a
WORLD HEALTH ORGANIZATIONORGANISATION MONDIALE DE LA SANTÉ
ЕВ68/3
13 A p r i l 1981
EXECUTIVE BOARD Sixty-eighth Session
INDuXv-^
Provisional agenda item 6
EXPERT COMMITTEE MEETINGS Report by the Director-General
In compliance with Regulation 10.6 of the Regulations for Expert Advisory Panels and Committees,^ the Director-General submits this
report on four meetings of expert committees w h o s e r e p o r t s ^ h a v e been prepared in English and French since the sixty-seventh session of the Executive B o a r d .
During the sixty-seventh session of the Executive Board in January 1981, it was agreed that measures should be studied for expediting the distribution of expert conmittee reports to Executive Board members, improving the quality of the Director-General's reports to the Board on these m e e t i n g s , and publishing the Director-General's and the Board's views on their public health implications. The Director-General w i l l submit the results of these studies to the sixty- ninth session of the Board in January 1 9 8 2 .
The four meetings of expert committees and their reports are reviewed h e r e u n d e r , in the following order:
1 . ENVIRONMENTAL M A N A G E M E N T FOR VECTOR CONTROL
Fourth report of the WHO Expert Committee on Vector Biology and Control 2 . RESISTANCE OF VECTORS OF DISEASE TO PESTICIDES
Fifth report of the WHO Expert Committee on Vector Biology and Control 3 . ASSESSMENT OF PUBLIC HEALTH AND SOCIAL PROBLEMS ASSOCIATED WITH THE
USE OF PSYCHOTROPIC DRUGS
Report of the WHO Expert Committee on Implementation of the Convention of Psychotropic Substances, 1971
4 . WHOLESOMENESS OF IRRADIATED FOOD
Report of a Joint FAo/IAEA/WHO Expert Committee 1. ENVIRONMENTAL MANAGEMENT FOR VECTOR CONTROL
Fourth report of the WHO Expert Committee on Vector Biology and Control Geneva, 13-19 November 1 9 7 9 ^ ~
1.1 Background information
The purpose of the Expert Committee ' s meeting on environmental m a n a g e m e n t for vector control was to review and assess those environmental m a n a g e m e n t m e t h o d s already in use and
1 WHO Basic Documents, 31st ed., 1981, p . 9 7 .
2 For easy reference, copies of these reports, either in their final form or as offset documents, are annexed to this report (for members of the Executive Board o n l y ) .
3 WHO Technical Report Series, N o . 649, 1980.
ЕВ68/3 p a g e 2
t h o s e u n d e r d e v e l o p m e n t . I t is w i d e l y r e c o g n i z e d that the i n c r e a s i n g l y s e r i o u s p r o b l e m c a u s e d b y v e c t o r r e s i s t a n c e to i n s e c t i c i d e s a n d t h e h i g h c o s t of a l t e r n a t i v e i n s e c t i c i d e s in a f f e c t e d p r o g r a m m e s can b e a l l e v i a t e d t h r o u g h the a d o p t i o n of i n t e g r a t e d or c o m p r e h e n s i v e c o n t r o l s t r a t e g i e s in w h i c h e n v i r o n m e n t a l m a n a g e m e n t is a b a s i c e l e m e n t .
1.2 T h e r e p o r t
T h e r e p o r t r e v i e w s e n v i r o n m e n t a l m a n a g e m e n t m e t h o d s , their c o s t e f f e c t i v e n e s s and c o s t b e n e f i t s , t h e i r e n v i r o n m e n t a l i m p a c t , t h e i r i n t e r r e l a t i o n w i t h a g r i c u l t u r e and i r r i g a t i o n p r a c t i c e s and d e v e l o p m e n t a c t i v i t i e s , a s w e l l a s t h e i r p l a n n i n g a n d a p p l i c a t i o n in v e c t o r c o n t r o l p r o g r a m m e s and a s p a r t of d e v e l o p m e n t p r o j e c t s , p a r t i c u l a r l y w a t e r d e v e l o p m e n t p r o j e c t s .
