Saving lives: How Important is the Time Factor Using Fire and - - PowerPoint PPT Presentation

Saving lives:

How Important is the Time Factor Using Fire and Rescue Services

• A statistical analysis!

Henrik Jaldell

Department of Economics Karlstad University

henrik.jaldell@kau.se

Economics

• Decision rule: If benefits outweigh costs go on with the project.
• Here: Should we try to reduce the response time?

– Benefits: Saved lives, reduced injuries, saved property value, reduced environmental damage – Investments cost money (not considered here) – Only saved lives considered in this study. – Only fires in residential homes (even if a reduction in response time affects all types of rescues) – No cost-benefit analysis (CBA) done in this study.

Benefits € Costs €

henrik.jaldell@kau.se

Background: The monetary value of fire and rescue service

responses (2004)

Type of rescue 5 minutes, Kronor Percent of responses % Weighted value Fires in buildings 137 800 22 30 900 Traffic accidents 86 200 25 21 500 Drowning 267 900 1 3 200 Fires other than buildings 5 000 34 1 700 Hazardous substances 3 900 4 150 Water 1 100 4 50 Landslides 14 200 0.2 25 Animals 800 2 15 Storms 250 2 5 Other rescues 26 300 6 1 500

Weighted sum

58 900

100 58 900

Values include

• Lives
• Injuries
• Property value
• Environmental

damage

henrik.jaldell@kau.se

Background: The monetary value of fire and rescue service

responses (2004)

Type of rescue 5 minutes, Kronor Percent of responses % Weighted value Fires in buildings 137 800 22 30 900

• lives and personal injuries

residential homes

6 000

1300 Traffic accidents 86 200 25 21 500 Drowning 267 900 1 3 200 Fires other than buildings 5 000 34 1 700 Hazardous substances 3 900 4 150 Water 1 100 4 50 Landslides 14 200 0.2 25 Animals 800 2 15 Storms 250 2 5 Other rescues 26 300 6 1 500

Weighted sum

58 900

100 58 900

Values include

• Lives
• Injuries
• Property value
• Environmental

damage

Time, definition

Time, theoretical relationship

”Marginal effect”

henrik.jaldell@kau.se

Data

• Focuses on residential homes (incl. nursing homes) in

Sweden, which are where 3/4 of all fatalities due to fires happen.

• Uses data from the fire and rescue services response

reports for nine years, 2005-2013.

• 51998 reports with 630 fatalities (0.012 per turn-out)
• (NB. not all fatalities in fires registered by the fire and

rescue service, about 20% missing)

Result.

Statistically estimated relation. Response time → Risk of fatality.

Risk of fatality Response time, seconds Fires in residential homes

Results, Marginal effects

• There are 5800 turn-outs per year to residential homes.
• A one minute decreased response time would then lead to a 2.8% reduction of

the fatalities.

Marginal effect i.e. how many lives are saved per minute Per response and minute Lives saved per year if response time reduced by

• ne minute

At 1 minute 0.00156 At 2.5 minutes 0.00078 At 5 minutes 0.00046 At 10 minutes 0.00027 At 20 minutes 0.00016 At mean (=570 seconds) 0.00032

1.9

At median (=480 seconds) 0.00027

1.6

Results – Type of building

Blocks of flats Detached houses Semi- detached/ terraced houses Summer/ winter houses Nursing homes

No of turn-outs per year 2 490 2 310 170 210 230 Percent of turn-outs with fatalities

1.1 % 1.1 % 1.4 % 1.0 % 0.5 %

Median response time, seconds 380 660 460 900 390 Marginal effect, lives saved per minute at median

0.00047 0.00024 0.00034 0.00020 0.00038

Lives saved per year if response time reduced by one minute

1.20 0.60 0.06 0.06 0.10

Results – Starting reason

Percent

• f

fatalities Mean no.

• f

fatalities

Overall

100 % 0.012

Unknown

61.9 % 0.042

Smoking

14.9 % 0.045

With intention (Arson)

5.9 % 0.009

Stove

4.0 % 0.003

Technical failure

3.0 % 0.004

Heat transfer

1.9 % 0.004

Candlelight

1.6 % 0.006

Sparks

1.4 % 0.011

Explosion

0.6 % 0.046

Children playing

0.5 % 0.007

Chimney fire

0.2 % 0.0001

Other

4.0 % 0.005

Results – Starting reason

Percent

• f

fatalities Mean no.

• f

fatalities

Overall

100 % 0.012

Unknown

61.9 % 0.042

Smoking ***

14.9 % 0.045

With intention (Arson) ***

5.9 % 0.009

Stove

4.0 % 0.003

Technical failure

3.0 % 0.004

Heat transfer

1.9 % 0.004

Candlelight

1.6 % 0.006

Sparks

1.4 % 0.011

Explosion

0.6 % 0.046

Children playing

0.5 % 0.007

Chimney fire

0.2 % 0.0001

Other

4.0 % 0.005 *** = Response time has statistical significant larger marginal effect

Conclusions:

• Every year there are about 6 000 turn-outs to residential homes in

Sweden, and about 90 fatalities.

• Assume the response time could be reduced by 1 minute on

average (Average today = 9.4 minuter)

– The statistically estimated curve indicates that this could save 2 lives per year.

• Largest marginal effect in blocks of flats
• Largest marginal effect for fires caused by smoking or with intention
• Small changes in response time would result in small changes in risk of fatalities.

– To reduce fatalities from fires perhaps concentrate on other things (i.e. more cost efficient)

• However, large changes in response time could result in large changes in risk of

fatalities.

– Example: 30 min → 8 min reduces risk of fatality by 25 %!

• Results indicated that the response time is about 3 times more important in this study than in

Jaldell (2004).

• Published as: Jaldell, H. (2017) How Important is the Time Factor? Saving Lives Using Fire and

Rescue Services, Fire Technology, 53(2):695-708, https://doi.org/10.1007/s10694-016-0592-4 henrik.Jaldell@kau.se