Book Reviews - Pesticides News No.24

Vietnam veterans and Agent Orange
Between 1962 and 1971, US military forces sprayed nearly 19 million gallons of herbicides over approximately 3.6 million acres of Vietnam. Agent Orange, a 50:50 mixture of the phenoxy herbicides 2,4,5-T and 2,4-D, accounted for approximately 11.2 million gallons of the total. Other herbicides used were picloram and cacodylic acid. The herbicides were used to defoliate the jungle canopy which concealed opposition forces, to destroy crops which might feed opposition forces, and to clear vegetation from the perimeters of US military installations.
    2,4,5-T is unavoidably contaminated during manufacture with TCDD (dioxin) at a rate of between 0.05 and 50 parts per million. Thus in total, nearly 170 kg of dioxin was sprayed over Vietnam.
    Following their terms of service, many US veterans of the Vietnam conflict developed health problems which included cancer, and many fathered children born with disabilities.
    In 1991, US Congress asked the National Academy of Sciences to carry out a comprehensive study of the health effects of exposure to herbicides such as Agent Orange and other chemicals used in Vietnam. Now published, the main conclusions of this voluminous report are that sufficient evidence exists to associate exposure to the herbicides used in Vietnam and the health outcomes soft tissue sarcoma, non-Hodgkin’s lymphoma, Hodgkin’s disease, chloracne and porphyria cutanea tarda (a skin disorder manifested in genetically susceptible individuals). There is also limited evidence to suggest an association between respiratory cancers, prostate cancer and multiple myeloma and exposure to the herbicides. The report is less conclusive about the link between herbicide exposure and a variety of reproductive and birth defects, and other types of cancer, but does not rule out a link.
    However, since there is inadequate information about the levels of exposure to herbicides which Vietnam veterans suffered, the report also recommends that further research and monitoring be carried out for epidemiological purposes.
    The report represents a comprehensive review of the toxicology of the herbicides 2,4,5-T, 2,4-D, picloram and cacolytic acid and the contaminant TCDD. It uses as references hundreds of reports and studies from around the world, and as such is a valuable, if rather specific resource.

Institute of Medicine, Veterans and Agent Orange: Health effects of herbicides used in Vietnam, National Academy Press, Washington 1994, US$65.95, 812pp.

Green timber treatment
Following reports in earlier editions of Pesticides News regarding the use of heat to control domestic insect infestations and hot water to kill weeds, we are now able to report the use of heat to eradicate wood rotting fungi in buildings.
    High temperatures as a means of controlling dry rot in structural timbers was reported by Danish researchers at a recent conference on the ‘green’ treatment of timber, held at Taymouth Castle, Scotland in February 1994.
    When heated to a temperature of 50oC which is held for 16 hours, all dry rot within the heated space is killed. This is a significantly more effective and less disruptive control method than the use of chemicals for a variety of reasons:

• chemicals such as those used in the treatment of fungi in structural timbers, are generally effective where they are applied. Since structural timbers are often difficult to access, some infections may be missed;

• the toxicity of chemicals often requires lengthy evacuations of treated  properties, where heat treatment can be completed in one day;

• chemicals can damage materials and surfaces on which they are applied, while heat treatment has been shown to be non-destructive particularly in historic buildings where preservation is of paramount importance;

• heat treatment does not place applicators, householders, animals or the environment at risk.

Heat treatment for dry rot treatment has been in use in Denmark since 1989, but is not yet commercially available in the UK. Trials will need to be carried out to ensure that the method is compatible with the materials and designs used in British buildings which may differ from Danish structures.
    It is hoped the necessary work will be carried out soon, and that heat treatment will become widely available as an effective alternative to pesticides in structural timber treatments.
    Other novel approaches to the control of dry rot in structural timber were presented at the conference. One method suggested the use of biological control agents to attack dry rot. Laboratory trials had demonstrated that Trichoderma  spp. had been used effectively in trials to control the dry rot fungus Serpula lacrymans. Field trials of this control method are currently running as part of the EU funded EUREKA project to research new methods for the detection and control of dry rot.
    On the ‘least toxic chemical’ front, the use of boron compounds in timber treatment was expanded upon. Boron is a naturally occurring element which is present throughout the environment. Its use as an insecticide and fungicide of relatively low toxicity has been widely reported. In Southern countries, unseasoned timber is commonly treated with boron solutions as a preventative anti-fungal measure. Such treatment and timbers treated in this way are rarely found in the UK since the relatively slow diffusion rate of boron in timber does not fit in with the commonly held UK philosophy of ‘treatment on demand’. New compounds have been developed which increase the rate of diffusion of the boron in timber, and these could replace many significantly more toxic fungicides currently in use in the timber treatment industry.

