NCT06570993

Assessing the Effects of Cool Roofs on Indoor Environments and Health in Niue

A Cluster Randomised Controlled Trial (cRCT) Evaluating the Effects of Cool Roofs on Health, Environmental and Economic Outcomes in Niue

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 288 (actual)
• Sponsor: Aditi Bunker · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Accepted

Summary

Ambient air temperatures in the Pacific have broken record highs in 2024. Solutions are needed to build heat resilience in communities and adapt to increasing heat from climate change. Sunlight-reflecting cool roof coatings may passively reduce indoor temperatures and energy use to protect home occupants from extreme heat. Occupants living in poor housing conditions in the Pacific are susceptible to increased heat exposure. Heat exposure can instigate and worsen numerous physical, mental and social health conditions. The worst adverse health effects are experienced in communities that are least able to adapt to heat exposure. By reducing indoor temperatures, cool roof use can promote physical, mental and social wellbeing in household occupants. The long-term research goal of the investigators is to identify viable passive housing adaptation technologies with proven health benefits to reduce the burden of heat stress in communities affected by heat in Niue. To meet this goal, the investigators will conduct a cluster-randomized controlled trial to establish the effects of cool roof use on health, indoor environment and economic outcomes in Niue.

Detailed description

Increasing heat exposure from climate change is causing and exacerbating heat-related illnesses in millions worldwide - particularly in low resource settings. June 2024 was the 13th consecutive hottest month on record globally - shattering previous records. Heat exposure can instigate and worsen health conditions including cardiovascular, metabolic, endocrine and respiratory disease, heat-related illnesses, pregnancy complications, and mental health conditions. Adaptation is essential for protecting people from increasing heat exposure. The built environment, especially homes, are ideal for deploying interventions to reduce heat exposure and accelerate adaptation efforts. However, there currently is a lack of evidence on a global scale - generated through empirical studies - guiding the uptake of interventions to reduce heat stress in low resource settings. Pacific Islands and other small island developing states are among the most vulnerable to the adverse impacts of climate change and are likely to experience increases in ambient air temperature over the coming decades. People in Niue are exposed to heat and humidity year-round. The Pacific Islands have a large burden of non-communicable diseases (NCDs), with nearly three-quarters of deaths due to NCDs. The combined burden of heat and NCDs places Pacific Island populations at greater risk of adverse health effects from heat extremes. Sunlight-reflecting cool roof coatings passively reduce indoor temperatures and lower energy use, offering protection to home occupants from extreme heat. The investigators therefore aim to conduct a cluster-randomized controlled trial investigating the effects of cool-roof use on health, environmental and economic outcomes in Niue. The trial will quantify whether cool roofs are an effective passive home cooling intervention with beneficial health effects for vulnerable populations in Niue. Findings will inform regional policy responses on scaling cool roof implementation to protect people from increasing heat exposure driven by climate change.

Conditions

• Resting Heart Rate
• Blood Glucose Control
• Depression
• Heat-related Symptoms
• Physician Diagnosed Heat-related Illnesses
• Food Insecurity
• Diet Quality
• Health-related Quality of Life
• Indoor Thermal Comfort
• Coping Ability
• Life Satisfaction
• Healthcare Provider Utilization
• Hospitalization
• Systolic Blood Pressure
• Diastolic Blood Pressure
• Inner Ear Canal Temperature
• Dehydration
• Sleep Quality
• Cognition
• Productivity
• Aggression
• Indoor Air Temperature
• Indoor Relative Humidity
• Indoor Heat Index
• Household Energy Expenditure

Interventions

Type	Name	Description
OTHER	Cool roof	Cool roofs are a heat-reflecting material that can be applied to existing household roofing in the form of a liquid-applied membrane. Cool roofs work by increasing solar reflectance (the ability to reflect the visible wavelengths of sunlight, reducing heat transfer to the surface) and thermal emittance (the ability to radiate absorbed solar energy) thereby reducing the amount of heat transferred into the home.

Timeline

• Start date: 2024-09-04
• Primary completion: 2026-01-31
• Completion: 2026-01-31
• First posted: 2024-08-26
• Last updated: 2026-02-27

Locations

1 site across 1 country: Niue