Dec 8, 2024 03:10 AM
https://www.eurekalert.org/news-releases/1066954
INTRO: Many recent studies assume that elderly people are at particular risk of dying from extreme heat as the planet warms. A new study of mortality in Mexico turns this assumption on its head: it shows that 75% of heat-related deaths are occurring among people under 35―a large percentage of them ages 18 to 35, or the very group that one might expect to be most resistant to heat.
“It’s a surprise. These are physiologically the most robust people in the population,” said study coauthor Jeffrey Shrader of the Center for Environmental Economics and Policy, an affiliate of Columbia University’s Climate School. “I would love to know why this is so.” The research appears this week in the journal Science Advances.
The researchers chose Mexico for the study because it collects highly granular geographical data on both mortality and daily temperatures. The researchers reached their conclusions by correlating excess mortality―that is, the number of deaths above or below the average―with temperatures on the so-called wet-bulb scale, which measures the magnified effects of heat when combined with humidity.
The analysis found that from 1998 to 2019, the country suffered about 3,300 heat-related deaths per year. Of these, nearly a third occurred in people ages 18 to 35―a figure far out of proportion with the numbers in that age bracket. Also highly vulnerable: children under 5, especially infants. Surprisingly, people 50 to 70 suffered the least amount of heat-related mortality.
Based on this, “we project, as the climate warms, heat-related deaths are going to go up, and the young will suffer the most,” said the study’s co-lead author, R. Daniel Bressler, a PhD. candidate in Columbia’s Sustainable Development program.
The researchers say several factors may be at work. Young adults are more likely to be engaged in outdoor labor including farming and construction, and thus more exposed to dehydration and heat stroke. The same goes for indoor manufacturing in spaces that lack air conditioning. “These are the more junior people, low on the totem pole, who probably do the lion’s share of hard work, with inflexible work arrangements,” said Shrader. Young adults are also more likely to participate in strenuous outdoor sports, the researchers point out. A previous separate analysis by Mexican researchers showed that death certificates of working-age men were more likely to list extreme weather as a cause than those of other groups.
The vulnerability of infants and small children came as somewhat less of a surprise. It is already known that their bodies absorb heat quickly, and their ability to sweat, and therefore cool off, is not fully developed. Their immune systems are also still developing, which can make them prey to ailments that become more common with humid heat, including vector-borne and diarrheal diseases... (MORE - details, no ads)
INTRO: Many recent studies assume that elderly people are at particular risk of dying from extreme heat as the planet warms. A new study of mortality in Mexico turns this assumption on its head: it shows that 75% of heat-related deaths are occurring among people under 35―a large percentage of them ages 18 to 35, or the very group that one might expect to be most resistant to heat.
“It’s a surprise. These are physiologically the most robust people in the population,” said study coauthor Jeffrey Shrader of the Center for Environmental Economics and Policy, an affiliate of Columbia University’s Climate School. “I would love to know why this is so.” The research appears this week in the journal Science Advances.
The researchers chose Mexico for the study because it collects highly granular geographical data on both mortality and daily temperatures. The researchers reached their conclusions by correlating excess mortality―that is, the number of deaths above or below the average―with temperatures on the so-called wet-bulb scale, which measures the magnified effects of heat when combined with humidity.
The analysis found that from 1998 to 2019, the country suffered about 3,300 heat-related deaths per year. Of these, nearly a third occurred in people ages 18 to 35―a figure far out of proportion with the numbers in that age bracket. Also highly vulnerable: children under 5, especially infants. Surprisingly, people 50 to 70 suffered the least amount of heat-related mortality.
Based on this, “we project, as the climate warms, heat-related deaths are going to go up, and the young will suffer the most,” said the study’s co-lead author, R. Daniel Bressler, a PhD. candidate in Columbia’s Sustainable Development program.
The researchers say several factors may be at work. Young adults are more likely to be engaged in outdoor labor including farming and construction, and thus more exposed to dehydration and heat stroke. The same goes for indoor manufacturing in spaces that lack air conditioning. “These are the more junior people, low on the totem pole, who probably do the lion’s share of hard work, with inflexible work arrangements,” said Shrader. Young adults are also more likely to participate in strenuous outdoor sports, the researchers point out. A previous separate analysis by Mexican researchers showed that death certificates of working-age men were more likely to list extreme weather as a cause than those of other groups.
The vulnerability of infants and small children came as somewhat less of a surprise. It is already known that their bodies absorb heat quickly, and their ability to sweat, and therefore cool off, is not fully developed. Their immune systems are also still developing, which can make them prey to ailments that become more common with humid heat, including vector-borne and diarrheal diseases... (MORE - details, no ads)