Study summary

What is this research project about? 

We will investigate to what extent exposure to air pollution during pregnancy and the first five years of life and poor housing conditions (such as overcrowding and damp/mould) contribute to hospital admissions for respiratory tract infections (RTIs) in children less than five years old.

Why are we doing this research?

RTIs, including bronchiolitis, pneumonia and croup, are the most common reason for hospital admission in young children in the UK. These admissions are stressful for children, their parents and costly for the National Health Service (NHS). Being admitted to hospital with an RTI during the first few years of life is also associated with the development of chronic respiratory problems, such as asthma, in later childhood. Previous research has found that children from poor backgrounds are more likely to need an RTI admission, but it is not clear which aspects of children's living conditions make the largest contribution to RTI hospital admissions. In this study, we will examine whether exposure to air pollution in the womb or during early childhood, and poor housing conditions are associated with a child's risk of being admitted to hospital with an RTI. Also, we will look at how many RTI admissions could be prevented in the UK if we reduced air pollution and/or improved housing conditions for families with young children.

How are we going to do it?

We will use data collected from birth certificates, linked to maternity records and hospital admission data for all children born in England between 2005 and 2014, and Scotland between 1997 and 2019: 8 million children in total. We will link in data about children's air pollution exposure during pregnancy and childhood, building characteristics, and information about housing and socio-economic background from the 2011 Census. All data will be kept on secure servers and linked using methods that protect the identities of mothers and children. We will use these data to examine whether exposure to air pollution and poor housing conditions are associated with an increased risk of being admitted to hospital with an RTI during the first five years of life. We will use statistical methods that allow us to take into account whether children have other underlying risk factors for RTI hospital admissions, such as chronic health problems. We will also make sure that other researchers can access these datasets to carry out maternal and child health research in the future.

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