Download - Heat stress and well-being impact
““HEAT STRESS, HEALTH AND WELLBEING:HEAT STRESS, HEALTH AND WELLBEING: FINDINGS FROM A LARGE NATIONAL FINDINGS FROM A LARGE NATIONAL
COHORT OF THAI ADULTS”COHORT OF THAI ADULTS”Benjawan Tawatsupa1 ,
Vasoontara Yiengprugsawan2, Tord Kjellstrom3, Sam-ang Seubsman4, Adrian Sleigh2
1Department of Health, MOPH, Thailand2National Centre for Epidemiology and Population Health, ANU, Australia,
3Centre for Global Health Research, Umeå University, Sweden,4Nonthaburi, School of Human Ecology, Sukhothai Thammathirat Open University, Thailand,
Area 5: Social, Environmental and Cultural Issues in Health Promotion26 August 2013
Heat stress in Thailand Tropical developing country: 65 M population
Rapid urbanization: 40% in urban areas (60% in 2030)
High average temperature: 28-30 °C
High relative humidity: 80-90%
Rising temperature By 0.74°C (from 1950 to 2007) (Limjirakan, 2008)
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Annual average of daily maximum temperature 1980-2090Source: SEA START RC, 2009
Objective: To examine the association between heat stress interference with
daily activities and health & well-being
Climate Change
Human exposure
HealthImpacts
Well-beingOverall life satisfaction
HeatStress
Physical health:Energy level
Socioeconomic status & Individual behaviour
(age, sex, marital status, work status, education, income, urban-rural residence, exercise, housework, hours of sleep,
BMI, smoking , and drinking)
Mental Health:Emotional problems
Daily activities: Sleeping Work Daily travel Housework Exercise
Health & wellbeing impacts
MethodsData from a large national Thai Cohort Study (TCS) of distance-
learning open-university adult students aged 15-87 years in 2009 (N=60,569)
Researching the health-risk transition in the Thai population (Sleigh et al, 2008)
Cross-sectional study using multinomial logistic regression analysis and adjusting for a wide array of potential confounders
For each health outcome, we report Odds Ratios (ORs) and 95% confidence intervals
Daily activities and heat interference category
Daily activities
N = 60,569
Heat interference (%)
Not applicable* Never Sometimes Often
Daily travel 3.0 33.7 25.8 37.5Work 14.0 30.3 21.2 34.5Housework 1.3 37.1 31.7 29.9Sleeping 15.7 24.3 32.5 27.4Exercise 0.8 43.1 30.1 25.9*e.g. Use air conditioning
Results
Health and wellbeing outcomes
Overall life satisfaction (score ranged from 0-10) %
9-10 very satisfied (highest) 37.68 (high) 28.86-7 (medium) 21.70-5 not very satisfied (low) 12.0
Energy level %
very much 14.9quite a lot 44.0some 32.0a little or none 9.1
Emotional problems %
not at all 11.3slightly 48.4moderately 25.8quite a lot/extremely 14.5
Daily activities and heat interference category
Adju
sted
Odd
s Ra
tios
Association between heat interference with daily activities and low energy level
Daily activities and heat interference category
Adju
sted
Odd
s Ra
tios
Association between heat interference with daily activities and worse emotional problems
Daily activities and heat interference category
Adju
sted
Odd
s Ra
tios
Association between heat interference with daily activities and low life satisfaction
ResultsNegative health and wellbeing outcomes associated
with increasing frequency of heat stress interfering with daily activities.Worse emotional problems (adj.ORs 1.5 - 4.8)Low energy level (adj.ORs 1.3 - 2.9)Low life satisfaction (adj.ORs 1.1- 2.5)
Adverse health outcomes were when heat stress interfered with Sleeping > daily travel > work > housework > exercise.
Limitations of this study1) Cannot prove that adverse health outcomes occurred at the
same time as the heat stress
2) Difficulties in interpreting causality between heat stress and health outcomes
3) we were not able to make direct measurement of environments or health outcomes - Must classify this study as preliminary in nature- Further studies are needed for more detailed direct observations
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ConclusionsIn tropical Thailand, there already are substantial
heat stress impacts on health and wellbeing
Increasing temperatures from climate change as well as the growing urban population could significantly worsen the situation
Results from this study point to the need for Improved public health surveillance & public awareness
regarding the risks of heat stress in daily life
Thank you• National Centre for Epidemiology
and Population Health, ANU,
Australia
• The Thai Cohort Study team (TCS)
• The ‘High occupational temperature
health and productivity suppression'
programme (Hothaps)
• Department of Health, Ministry of
Public Health, Thailand
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Heat lossCooling by Evaporation
Na+Cl-
H2OH2O
H
Heat gainFrom internal heat source
(Physical activity)
Heat gainFrom external heat source
(Environment)
"Heat stress" (ACGIH, 2008)
Overall heat burden on the body from the combination of:
Body heat generated
Environmental sources Air temperature Humidity Air movement Radiation from the sun or hot
surfaces/sources
Clothing requirements
Background
Motorcyclists were using any shade they could find to get through one of the hottest days in April 2012.
(Ainakul, Bangkok post 21/04/2012)
Heat stress interfered with daily travel
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Why heat stress is interesting:
1) Worldwide interest but insufficient evidence on heat stress & health outcomes in Thailand
2) Heat stress is already a problem in tropical countries
3) Rising temperature may influence the future pattern of deaths or illness
What we know:
1) Increasing temperature in Thailand already occurring (Limjirakan, 2008)
2) The effects of daily heat stress exposure can have a major influence on human daily activities but there is limited information regarding the impact on overall health and wellbeing
What we do not know (research questions):
1) If temperature increases over time, are there any impacts of heat stress on overall health and wellbeing?
Aim: To examine the association between heat stress interference with daily activities and health and wellbeing outcomes
Research questions & Aim of study
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1) Access to a large national cohort (TCS) Represents well the Thai population for geographic location, age,
and socioeconomic status for both sexes
2) Epidemiologic results remained statistically significant When adjusted for a variety of potential explanatory variables
3) Self-reported heat stress was unlikely to be biased Questionnaires included a substantial number of questions on
different exposures and health outcomes Respondents would not be aware of any connection to health
outcomes & would not benefit by over or under reporting
Strengths of this study
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