Geographical variation in risk of work-related injuries and illnesses associated with ambient temperatures: A multi-city case-crossover study in Australia, 2005-2016

Background: The thermal working environment can have direct and in-direct effects on health and safety. Ambient temperatures have been associated with an increased risk of occupational injuries but it is unknown how the relationship can vary by weather, location and climate. Objectives: To examine the relationship between ambient temperatures and work-related injury and illness compensation claims in three Australian cities: Melbourne and Perth (temperate climate) and Brisbane (subtropical climate) in order to determine how hot and cold weather influences the risk of occupational injury in Australia. Methods: Workers' compensation claims from each city for the period 2005 to 2016 were merged with local daily weather data. A time-stratified case-crossover design combined with a distributed lag non-linear model was used to quantify the impacts of daily maximum temperature (T-max) on the risk of work-related injuries and illnesses. Results: Compared to the median maximum temperature (T-max), extremely hot temperatures (99th percentile) were associated with a 14% (95% CI: 3-25%) increase in total workers' compensation claims in Melbourne, but there were no observed effects in Brisbane or Perth, with the exception of traumatic injuries that increased by 17% (95% CI: 3-35%) during extreme heat in Perth. For extremely low temperatures (1st percentile), there was a protective effect in Brisbane (RR 0.89; 95% CI: 0.81-0.98), while no effects were observed in Melbourne or Perth. Conclusion: The relationship between injury and ambient temperature appears to be variable depending on location and climate. In general, work-related injuries and illnesses appear to be more common at higher temperatures than lower temperatures. Adopting adaptation and prevention measures could reduce the social and economic burden of injury, and formulating effective measures for dealing with high temperatures should be prioritised given the predicted increase in the frequency and intensity of hot weather. (C) 2019 Elsevier B.V. All rights reserved.