The Physical Health Effectsof Terrorism and Disasters University of St Andrews, November 2012

Mike Catchpole, Health Protection Agency

Outline

1. Immediate and sub-acute effects

2. Long term effects

3. Assessment – importance and challenges

4. Planning for the future

Immediate and sub-acute effects:Blast-related injuries

Health effects may be immediate, sub-acute or delayed

Health effects depend on proximity to blast and environmental context (closed or open environment)

• explosions near or within hard solid surfaces become amplified two to nine times due to shock wave reflection - as a result, individuals between the blast and a building generally suffer two to three times the degree of injury compared to those in open spaces.

• A blast-induced overpressure of 400-500 kPa is considered potentially lethal and may generate a blast wave that travels at over 2,000 km/h (by contrast, a hurricane will typically generate an overpressure of 2 kPa, with wind speeds of up to 200 km/h)

Blast Injuries

Primary result from pressure of blast waverisks increased in confined space blasts, may be unrecognised initially

Secondary result from flying fragments and debrisusually the most common type of injury unless blast associated with structural collapse

Tertiary result from displacement of victims by blast windyoung children at particular risk

Quaternary burns, crush and other injuriesmajor cause of immediate fatality in incidents involving structural collapse e.g. 2001 World Trade Center attacks (91% of fatalities)

Immediate and sub-acute effects:Blast-related injuries

London Bombings - 7 July 20054 bombs (3 on underground trains, 1 on bus)222 in the immediate vicinity of the explosions• 52 (+4) deaths: 26% fatality rate on trains, 18% on bus• Another 21 critically injured• 69 amputations (29 fatalities, 15 survivors) • 2m from device maximum amputation distance

Madrid Bombings - 11 March 200410 explosions occurred aboard 4

commuter trains, 191 dead and approximately 1,800 injured

Immediate and sub-acute effects:Chemical, biological and radiological exposure

Sarin release in Tokyo, 20 March 1995Gave rise to difficulty in breathing, nausea and vomiting,

extreme sensitivity to light, bleeding from the nose and mouth, neurological symptoms, and coma. Estimates of the

injured range from 3,800 up to 6,000, with 12 deaths.

• Exposure may be to deliberately released materials (gas attack, dirty bomb, ‘white powder’) or to ‘normal’ environmental materials released by a blast (dust, asbestos, industrial chemical fumes)

• Health effects may be immediate, sub-acute or delayed

• Released materials may cling to the clothes and bodies of its victims, affecting those who provide aid

• Symptoms depend on the nature of the exposure

London: Acute assessment and response to threats to physical health

• Significant exposures to blood and tissues

– Hepatitis B vaccination of those at risk

• Significant number of survivors reporting

ear trauma and/or hearing loss

– Guidance issued on assessment and

management of blast injury, particularly blast

lung injury

Long term effects

Clearest and most consistent evidence of long term health effect is for psychological consequences

Growing evidence of long term somatic health effects following exposure to terrorism or natural disasters

• Some health effects appear to be causally correlated with the nature of exposure during the acute incident e.g. respiratory symptoms showing dose-response relationship to dust exposure following the New York World Trade Center attacks

• Some health effects appear to be correlated with the perceived overall ‘threat to life’ that the exposure represented, rather than with nature of exposure e.g. reporting of physical symptoms 14 months after exposure to the 2004 Indian Ocean tsunami

New York World Trade Centre Registry

The World Trade Center (WTC) Health Registry is tracking the health of more than 71,000 people directly exposed to the WTC disaster (approximately 50% have responded).

Key Findings (mental health effects)

Post-traumatic stress symptoms are the most common health effect of 9/11 • Almost one in five adults reported post-traumatic stress symptoms 5-6 years

after 9/11, roughly 4 times the rate in the general population

Risk factors for probable PTSD included:

• intense dust cloud exposure or suffering an injury on 9/11• being on a high floor of the World Trade Center, evacuating late or working

for an employer that sustained fatalities.• witnessing horror or knowing someone killed or injured on 9/11• little or no social support after 9/11• respiratory illness• Being a rescue and recovery worker who started rescue work on or soon

after 9/11 or who worked at the WTC site for a long time

New York World Trade Centre Registry

Key Findings (physical health effects)

Those exposed to WTC-related dust were more likely to develop respiratory symptoms, sinus problems, asthma or lung problems.