1.3 T h e r e c o m m e n d a t i o n s
T h e C o m m i t t e e r e c o m m e n d e d i n c r e a s e d m u l t i s e c t o r a l c o l l a b o r a t i o n , b o t h a t the n a t i o n a l a n d i n t e r n a t i o n a l l e v e l , b e t w e e n d e v e l o p m e n t a g e n c i e s , as w e l l a s b e t w e e n g o v e r n m e n t and p r i v a t e s e c t o r s i n v o l v e d in h e a l t h a n d d e v e l o p m e n t p r o j e c t s , e s p e c i a l l y t h o s e r e l a t e d to w a t e r a n d land u s a g e . S u c h i n c r e a s e d c o l l a b o r a t i o n w i l l e n a b l e a g r e a t e r e x c h a n g e of i n f o r m a t i o n w h e n o r g a n i z e d t h r o u g h a n e t w o r k o f n a t i o n a l c o m m i t t e e s , i n t e r n a t i o n a l r e f e r e n c e c e n t r e s a n d e x p e r t p a n e l s , a n d a b e t t e r u n d e r s t a n d i n g of the h e a l t h p r o b l e m s and t h e i r p o s s i b l e s o c i o e c o n o m i c i m p l i c a t i o n s .
1.4 S i g n i f i c a n c e of the r e p o r t for p u b l i c h e a l t h and the O r g a n i z a t i o n1s p r o g r a m m e
T h e r e p o r t of the Committee， and p a r t i c u l a r l y the i m p l e m e n t a t i o n of its r e c o m m e n d a t i o n s , is e x p e c t e d to s t r e n g t h e n the i n t e g r a t e d a p p r o a c h in d i s e a s e / v e c t o r c o n t r o l p r o g r a m m e s .
A b o v e a l l , the C o m m i t t e e ' s r e c o m m e n d a t i o n s o n i n t e r a g e n c y c o l l a b o r a t i o n a r e e x p e c t e d to e n s u r e t h e i n t r o d u c t i o n of t h e i n d i s p e n s a b l e p u b l i c h e a l t h s a f e g u a r d s w h i c h a r e a t p r e s e n t o f t e n l a c k i n g i n i m p o r t a n t w a t e r r e s o u r c e s p r o j e c t s in the d e v e l o p i n g c o u n t r i e s .
A s a f o l l o w - u p of t h e r e c o m m e n d a t i o n s of the E x p e r t Committee， a n i n t e r a g e n c y P a n e l of E x p e r t s h a s b e e n e s t a b l i s h e d i n c l u d i n g F A O , U N E P and W H O ; o t h e r a g e n c i e s a r e e x p e c t e d to j o i n l a t e r . The P a n e l of E x p e r t s w i l l c o o r d i n a t e m u l t i s e c t o r a l a c t i v i t i e s in the field of e n v i r o n m e n t a l m a n a g e m e n t and w i l l i n i t i a t e c o l l a b o r a t i v e p r o j e c t s for d e v e l o p i n g a p p r o a c h e s and s t r a t e g i e s u t i l i z i n g t h e s e m e a s u r e s for h e a l t h p r o t e c t i o n and a g r i c u l t u r a l d e v e l o p m e n t . T h e f i r s t m e e t i n g of the P a n e l w i l l b e h e l d in G e n e v a f r o m 22 to 29 S e p t e m b e r 1 9 8 1 and s u b s e q u e n t m e e t i n g s w i l l b e h e l d in R o m e a n d N a i r o b i and a t the field p r o j e c t s .
A n i n t e r r e g i o n a l s e m i n a r on i n t e g r a t e d v e c t o r c o n t r o l u t i l i z i n g e n v i r o n m e n t a l
m a n a g e m e n t w i l l b e h e l d f r o m 2 to 14 N o v e m b e r 1 9 8 1 in T u r k e y . A n o t h e r s e m i n a r , for t r a i n i n g o f e n g i n e e r s in h e a l t h safety d e s i g n s and o p e r a t i o n s , w i l l b e h e l d in 1 9 8 2 w i t h U N E P ' s
a s s i s t a n c e . A W H O c o m p r e h e n s i v e m a n u a l on e n v i r o n m e n t a l m a n a g e m e n t for m o s q u i t o c o n t r o l is in p r e p a r a t i o n . S e v e r a l t e c h n i c a l p a p e r s o n the h e a l t h a s p e c t s of w a t e r r e s o u r c e s d e v e l o p - m e n t h a v e b e e n i s s u e d , p r e s e n t e d a t i n t e r n a t i o n a l m e e t i n g s , and d i s s e m i n a t e d .
