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Completed

NCT Number: NCT03104387

Health Effects of Occupational Exposure to Combustion Particles - a Study on Volunteers Performing as Train Conductors

Ambient air pollution is a complex mixture of gaseous pollutants and particulate matter (PM). PM has a recognized important role in human health. There is a strong scientific consensus on the independent association of PM and adverse cardiovascular and respiratory effects, as well as cancer. It is reasonable to expect that the smaller particles (ultrafine particles, UFP) may have an enhanced toxicity relative to other PM size fractions, due to physical properties and potential to translocation beyond the lung.

A recent Danish report concluded that train conductors on a working day, and in two specific diesel engine trains, are exposed to higher concentrations of diesel exhaust than by constant stay in a busy street. Indeed, the average exposure for train conductors on such engines was around 100,000-150,000 UFP per cm3 as compared with around 40,000 per cm3 on a busy street in Copenhagen [1]. The aim of this study is to investigate if this occupational exposure is associated with vascular and respiratory impairment and DNA damage.

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Key information

Conditions

Cardiovascular Function Genotoxicity

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of Copenhagen

Copenhagen, Denmark

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Healthy volunteers
  • Legally competent subjects

Exclusion criteria

  • Current smokers
  • Pregnancy
  • Alcohol and drug abuse
  • Prescriptionary use of anti-inflammatory or cardiovascular medication

Treatment and study plan

Electric train

Other

Exposure to air with low level of ultrafine particles (Electric train)

Diesel train

Other

Exposure to air with high level of ultrafine particles (Diesel train)

Primary outcomes

  1. Reactive hyperemia index measured by peripheral arterial tonometry

    Time frame: Peripheral arterial tonometry is assessed after each exposure scenario (on the third day after 6 hours on defined train routes per day)

    The primary outcome will be measured in the form of post-ischemic variation followed by the measurement of the vasomotor function after the administration of nitroglycerin, to allow the investigation of the endothelium independent vasodilatation. The portable device EndoPAT 2000 will be used (Itamar Medical Ltd, Israel) [2-6].

  2. Heart rate variability

    Time frame: Assessed after each exposure scenario (on the third day after 6 hours on defined train routes per day)

    Heart rate variability is measured with the EndoPAT 2000 device during baseline recording. It includes time domain measures (SDNN, pNN50 and RMSSD), high (HF) and low frequency (LF) components as well as LF/HF ratio, based on measurements over 5 minutes.

  3. DNA damage in peripheral blood mononuclear cells

    Time frame: Blood is sampled, prepared and stored after each exposure scenario (on the third day after 6 hours on defined train routes per day). Analysis is performed after sample collection completion.

    The levels of strand breaks and formamidopyrimidine-DNA-glycosylase (FPG) sites are measured with the single cell gel electrophoresis assay (comet assay) [7-13]

Secondary outcomes

  1. Lung function

    Time frame: The lung function is assessed after each exposure scenario (on the third day after 6 hours on defined train routes per day)

    The lung function is measured with EasyOne 2001 spirometer device (Switzerland). Lung function measurements includes forced vital capacity (FVC), forced expiratory volume after 1 second (FEV1), peak expiratory flow (PEF) and FEV1/FVC.

  2. Systemic inflammatory markers

    Time frame: Blood is sampled, prepared and stored after each exposure scenario (on the third day after 6 hours on defined train routes per day). Analysis is performed after sample collection completion.

    Acute phase reactants, pro-inflammatory cytokines and cell adhesion molecules

  3. Urinary excretion of 1-hydroxypyrene

    Time frame: Morning urine is sampled, prepared and stored after each exposure scenario (on the morning of the third day after two days with 6 hours on defined train routes). Analysis is performed after sample collection completion.

    The urinary biomarker of exposure to polycyclic aromatic hydrocarbons, 1-hydroxypyrene, is measured with reverse-phase HPLC and standardized for diuresis with the concentration of creatinine

  4. Serum/plasma bioactivity

    Time frame: Blood is sampled, prepared and serum is stored after each exposure scenario (on the third day after 6 hours on defined train routes per day). Analysis is performed after sample collection completion.

    To assess the potential effects on vascular and endothelial function [14, 15]

Other outcomes

  1. Augmentation index

    Time frame: Assessed after each exposure scenario (on the third day after 6 hours on defined train routes per day)

    Measured with the EndoPAT 2000 device during baseline recording.

  2. Blood pressure

    Time frame: Assessed after each exposure scenario (on the third day after 6 hours on defined train routes per day)

    Measured with an aneroid sphygmomanometer.

  3. Heart rate

    Time frame: Assessed after each exposure scenario (on the third day after 6 hours on defined train routes per day)

    Measured with the EndoPAT 2000 device during baseline recording.

Sponsors and collaborators

Lead sponsor

University of Copenhagen

Other

Collaborators

  • National Research Centre for the Working Environment, Denmark

Registry information

Official study title

Effects of Diesel Combustion Generated Air Pollution on Cardiovascular Function and Oxidatively Damaged DNA in Healthy Volunteers

Acronym: BioTrack

Important dates

Study start
2017
Primary completion
2018
Study completion
2020
First posted
Apr 7, 2017
Registry last updated
Aug 10, 2020

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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