Some Crucial Issues Concerning the Safety Provided by Occupational Health Standards

Traditionally occupational health standards for chemicals and other hazards in the workplace have been established by "expert committees" with no involve1nent of the victims of the effects of the hazards, namely the workers themselves. This has led to standards that do not protect workers against all ill effects. The example of trichloroethylene is typical. The New Zealand standard lags behind the World Health Organisation and Swedish standards. Workers have a moral right to be involved in the standard setting and the enforcement procedures. The crucial issue for them is the definition of the "acceptable risk" for a particular hazard, as they are putting their own health at stake. It is 34 years since Sweden established the system of workers health and safety representatives in all workplaces and in government agencies dealing with occupational health. Maybe it is time for New Zealand to follow this example

Workplace heat stress, health and productivity – an increasing challenge for low and middle-income countries during climate change

BACKGROUND Global climate change is already increasing the average temperature and direct heat exposure in many places around the world. OBJECTIVES To assess the potential impact on occupational health and work capacity for people exposed at work to increasing heat due to climate change. DESIGN A brief review of basic thermal physiology mechanisms, occupational heat exposure guidelines and heat exposure changes in selected cities. RESULTS In countries with very hot seasons, workers are already affected by working environments hotter than that with which human physiological mechanisms can cope. To protect workers from excessive heat, a number of heat exposure indices have been developed. One that is commonly used in occupational health is the Wet Bulb Globe Temperature (WBGT). We use WBGT to illustrate assessing the proportion of a working hour during which a worker can sustain work and the proportion of that same working hour that (s)he needs to rest to cool the body down and maintain core body temperature below 38 degrees C. Using this proportion a 'work capacity' estimate was calculated for selected heat exposure levels and work intensity levels. The work capacity rapidly reduces as the WBGT exceeds 26-30 degrees C and this can be used to estimate the impact of increasing heat exposure as a result of climate change in tropical countries. CONCLUSIONS One result of climate change is a reduced work capacity in heat-exposed jobs and greater difficulty in achieving economic and social development in the countries affected by this somewhat neglected impact of climate change.The research was supported by funds from the Australian National University and Lund University

The association between overall health, psychological distress, and occupational heat stress among a large national cohort of 40,913 Thai workers

BACKGROUND Occupational heat stress is a well-known problem, particularly in tropical countries, affecting workers, health and well-being. There are very few recent studies that have reported on the effect of heat stress on mental health, or overall health in workers, although socioeconomic development and rapid urbanization in tropical developing countries like Thailand create working conditions in which heat stress is likely. OBJECTIVE This study is aimed at identifying the relationship between self-reported heat stress and psychological distress, and overall health status in Thai workers. RESULTS 18% of our large national cohort (>40,000 subjects) often works under heat stress conditions and males are exposed to heat stress more often than females. Furthermore, working under heat stress conditions is associated with both worse overall health and psychological distress (adjusted odds ratios ranging from 1.49 to 1.84). CONCLUSIONS This association between occupational heat stress and worse health needs more public health attention and further development on occupational health interventions as climate change increases Thailand's temperatures.This study was supported by the International Collaborative Research Grants Scheme with joint grants from the Wellcome Trust UK (GR0587MA) and the Australian NHMRC (268055)

Impact of climate change on occupational health and productivity: a systematic literature review focusing on workplace heat

Background: With climate change, mean annual air temperatures are getting hotter and extreme weather events will become more and more common in most parts of the world. Objectives: As part of the EU funded project HEAT-SHIELD we conducted a systematic review to summarize the epidemiological evidence of the effects of global warming-related heat exposure on workers’ health and productivity. Methods: Three separate searches, focused, respectively, on: i) heat-related illness (HRI), cardiovascular, respiratory and kidney diseases; ii) traumatic injuries; and iii) vector-borne diseases or vectors distribution, were conducted in PubMed. EMBASE was also consulted to retrieve relevant studies focused on the health effects of climate change. A fourth search strategy to assess the effects on work productivity was conducted both in PubMed and in the SCOPUS database. Results: A significant proportion of studies reported findings regarding the Mesoamerican nephropathy issue. This is a disease occurring especially among young and middle-aged male sugarcane workers, without conventional risk factors for chronic kidney disease. For injuries, there is a reversed U-shaped exposure-response relationship between Tmax and overall daily injury claims. Outdoor workers are at increased risk of vector-borne infectious diseases, as a positive correlation between higher air temperatures and current or future expansion of the habitat of vectors is being observed. As for productivity, agriculture and construction are the most studied sectors; a day with temperatures exceeding 32°C can reduce daily labour supply in exposed sectors by up to 14%. Conclusions: The present findings should inform development of further research and related health policies in the EU and beyond with regard to protecting working people from the effects of workplace heat during climate change.This study has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 668786, as part of the Project “HEATSHIELD - Integrated inter-sector framework to increase the thermal resilience of European workers in the context of global warming”

Implications for workability and survivability in populations exposed to extreme heat under climate change: A modelling study