T h e B l u e N i l e h e a l t h p r o j e c t in the S u d a n , w h i c h h a s a n i n t e g r a t e d a p p r o a c h to the m a j o r h e a l t h and s o c i o e c o n o m i c p r o b l e m s of i r r i g a t i o n s c h e m e s , w i l l b e used to e n h a n c e
t e c h n i c a l c o o p e r a t i o n a m o n g d e v e l o p i n g c o u n t r i e s in the field o f h e a l t h and s o c i o e c o n o m i c d e v e l o p m e n t .
EB68/3 page 3 2. RESISTANCE OF VECTORS OF DISEASE TO PESTICIDES
Fifth report of the WHO Expert Committee on Vector Biology and Control
Geneva，3-9 June 1 9 8 01 ^ ^ — ~
2•1 Background information
The number of vector species resistant to insecticides and the size of the endemic area affected by resistance have continued to increase, while new types of resistance and cross-resistance have also been observed. The situation has become very critical in certain areas of the world where m a l a r i a vectors, for example, can no longer be controlled
satisfactorily by the use of insecticides.
2.2 The report
The Committee reviewed the present status of resistance of disease vectors to
pesticides. It stressed the need of reporting on specific types of resistance to organo- phosphorus compounds. The Committee cited instances where simple or combined resistance has caused operational problems in malaria control in Gujarat and Maharashtra States in India, in Iran, Iraq, Pakistan, parts of the Syrian Arab Republic, Turkey, and Central A m e r i c a . Cross- resistance to synthetic pyrethroids in several DDT-resistant arthropods, including Aedes aegypti and some strains of houseflies, was also considered of particular importance.
The Committee underlined the variety and complexity of the physiological and biochemical mechanisms leading to the detoxification of each main category of insecticides. Whenever an insecticide-resistant population of a vector develops, its cross-resistance spectrum depends on the particular physiological or biochemical mechanism concerned in the selection process, and this in turn depends upon the genetic background and past insecticide exposure of that population. This m a k e s it very unlikely that the resistance pattern of any given vector population could be accurately forecast before it actually appears under field conditions.
The early detection of resistance is thus essential so that resistance mechanism(s) and cross-resistance spectrum can be rapidly determined arid provide a sound basis for the selection of alternative insecticides or other countermeasures.
The Committee reviewed the status and research on countermeasures for resistance including use of alternative chemicals.
2•3 The recommendations
The Committee m a d e a number of recommendations covering the operational aspects of detection of resistance, its correct interpretation, and the significance of the resistance.
In this regard the Committee re-emphasized that before making any change in the insecticide employed, a multidisciplinary investigation including both epidemiological and entomological aspects should be carried out, since replacement insecticides are generally more expensive.
Early detection of resistance was considered m o s t vital, and recommendations were m a d e to improve the situation speedily by measures such as using the services of existing suitably equipped laboratories and if necessary by creating special insecticide reference laboratories.
The Committee recommended that the type of resistance be thoroughly characterized in every important instance arid that the cross-resistance spectra be characterized; where possible laboratory investigations on the biochemistry and genetics of resistance should be carried out. In order to inhibit the evolution of resistance, research was also recommended on innovative approaches to vector control such as quantitative studies of the dynamics of resistance and the fitness of resistance genotypes, and the development of formulations "that provide a range of environmental persistence and minimal nontarget effects'1. Recognizing
that the present critical situation regarding resistance in vector species has developed through control campaigns that have relied exclusively on insecticides, the Committee urged that w o r k be conducted to reduce this reliance.
1 WHO Technical Report Series, N o . 655, 1980.
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2.4 Significance of the report for public health and the Organization's programme
The critical review m a d e by the Committee of the standardized test kits, methods and strategies for detecting and monitoring vector resistance to pesticides has already enabled the Secretariat to produce revised test kits and guidelines for improving the operational effectiveness of this monitoring without increasing its c o s t .
The report w i l l assist public health authorities in the selection and use of pesticides for long-term vector control operations by providing an improved basis for the formulation of control strategies.
The report will help to reorient the WHO programme for the development and evaluation of public health pesticides, h e n c e improving the promoting and coordinating role of the Organization in this field.
Although vector control using pesticides remains the single most effective weapon for the control of m a j o r vector-borne communicable diseases in the developing countries,
especially since suitable vaccines are for the m o s t part not readily available, resistance to pesticides in vectors has seriously affected many control programmes. In some cases cheaper insecticides have had to be replaced by m o r e expensive o n e s . In many instances outbreaks of diseases which had formerly been kept under control by the use of pesticides have o c c u r r e d . The recent discovery of cross-resistance linkages affecting simultaneously several
insecticides belonging to different chemical categories provides a clear warning that high priority must be given to the development of non-conventional pesticides and to the speeding-up of the evaluation of alternative vector control strategies. Research on vector control
w i l l be reoriented accordingly.
