Book reviews - Pesticides News No.52

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Bt safety assessment
New Zealand academics Maureen O’Callaghan and Travis Glare provide an encyclopaedic review of the environmental, non-target and mammalian safety of the insecticidal bacteria Bacillus thuringiensis.
Bt forms the basis of over 90% of all biopesticides sold around the world. In 1990, (the latest year for which figures are available) sales of Bt products constituted US$110 million of a US$120 million worldwide biopesticide market.
    Bt was first isolated around 1901 in Japan, but it is in fact named after the later discovery of a bacterium killing flour moths in Thuringia, Germany. The use of Bt for insect control was originally developed in France in 1938, but commercial interest did not develop in most other countries until the late 1950s.
    For many years Bt was regarded as a ‘safe’ biopesticide, with toxicity limited to a few lepidopteran insects (butterfly and moth caterpillars) and no indications of mammalian or non-target impacts. But knowledge of Bt has rapidly advanced in recent years as new strains and toxins produced by the bacteria have been identified and the whole picture has become more confused. The new strains mean Bt now has an effect on a wider number of species, which worked against one of the original safety tenets – that Bt was specific to lepidopteran insects.
    Glare and O’Callaghan report that more than 3,000 insect and mite species from over 15 orders are recorded as susceptible to at least one serovar (subdivision) of Bt. Susceptible insects are primarily herbivores, rarely carnivores.
    Bt toxin genes are now expressed in other organisms and the rapid advances in transgenics have led to marked changes in public and scientific perception of risk. But despite wide spread use over the last 50 years, large-scale studies on human populations have not reported significant increases in any disorders or health concerns. Some strains of Bt that produce toxins, known as beta-endotoxins, have demonstrated activity against a wide range of insect hosts, including some beneficial insects, fish and mammals. Regulatory authorities generally require that Bt products are free of ß-endotoxins and the use of standardised production methods is designed to minimise the presence of unwanted toxins in the final product.
    Bt spores and delta-endotoxins (normally produced by commercial Bt) have rarely been found to impact on non-target organisms, and show little residual activity and a lack of mammalian toxicity.
    Bacillus thuringiensis: Biology, Ecology and Safety cites over 8,000 papers. The authors finally agree that Bt is ‘safe to use’.

Bacillus thuringiensis: Biology, Ecology and Safety, Travis Glare and Maureen O’Callaghan, John Wiley, Baffins Lane, Chichester, PO19 1UD, UK, Tel +44 (0)1243 779 777, 2000, 350pp. Order direct from Amazon.co.uk.

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The price of cheap food?
The author is a well-known journalist and broadcaster and was also a dairy farmer for some years. ‘The big question the industry and most politicians have been so reluctant to address is whether ‘cheap’ food is really cheap,’ writes John Humphrys. ‘To do so is to raise doubts about their judgement or even their motives. What price, for instance, should society put on the destruction of so much of our rural heritage.’ To answer these questions, he covers the history of pesticides and their usage, and the nature and structure of the soil. He takes the examples of fish farming and antibiotic resistance in animals to illustrate the pitfalls of chemicals, and views the potential of GM crops with foreboding.
John Humphrys observes that the last revolution in agriculture in living memory was in the 1950s following the war. ‘It gave us bigger harvests. It also gave us environmental destruction and pesticide residues and antibiotic resistance and the horrors of mad cow disease.’ He argues for less arrogance in attempting to control nature. He wants to avoid the GM revolution and opts instead for what he sees as the counter-revolution, based on the recognition that ‘agriculture is, in effect, the nation’s primary health service.’ His arguments will strike many chords with the public.

John Humphrys, The Great Food Gamble, Hodder and Stoughton, 338 Euston Road London, NW1 3BH, 2001, 306pp. Order direct from Amazon.co.uk.

