Unit of risk ? one-in-a-million chance of death
This article is about the measure of mortality risk. For the computer program, see
Micromort (software)
.
A
micromort
(from
micro-
and
mortality
) is a unit of
risk
defined as a one-in-a-million chance of
death
.
[1]
[2]
Micromorts can be used to measure the riskiness of various day-to-day activities. A
microprobability
is a one-in-a million chance of some event; thus, a micromort is the microprobability of death. The micromort concept was introduced by
Ronald A. Howard
who pioneered the modern practice of
decision analysis
.
[3]
Micromorts for future activities can only be rough assessments, as specific circumstances will always have an impact. However, past historical rates of events can be used to provide a rough estimate.
Sample values
[
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]
Baseline
[
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]
Death from
|
Context
|
Time period
|
N deaths
|
N population
|
Micromorts per unit of exposure
|
Reference
|
All causes
|
England and Wales
|
2012
|
499,331
|
56,567,000
|
24 per day
8,800 per year
|
ONS Deaths
[4]
Table 5.
|
Canada
|
2011
|
242,074
|
33,476,688
|
20 per day
7,200 per year
|
Statistics Canada
[5]
|
US
|
2010
|
2,468,435
|
308,500,000
|
22 per day
8,000 per year
|
CDC Deaths
[6]
Table 18.
|
Non-natural cause
|
England and Wales
|
2012
|
17,462
|
56,567,000
|
0.8 per day
300 per year
|
ONS Deaths
[4]
Table 5.19.
|
US
|
2010
|
180,000
|
308,500,000
|
1.6 per day
580 per year
|
CDC Deaths
[6]
Table 18
|
Non-natural cause (excluding suicide)
|
England and Wales
|
2012
|
12,955
|
56,567,000
|
0.6 per day
230 per year
|
ONS Suicides
[7]
|
US
|
2010
|
142,000
|
308,500,000
|
1.3 per day
460 per year
|
CDC Deaths
[6]
Table 18.
|
All causes ? first day of life
|
England and Wales
|
2007
|
|
|
430 per first day of life
|
Walker, 2014
[8]
|
US
|
2013
|
|
|
16.7 per day
6100 per year
|
CDC Life Tables
[9]
Blastland & Spiegelhalter, 2014
[10]
|
Murder/homicide
|
England and Wales
|
2012/13
|
551
|
56,567,000
|
10 per year
|
ONS Crime
[11]
|
Homicide
|
Canada
|
2011
|
527
|
33,476,688
|
15 per year
|
Statistics Canada
[12]
|
Murder and non-negligent
manslaughter
|
US
|
2012
|
14,173
|
292,000,000
|
48 per year
|
FBI
[13]
Table 16
|
Leisure and sport
[
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]
Death from
|
Context
|
Time period
|
N deaths
|
N exposure
|
Micromorts per unit of exposure
|
Reference
|
Scuba diving
|
UK: BSAC members
|
1998?2009
|
75
|
14,000,000 dives
|
5 per dive
|
BSAC
[14]
|
UK: non-BSAC
|
1998?2009
|
122
|
12,000,000 dives
|
10 per dive
|
BSAC
[14]
|
US ? insured members of DAN
|
2000?2006
|
187
|
1,131,367 members
|
164 per year as member of DAN
5 per dive
|
DAN
[15]
p75
|
Paragliding
|
Turkey
|
2004?2011
|
18
|
242,355 flights
|
74 per launch
|
Canbek 2015
[16]
|
Skiing
|
US
|
2008/9
|
39
|
57,000,000 days skiing
|
0.7 per day
|
Ski-injury.com
[17]
[
unreliable source
]
|
Skydiving
|
US
|
2000?2016
|
413
|
48,600,000 jumps
|
8 per jump
|
USPA
[18]
|
UK
|
1994?2013
|
41
|
4,864,268 jumps
|
8 per jump
|
BPA
[19]
|
BASE jumping
|
Kjerag Massif, Norway
|
1995?2005
|
9
|
20,850 jumps
|
430 per jump
|
Soreide 2007
[20]
|
Mountaineering
|
Ascent to Matterhorn
|
1981?2011
|
213
|
about 75,000 ascents
(about 2500 per year)
|
about 2,840 per ascent attempt
|
Bachmann 2012
[21]
|
Ascent to Mt. Everest
|
1922?2012
|
223
|
5,656 successful ascents
|
37,932 per successful ascent
|
NASA 2013
[22]
|
Travel
[
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]
Activities that increase the death risk by roughly one micromort, and their associated cause of death:
Other
[
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]
Increase in death risk for other activities on a per-event basis:
