7.  Organic farming.

Organic farming is widely perceived as being natural and therefore environmentally friendly, largely as a result of the Soil Associationís successful campaigning. Their reiteration of the health benefits of organic produce and of working in harmony with nature has struck a chord in an anxious population nurtured by the media with a succession of food scares. Some of their policies are very acceptable to many people e.g. recycling of waste and crop rotation and they have managed to portray organic farmers as being representatives of the small producer fighting the might of the multinational agribusinesses and the large farmers. The Soil Associationís system of accreditation and regular inspection of organic producers also has considerable merit in that it would appear to provide guarantees of regular quality audit of production methods.

It is certainly the case that a well-managed organic farm is environmentally superior to a poorly managed conventional farm but managerial competence varies in farming much as it does in other professions in the UK. If there are problems with UK farming we believe they lie mainly in managerial competence-not farming method.  Many comparisons between well-managed conventional farms and organic farms emphasise the point and indicate that a clear distinction is certainly difficult to detect (see for example the numerous comparisons on soil structure and fertility summarised in ìSoil Use and Managementî supplement volume 18, September 2002). This was also the conclusion of much of the 10 year study at Boarded Barns referred to in the main document. If Hedden-on-the-Wold where the recent foot-and-mouth outbreak started is used as a comparator then any form of farming would be seen as improvement. Fortunately we believe such farms to be rare.

As scientists we have no objection in principle to the system of organic farming but we do quarrel with almost all of their basic assertions that other forms of farming are not environmentally friendly and that organic produce is necessarily healthier and more nutritious than conventional food. Of considerable concern to us is their continued reiteration of the 'unwelcome' presence of chemical residues in conventional food and that the only way to avoid these is by ëgoing organicí and therefore to be healthy. There is no doubt that this kind of campaigning has succeeded in persuading many to buy organic produce entirely on the basis of unwarranted anxiety about food produced by other forms of agriculture.

8. Is organic food healthier?

The Food Standards Agency and the British Nutrition Foundation are on record as stating that no nutritional advantage will be gained by replacement of conventional fruit and vegetables in the diet by equivalent organic produce. There are no statistics available that investigate the effects on health of a lifetime consumption of organic food; the only information present is obtained from populations consuming a conventional diet. These indicate that since 1840, when chemical fertilisers were first used and thus food production in the UK was no longer organic, life expectancy has continued to increase unabated (Oeppen and Vaupel 2002). In 1840 life expectancy was 45 years, it is now nearly 80 years and is predicted to rise to 95 by 2040. Centenarians in the last 50 years have increased some tenfold. Although synthetic pesticides were first introduced in the early 50's again there are no indications of anything untoward in life expectancy figures. The other index of health, cancer statistics, indicates a continued overall decline in the last 50 years despite the fact that cancer is a disease of old age and that we have increasing numbers of elderly people in the UK (Coggons and Inskip, 1994, National Census 2002)). More particularly, the introduction of synthetic pesticides in the early 50's led to rapid increases in use peaking in the early 70's and then declining. Such characteristics of change in use would, if they had any health implications, would immediately be obvious in life expectancy tables. More specifically and according to Sir Richard Doll (who first reported the link between smoking and lung cancer) it is in the young and middle aged that anything untoward would first appear, but it is in this group of people that the biggest declines in cancer have emerged in the last 50 years (Coggons and Inskip, 1994;Doll, 1992).

Because the use of fertiliser minerals and  synthetic pesticides are banned by the organic associations, organic produce requires a higher price for the system to remain economically viable. This is the direct result of increased manpower required and of lower yields. It is quite clear that many of the constraints on organic yield arise because soil nitrate is not present in sufficient quantities to permit maximal crop growth when it is needed in springtime (Berry et al., 2002) -in spite of the fact that overall nitrate loss is the same for organic and conventional farms (Stopes et al 2000). Thus for wheat, organic yields are routinely only 50-70% of conventional wheat production (see also below).

