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Space-Time Covariation of Mortality with Temperature: A Systematic Study of Deaths in France, 1968-2009.

Todd N, Valleron AJ - Environ. Health Perspect. (2015)

Bottom Line: The temperature-mortality relationship has repeatedly been found, mostly in large cities, to be U/J-shaped, with higher minimum mortality temperature (MMT) at low latitudes being interpreted as indicating human adaptation to climate.The RM25/18 ratio of mortality at 25°C versus that at 18°C declined significantly (p = 5 × 10-5) as warming increased: 18% for P1, 16% for P2, and 15% for P3.Results of this spatiotemporal analysis indicated some human adaptation to climate change, even in rural areas.

View Article: PubMed Central - PubMed

Affiliation: U1169, INSERM (Institut national de la santé et de la recherche médicale), Le Kremlin-Bicêtre, France.

ABSTRACT

Background: The temperature-mortality relationship has repeatedly been found, mostly in large cities, to be U/J-shaped, with higher minimum mortality temperature (MMT) at low latitudes being interpreted as indicating human adaptation to climate.

Objectives: Our aim was to partition space with a high-resolution grid to assess the temperature-mortality relationship in a territory with wide climate diversity, over a period with notable climate warming.

Methods: The 16,487,668 death certificates of persons > 65 years of age who died of natural causes in continental France (1968-2009) were analyzed. A 30-km × 30-km grid was placed over the map of France. Generalized additive model regression was used to assess the temperature-mortality relationship for each grid square, and extract the MMT and the RM25 and RM25/18 (respectively, the ratios of mortality at 25°C/MMT and 25°C/18°C). Three periods were considered: 1968-1981 (P1), 1982-1995 (P2), and 1996-2009 (P3).

Results: All temperature-mortality curves computed over the 42-year period were U/J-shaped. MMT and mean summer temperature were strongly correlated. Mean MMT increased from 17.5°C for P1 to 17.8°C for P2 and to 18.2°C for P3 and paralleled the summer temperature increase observed between P1 and P3. The temporal MMT rise was below that expected from the geographic analysis. The RM25/18 ratio of mortality at 25°C versus that at 18°C declined significantly (p = 5 × 10-5) as warming increased: 18% for P1, 16% for P2, and 15% for P3.

Conclusions: Results of this spatiotemporal analysis indicated some human adaptation to climate change, even in rural areas.

No MeSH data available.


Related in: MedlinePlus

Distributions of minimum mortality temperatures (MMT) and relative risk of mortality expressed as the ratios of mortality observed at 25°C to that observed at MMT (RM25), computed for three successive periods in France (1968–2009).
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f3: Distributions of minimum mortality temperatures (MMT) and relative risk of mortality expressed as the ratios of mortality observed at 25°C to that observed at MMT (RM25), computed for three successive periods in France (1968–2009).

Mentions: The temperature–mortality relationship in France during three successive 14-year periods. A U/J-shaped curve was found for all three periods in 211 (94%) of the 224 squares (see By-period analysis: “Map 1. Cut off at 7,500” at http://www.isis-diab.org/isispub/ehp/interactive_map_co75.htm). The global MMT distribution for those 211 squares with U/J-shaped curves shifted to higher temperatures over time. For P1, P2, and P3, respectively, the values at the 25th percentile were 16.4°C, 16.8°C, and 17.2°C, and the values at the 75th percentile were 18.2°C, 18.6°C, and 19.3°C. The mean MMT rose from 17.5°C to 17.8°C and 18.2°C, and the whole MMT distribution shifted toward higher temperatures with time (Figure 3). This increase paralleled that of MST (+1.5°C between P1 and P3) and MWT (+0.8°C between P1 and P3) (Table 1). RM25 and RM25/18 shifted to lower values with time (Figure 3). The mean values of RM25 and RM25/18 (Table 1) were significantly lower at P3 than at P1 (p-values: 10–7 for RM25; 5 × 10–4 for RM25/18). The unemployment rate was the only sociodemographic variable significantly correlated with MMT for each of the three periods (Table 2).