Background: Changes in temperature and humidity due to climate change affect living and working conditions. An understanding of the effects of different global temperature changes on population health is needed to inform the continued implementation of the Paris Climate Agreement and to increase global ambitions for greater cuts in emissions. By use of historical and projected climate conditions, we aimed to investigate the effects of climate change on workability (ie, the ability to work) and survivability (the ability to survive). Methods: In this modelling study, we estimated the changes in populations exposed to excessive heat stress between the recent past (ie, 1986–2005) and 2100. We used climate data from four models to calculate the wet-bulb globe temperature, an established heat exposure index that can be used to assess the effects of temperature, humidity, and other environmental factors on humans. We defined and applied thresholds for risks to workability (where the monthly mean of daily maximum wet-bulb globe temperature exceeds 34°C) and survivability (where the maximum daily wet-bulb globe temperature exceeds 40°C for 3 consecutive days), and we used population projections to quantify changes in risk associated with different changes to the global temperature. Findings: The risks to workability increase substantially with global mean surface temperature in all four climate models, with approximately 1 billion people affected globally after an increase in the global temperature of about 2·5°C above pre-industrial levels. There is greater variability between climate models for exposures above the threshold for risks to survivability than for risks to workability. The number of people who are likely to be exposed to heat stress exceeding the survivability threshold increases with global temperature change, to reach around 20 million people globally after an increase of about 2·5°C, estimated from the median of the models, but with a large model uncertainty. More people are likely to be exposed to heat stress in urban than in rural areas. Population exposure can fluctuate over time and change substantially within one decade. Interpretation: Exposure to excessive heat stress is projected to be widespread in tropical or subtropical low-income and middle-income countries, highlighting the need to build on the Paris Agreement regarding global temperature targets, to protect populations who have contributed little to greenhouse gas emissions. The non-linear dependency of heat exposure risk on temperature highlights the importance of understanding thresholds in coupled human-climate systems

The ‘Hothaps’ programme for assessing climate change impacts on occupational health and productivity: an invitation to carry out field studies

The ‘high occupational temperature health and productivity suppression’ programme (Hothaps) is a multi-centre 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. It will also identify and evaluate preventive interventions in different social and economic settings

Climate projections of a multivariate heat stress index: the role of downscaling and bias correction

Along with the higher demand for bias-corrected data for climate impact studies, the number of available data sets has largely increased in recent years. For instance, the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP) constitutes a framework for consistently projecting the impacts of climate change across affected sectors and spatial scales. These data are very attractive for any impact application since they offer worldwide bias-corrected data based on global climate models (GCMs). In a complementary way, the CORDEX initiative has incorporated experiments based on regionally downscaled bias-corrected data by means of debiasing and quantile mapping (QM) methods. In light of this situation, it is challenging to distil the most accurate and useful information for climate services, but at the same time it creates a perfect framework for intercomparison and sensitivity analyses. In the present study, the trend-preserving ISIMIP method and empirical QM are applied to climate model simulations that were carried out at different spatial resolutions (CMIP5 GCM and EURO-CORDEX regional climate models (RCMs), at approximately 150, 50 and 12 km horizontal resolution) in order to assess the role of downscaling and bias correction in a multivariate framework. The analysis is carried out for the wet-bulb globe temperature (WBGT), a heat stress index that is commonly used in the context of working people and labour productivity. WBGT for shaded conditions depends on air temperature and dew-point temperature, which in this work are individually bias corrected prior to the index calculation. Our results show that the added value of RCMs with respect to the driving GCM is limited after bias correction. The two bias correction methods are able to adjust the central part of the WBGT distribution, but some added value of QM is found in WBGT percentiles and in the inter-variable relationships. The evaluation in present climate of such multivariate indices should be performed with caution since biases in the individual variables might compensate, thus leading to better performance for the wrong reason. Climate change projections of WBGT reveal a larger increase in summer mean heat stress for the GCM than for the RCMs, related to the well-known reduced summer warming of the EURO-CORDEX RCMs. These differences are lowered after QM, since this bias correction method modifies the change signals and brings the results for the GCM and RCMs closer to each other. We also highlight the need for large ensembles of simulations to assess the feasibility of the derived projections.This research has been supported by the European Commission (HEAT-SHIELD (668786))

Associations between urbanisation and components of the health-risk transition in Thailand. A descriptive study of 87,000 Thai adults

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. DESIGN: Baseline data from a cohort of 87,134 Thai open university students surveyed in 2005 (mean age 31 years). Four urbanisation status groups were defined according to self-reported location of residence (rural: R or urban: U) in 2005 and when the respondent was 10 12 years old (yo). RESULTS: Fourty-four percent were living in rural areas in 2005 and when they were 10 12yo (Group RR: ruralites); 20% always lived in urban areas (UU: urbanites); 32% moved from rural to urban areas (RU: urbanisers); 4% moved in the other direction (UR: de-urbanisers). The ruralites and urbanites often were the two extremes, with the urbanisers maintaining some of the determinants patterns from ruralites and the deurbanisers maintaining patterns from urbanites. There was a strong relationship between urbanisation status, from RR to RU to UR to UU, and personal income, availability of modern home appliances, car ownership, consumption of ‘junk food’ and physical inactivity. Urbanisers reported worse socio-environmental conditions and worse working conditions than the other groups. De-urbanisers had the highest rates of smoking and drinking. CONCLUSIONS: An urbanisation measure derived from self-reported location of residence gave new insights into the health risk exposures of migrants relative to permanent rural and permanent urban dwellers. Living in urban areas is an important upstream determinant of health in Thailand and urbanisation is a key element of the Thai health-risk transition