In 1992, Block et al., summarised information from about 200 epidemiological investigations that clearly indicates a strong protective effect against a range of cancers from a diet high in fruit and vegetables. But all of these 200 investigations involved consumption of conventionally farmed produce containing inevitably pesticide residues and the results can be summarised as "the more you eat the healthier you become". This is the reverse of what might have been expected if pesticide traces were in any way damaging or caused cancer. Figures determined by the Food Standards Agency indicate that only 25% of the UK population eat the minimal fruit and vegetable diet necessary for protection; consequently, 75% are at increased risk of cancer and premature death and inevitably a greater burden on health services and lost value to the community. This being so, higher organic prices will bring about a reduced consumption of fruit and vegetables more particularly in those on lower incomes (Lutz and Smallwood 1995).In addition ,the concurrent campaigns run by the Soil Association and other groups questioning the safety of conventional food crops will certainly not encourage lower income consumers to increase the fruit and vegetable content  of their diet.

Recently, the Soil Association has stated that the current increased subsidies to promote organic farming are a vote of confidence by the government in organic products. In this situation, it would be better if the government requested that no such conclusions could be drawn and refer questions to the proper authority, the Food Standards Agency.

9.  The pesticide question.

The commonest reason given for purchase of organic produce is the uncertainty of safety of pesticides in food. The underlying history for this perception comes from Rachel Carson's ëSilent Springí.  It is necessary to emphasise that Rachel Carson was an ecologist and not a toxicologist and she freely used lay anecdotal evidence in her book. She is regarded as the icon of the Green movement and her assertions of 40 years ago have now an almost biblical authority. This has led to the assumption that chemicals that can be demonstrated to be damaging at high concentrations must therefore be damaging at low ones such as the traces of pesticide found in current conventional produce.  However, this assumption is contradicted by what is known concerning the effects of many pharmaceutical products like aspirin, ibuprofen, antibiotics, vaccines, water chlorination, vitamins and minerals. Each of these chemicals, (many synthetic) are beneficial at low concentrations but toxic at high ones.  Each of us needs exposure to some sunshine to produce necessary vitamin D but overexposure can lead to skin cancer. There is also an argument put forward by some that low levels of radiation can be beneficial-based on natural exposure to radon in some geographical areas (Pollycove 1997).We would accept that no simple basis of cancer induction is likely unless the carcinogen is overwhelming such as occurs in heavy smoking but it indicates clearly that campaigns against pesticide traces on the assumption they may be harmful are not soundly based.  Pesticide traces could as well be beneficial but at the very low concentrations in food it will be impossible to determine. The most likely conclusion is that pesticide residues have no effect on human health whatsoever because the residues are too tiny. The accepted level of pesticide traces in food are one hundredth of the determined safe dose and a safe dose is a concentration at which no biological effect can be detected in animal model systems. (It is interesting that items in everyday use such as basil and caffeine are much more toxic than pesticides in this model). The use of pesticides and herbicides to keep fruit and vegetable prices low and thereby reduce cancer rates and obesity is crucial and needs better publicity amongst the population. These well -established findings are however ignored by some groups who campaign to ban the use of all synthetic pesticides (but not apparently those approved by for organic farming-see below) on the assertion that they are toxic to humans. Plainly such groups are not toxicologists or versed with any medical or scientific expertise. Nevertheless their propaganda has succeeded in creating unfounded anxieties in the population with considerable long-term implications for their health.

The concern over ëchemicalsí in food fails to recognise that to the stomach every meal is simply a very complex mixture of several million chemicals, many of which are broken down during digestion. More critically, several thousand, so-called natural pesticides are made by plants to restrict herbivore and pest damage and these are also present in a natural diet. At least two thirds of these are carcinogenic when tested at high concentrations-the same proportion as synthetic pesticides. The numbers and amount of these natural pesticides outweigh synthetic pesticide traces in the diet by about 20,000 to 1 (Ames and Gold, 1999; 2000). Although humankind has consumed most of these natural pesticides for some hundreds, sometimes thousands of years, it is quite clear we are not in any way adapted to their consumption.  The mycotoxin, aflatoxin, and salts of nickel or arsenic for example which are products found in many foods, organic and conventional alike, are certainly human carcinogens when assessed by these techniques (Ames and Gold 1999). Occasional plant breeding accidents have produced crops in which the natural pesticide content (for example of solanine, cucurbitacin or psoralen) increased some 7-10 fold and morbidity has resulted.  To put this topic in perspective, the UK Food Standards Agency has issued figures indicating that whereas 130,000 die from poor diets every year, none die from pesticide residues in food.

We believe that these campaigns against the use of pesticides have created an imbalance in the publicís perception of the quality of our food and that much stronger efforts should be made to get UK citizens to eat a more balanced diet high in fruit and vegetables, to reduce fat intake and stop smoking, all primary risk factors for cancer and obesity.