Birds at risk from seed treatment
Pesticide seed treatments are widely used on arable crops, and some of these treatments may pose a risk to birds. About 90% of arable crops seeds are treated with pesticide before planting. A Ministry of Agriculture, Fisheries and Food (MAFF) funded study has shown that some birds that are not normally thought of as feeders of grain may eat crop seeds and so may need to be considered in risk assessments for pesticide seed treatment.
Tests using baits of different seeds (not treated with pesticides) at the Central Science Laboratory recorded that a wider than expected range of bird species took most types. Larger birds such as rooks and pigeons were expected to take maize and peas, but sparrows took both.
The amount of pesticide that each seed would have contained had it been treated was calculated, showing that the amounts of seed consumed during single visits to the bait stations were sufficient to pose a potential risk to the birds. It is likely that birds made repeated visits. Until now, risk assessment for seed treatments has tended to focus on one or two predominantly seed eating birds, especially wood pigeon and house sparrow. This research has provided a much better understanding of the range of species that may be at risk, and the factors which influence their exposure.

Phil Prosser, Project PN0907, CSL, Sand Hutton, York, YO4 1LZ, p.prosser@csl.gov.uk

NEW resources on-line at PAN UK
Reducing pesticide hazards in developing countries

A widely-praised series of publications on Control of Pesticides and Integrated Pest Management (IPM): Implementation of Farmer Participatory IPM and Better Chemical Management is now available on-line. PAN UK developed the material to guide policy makers in governments and development agencies, and others concerned about pesticides. The materials include:
Progressive Pest Management: Controlling pesticides and implementing IPM (24pp). A booklet recommending a strategy on: establishing control of pesticides; reducing use, risks and dependency on pesticides; and taking action for IPM.
Pest Management Notes a series of short (4-page) briefings, which will be periodically supplemented, now includes:

Pest management – a new approach
Integrated Pest Management
Disposal of obsolete pesticides
Desert locust control in Africa
Prior Informed Consent
International chemical initiatives
Pesticide procurement
Pesticide residues in food
Growing coffee with IPM
Success with cotton IPM

Guide to Active Ingredient Hazards This tabulated guide to over 1,000 active ingredients provides a quick reference point for chemical names, types, uses, acute toxicity (WHO classification), the Acceptable Daily Intake, reproductive and chronic effects, endocrine disrupting pesticides, environmental effects, national regulation, inclusion in the PIC Conventions known evaluations.
Resource guide to pest management topics, agencies, web sites and databases (32pp). Topics provides a quick guide to commonly-used terms. Agencies lists major international bodies, NGOs, research institutes, industry contacts. Computer resources offers fully updated web-links and on-line databases.
Country profiles: the state of IPM and chemical management in Africa (34pp), provides an overview and information on selected African countries. The profiles include details (current to 1999) of projects which contain a strong element of participatory IPM.

Information will be added to and up-dated periodically: www.pan-uk.org/internat/intindex.htm
This material was produced with the support of, and for use by, the European Commission.

Public health pesticides
This report presents the conclusions of a World Health Organisation (WHO) Expert Committee commissioned to make recommendations on specifications for pesticides used in public health.
    A section on analytical methods and quality control in developing countries addresses the major problem of substandard products and the need to make quality control capacity available in all countries.
    The committee also considered pesticide containers and packaging, marketing and storage, as well as the problems of disposal and unusable pesticides and their containers.
    Recommendations suggested WHO should facilitate and promote the search for alternative pesticides and control measures that pose minimal risk to human health and the environment.

Chemistry and Specifications of Pesticides, WHO Expert Committee on Vector Biology and Control, WHO Publications, 1211 Geneva, 27 Switzerland, Fax +41 22 791 4857, bookorders@who.ch, 2000, 68pp. Order direct from Amazon.co.uk.

DNOC
The World Health Organisation (WHO) has evaluated the risks to humans and the environment posed by exposure to dinitro-ortho-cresol (DNOC), a pesticide used for over a century as an acaricide, and insecticide in orchards and on potatoes to prevent virus and disease contamination of the tubers. The chemical’s use as a pesticide has been banned in many countries (in some cases since the mid-1960s) because of its high acute toxicity, but significant volumes of obsolete stocks still exist and use continues in some countries.
DNOC is acutely toxic to humans. Symptoms associated with DNOC toxicity are restlessness, a sensation of heat, flushed skin, sweating, thirst, deep and rapid respiration, tachycardia, severe increase in body temperature, and cyanosis leading to collapse, coma and death. Effects are enhanced at high environmental temperature.