• One in 10 Registry enrollees developed new-onset asthma within 6 years of 9/11, 3 times the national rate.

• New cases were highest during the first 16 months after 9/11.

• Intense dust cloud exposure on 9/11 increased everyone's risk for developing asthma.

• Steep declines in pulmonary function first detected among firefighters and emergency medical service (EMS) workers within a year of 9/11 have largely persisted even among those who never smoked.

• Rescue and recovery workers who wore respirators on 9/11 were less likely to report respiratory problems five to six years after 9/11 than those who went without adequate respiratory protection

New York World Trade Centre Registry

Key Findings (physical health effects)

Many adults directly exposed to the WTC attacks developed lasting heartburn, indigestion, acid reflux and other symptoms of gastroesophageal reflux disease

Rescue and recovery workers who worked on the debris pile on 9/11 appear to be at increased risk for sarcoidosis

Non-rescue/ recovery workers who were more highly exposed to the WTC disaster may be at an increased mortality risk, especially cardiac-related, in comparison to those less exposed

Research about cancer and mortality in WTC-exposed populations is in its early stages because it takes a longer time for these potential health consequences to become evident.

Findings have been inconsistent regarding the impact of WTC exposure on birth outcomes.

London Bombings Register

• Most individuals experienced health symptoms for less than four weeks

• Nearly 55% of individuals reporting hearing problems after four weeks. A similar proportion of individuals reported hearing problems following the terrorist bombings in Madrid (41%) and Oklahoma City (49%).

784 eligible individuals were identified• 258 (33%) agreed to participate in the register• 173 (22%) returned completed questionnaires between 8 to 23

months after the explosions

Results• Over two-fifths reported exposure to blood• Four-fifths of individuals felt that they had suffered emotionally

and half of them were receiving counselling. • In addition to cuts and puncture wounds, the most frequent

injury was ear damage.

Incident Registers: Purpose

• Identification of delayed health effects

– Health monitoring and response, as recommended by Study Group following up

World Trade Center incident1

• Public reassurance

– Surveillance (health monitoring and feedback)

• Learning for the future

– Evaluation of health impact and health response

1. Landrigan PH, Lioy PJ, Thurston et al. Health and Environmental Consequences of the World Trade Center Disaster. Environmental Health Perspectives 2004; 112, 6: 731-739.

Registers: The Challenges

• Defining the target population

• Reaching the target population

• Collecting accurate and complete data

Case ascertainment for public health monitoring needs to be built into major incident plans

Public Health Follow-up

Lessons from the London follow up

Mechanisms should be developed for those who are difficult to reach if they are not easily contacted at the site of the incident

Avoidance of bias requires high level of ascertainment of at risk population

Extended follow-up may be required, and should be coordinated with supporting health service provision

Contacting individuals via acute clinical service providers has yielded patchy, and overall poor, response. Longer term follow-up was greatly facilitated by close collaboration with psychological services

The target population for assessing long term health effects may be larger than that for assessing the immediate public health threat

Have some preliminary results from environmental sampling ready for release as early as possible. Otherwise suspicions are raised unnecessarily

Public Health Follow-upNeeds for the Future

• Nationally agreed protocol and materials• Emergency services, NHS, Occupational Health Services, HPA

• Trained epidemic intelligence officers• Public health workforce

• Mechanisms for contacting those not recorded by the emergency services• Partnership with media, information and training for NHS and support organisations

• Absolute clarity about data protection and ethical issues• Building on work of the Department of Constitutional Affairs and UK Resilience

• (Even) closer working between response organisations, strengthened through exercises