The study will be based from a newly formed NHS service, the children's environmental health service. Participants will be children with a known chronic respiratory condition. Participants will undergo personal environmental exposure monitoring as well as home environmental assessments, before personalised exposure reports will be provided including a summary of their exposure and advising mitigation strategies based on exposure patterns and behaviours. The monitoring will be repeated after introduction of mitigation strategies. This will allow a comparison of the effectiveness of each method of mitigation.

Data will be collected from multiple sources during the study, including retrospective medical records and results, as well as data recorded as part of the study. These will include the following sources; Medical records from Royal London (including investigation results), Questionnaire responses, clinical interviews at clinic visits, new clinical investigations and home assessments.

These data will be both quantitative and qualitative. The data will be recorded on bespoke electronic databases, which will be securely stored on servers within the Bart's Health/ QMUL, More information on the collection and storage of each type of data can be found below.

Medical records from Royal London: Relevant clinical information and demographics will be extracted from the NHS electronic medical records as baseline information for the assessment in the environmental health clinic. This will be performed by members of the investigative team. Extracted information will include demographics, medical diagnoses, respiratory history, hospital visit history and clinical investigation results. Investigation results may include lung function, FeNO, blood test results, chest x-ray reports and any other relevant results from the child's medical history.

Questionnaires: Participants or their families will complete and return an Environmental Health Questionnaire which was designed for the purposes of the study. Answers to questions from the environmental health questionnaire will be in the form of multiple choice and short answer written questions. The questionnaire will be repeated throughout the participant's involvement in the clinic at designated points. The data from the questionnaires will be recorded in a digital database, will be created for the purpose of the clinic. This database will be stored securely within Barts Health / QMUL servers.

Medical Reviews: At visits in the clinic, interviews of the participants and their families will take place. This will include detailed medical and social history taking by medical sub investigators and a formal physical examination. To improve standardisation of data collected during interviews, a structured proforma will be developed, to be used while the interviews are being conducted. The data collected during these interviews will be recorded in the medical notes, as well as used to create personalised exposure reports.

Clinical investigations will be performed as part of the clinic. This will include blood eosinophils, FeNO, salivary cotinine and custom mould sensitivity. These investigations will be performed by medical members of staff during clinic visits. The results of these tests will be recorded in the medical notes, as well as in the digital database and secure in the servers based at Barts Health

Home assessments: During the period of home monitoring, participants will undergo assessments of their homes, their personal exposure to pollutants and undergo further health monitoring through the monitoring period. The home assessment will review mould and include a custom mould test comparing the child's blood IgG with a scraping from the mould in their home. The assessment of personal exposure will be performed using the Atmotube air quality monitor attached to a backpack (this is not a medical device). This monitor will be kept with the child at home, on their commutes and also at school. The portable air quality monitor measures air concentrations of particulate matter and volatile organic compounds (VOCs), humidity, temperature as well as GPS data and compares this against time. The encrypted anonymous data is then uploaded to a secure API before being stored within secure databases within the Barts health NHS servers. This database is stored securely within protected servers. No personal identifiable data or demographics is shared with Atmo or any other team otuside the clinic team.

After initial data collection and the home monitoring period, the data is collated and analysed by a medical member of the team to create a personal exposure report for each participant. This report will be provided to the participant, saved in the medical records, and used to recommend any appropriate exposure mitigation strategies. Follow up reviews will repeat the monitoring process and update the database, to compare the results before and after mitigation strategies have been introduced.

Inclusion Criteria:

• Parent/Guardian able to provide written informed consent

Referral made by paediatric asthma team

Child aged 4-17 years at the time of consent to study

A diagnosis of a chronic respiratory condition (diagnosis by a medical professional)

Contactable for regular follow up by the research team

Reasonable level of English language

Ability to engage with technology and devices used in the study

Exclusion Criteria:

• Inability to use the tools and devices in the research study

Inability to visit the hospital for the initial hospital visit

Inability to allow home environmental assessment

no masking