Green Treatment of Timber Conference, 17-18 February 1994, Taymouth Castle, organised by the Scottish Ecological Design Association (SEDA), and Dundee Institute of Technology.

California review of food safety
The California Environmental Protection Agency (CalEPA) has produced a report designed to protect children from the effects of pesticide residues in food. It comes after the US National Academy of Sciences produced a pubication on pesticides and children last year. The CalEPA report prepared by government officials and academics finds that California has the strongest pesticide regulatory system in the US—although there was still room for improvement in the food safety programme.  The report makes a number of recommendations, including:

• additional toxicity data should be gathered, with a special emphasis on any special susceptibility children may have to certain pesticides;

• improved data should be gathered on typical food consumption by different population sub-groups. This would supplement existing studies which do not adequately represent some segments of the population, particularly in the younger age groups;

• residue monitoring of fresh produce and processed foods should be tailored toward foods typically consumed by children, to help scientists better assess potential risks to these age groups;

• new risk assessment methodology needs to be developed to reduce the inherent uncertainties of current methods, which can lead to overstatement or understatement of risk.

Some recommendations, for example the development of new approaches to risk assessment, may require further study or the development of new methodology or data. The financial costs for implementing some recommendations, such as acquiring new data and establishing additional testing requirements is expected to be significant.

A Joint Review of Existing Federal and State Pesticide Registration and Food Safety Programs, Department of Pesticide Regulation, 1020 N Street, Sacramento 95814, US, May 1994, US$5.

Soil and water protection
The Board of Agriculture of the National Research Council in the US has investigated policies needed to protect soil and water quality—whilst maintaining food production. It is recognised that the treatment of drinking water to remove pesticides is expensive and in some cases ineffective. The goal suggested is to reduce the total mass of pesticides that are lost to the environment. The Board recommended a national US policy should seek to: conserve and enhance soil quality; increase nutrient, pesticide and irrigation use efficiencies; promote farming systems that reduce erosion and run-off and make greater use of field and landscape buffer zones.

Soil and Water Quality: An agenda for agriculture, Board on Agriculture—National Research Council, National Academy Press, Washington, D.C., 1993, 516pp.

UK food surveillance report
The Ministry of Agriculture has produced the annual report for 1993 of the Steering Group on Chemical Aspects of Food Surveillance. Their work covers natural toxicants, food authenticity, dietary surveys, contaminants and the residues from the use of pesticides and veterinary products. Among other things they oversee the work of the Working Party on Pesticide Residues.

Steering Group on Chemical Aspects of Food Surveillance, Annual Report 1993, Paper No. 41, Ministry of Agriculture, London HMSO, £11.50, 94pp.

Pesticide directory
This directory contains the addresses of national governmental organisations in 160 countries which are involved in pesticides and their control. International organisations are also listed, including those of the regional offices of the  Pesticides Action Network. Unfortunately three of the six addresses are out of date.
    The book also contains a thorough report examining pesticides as environmental pollutants.

World Directory of Pesticide Control Organisations, Second Edition, George Ekström (Ed), British Crop Protection Council & Royal Society of Chemistry, Cambridge, UK, £40.00, US$69.00, 423pp.