10.   Organic pesticides and fertilisers.

Organic farmers use "natural" pesticides when needed to combat infestations, although the list available to them is smaller than those used by other farmers.  However the safety of some of these is unknown and indeed untested so far as we can establish. Furthermore, as demonstrated in the recent House of Lords report (Leake, 1999) some natural pesticides are more toxic (see above) and persistent than their synthetic equivalents. Surprisingly, organic food appears not to be screened for organic pesticide residues. The UK list of approved chemicals for organic use contains 33 natural pesticides and chemical fertilisers including blood, bone and meat meal.  The stability of BSE prions in soil or manure does not seem to have been established but we assume that government regulations no longer permit this source of material to come from cows under the age of 2.5 years. There is also the increasing problem of the prevalence of infection by E.Coli O157 in all farm animals.

Although green manure and cattle dung are used as the major sources of fertiliser, these vary enormously in their content of minerals for crop growth. But, in general, the self-same minerals (NH4, Ca, Mg, K, SO4, PO4) are found in manure as are used by conventional farmers with the greatest variations (10 fold) found in nitrogen.  Nitrate pollution from organic farms is similar to conventional farms expressed on an area basis but when expressed on yield is substantially worse (Stopes et al., 2002). Furthermore, Stockdale et al., (2002) after reviewing all the evidence concluded that although nutrient management in organically managed soils is fundamentally different to soils managed conventionally, the underlying processes are not. The same nutrient cycling processes operate in organically farmed soils as those that are farmed conventionally. Shepherd et al.,(2002) after examination of many UK soils concluded that it is not the farming system per se that is important in promoting better quality soil but the amount and quality of organic matter returned to the soil. Farm management determines these features of the soil-not farming methods.  Failure to relate organic content to soil fertility has also been described elsewhere (Cassmann, 1999).

Nevertheless in spite of the organic regulations it has been demonstrated that that organic food is not free of synthetic pesticide traces.  Measurements that have been made indicate synthetic pesticide levels in variable quantities although they are generally lower on average than conventionally produced products (Baker et al 2002). To meet this situation organic regulations compromise on acceptable levels of synthetic pesticide traces for a description of a product to be described as organic.

11.   The question of yield.

Yield and price are major considerations in comparing different farming procedures.  Since organic farming routinely produces yields substantially lower than conventional farming, this means that many claimed differences and advantages disappear when expressed on a yield basis. In the two studies above (Boarded Barns and CWS), organic yields were usually only 50-70% of conventional yields. While this is not necessarily a disadvantage to more prosperous consumers, it does have an important bearing on the question of improving the efficiency of farming in a worldwide context.

The Broadbalk (2002) experiments conducted at Rothamsted continuously for 159 years using winter wheat monocultures have demonstrated quite clearly that winter wheat yield is not influenced in any way by additions of organic material to the soil. Yields throughout these 159 years have remained identical in wheat from soil that only received minerals and soil that received only manure (see Figure). The same studies showed substantial increase in yield on addition of herbicides and pesticides.

12.    Publicity for Committee Findings.

The issue of pesticides and food is a complex one but we suggest that more publicity should be given to the government committees that make recommendations in this area.  The Food Standards Agency has produced many important results based on research specifically commissioned to tackle topical concerns and have illustrated that transparency is important in raising confidence in their work. We believe that the conclusions of, for example, the Committee on Carcinogenicity (COC) and the Royal Committee of Environmental Pollution should receive equal transparency and publicity. Only too often the sole indication that the public gets of the findings of these committees are selective ones released and promoted in the press by pressure groups with alternative agendas.  The Soil Association recently documented its opposition to Lindane seemingly unaware that the COC (1999) had found that its use as a pesticide was irrelevant for human health because the levels were too low for any concern.  Lindane is described as a xeno-oestrogen but we consume other xeno-oestrogens such as geniestein in our food at million times higher amounts. When compared with other additional sources of oestrogen in the environment (the birth control pill for example), the presence of traces of lindane are irrelevant. (Lindane is useful to treat head lice and is an important tool to deal with the current epidemic in children). A case is also made against lindane, based on it being an organo-chlorine and therefore environmentally stable. But recent investigations have also shown that organo-chlorine molecules like Lindane are made naturally in decaying plant material and in very substantial amounts (mg/Kg; Myeni, 2002).  We have always been exposed to substantial amounts of these chemicals that organic associations and environmentalist claim are highly dangerous and should be banned. However Myeni (2002) raises questions concerning the use of decaying plant products in agriculture which currently are mainly limited to organic farming through legume rotations-although no-till agriculture could experience the same concern. Clearly more research is needed to examine the ecology of natural plant cycles.
 

