likely that guidelines will not be adhered to. David Hill, NFU chairman in Devon, said on Farming Today radio programme that animals that should have been taken too rendering had been burned. The regualtions must be enforced. It is recommended that EHOs take on this role.

-

Based on relative BSE incidence in the year 2000 SEAC also accepted that the risk from burning or burying dairy cattle would be approximately 41/2 times more than disposing of same number of beef cattle.
At the end of April, dairy cattle must be turned out to pasture. If sheep have been on this pasture, it is probable that the pasture will be infected with FMD virus. It must be expected that dairy cattle will become infected at this point. It is vital therefore that dairy cattle in FMD exclusion zones should be vaccinated now.

Other Issues

In disscussion SEAC drew attention to the following points. (Additional more detailed points are included in the annexe).
\
The health and safety issues arising from dispersal of brain tissue during slaughter must be considered and appropriate protective measures taken The risk arising from an uncovered face (and especially eyes) in close proximity to the slaughter point was of particular concern.
The danger here is of splash back of CNS tissue from the impact of the bolt gun. Are slaughterers wearing face protection? If not, why has this urgent message not been passed through?

It unlikely that sufficient lime could be added to buried cattle or ash to have any impact on potential infectivity.

It is important that the potential for animal re-infection by TSEs (i.e. BSE agents) through contaminated drinking water or pasture land is considered, particularly in the immediate vicinity of a burning or burial site. This applies both to BSE in cattle and to scrapie in sheep.

We need an estimate of the length of time that these contaminated lands will be unable to support cattle.

SEAC April 2001

Annex

1. The testing of OTMS cattle identifies animals within about 3 months of clinical symptoms only. The true rate of cattle over 5 years infected with BSE could therefore be higher than the 0.49% assumed although this factor was not quantified.

2. 0.lg is a reasonable, probably conservative, estimate of the infectious dose for cattle. However, a range downwards from 1g, and including values less than 0.lg, should be used..
This implies a tenfold upward revision of the risk estimates.

3. An assumption that 10% of infectivity remains after pyre burning was agreed to be a reasonable if unsupported, value to use. It was noted that the burn achieved in a pyre was likely to be variable and likely to be less effective than controlled incineration. More information about the extent of combustion should be collected.
Field work is needed to sample the pyre smoke and test for BSE agent. Dr Harash Nareng can produce an indicative test in one day at a cost of a few pounds. Definitive studies using mice will take 300+ days to produce an answer. The delay is not a valid reason to avoid this work. Sampling may produce false negative results.
4. Discussion about the methods of slaughter led to a conclusion that skulls are not left intact. However, no firm view was possible on the extent of brain combustion, an important element when considering the proportion of infectivity which burning would destroy.
Each carcass has been killed by a bolt gun or a bullet to the head. When the fire reaches the head, the brain fluids will boil, and potentially infective tissue will be voided with force. Unless the head is oriented so that the jet of tissue is directed into the fire, this tissue will escape unburnt into the smoke column. Until this practice is in place, the 10% figure that escapes destruction is too low.

5. Environment Agency advice that, on average, the extent of leaching from ash in pits is more than from dilute and disperse landfills in rock, was noted.

6. In considering the dose that might be ingested from contaminated groundwater, it is important to take account of the time over which the dose is transmitted. For some situations (such as Karst geology) this will be a matter of hours. For others, it may extend over tens or even hundreds of years. The (immediate ) human exposure risk would be much reduced in the latter.
We are leaving a vCJD/BSE legacy for succeeding generations as a result of the policy of mass slaughter.

7. The risk assessment model when applied on a site-specific basis must be looked at in a local context, including with respect to hydrogeology and the size of the population exposed to a water source. SEAC was not able to comment on specific local factors