Kjellstrom T

Background: Social and environmental changes have accompanied the ongoing rapid urbanisation in a number of countries during recent decades. Understanding of its role in the health-risk transition is important for health policy development at national and local level. Thailand is one country facing many of the health challenges of urbanisation. Objective: To identify potential associations between individual migration between rural and urban areas and exposure to specific social, economic, environmental and behavioural health determinants.

Global climate change is progressing and health impacts have been observed in a number of countries, including Australia. The main health impacts will be due to direct heat exposure, extreme weather, air pollution, reduced local food production, food- and vectorborne infectious diseases and mental stress. The issue is one of major public health importance. Adaptation to reduce the effects of climate change involves many different sectors to minimise negative health outcomes. Wide-scale mitigation is also required, in order to reduce the effects of climate change.

Although health has improved for many people, the extent of health inequities between and within countries is growing. Meanwhile, humankind is disrupting the global climate and other life-supporting environmental systems, thereby creating serious risks for health and wellbeing, especially in vulnerable populations but ultimately for everybody.

While climate change continues to increase ambient temperatures, the resulting heat stress exposure to workers in non-climate controlled settings is not well characterized, particularly in low and middle income countries. This preliminary report describes current heat stress in Nica-raguan work places and estimates occupational heat stress in 2050. From over 400 measurements of heat exposure using wet bulb globe temperature, more than 10% of all measurements exceeded the safety threshold for the combination of light work and rest at the ratio of 25:75.

A feature of climate impacts on occupational health and safety are physiological limits to carrying out physical work at high heat exposure. Heat stress reduces a workers work capacity, leading to lower hourly labour productivity and economic output. We used existing weather sta-tion data and climate modeling grid cell data to describe heat conditions (calculated as Wet Bulb Globe Temperature, WBGT) in South-East Asia.

The WBGT heat stress index has been well tested under a variety of climatic conditions and quantitative links have been established between WBGT and the work-rest cycles needed to prevent heat stress effects at the workplace. While there are more specific methods based on indi-vidual physiological measurements to determine heat strain in an individual worker, the WBGT index is used in international and national standards to specify workplace heat stress risks.

The ‘high occupational temperature health and productivity suppression’ programme (Hothaps) is a multicentre health research and prevention programme aimed at quantifying the extent to which working people are affected by, or adapt to, heat exposure while working, and how global heating during climate change may increase such effects. The programme will produce essential new evidence for local, national and global assessment of negative impacts of climate change that have largely been overlooked.

More than half of the global population now live in urban settings. Urbanization can and should be beneficial for health. In general, nations with high life expectancies and low infant mortality rates are those where city governments address the key social determinants of health.