- Hang gliding
? 8 micromorts per flight
[23]
- Ecstasy
(MDMA) ? 0.5 micromorts per tablet, rising to 13 if using other drugs
[26]
[27]
- Giving birth (
vaginal
) ? 120 micromorts
[28]
- Giving birth (
caesarean
) ? 170 micromorts
[28]
- AstraZeneca
vaccination against
COVID-19
? 2.9 micromorts
[29]
- COVID-19
infection at age 10 ? 20 micromorts
- COVID-19 infection at age 25 ? 100 micromorts
- COVID-19 infection at age 55 ? 4,000 micromorts
- COVID-19 infection at age 65 ? 14,000 micromorts
- COVID-19 infection at age 75 ? 46,000 micromorts
- COVID-19 infection at age 85 ? 150,000 micromorts (As of December 2020
[update]
)
[30]
Value of a micromort
[
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]
Willingness to pay
[
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]
An application of micromorts is measuring the value that humans place on risk. For example, a person can consider the amount of money they would be
willing to pay
to avoid a one-in-a-million chance of death (or conversely, the amount of money
they would receive to accept
a one-in-a-million chance of death). When offered this situation, people claim a high number. However, when looking at their day-to-day actions (e.g., how much they are willing to pay for safety features on cars), a typical value for a micromort is around $50 (in 2009).
[31]
[32]
This is not to say the $50 valuation should be taken to mean that a human life (1 million micromorts) is valued at $50,000,000. Rather, people are
less inclined to spend money after a certain point
to increase their safety. This means that analyzing risk using the micromort is more useful when using small risks, not necessarily large ones.
[32]
Value of a statistical life
[
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]
Government agencies use a nominal
Value of a Statistical Life
(VSL) ? or
Value for Preventing a Fatality
(VPF) ? to evaluate the cost-effectiveness of expenditure on safeguards. For example, in the UK, the VSL is £1 million
GBP
in 1997 value (equivalent to £2 million in 2023
[33]
).
[34]
Since road improvements have the effect of lowering the risk of large numbers of people by a small amount, the
UK Department for Transport
essentially prices a reduction of 1 micromort at £1.60. The
US Department of Transportation
uses a VSL of US$6.2 million, pricing a micromort at US$6.20.
[35]
Chronic risks
[
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]
Micromorts are best used to measure the size of
acute
risks, i.e. immediate deaths. Risks from lifestyle, exposure to air pollution, and so on are
chronic
risks, in that they do not kill straight away, but reduce life expectancy. Ron Howard included such risks in his original 1979 work,
[24]
for example, an additional one micromort from:
- Drinking 0.5 liter of
wine
(cirrhosis of the liver)
[24]
- Smoking
1.4 cigarettes (cancer, heart disease)
[24]
- Spending 1 hour in a coal mine (black lung disease)
[24]
- Spending 3 hours in a coal mine (accident)
[24]
- Living 2 days in New York or Boston in 1979 (air pollution)
[24]
- Living 2 months with a smoker (cancer, heart disease)
[24]
- Drinking Miami water for 1 year (cancer from chloroform)
[24]
- Eating 100 charcoal-broiled steaks (cancer from benzopyrene)
[24]
- Traveling 6000 miles (10,000 km) by jet (cancer due to increased background radiation)
[36]
Such risks are better expressed using the related concept of a
microlife
.
See also
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]
Notes
[
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]
References
[
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]
- ^
Fry, A.M.; Harrison, A.; Daigneault, M. (February 2016). "Micromorts - what is the risk?".
