"A Widespread Superstition": The Purported Invulnerability of Workers of Color to Occupational Heat Stress.

This study explores the history of the denial of the vulnerability of non-White workers to risks of heat illness. Defenders of chattel slavery argued for the capacity of workers of African descent to tolerate extreme environmental temperatures. In Hawai'i, advocates of racial segregation emphasized the perils to Whites of strenuous work in tropical climates and the advantages of using Chinese immigrants. Growing reliance on Mexican immigrants in agriculture and other outdoor employment in the early 20th century brought forth claims of their natural suitability for unhealthful working conditions. These efforts to naturalize racial hierarchy fell apart after 1930. The Great Depression subverted the notion that people of European descent could not endure hot work. More rigorous investigation refuted contentions of racial difference in heat tolerance.

The relation between temperature, ozone, and mortality in nine French cities during the heat wave of 2003.

BACKGROUND: During August 2003, record high temperatures were observed across Europe, and France was the country most affected. During this period, elevated ozone concentrations were measured all over the country. Questions were raised concerning the contribution of O3 to the health impact of the summer 2003 heat wave. METHODS: We used a time-series design to analyze short-term effects of temperature and O3 pollution on mortality. Counts of deaths were regressed on temperatures and O3 levels, controlling for possible confounders: long-term trends, season, influenza outbreaks, day of the week, and bank holiday effects. For comparison with previous results of the nine cities, we calculated pooled excess risk using a random effect approach and an empirical Bayes approach. FINDINGS: For the nine cities, the excess risk of death is significant (1.01% ; 95% confidence interval, 0.58-1.44) for an increase of 10 microg/m3 in O3 level. For the 3-17 August 2003 period, the excess risk of deaths linked to O3 and temperatures together ranged from 10.6% in Le Havre to 174.7% in Paris. When we compared the relative contributions of O3 and temperature to this joint excess risk, the contribution of O3 varied according to the city, ranging from 2.5% in Bordeaux to 85.3% in Toulouse. INTERPRETATION: We observed heterogeneity among the nine cities not only for the joint effect of O3 and temperatures, but also for the relative contribution of each factor. These results confirmed that in urban areas O3 levels have a non-negligible impact in terms of public health.

Declining vulnerability to temperature-related mortality in London over the 20th century.

The degree to which population vulnerability to outdoor temperature is reduced by improvements in infrastructure, technology, and general health has an important bearing on what realistically can be expected with future changes in climate. Using autoregressive Poisson models with adjustment for season, the authors analyzed weekly mortality in London, United Kingdom, during four periods (1900-1910, 1927-1937, 1954-1964, and 1986-1996) to quantify changing vulnerability to seasonal and temperature-related mortality throughout the 20th century. Mortality patterns showed an epidemiologic transition over the century from high childhood mortality to low childhood mortality and towards a predominance of chronic disease mortality in later periods. The ratio of winter deaths to nonwinter deaths was 1.24 (95% confidence interval (CI): 1.16, 1.34) in 1900-1910, 1.54 (95% CI: 1.42, 1.68) in 1927-1937, 1.48 (95% CI: 1.35, 1.64) in 1954-1964, and 1.22 (95% CI: 1.13, 1.31) in 1986-1996. The temperature-mortality gradient for cold deaths diminished progressively: The increase in mortality per 1 degree C drop below 15 degrees C was 2.52% (95% CI: 2.00, 3.03), 2.34% (95% CI: 1.72, 2.96), 1.64% (1.10, 2.19), and 1.17% (95% CI: 0.88, 1.45), respectively, in the four periods. Corresponding population attributable fractions were 12.5%, 11.2%, 8.7%, and 5.4%. Heat deaths also diminished over the century. There was a progressive reduction in temperature-related deaths over the 20th century, despite an aging population. This trend is likely to reflect improvements in social, environmental, behavioral, and health-care factors and has implications for the assessment of future burdens of heat and cold mortality.

The 2003 heat wave in France: dangerous climate change here and now.

In an analysis of the French episode of heat wave in 2003, this article highlights how heat wave dangers result from the intricate association of natural and social factors. Unusually high temperatures, as well as socioeconomic vulnerability, along with social attenuation of hazards, in a general context where the anthropogenic contribution to climate change is becoming more plausible, led to an excess of 14,947 deaths in France, between August 4 and 18, 2003. The greatest increase in mortality was due to causes directly attributable to heat: dehydration, hyperthermia, heat stroke. In addition to age and gender, combinatorial factors included preexisting disease, medication, urban residence, isolation, poverty, and, probably, air pollution. Although diversely impacted or reported, many parts of Europe suffered human and other losses, such as farming and forestry through drought and fires. Summer 2003 was the hottest in Europe since 1500, very likely due in part to anthropogenic climate change. The French experience confirms research establishing that heat waves are a major mortal risk, number one among so-called natural hazards in postindustrial societies. Yet France had no policy in place, as if dangerous climate were restricted to a distant or uncertain future of climate change, or to preindustrial countries. We analyze the heat wave's profile as a strongly attenuated risk in the French context, as well as the causes and the effects of its sudden shift into amplification. Research and preparedness needs are highlighted.

The contributions of Lavoisier, Carnot, and Mayer to understanding heat illness.

Although heat illness has been described throughout recorded history, an understanding of its pathophysiology was only achieved in the 20th century. Lavoisier, Carnot, and Mayer described fundamental concepts about thermodynamics in the late 18th and early 19th centuries that were crucial to the eventual understanding of heat illness. Lavoisier recognized that the human body was a heat engine. Carnot recognized that useful heat engines must dissipate heat. Mayer recognized that humans possess the capacity to regulate body heat. The fundamental contributions of Lavoisier, Carnot, and Mayer to the understanding of heat illness have gone largely unacknowledged.