Dose Response Relations for Health Effects Caused by Office Dust

Summary

The study is focused at the dose response relation for office dust and such office dust spiked with components from fungi known from damp buildings.

The first aim of this study is to investigate if dust causes objective changes such as changes of lung function, nasal geometry, inflammatory indicators in tears and nasal lavage, tear film stability and cells at exposure levels relevant to indoor air. The controlled exposure variable is air concentration of office dust spiked with Glucan to simulate a worse case scenario.

Aim 1: Confirm or support the causality between objective effects and exposures to dust spiked with Glucan with focus on inflammatory responses. This is done by negation of the hypothesis that no significant effects are found for the variables in question.

Aim 2 is to estimate the thresholds and slopes of the DR relation for effect measures which show effects of exposures. At best the study will supply for each variable a zero response to clean air and three non-zero responses to dust. Thresholds and slopes are estimated graphically by linear regression or by an accumulated response model.

Aim 3 is a confirmation that atopic persons and histamine sensitive persons in nasal provocation tests have different responses in the effect measures showing significant effects of exposures to dust spiked with Glucan. Risk group status is therefore included in the analyses of the main variables as explaining variable.

Potential additional aim 4: Chemical and biological characterization of the office dust used in the study.

Aim 4 is an investigation of dose response relations for explorative measures, which in previous investigations have showed indications of a dose response relation. For these no a priory hypotheses exists and the analyses must be arranged ad hoc. The explaining variables are exposure and risk group status.

One challenge in investigations of unspecific effects caused by mixed exposures is that few specific objective effects measures are available and subjective measures have to be introduced. Therefore there is a need for developments of new objective measures of health effects of air pollution. Some of these are related to new biomarkers of respiratory effects in a bio-sample taken as condensed exhaled breath.

Aim 5: Developments of new objective measures of health effects of air pollution. After the experiment it will be investigated by logistic regression if a sensitivity index can be established.

Conditions

• Discomfort Symptoms
• Changed Lung Function

Interventions

OTHER

Office dust

airborne office dust spiked with glucan

OTHER

clean air

Clean air

Sponsors & Collaborators

• The Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning (FORMAS)

  collaborator OTHER_GOV

• Service Branchens Arbejdsgiverforening i Danmark

  collaborator UNKNOWN

• University of Aarhus

  lead OTHER

Principal Investigators

• Lars Mølhave, DMSc, Ph.D. · The Air Pollution Unit, Department of Environmental and Occupational Medicine, Institute of Public Health, The University of Aarhus.

Study Design

Allocation

NON_RANDOMIZED

Purpose

PREVENTION

Masking

TRIPLE

Model

CROSSOVER

Eligibility

Min Age

18 Years

Max Age

64 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2005-05-31

Primary Completion

2006-11-30

Completion

2006-11-30

Countries

• Denmark

Study Locations