3 . ASSESSMENT OF PUBLIC HEALTH AND SOCIAL PROBLEMS ASSOCIATED WITH THE USE OF PSYCHOTROPIC DRUGS
Report of the WHO Expert Committee on Implementation of the Convention on Psychotropic Substances， 1971
Geneva, 15-20 September 1 9 8 01
3.1 Background information
The widespread availability and use of psychotropic substances in many parts of the world h a s resulted in public health and social problems related to the abuse of certain of these substances. The Convention on Psychotropic Substances, 1971, is an instrument
available to countries to protect the health of people from the harmful effects of substances w h i l e still making it possible for the health services to use effective psychotropic
substances. An earlier expert committee addressed itself to the psychopharmacological evaluation of these substances.2 The terms of reference of the Committee in 1980 were to advise on the appropriate technology for assessment of the public health and social problems and to make the health professions aware of the risks. This type of evaluation is a new requirement for establishing the benefit/risk ratio of these substances for the whole of the United Nations family of organizations, including W H O .
3.2 The report
The report sets out in section 2, on technology for the assessment of extent of use of psychotropic substances, the methodology by which parties to the 1971 Convention and WHO assess the findings in order to establish the extent of harm caused by these drugs, and develop recommendations in respect of the public health and social problems associated with
their use, with a view to national and international control, as well as recommendations on the level of control, in fulfilment of their responsibilities under the Convention. Section 3 describes techniques for the assessment of drug-related health problems ranging from mild and
1 WHO Technical Report Series, N o . 656, 1981.
2 WHO Technical Report Series, N o . 618, 1978.
EB68/3 Page 5 a c u t e effects of psychoactive substances to the part these d r u g s play in causing d e a t h . Section 4 reviews techniques for the assessment of d r u g - r e l a t e d social p r o b l e m s . The b e h a v i o u r a l problems include effects on d r i v i n g , a l c o h o l and d r u g i n t e r a c t i o n , c r i m i n a l
b e h a v i o u r and socioeconomic e f f e c t s . This investigation of b r o a d e r health and social effects of d r u g s w i l l supplement W H O ' s earlier technical r e p o r t s1 regarding the p r i n c i p l e of
e s t a b l i s h i n g d r u g efficacy and s a f e t y . 3 .3 The recoimnendations
In carrying out a realistic evaluation of the b e n e f i t / r i s k ratio of a p s y c h o t r o p i c substance, the Committee noted that the m a j o r p r o b l e m is the lack of uniform and valid d a t a on the extent of use of psychotropic substances and of h e a l t h and social problems a r i s i n g t h e r e f r o m . The Committee therefore m a d e a n u m b e r of r e c o m m e n d a t i o n s which are summarized in section 5 of the r e p o r t . These relate to issues such as improving d a t a collection at country level w i t h the support of W H O as w e l l as to the review of various groups of psycho- tropic substances to d e t e r m i n e w h e t h e r or n o t some further d r u g s should be proposed for control under the Convention on Psychotropic S u b s t a n c e s , as w e l l as to the i d e n t i f i c a t i o n of the relationship between alcohol and psychotropic substances, on the one h a n d , and injury, d i s a b i l i t y and death from road traffic accidents on the other; as w e l l as to other m e a s u r e s
to be taken by countries, the United N a t i o n s Division of N a r c o t i c D r u g s , W H O and its collaborating centres, and n o n g o v e r n m e n t a l o r g a n i z a t i o n s .
3.4 Significance of the report for public health and the O r g a n i z a t i o n ' s p r o g r a m m e
The extension of W H O ' s r e s p o n s i b i l i t i e s under the 1971 Convention, and especially in the area under d i s c u s s i o n , requires m o r e and closer c o l l a b o r a t i o n w i t h M e m b e r States -
especially the developing countries - and other United N a t i o n s b o d i e s and a g e n c i e s . M o r e w o r k is needed to develop techniques and collect and interpret d a t a . This is the u r g e n t
task a h e a d .
