simtars shiftwork at burton mine © simtars 2000. objectives of project determine alertness levels...

SIMTARS

SHIFTWORK AT BURTON MINE

© SIMTARS 2000

Objectives of Project

• Determine alertness levels during work periods

• Sleep quantity and quality during home and work periods

• Factors affecting fatigue including: – job activity, alcohol, exercise, caffeine,

medication, environmental factors

© SIMTARS 2000THIESS


Data Collection - Part 1

• Lifestyle Questionnaire• Demographic and background information;

• Food and drink, including alcohol usage;

• Activity and exercise;

• Smoking status;

• Drug usage including medication, sleeping pills, recreational or illegal drugs;

• Work environment.

– 145 responses



• Sleep logs– Sleep ruler– Sleep scale– Sleep factors

questions

• Alertness logs– Time– Break– Activity– Environment– Rating of shift


Data Collection - Part 2SLEEP RULER/ SLEEP SCALE/ SLEEP FACTORS QUESTIONS FOR WORK PERIODS

MARK WITH AN "X" THE TIME YOU WENT ASLEEP; MARK WITH A " " THE TIME YOU WOKE UP.

10 11 12

Midnight

Evening Morning Afternoon

Noon

1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9

USING THE SCALE BELOW, HOW WOULD YOU RATE YOUR LAST MAJOR SLEEP (PLACE AN "X´ON THE SCALE)

DATE OF SLEEP:

1 2 3 4 5 6 7 8 9 10very restless sometimes restless sound sleep

PLEASE ANSWER THE FOLLOWING QUESTIONS WHEN YOU WAKE FROM YOUR LAST MAJOR SLEEP

I consumed 'x'amount caffeinateddrinks(cola, coffeeetc) in the

Approximately 2-3 hrsbefore going to bed, Iconsumed:

I exercised at least 20minutes

Medication(s) I took -(list the name of medications/timeeg 2 x Panadol at 7am)

My sleep last night wasdisturbed by:

record numberbeside time of day

Morning _____

Afternoon ____

About 2-3 hrs beforegoing to bed _____

Not applicable ____

Alcohol_________record number

Heavy Meal

Not Applicable

tick appropriate time

Before work

After work

About 2-3 hrs beforegoing to bed

Not applicable


Data Collection - Part 2ALERTNESS SCALE Date Shift Commenced………………….

Feeling Active, alert or wide awake…………………………………….…. (1)

Functioning at high levels but not at your peak, able to concentrate…….…(2)Awake but relaxed; responsive but not fully alert………………………….(3)Somewhat foggy, let down…………………………………………………(4)Sleepy woozy fighting sleep prefer to lie down………………...………….(5)

HOURS BREAK( )

ACTIVITY(eg driving)

ENVIRONMENT(eg hot , air conditioned, noisy)

ALERTNESS(use scale)

0600

0700

0800

0900

1000

*****

0400

0500

Was this shift: Easy Physical Stressful



• FIT2000 Measurements– Some measurements relate to fatigue

– Compare before and after shift to subjective alertness scales

– Readings taken at end of shift only


Results - Part 1Demographics

• Number of Males - 133• Number of Females - 10• Undecided - 2

Workgroup Average Age Time in Mining Industry

(years) (years)

Production 39 7.4

Maintenance 38 4.0

CPP 34 7.5

Administration 34 5.7

Management 43 7.5

Other 39 2.7

The average age of all work groups at Burton mine is 38 years.


Results - Part 1Alcohol Consumption

Alcohol intake Home Work

More than 4 standarddrinks per day 39% 15%

Persons drinking onmore than 5 days perweek

11%


Part 1 - Results

• Food – No major differences in terms of unsaturated

fats, fruit and vegetables, grains and cereals

• Exercise– More workers exercise at home

– If regular exercisers, maintain this at work


Part 1 - Results

• Smoking– 35% of workers still regularly smoke– 25% have never smoked

• Medication– very few use medication regularly (5)– 7 use sleeping pills when working night shift


Part 1 - ResultsWork environment and shift system

• 75% - happy with shift arrangements

• ~10% - problems balancing • Shiftwork

• Family commitments

• Work performance

May have an important

effect on safety!

