Heat and Mortality (NHMRC project):

The aims are to characterise the heat-mortality relationship in Australia, project into the near future, and assess possible adaptations to minimise risk. Methods: regression modelling of mortality against weather, followed by systems modelling of local populations to evaluate adaptive strategies. Joint work with Monash Uni (Prof Neville Nichols, Margaret Loughnan); GP Peter Tait; PhD student Julie Ramsay.

People: Dr Keith Dear, Dr Liz Hanna, Dr Geoff Mercer

The Population Heat Exposure Profile (PHEP) project

This project aims to describe and project heat exposure at different times and in different locations around the world in order to estimate health impacts on working people and reductions in work productivity due to extreme heat in the workplace. The WBGT index of heat stress (Wet Bulb Globe Temperature, adopted as an international standard heat indicator) can be approximated from routine weather records, and has known relationships to reduced hourly work capacity in experimental situations. In collaboration with researchers in tropical countries, Hothaps field research (High Occupational Temperature Health and Productivity Suppression)  is carried out in order to seek further quantitative evidence of heat related impacts now and after further climate change.  This project will also  alternatives to WBGT, such as Apparent Temperature and the new UTCI index that claims to capture physiological heat stress more accurately.

People: Prof Tord Kjellstrom, Dr Keith Dear

Other internal contributors: Dr Liz Hanna, Charmian Bennett, A/Prof Sharon Friel

Collaboration with external researchers: Umea University, Sweden (Maria Nilsson, Rainer Sauerborn, Birgitta Evengard), University of Tromso, Norway (Jon Oyvind Odland), Nelson-Marlborough Institute of Technology, New Zealand (Bruno Lemke, Matthias Otto).

Optimisation of heatwave indices

A plethora of measures of “hot weather” exist, from simple routinely collected data such as daily maximum temperature to complex formula-based indices such as UTCI. Most have been devised to meet the needs of meteorologists and agriculturalists, and though some are designed with a more human focus (Apparent temperature; WBGT) there is little work that compares them objectively in relation to health outcomes. This project aims to identify the best index for this purpose, or if necessary to propose an evidence-based new one, and perhaps to suggest a suit of related indices that best predict risk to particular sub-populations such as the elderly or people with chronic conditions such as diabetes, renal insufficiency or hypertension.
People: Charmian Bennett, Dr Keith Dear

Modelling future heat-related risks (Garnaut updated)

Background: work done as input to the 2008 Garnaut Report involved estimating the U-shaped temperature-mortality curve separately for each major city and each state of Australia, and applying climate change scenario forecasts to project future deaths from cold and from heat throughout the country, allowing for demographic predictions (by ABS) of future populations profiles out to 2100. The work is being updated to use more sophisticated models of the geographical variation in response and of age-specific mortality in an ageing population.
People: Dr Keith Dear

Novel methods

Scenario-based risk estimation: calculations for the Garnaut report were done in Stata, a general-purpose statistics package. Special-purpose risk-modelling software (@Risk; Vensim; Anylogic) may be more flexible and powerful.

Future research

1. Hothaps Studies in Australia (NHMRC project application, 2011): Dr Liz Hanna, Prof Tord Kjellstrom, Dr Keith Dear, Prof Tony McMichael. This project plans to measure dehydration in Australian workers during hot summer days, and relate the levels of physiological stress to workplace conditions, practices and policies.
2. Long time-series of national mortality in relation to climate (Dr Keith Dear). This international collaboration includes Australia, the UK, South Korea, Taiwan and Japan, and aims to relate decadal trends in mortality to trends in climate using common methods agreed with each country.