Climate change: health effects in the UK: Chapter 5. Impact of climate change policies on indoor environmental quality and health in UK housing

This is the fourth Health Effects of Climate Change in the UK report, which provides evidence, analysis and recommendations based on climate change projections for the UK

People in the UK spend on average more than 95% of their time in indoor environments, and 66% of time in their own homes. Chapter 5 presents a review of evidence on the impact of climate change policies on indoor environmental quality and health in the UK. The chapter synthesises new evidence published since the last ‘Health Effects of Climate Change in the UK’ report, including the impact of climate mitigation and adaptation policies. The chapter was written by scientists at the UK Health Security Agency (UKHSA), University College London, University of Nottingham, University of Strathclyde and London School of Hygiene and Tropical Medicine.

The UK building stock is among the oldest in Europe, and large-scale home retrofits are required to reduce energy demand and achieve net zero. This can include insulating external walls, double or triple glazing, low-carbon heating with heat pumps, and draught proofing. Arrangements for new builds include high levels of airtightness with mechanical ventilation and heat recovery, cooling measures, triple glazed windows and low-carbon heating. However, energy efficiency measures, if poorly installed, may increase indoor air pollutant concentrations from internal sources, such as carbon monoxide, particulate matter, nitrogen dioxide, radon and biological contamination (for example, allergens, mould, viruses and bacteria). Exposure to increased levels of these contaminants is associated with adverse health effects including respiratory, cardiovascular or neurological conditions and cancer. Ventilation is necessary to maintain good indoor air quality and reduce risk from some infectious diseases, although this is outside of the scope of this chapter. Maintaining indoor temperatures at recommended levels and reducing exposure to air ollution should also be considered.

This chapter highlights several key insights for public health. Measures to mitigate climate change such as passive or low-carbon heating and cooling, energy efficient lighting, and solar energy will enable existing homes to become more energy efficient, may help alleviate fuel poverty and improve thermal comfort in winter. However, such measures also increase building airtightness and without accompanying improvements in ventilation, retrofitted homes may experience degraded indoor environmental quality. Overheating in summer is associated with adverse physical and psychological health impacts. The effects of exposure to noise from mechanical ventilation are not yet understood; however, the ingress of environmental noise from transport has adverse psychological and physiological impacts on health, such as sleep disturbance and cardiovascular and metabolic diseases. People spend a large proportion of their time indoors and, therefore, the indoor environment is an important determinant of health. Further work is needed to increase awareness among people and professionals and to develop interventions to reduce exposure to indoor air pollutants.