Sustainable use of pesticides in the European Union
One of the hurdles standing in the way of a pesticide policy in the EU is about to be surmounted. The two most important Directorates concerned with pesticides are co-operating in a closed workshop on the sustainable use of pesticides in the EU—to be held in Brussels on 14-15 June. A significant reduction of pesticide use per unit land is required by the EU’s Fifth Environmental Action Plan. The workshop will examine the use of pesticides, their environmental impact, farm management, and instruments for pesticides policy. In support of the workshop, two publications supported by DGXI (Environment) and the Netherlands Government have been produced. 
    Pesticides in the EC  looks at the sale and use of pesticides in the EU, including the relative costs of products and the costs of pesticides for the main farm types, and distribution and disposal arrangements. Towards a Future EC Pesticide Policy reviews the risks, present policies, solutions and policy instruments of pesticides use in the EU. Both will be reviewed in greater detail in conjunction with the workshop report, in the next issue.

Pesticides in the EC. F.M. Brouwer, I.J. Terluin, and F.E. Godeschalk. Agricultural Economics Research Institute (LEI-DLO)(PO Box 29703, 2502 LS The Hague), Netherlands. ISBN 90-5242-252-4,  51DFl, 159pp.

Towards a Future EC Pesticide Policy: an Inventory of Risks of Pesticide Use, possible solutions, and policy instruments. J.A.W.A. Reus, H.J. Weckseler, G.A. Pak. Centre for Agriculture and Environment (CLM, PO Box 10015, 3505 AA Utrecht), Netherlands 25DFl (plus 15DFl p&p for overseas orders) 116pp.

Holistic Atlas
This revised and extended Gaia Atlas updates a decade of environmental and political change. The extensive illustrations, new maps and analysis provide a wealth of information on the wide range of issues that affect the well being of the living planet. A clear and structured approach presents the problems as well as what can be done towards prevention and a cure. The Atlas sets out the agenda of the environment movement to the year 2000. This edition is published to coincide with the post-Rio Earth Summit, 'Global Forum', which takes place in June 1994.

The Gaia atlas of planet management, Norman Myres General Editor, Gaia Books, 20 High Street, Stroud, Glos, GL5 1AS, UK, £16.99, 272pp.

International food residue levels
The Joint FAO/WHO Meeting on Pesticides Residues meets each year to consider residue limits to recommend to the Codex Committee and to review the toxicology of certain pesticides. The meeting to which this publication refers was held in Geneva from 20-29 September 1993. It reviews 18 active ingredients of which etofenprox, fenpropathrin and metiram are the first full evaluations. Most of the pesticides considered therefore, have been evaluated at previous meetings. The reviews are presented in detail referring to a wide range of material, some of which is not published Part I—Residues—is also published each year. 

Pesticide residues in food—1993: Evaluations Part II—Toxicology, International Programme on Chemical Safety, (FAO/WHO), Geneva, 1994, 60 Sw. Fr., 414pp.

Forestry Books

The forest environment
Increasing recognition of the consequences of deforestation, together with a greater awareness of unpriced factors such as recreation, wildlife and other environmental values has demanded a re-examination of public forest policies. Cases studies from Malawi, Nepal, Costa Rica and Malaysia are presented.

Forestry and the Environment: Economic perspectives, W.L. Adamowicz, W.White, & W.E. Phillips (Eds), CABI, Wallingford, Oxon, UK, 1993, £35.00, 304pp.

Ecological effects
This book provides a series of case studies from the UK, Italy, Spain, Ireland and Belgium on how the ecological effects of afforestation can be examined. Until recently, the ecological and environmental consequences of afforestation over a significant period of time have not been investigated extensively. Case studies are drawn from the UK, Italy, Spain, Ireland and Belgium.

Ecological Effects of Afforestation, Charles Watkins (Ed), CABI & on behalf of the European Science Foundation, Wallingford, Oxon, UK, 1993, £32.50, 224pp.

Private forestry
The Scottish Forestry Trust [now PAN UK] commissioned this book in order to examine the policies for private forestry in Western Europe. Methods of policy formulation and trends are assessed.

Private Forestry Policy in Western Europe, A.J. Grayson, CABI, Wallingford, Oxon, UK, 1993, £40.00, 329pp.

[This article first appeared in Pesticides News No. 24, June 1994, page 22-23]