WORLD HEALTH ORGANIZATION
FIFTY-FIFTH WORLD HEALTH ASSEMBLY A55/20
Provisional agenda item 13.15 16 April 2002
Deliberate use of biological and chemical agents
to cause harm
Public health response
Report by the Secretariat
1. During the past two decades, Member States have on several occasions expressed concerns
about the possibility that biological and chemical agents might deliberately be used to harm
populations. An alert about the risk of such agents being used for this purpose usually comes from a
nation’s security or defence sectors. The responsibility for responding usually lies with the health
2. In recent months, health ministries of several countries have reported that they have increased
their state of alert for the intentional malevolent use of biological or chemical agents, such as
pesticides, by spread through air, water or food. Their responses, based on various scenarios, have
included (a) increased preparedness within the national public health system, including identifying the
location – and even stockpiling – of critical medicines and other commodities, (b) informing members
of the public, particularly those thought to be at greatest risk, and (c) readiness to handle large
numbers of “suspect incidents”. Increased preparedness of the public health system usually includes
improved surveillance of incidents and illness, enhanced contingency planning and more effective
national response capacity.
3. The scenarios used by some health ministries for planning have included the release of
combinations of biological and chemical agents, simultaneous release in more than one location,
and/or use of unknown chemicals or genetically modified organisms. Such threats would pose extreme
difficulties for public health systems.
4. Several Member States have asked WHO for advice. All activities implemented by WHO on the
public health aspects of prevention, preparedness and response to natural, accidental or deliberate
releases of biological, chemical and radiological agents involve the closest possible coordination with
relevant national and international organizations. A deliberate release of a biological, chemical or
radiological agent would likely be considered initially as a natural event, unless the agent had been
spread overtly or on a massive scale.
5. WHO focuses on the possible public health consequences of such an incident, regardless of
whether it is characterized as a deliberate act or a naturally occurring event. The Organization’s basic
activity in this area is to strengthen public health disease alert and response systems at all levels, as
such a system will detect and respond to diseases that may be deliberately caused.1
6. When a Member State is concerned and wants to be prepared, WHO advises strengthening
public health surveillance and response activities, with an emphasis on:
• more effective national surveillance of outbreaks of illness;
• better communication between responsible agencies (public health, water supply, food safety,
veterinary,2 radiological, nuclear safety, poison-control and related services), and better
coordination of their responses;
• improved assessments of vulnerability, and effective communication about risks to both
professionals and the public;
• preparation for handling the psychosocial consequences of the deliberate use of pathogens
and chemicals to cause harm; and
• contingency plans for an enhanced response capacity (with the ability to enlist additional
resources for public health, such as civil defence, security, law-enforcement authorities and
other bodies, and the preparedness to work together, spelt out through cooperative
7. WHO’s guidance to countries on strengthening national preparedness and effective responses is
set out in the document “Public health response to biological and chemical weapons: WHO
guidance”.3 WHO country teams, regional offices, headquarter units and the WHO/CSR Office in
Lyon, France, may all be involved in the communication between the Organization and countries at
risk. The WHO/CSR Office in Lyon offers support in strengthening national laboratory and
8. In resolution WHA54.14 the Health Assembly asked the Director-General to make appropriate
arrangements for the development of plans for regional preparedness and responses. WHO has helped
to elaborate an efficient and proven system for global alert and response,4 based on a network of many
regional and subregional networks. This global public health network provides access to technical
expertise for alerting and responding to disease-causing biological and chemical agents.
9. The existing capacity for surveillance of and response to biological disease outbreaks has
evolved well during more than 10 years. The focus of activities has been on naturally occurring
epidemic diseases (such as Ebola haemorrhagic fever). However, such alert and response mechanisms
still need to be strengthened, especially with respect to chemicals and threats involving the food and
water supply chains, and especially in developing countries.
1 WHO document “WHO Efforts to Counter Terrorism” sent to Patrizio Civili, United Nations Assistant Secretary-
General for Economic Affairs on 21 December 2001, in response to his request to United Nations bodies, 10 December 2001.
2 Almost all agents known to have been weaponized are zoonotic pathogens.
3 See www.who.int/emc/book_2nd_edition.htm .
4 See document A54/9.
10. Technical expertise for the public health response to diseases caused by biological or chemical
agents is maintained by WHO through a roster of experts and can be made available to Member States,
should the need arise. The United Nations has mandated the Secretary-General “to carry out promptly
investigations in response to allegations that may be brought to his attention by any Member State
concerning the possible use of chemical and bacteriological (biological) or toxin weapons […] in order
to ascertain the facts of the matter …”.1 Initial contacts on the issue of cooperation in the case of
investigations have been established with the United Nations. The Chemical Weapons Convention of
1993 requires the Organisation for the Prohibition of Chemical Weapons to investigate any alleged use
of chemical weapons against a State Party, in cooperation with the Secretary-General if a State not
party to the Convention is involved. According to the Biological and Toxin Weapons Convention of
1972, any State Party that finds that any other State Party is in breach of its obligations under the
Convention may lodge a complaint with or request assistance from the United Nations.
11. Should the United Nations be called on to respond to a request to investigate, WHO could be
asked to provide technical expertise or to make available its existing resources and mechanisms. Nonpublic
health issues related to investigations of reports on possible use of chemical and bacteriological
(biological) or toxin weapons, however, remain the responsibility of the United Nations. If such a
request were made, information about the public health response, including the results of
epidemiological and laboratory investigations, would be reported by WHO to the government of the
country or countries where the event was occurring. Health Assembly resolution WHA54.14 on global
health security provides a mandate for WHO to facilitate a forum for discussion and joint action in
cases where an event might constitute a public health risk for more than one country.
12. WHO also works closely with a wide range of international organizations that may have an
interest in this field – such as IAEA, FAO, the Office international des épizooties and the Organisation
for the Prohibition of Chemical Weapons. WHO exchanges technical information with experts who
work with the Biological and Toxin Weapons Convention. WHO, in partnership with IAEA, responds
to reports of radiation incidents that may entail a risk to human health.
ACTION BY THE HEALTH ASSEMBLY
13. The Health Assembly is invited to consider the resolution contained in resolution EB109.R5.
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1 Resolution 620 (1988) of the United Nations Security Council and resolution 44/115B of the United Nations
WORLD HEALTH ORGANIZATION