Dinitro-ortho-cresol, Environmental Health Criteria, WHO Publications, (see above), 2000, 87pp.

Toxic trail across Southeast Asia

With annual sales over US$30 billion, the pesticide industry is big business – according to a recent BBC documentary the Toxic Trail. While the major manufacturers say they try to encourage responsible practices an estimated 25 million cases of pesticide poisoning occur each year. Nearly all the victims are in developing countries.

Toxic Trail, produced by the Television Trust for the Environment (TVE) for the BBC, set out to uncover the scale of the problem by following the flow of chemicals from their manufacturers in Thailand across the open border into Cambodia where they are posing a serious threat to human health and the environment.
As the documentary details, ‘multinational companies disclaim responsibility for what happens to their products in Cambodia since they have no formal operations there, leaving the responsibility to the government. But after decades of civil war, the impoverished Cambodian Ministries are struggling to build regulatory capacity in an attempt to control illicit trade and use of pesticides.
As 85% of Cambodians rely on agriculture for their livelihood, the market for pesticides in that country is enormous as many farmers believe that pesticides are a miracle ally in the war against pests while the country’s recently opened borders have become a highway for these products. But few of Cambodia’s poorly educated and impoverished farmers, the documentary concludes, realise how dangerous chemicals are.

Stark facts revealed
Over US$30 billion a year is spent on chemical poisons with 25% of that total being spent in Asia, where sales were up by more than 10% in 2000. Outside Japan, Thailand is the biggest spender in the South Asia Region with pesticide sales reaching US$247 million.
Some 73% of the imports into Thailand are WHO categories Ia and Ib, extremely toxic and highly toxic. In developed countries these chemicals are either banned, or they can only be used by licensed specialists who must carry out a number of stringent precautions. In south-east Asia, however, the chemicals are freely used without protective measures. Labels are often written in a foreign language or they fail to provide data on the active ingredient, application, date of manufacture or safe handling of the chemical.
Between 1992 and 1994, more than 344 million pounds (156 million kg) of hazardous chemical poisons were exported from the US – at least 25 million pounds (11 million kg) of which were forbidden for domestic use – the majority of which went to destinations in the developing world.

Looking forward
But there is a positive side to this otherwise grim picture. Across the region, Community IPM farmers are learning about rice ecology and how pesticides disturb the natural ecological balance. In Indonesia, IPM farmers have reduced the amount of pesticides they use and created farmer associations that sell pesticide-free rice and organic fertiliser at their own IPM kiosk. Toxic Trail visits a farmer group in West Java, which has started their own farmer newspaper to spread news of alternative methods of pest control. These farmers are meeting with local governments, doing their own research and experiments, and encouraging ecologically sustainable farming in their community.

Accompanying resources
A valuable package of material supports this video. These include:

Relationship of pesticide spraying to signs and symptoms in Indonesian farmers. Misa Kishi, Norbert Hirschhorn, et.al., published in the Scandinavian Journal of Work and Environmental Health, 1995.
Farmer Self-Surveillance of Pesticide Poisoning Episodes. Carried out by a group of farmers from Nam Dinh Province, Vietnam, 2000.
Claim No Easy Victories: Evaluating the Pesticide Industry’s Global Safe Use Campaign. Douglas L. Murray and Peter Leigh Taylor, published in World Development, 2000.

Full resource list published in Current Research Monitor and available on www.toxictrail.org.
‘Toxic Trail’ was broadcast in two parts on BBC World Earth Report, in April 2001. Earth Reports are produced by TVE. For copies of the documentaries (on compact disk), contact: ToxicTrail@attglobal.net.

[This article first appeared in Pesticides News No. 52, June 2001, pages 22-23]