印度貧民窟加裝「涼感屋頂」對抗炎熱高溫
Source:VOA | South & Central Asia
Indian slums get 'cool roofs' to combat extreme heat
March 10, 2025 3:58 AM
近期，印度西部古吉拉特邦阿默達巴德市的貧民窟中，大約有400戶家庭的屋頂塗上白色反射塗層，以對抗逐年加劇的夏季高溫。這其實是一項國際研究的一部分。這份研究旨在探討這個由白色塗層打造的「涼屋頂」可以如何幫助降低室內高溫對健康與經濟的影響。研究團隊指出，低收入家庭多缺乏隔熱設施，涼屋頂能有效反射陽光、降低室內溫度。而且，這項跨國研究先前在布吉納法索的試驗顯示，涼屋頂能使室內溫度下降約1.2至1.7度，並改善心率。
AHMEDABAD, India —
Hundreds of roofs in the informal settlements of India’s western Gujarat state have been painted in a reflective, white coating over the last two months to try to keep their occupants cooler as the hottest time of year approaches.
The effort, which involves 400 households in Ahmedabad, is part of a global scientific trial to study how indoor heat impacts people’s health and economic outcomes in developing countries – and how “cool roofs” might help.
“Traditionally, home is where people have come to find shelter and respite against external elements,” said Aditi Bunker, an epidemiologist at the University of Heidelberg in Switzerland who is leading the project, supported by the UK-based Wellcome Trust.
“Now, we’re in this position where people are living in precarious housing conditions, where the thing that was supposed to be protecting them is actually increasing their exposure to heat.”
As climate change has made India’s summers more extreme, Ahmedabad has suffered temperatures in excess of 46 C (115 F) in recent years.
In the Vanzara Vas slum in the Narol area of the city, which has more than 2,000 dwellings, most of them airless, one-room homes, residents that are part of the project, such as Nehal Vijaybhai Bhil, say they have already noticed a difference.
“My refrigerator doesn’t heat up anymore and the house feels cooler. I sleep so much better and my electricity bill is down,” said Bhil, whose roof was painted in January.
Across the world, heatwaves that, prior to the industrial revolution, had a 1-in-10 chance of occurring in any given year are nearly three times as likely, according to a 2022 study in the journal Environmental Research Letters.
By painting roofs with a white coating that contains highly reflective pigments such as titanium dioxide, Bunker and her team are sending more of the sun’s radiation back to the atmosphere and preventing it from being absorbed.
“In a lot of these low socioeconomic homes, there’s nothing to stop the heat transfer coming down — there’s no insulation barrier from the roof,” Bunker said.
Before joining Bunker’s experiment, Arti Chunara said she would cover her roof with plastic sheets and spread grass over them.
Some days, she and her family sat outside for most of the day, going into the house only for two to three hours when the heat was bearable.
The trial in Ahmedabad will run for one year, and scientists will collect health and indoor environment data from residents living under a cool roof – and from those who do not.
Other study sites are in Burkina Faso, Mexico and the island of Niue in the South Pacific, spanning a variety of building materials and climates.
Early results from the Burkina Faso trial, Bunker said, show that cool roofs reduced indoor temperature by between 1.2 C in tin- and mud-roofed homes, and 1.7 C in tin-roofed homes over two years, which subsequently lowered residents’ heart rates.
Language Notes
- respite: 暫緩；短暫的延緩；喘息（時間） ⬆
- precarious: 危險的；不牢靠的，不穩的 ⬆
- in excess of: 超過；多於 ⬆
- pigment: 色素；顏料 ⬆
- insulation: 隔熱；隔音；絕緣（材料） ⬆
Check your comprehension!
Choose the BEST answer to each of the questions below. After you finish, highlight the parentheses to reveal the hidden answers.1. ( C ) What change did resident Nehal Vijaybhai Bhil notice after his roof was painted white?
A. The fresh air entered the house more frequently, but electricity costs increased.
B. The house felt hotter, but the refrigerator worked better.
C. The house felt cooler, he slept better, and his electricity bill went down.
D. He had to spend more time outdoors.
2. ( B ) According to the early results from Burkina Faso, what effect did “cool roofs” have on indoor temperatures?
A. Increased indoor temperatures by about 2 degrees.
B. Reduced indoor temperatures by 1.2 to 1.7 degrees Celsius.
C. Only worked in concrete-roofed homes.
D. Completely eliminated heat indoors.
3. ( D ) What might happen after the one-year trial in Ahmedabad?
A. The researchers may find that heatwaves occur less frequently in Ahmedabad.
B. The researchers may find that more low-income families are settling in slums in Ahmedabad.
C. The indoor environment data may indicate that plastic sheets work more effectively than the white coating.
D. The health data may show that residents living under a cool roof have better health conditions than those without one.