British Journal of Oral and Maxillofacial Surgery
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54
(2): 230?231.
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PMID
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Walker, KF; Cohen, AL; Walker, SS; Allen, KM; Baines, DL; Thornton, Jg (May 2014). "The dangers of the day of birth".
BJOG
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121
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Archived
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Archived
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KF Walker; AL Cohen; SH Walker; KM Allen; DL Baines; JG Thornton (13 February 2014). "The dangers of the day of birth".
British Journal of Obstetrics and Gynaecology
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121
(6). London:
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: 714?8.
doi
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.
cdc.gov
.
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Archived
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ISBN
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.
- ^
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.
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Archived
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- ^
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.
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Archived
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. Retrieved
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2015
.
- ^
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.
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.
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.
Archived
from the original on 29 May 2016
. Retrieved
12 June
2014
.
- ^
a
b
British Sub-Aqua Club.
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. Archived from
the original
on 28 July 2014
. Retrieved
12 June
2014
.
- ^
Divers Alert Network (DAN).
"Fatalities_Proceedings.pdf"
(PDF)
.
Archived
(PDF)
from the original on 16 January 2015
. Retrieved
12 June
2014
.
- ^
Canbek, Umut; Ahmet ?merci; Ula? Akgun; Murat Ye?il; Ali Aydin; Yasemin Balci (1 September 2015).
"Characteristics of injuries caused by paragliding accidents: A cross-sectional study"
.
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.
6
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doi
:
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.
PMC
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- ^
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. Archived from
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on 28 May 2014
. Retrieved
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2014
.
- ^
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.
Archived
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. Retrieved
10 April
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.
- ^
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. Retrieved
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2014
.
- ^
Soreide, Kjetil; Ellingsen, Christian Lycke; Knutson, Vibeke (May 2007). "How Dangerous is BASE Jumping? An Analysis of Adverse Events in 20,850 Jumps From the Kjerag Massif, Norway".
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doi
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.
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- ^
Bachmann, Stefan (September 2012).
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(PDF)
.
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(in German).
- ^
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.
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. NASA. 2 January 2014.
Archived
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. Retrieved
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a
b
c
d
e
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Archived
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. Retrieved
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.
- ^
a
b
c
d
e
f
g
h
i
j
k
* Howard, Ron
Risky Decisions
(Slide show), Stanford University
- ^
de Hartog, Jeroen Johan; Boogaard, Hanna; Nijland, Hans; Hoek, Gerard (August 2010).
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.
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.
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.
- ^
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. London:
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.
- ^
Blastland, Michael; Spiegelhalter, David (2014).
The Norm Chronicles: Stories and Numbers About Danger and Death
(1 ed.). Basic Books. p. 8.
ISBN
9780465085705
.
- ^
a
b
Spiegelhalter, David; Blastland, Michael (30 May 2013).
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(Main ed.). London: Profile Books.
ISBN
9781846686207
.
- ^
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.
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(in German).
Archived
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. Retrieved
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.
- ^
Levin AT, Hanage WP, Owusu-Boaitey N, Cochran KB, Walsh SP, Meyerowitz-Katz G (December 2020).
"Assessing the age specificity of infection fatality rates for COVID-19: systematic review, meta-analysis, and public policy implications"
.
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35
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.
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Creative Commons Attribution 4.0 International License
Archived
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UK
Retail Price Index
inflation figures are based on data from
Clark, Gregory (2017).
"The Annual RPI and Average Earnings for Britain, 1209 to Present (New Series)"
.
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- ^
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(PDF)
.
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. London:
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. January 2014. p. 6.
- ^
US Department of Transportation, "Treatment of the Economic Value of a Statistical Life in Departmental Analyses?2011 Interim Adjustment", 2011,
http://www.dot.gov/policy/transportation-policy/treatment-economic-value-statistical-life
Archived
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- ^
"Radiation dose issues and risk"
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. European Society of Radiology. Archived from
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.
Further reading
[
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External links
[
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]