Impact of indoor environment on children’s pulmonary health

ABSTRACT

Introduction

A child’s living environment has a significant impact on their respiratory health, with exposure to poor indoor air quality (IAQ) contributing to potentially lifelong respiratory morbidity. These effects occur throughout childhood, from the antenatal period through to adolescence. Children are particularly susceptible to the effects of environmental insults, and children living in socioeconomic deprivation globally are more likely to breathe air both indoors and outdoors, which poses an acute and long-term risk to their health. Adult respiratory health is, at least in part, determined by exposures and respiratory system development in childhood, starting in utero.

Areas covered

This narrative review will discuss, from a global perspective, what contributes to poor IAQ in the child’s home and school environment and the impact that indoor air pollution exposure has on respiratory health throughout the different stages of childhood.

Expert opinion

All children have the right to a living and educational environment without the threat of pollution affecting their health. Action is needed at multiple levels to address this pressing issue to improve lifelong respiratory health. Such action should incorporate a child’s rights-based approach, empowering children, and their families, to have access to clean air to breathe in their living environment.

KEYWORDS:

• Asthma
• children
• homes
• LMICs
• mould
• pollution
• schools
• smoking
• ventilation

Article highlights

• Indoor air quality in the child’s home and school environment is affected significantly by a complex interrelationship between numerous factors including building characteristics, biological and non-biological pollution sources (originating from outside or inside) and dwelling/space occupancy.

• Exposure to poor indoor air quality affects lung development, lung function, respiratory symptoms and risk of respiratory morbidity throughout their life course, beginning in utero through to adolescence.

• Antenatal exposure to air pollution impacts life-long respiratory health through direct insults to developing lungs and lung function, by its association with low birth weight, and by driving epigenetic DNA changes which have multigenerational effects. Further research is required to understand the differences between antenatal exposure to indoor, rather than ambient, air pollution.

• Younger children and infants appear particularly vulnerable to the respiratory sequalae of poor indoor air quality compared to older children and adults. This is likely due to their immature respiratory and immune systems. Younger children also spend a larger proportion of their time indoors. Exposure to indoor pollutants including particulate matter, mold and secondhand smoke increase their risk of respiratory tract infections and respiratory symptoms.

• Wheezing disorders in pre-school aged children are common but the risk of pre-school wheeze and pre-school onset asthma is increased by exposure to poor indoor air quality (for example, exposure to particulate matter, mold, and secondhand smoke). Exposure to mold in the home also increases the risk of chronic respiratory symptoms including cough and excess sputum production.

• School-aged children are at an increased risk of chronic respiratory symptoms (including cough and wheeze), asthma and respiratory tract infections when exposed to poor indoor air quality. Exposure to indoor air pollution also predisposes children to poorer lung function measures, signifying impact on lung growth.

• Children living in low- and middle-income countries face increased challenges in terms of indoor air quality, particularly due to additional sources of indoor pollution including increased reliance on solid fuels, open fires, and rapid urbanization. This significantly impacts lung development, respiratory symptoms, lung function, and respiratory morbidity.

Declaration of interest

KA Holden, DB Hawcutt, and IP Sinha are investigators on a study assessing the use of air purifiers (manufactured by Rensair Ltd.) in the homes of children with asthma. They have not received any payments for this work and the air purifiers were not donated. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer disclosures

A peer reviewer on this manuscript has received an honorarium from Expert Review of Respiratory Medicine for their review work. Peer reviewers on this manuscript have no other relevant financial relationships or otherwise to disclose.

Acknowledgments

This paper was supported by the NIHR Alder Hey Clinical Research Facility. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health and Social Care.

Additional information

Funding

This paper was not funded.