13. Separation of GM crops from organic crops.

Of major concern to us is the dogma of the Soil Association that GM crops must not ëcontaminateí organic produce and the demand that they be a defined distance from any GM plants.
Low levels of cross fertilisation could indeed occur if the GM and organic crops are the same or a related species(see also Appendix 2) but since none of the currently approved GM and organic crops fall into this category then this is not  at all relevant . Thus, while we are happy to accept that many consumers wish to buy organic produce we do not think that the dogma of the Soil Association should define the conditions under which other forms of agriculture are progressed. We discuss in Appendix 2 those aspects of GM farming the organic associations have highlighted as being detrimental to the environment.

The future is uncertain; flexibility in farming technology would seem to be the safest option to guarantee food security. If increased global warming leads to wetter summers then we suggest that disease is likely to become more prevalent and with the present exhaustion of conventional breeding to combat pests, it is likely that only GM technology can provide the necessary disease resistant crops.

Ames B.N. and Gold, L.S. (2000). Paracelsus to parascience: the environmental cancer distraction.  Mutation Research 447, 3-13.

Ames, B.N. and Gold, L.S. (1999). Pollution, pesticides, and cancer misconceptions. In ìFearing Foodî (eds J.Morris and R.Bate). Butterworth, Oxford. 19-38.

Baker,B.P.,Benbrook,C.M.,Groth,E. and Benbrook, K.L. (2002). Pesticide residues in conventional, integrated pest management-grown and organic foods: insights from three US data sets.  Food Additives and Contaminants 19, 442-447.

Berry, P.M. Sylvester-Bradley, R., Phillips, L., Hatch, D.J., Cuttle, S.P., Rayns, F.W., and Gosling, P. (2002). Is the productivity of organic farms restricted by the supply of available nitrogen? Soil Use and Management 18, 248-255.

Block, G., Patterson, B., and Subar, A. (1992). Fruit, vegetables and cancer prevention: a review of the epidemiological evidence. Nutrition and Cancer 18, 1-29.

Broadbalk (2002)  http://www.iacr.bbsrc.ac.uk/res/corporate/ltexperiments/tbwinterwheat.html.

Cassmann, K.G. (1999). Ecological intensification of cereal production systems:yield potential, soil quality and precision agriculture. Proceedings National Academy of Sciences USA 96, 5952-5959.

COC 1999. Committee on the Carcinogenicity of Chemicals in Food, Consumer products and the Environment (COC) (1999). Breast cancer risk and exposure to organochlorine insecticides: Consideration of the Epidemiology of data on dieldrin, DDT and certain hexachlorocyclohexane isomers. pages 62-71.

Coggons, D., and Inskip, H. (1994). Is there an epidemic of cancer? British Medical Journal 308, 705-708.

Doll, R. (1992). Health and the environment. American Journal of Public Health 82, 933-941.

Leake, A. (1999) In. Organic farming and the European Union.  House of Lords 16th report. HMSO. Page 81.

Lutz, S.M. and Smallwood, D.M. (1995). Limited financial resources constrain food choices. Food Review 18, 13-27.

Myeni, S.C.B.  (2002) Formation of stable chlorinated hydrocarbons in weathering plant material. Science 295, 1039-1041.

Oeppen, J., and Vaupel, J.W. (2002) Broken limits to life expectancy. Science 296, 1029-1031.

Pollycove, M. (1997). Low Dose Linearity: the Rule or the Exception. BELLE Newsletter. 6, 15-21. Also published in http://www.belleonline.com/vol6-1.html

Shepherd,M.A.,Harrison,R.and Webb,J.(2002) Managing soil organic matter-implications for soil structure on organic farms. Soil Use and Management 18,284-293.

Stockdale, E.A., Shepherd, M.A. Fortune, S., and Cuttle, S.P. (2002) Soil fertility in organic farming systems- fundamentally different? Soil Use and Management 18, 301-308.

Stopes, C., Lord, E.I. Phillips, L., and Woodward, L. (2002). Nitrate leaching from organic farms and conventional farms following best practice.  Soil Use and Management 18, 256-263.