These requirements go beyond the O r g a n i z a t i o n ' s earlier w o r k related to the c o n t r o l of n a r c o t i c d r u g s . B e c a u s e of the widespread use of p s y c h o t r o p i c substances throughout the w o r l d , d a t a can b e obtained from both developing and developed countries w i t h the
collaboration of n a t i o n a l experts from a broad variety of d i s c i p l i n e s . W H O c o l l a b o r a t i n g centres and routine d a t a collecting systems w i l l b e u s e f u l in this w o r k , b u t n e w m e c h a n i s m s h a v e to b e established at country level to obtain d a t a necessary for d e c i s i o n - m a k i n g a b o u t
levels of control and e f f e c t i v e use of d r u g s . Training of d i f f e r e n t categories of h e a l t h p e r s o n n e l w i l l h a v e to be complemented by appropriate a d d i t i o n a l instruction on these m a t t e r s .
In the context of p r o v i d i n g to countries information that w i l l h e l p them to select a limited n u m b e r of essential d r u g s , the subject m a t t e r of this report h a s b e c o m e urgent in respect to those for neuropsychiatrie d i s o r d e r s .
4 . W H O L E S O M E N E S S OF IRRADIATED FOOD
Report of a Joint FAO/IAEA/WHQ Expert Committee Geneva, 27 October - 3 N o v e m b e r 19802
4 • 1 Background information
The ever-growing world food demands m a k e it n e c e s s a r y n o t only to increase food
production but also to consider all possible m e a n s of p r e v e n t i n g spoilage; h e n c e the interest in ionizing radiation for food storage and p r e s e r v a t i o n . W h i l e FAO is interested m a i n l y in the usefulness of irradiation for food preservation and the w h o l e s o m e n e s s of p r o d u c t s so treated, and IAEA in the technological feasibility of the p r o c e s s , W H O is concerned a b o v e all w i t h the safety of irradiated food.
1 WHO Technical Report Series, N o . 312， 1965; N o . 364， 1967; N o . 4 0 3 , 1968; N o . 4 2 5 , 1969; N o . 4 2 6 , 1969; N o . 482， 1971; N o . 5 3 6 , 1974; N o . 563， 1975 and N o . 618， 1 9 7 8 .
2 W H O Technical Report Series, N o . 659, 1981 (English only; French text reproduced p r o v i s i o n a l l y as an offset document)-
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4.2 The report
The Coiranittee having considered the two previous expert committee reports on the subject"^"
and the new data that had b e c o m e available in the meantime, and stressing the need for applying to irradiated products the general principles of food hygiene, concluded that:
(1) although the evidence presented indicated that irradiation caused certain nutrient losses (e.g., destruction of thiamine, which could be important wherever rice was the staple food), such nutrient losses w e r e no greater than those resulting from other food preservation processes;
(2) the changes induced by irradiation, at a standard dose of 10 kGy, were no greater 2 than those resulting from other processes, e.g., heating, and that radiolytic products did not, in the light of present knowledge, give cause for concern;
(3) the safety of irradiated food compared well with that of food preserved by other means; the Committee found no evidence of radiation-induced microbial mutations or
resistance, or of enhanced pathogenicity; on the contrary, irradiation tended to reduce the microbial load (Salmonella, Vibrio parahaemolyticus, etc.) of foodstuffs so treated; animals fed with irradiated food products for many years had shown no adverse effects; irradiated food products had been used for maintaining patients on immuno- suppressive therapy, and no adverse effects had been reported.
4•3 The recommendations
A f t e r giving some indications for future research in this field, the Coiranittee recommended that the technological and economic feasibility of food irradiation on an industrial scale be established. A wider variety of foods should also be studied w i t h respect to their suitability for processing by irradiation. IAEA and FAO should facilitate such studies and collect data for the purpose of making recommendations.
The use of high-dose radiation for the treatment of certain foods has been recognized as being technologically feasible. To assess the safety of this process, further information is needed on its nutritional, microbiological and toxicological implications. Such
information is being generated and should b e brought together by FAO, IAEA and WHO for future e v a l u a t i o n .
4.4 Significance of the report for public health and the Organization's programme It is incumbent upon WHO to review and keep abreast of all studies on the subject.
A series of actions to be taken as a result of this report also devolve upon FAO and IAEA, as the recommendations require the dissemination of technological know-how and information on the economic implications to those countries interested in improving good storage by means of irradiation.
1 WHO Technical Report Series, N o . 451， 1970， and N o . 604, 1977.
о
kGy = kilogray. The gray (Gy) is the standard international unit of absorbed dose of r a d i a t i o n .