All Workers - Problems with Shiftwork

0

5

10

15

20

25

30

% o

f R

esp

on

ses

Sleep Family Social Work Performance


Limitations of Data

• Total of 199 log books completed - small number for third period

• Some log books only partially completed

• Results based on aggregated data and individuals may differ significantly


Part 2 - ResultsSleep Logs

5

6

7

8

9

Day Shift NightShift

Home

Sleep Quantity (hours)Sleep Quality


Results - Part 2Sleep Logs

• Alcohol

• Medication

• Exercise

• Caffeine Consumption

• Environmental Factors


"A" CREW ALERTNESS

0

1

2

3

4

6AM 9AM 12PM 3PM 6PM 9PM 12AM 3AM

TIME

AL

ER

TN

ES

S

SC

AL

E

MEAN ALERTNESS ("A" CREW - DAY SHIFT)

MEAN ALERTNESS ("A" CREW - NIGHT SHIFT)

DAY SHIFT - LESS ONE STD DEV

DAY SHIFT - PLUS ONE STD DEV

NIGHT SHIFT - LESS ONE STD DEV

NIGHT SHIFT - PLUS ONE STD DEV

Results - Part 2Alertness Logs


"B" CREW (NIGHT SHIFT) ALERTNESS PER SHIFT

1

2

3

6PM 7PM 8PM 9PM 10PM 11PM 12AM 1AM 2AM 3AM 4AM 5AMTIME

AL

ER

TN

ES

S S

CA

LE

MEAN ALERTNESS ("B" CREW - NIGHT SHIFT - DAY 1 )




"B" CREW (DAY SHIFT) ALERTNESS PER SHIFT

1

2

3

6AM 7AM 8AM 9AM 10AM 11AM 12PM 1PM 2PM 3PM 4PM 5PM 6PMTIME

AL

ER

TN

ES

S S

CA

LE

MEAN ALERTNESS ("B" CREW - DAY SHIFT - DAY 1 )






ALL CREW DAY SHIFTBREAK TIMES

0

20

40

60

600

700

800

900

1000

1100

1200

1300

1400

1500

1600

1700

1800

Time of Breaks

Nu

mb

er

of

Bre

ak

s

A B C D

ALL CREWS - NIGHT SHIFTBREAK TIMES

0

20

40

60

1800 1900 2000 2100 2200 2300 2400 100 200 300 400 500 600

Time of Breaks

Nu

mb

er

of

Bre

ak

s

A B C D



% of Responses

Shift Easy Physical Stressful

Day 54% 24% 22%

Night 32% 32% 36%

First day shift was the most stressful Third night was most stressful



Results - Part 3FIT2000 Measurements

• Average alertness levels at start of shift correlated with saccadic velocity for day shift but not night shift

• Length of sleep correlated with constriction latency for night shift but not day shift

• Quality of sleep not significantly correlated


Summary

• Lifestyle factors such as food intake and exercise not different to home

• Reduced alcohol consumption during work periods

• 75% are happy with shift arrangements but 10% adversely affected by shiftwork and the effect on safety may be significant


Summary

• Sleep quantity and quality on night shift reduced - significant sleep debt unlikely

• Caffeine, alcohol or exercise did not affect the quantity or quality of sleep

• Small number of reported uses of medication and environmental disturbances - effect not determined– Site level unlikely to be problem– Individual level needs consideration and management


Summary

• Alertness levels fall over night shift more rapidly than during the day shift

• Alertness level at the end of night shift is lower

• Considerable individual variation in the alertness levels reported

• The timing of breaks important and different on day and night shifts


Summary

• Workers find working the night shift more stressful than working the day shift

• The limitations of data prevented determining effect of change of activity/ environmental factors

• Effective site management of fatigue at Burton - individual worker need management at an individual level


Conclusions

• Education and information programs at individual level should continue - diet and exercise for general health – important for the 10% having difficulties

• High standard of accommodation and catering for quantity and quality of sleep

• Flexibility when scheduling breaks


Conclusions

• Scheduling - – lowered alertness levels at the end of each night shift

– effect of unfavourable environmental conditions

– time in unfavourable conditions or high levels of concentration should be scheduled during times of higher alertness

• Fitness for duty testing - part of shiftwork management


Thank you!

• Murray Wiggins - DME

• Workers and Management at Burton Mine

simtars shiftwork at burton mine © simtars 2000. objectives of project determine alertness levels...

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