Assessing the Impact of Non-tailpipe Emissions From Traffic on the Asthmatic Airway

Summary

The goal of this observational study is to explore the health impacts of exposure to nontailpipe vehicle air pollution. The main question it aims to answer is: Does short term exposure to increased non-tailpipe course mode PM induce negative respiratory responses in adults living with asthma?

We will recruit 48 non-smoking adults with mild-moderate asthma. Participants will be recruited from central and east London

Participants will be exposed to three contrasting air quality environments, in field laboratories at the following locations:

1. High-speed continuous traffic location, to enhance tire wear emissions
2. An urban background location away from nearby traffic sources
3. A busy road junction characterized by stop-go traffic to enhance emissions from brake wear

Sites 1 and 2 are permanent air quality measurement supersites. Site 1 is located close to a major trunk road in Central London (Marylebone Road). Site 2 is a suburban park in South London (Honor Oak Park). An additional measurement location will be established at Imperial College London's (ICL) White City campus (Site 3) for the duration of the study using ICL's mobile measurement facility, equipped with the same highly time-resolved chemical composition measurement capability as the supersites.

To maximise exposure to different air quality environments participants will intermittently cycle on static exercise bikes at a standardised intensity of 60% estimated VO2max for a duration for 2.5 hours at the field laboratories.

Comparators variables:

Air quality will be monitored at all three sites for the duration of the testing visits (approximately 5 hours). Air quality parameters that will be recorded are PM2.5, PM10, NO2, NO, NOX, O3, Organic Mass, NO3, SO4, NH4, elements and black carbon.

Outcome variables:

The primary outcome of the study is lung function as measured by Forced Expiratory Volume in one second (FEV1). With secondary health endpoints including: Spirometry (FVC, FVC/FEV1 ratio, z Scores), fractional expired nitric oxide (FeNO), oscillometry, asthma symptoms, MRC breathlessness score, asthma control test and Asthma Quality of Life Questionnaire (AQLQ). Blood, nasal mucus and urine samples will be collected. Measure will be collected before after and 24 hours after exposure.

Conditions

• Asthma

Interventions

OTHER

Exercise exposure

Participants are exposed to three different air quality environments in central London, chosen to maximise differences in nontailpipe air pollution. Participants will cycle at 60% of estimated maximum vo2 on static bikes for six 15 minute bouts with 15 minutes rest between bouts.

Sponsors & Collaborators

• Asthma UK

  collaborator OTHER

• Health Effects Institute

  collaborator OTHER

• Imperial College London

  collaborator OTHER

• Queen Mary University of London

  lead OTHER

Principal Investigators

• James Scales, PhD · Queen Mary University London

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2022-12-01

Primary Completion

2023-08-01

Completion

2023-08-01

Countries

• United Kingdom

Study Locations