Space-Time Covariation of Mortality with Temperature: A Systematic Study of Deaths in France, 1968-2009.

Todd N, Valleron AJ - Environ. Health Perspect. (2015)

Distributions of minimum mortality temperatures (MMT) and relative risk of mortality expressed as the ratios of mortality observed at 25°C to that observed at MMT (RM25), computed for three successive periods in France (1968–2009).
© Copyright Policy - public-domain
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4492259&req=5

f3: Distributions of minimum mortality temperatures (MMT) and relative risk of mortality expressed as the ratios of mortality observed at 25°C to that observed at MMT (RM25), computed for three successive periods in France (1968–2009).
Mentions: The temperature–mortality relationship in France during three successive 14-year periods. A U/J-shaped curve was found for all three periods in 211 (94%) of the 224 squares (see By-period analysis: “Map 1. Cut off at 7,500” at http://www.isis-diab.org/isispub/ehp/interactive_map_co75.htm). The global MMT distribution for those 211 squares with U/J-shaped curves shifted to higher temperatures over time. For P1, P2, and P3, respectively, the values at the 25th percentile were 16.4°C, 16.8°C, and 17.2°C, and the values at the 75th percentile were 18.2°C, 18.6°C, and 19.3°C. The mean MMT rose from 17.5°C to 17.8°C and 18.2°C, and the whole MMT distribution shifted toward higher temperatures with time (Figure 3). This increase paralleled that of MST (+1.5°C between P1 and P3) and MWT (+0.8°C between P1 and P3) (Table 1). RM25 and RM25/18 shifted to lower values with time (Figure 3). The mean values of RM25 and RM25/18 (Table 1) were significantly lower at P3 than at P1 (p-values: 10–7 for RM25; 5 × 10–4 for RM25/18). The unemployment rate was the only sociodemographic variable significantly correlated with MMT for each of the three periods (Table 2).

Bottom Line: The temperature-mortality relationship has repeatedly been found, mostly in large cities, to be U/J-shaped, with higher minimum mortality temperature (MMT) at low latitudes being interpreted as indicating human adaptation to climate.The RM25/18 ratio of mortality at 25°C versus that at 18°C declined significantly (p = 5 × 10-5) as warming increased: 18% for P1, 16% for P2, and 15% for P3.Results of this spatiotemporal analysis indicated some human adaptation to climate change, even in rural areas.

View Article: PubMed Central - PubMed

Affiliation: U1169, INSERM (Institut national de la santé et de la recherche médicale), Le Kremlin-Bicêtre, France.

ABSTRACT

Background: The temperature-mortality relationship has repeatedly been found, mostly in large cities, to be U/J-shaped, with higher minimum mortality temperature (MMT) at low latitudes being interpreted as indicating human adaptation to climate.

Objectives: Our aim was to partition space with a high-resolution grid to assess the temperature-mortality relationship in a territory with wide climate diversity, over a period with notable climate warming.

Methods: The 16,487,668 death certificates of persons > 65 years of age who died of natural causes in continental France (1968-2009) were analyzed. A 30-km × 30-km grid was placed over the map of France. Generalized additive model regression was used to assess the temperature-mortality relationship for each grid square, and extract the MMT and the RM25 and RM25/18 (respectively, the ratios of mortality at 25°C/MMT and 25°C/18°C). Three periods were considered: 1968-1981 (P1), 1982-1995 (P2), and 1996-2009 (P3).

Results: All temperature-mortality curves computed over the 42-year period were U/J-shaped. MMT and mean summer temperature were strongly correlated. Mean MMT increased from 17.5°C for P1 to 17.8°C for P2 and to 18.2°C for P3 and paralleled the summer temperature increase observed between P1 and P3. The temporal MMT rise was below that expected from the geographic analysis. The RM25/18 ratio of mortality at 25°C versus that at 18°C declined significantly (p = 5 × 10-5) as warming increased: 18% for P1, 16% for P2, and 15% for P3.

Conclusions: Results of this spatiotemporal analysis indicated some human adaptation to climate change, even in rural areas.

No MeSH data available.


Related in: MedlinePlus