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Attention ImpairedATENC!ÓNCT03762239

Effect of Air Pollution on the Cognitive Function of Adolescents

A study testing Purifying the air with a Pure Airbox device (Zonair 3D) in people with Attention Impaired and Risk-Taking, run by Barcelona Institute for Global Health at 1 site in Spain.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Previous observational studies have reported an association between higher air pollution exposure and lower attention in children. With this project, the investigators aim to confirm this association in adolescents using an experimental design. Read more about this study

Who is it for?
Ages 13 to 16 yearsHealthy volunteers can take part
Conditions the study is for
Attention Impaired, Risk-Taking, Risk Behavior
What is being tested?
Purifying the air with a Pure Airbox device (Zonair 3D)
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
2,123 participants
Where
1 siteSpain
Study dates
23 Nov 2018to 11 Jun 2019
Phase
Interventional
Are there results?
Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 13 to 16 years
  • All sexes
  • Healthy volunteers accepted
  • Child

Who may be able to join

  • Students in the 3rd ESO course in participating high schools with signed informed consent

Who cannot join

  • None

Trial locations and contacts

1 site in 1 country.

Spain1 site
  • ISGlobal

    Barcelona, 08003

Other trials in Spain

About this study

Official title: Citizen Science for Analysing the Effect of Air Pollution on the Cognitive Function of Adolescents

Previous observational studies have reported an association between higher air pollution exposure and lower attention in children. With this project, the investigators aim to confirm this association in adolescents using an experimental design. In addition, the study will assess the relationship between air pollution exposure and individual preferences with respect to risk, time and social considerations. High school students in 3rd grade (ESO, 14-15 years of age) in different high schools in the Barcelona province (Spain) will be invited to participate. For each class in each high school, participating students will be randomly split into two equal-sized groups. Each group will be assigned to a different classroom where they will complete several activities during two hours, including an attention test (Flanker task) and a reduced version of the Global Preferences Survey. One of the classrooms will have an air purifier that will clean the air. The other classroom will have the same device but without the filters, so it will only re-circulate the air without cleaning it. Students will be masked to intervention allocation. The investigators hypothesize that students assigned to the clean air classroom will have better scores in the attention test, and that decision-making will also present differences in the two classrooms.

Being tested
Purifying the air with a Pure Airbox device (Zonair 3D), Using a sham air purifier (same device without filters)
Keywords
Attention, Air pollution, Black carbon, Particulate matter, Risk behavior, Social preferences, Decision making, Air purifier, Air cleaner
Medical subject headings
Risk-Taking

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Purifying the air with a Pure Airbox device (Zonair 3D)Other

    Also called Air filtering, Air cleaning

    Purifying the air of the classroom where the experiment is conducted using a Pure Airbox device (Zonair 3D)

  • Using a sham air purifier (same device without filters)Other

    Also called Sham air cleaner

    Use the air purifier (Pure Airbox, Zonair 3D) without filters in the classroom where the experiment is conducted

Study groups in NCT03762239
Study groupRoleWhat they receive
Purified airActive comparatorPurifying the air with a Pure Airbox device (Zonair 3D). Use of air purifier (Pure Airbox, Zonair 3D) in the classroom 30 minutes before the participants enter the room and during the 2 hours of the experiment.
Receives: Other: Purifying the air with a Pure Airbox device (Zonair 3D)
Normal airSham comparatorUsing a sham air purifier (same device without filters). Use of the same air purifier but without filters, so that it only recirculates the air without purifying it. Used for the same time period than the other arm.
Receives: Other: Using a sham air purifier (same device without filters)

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Response Speed Consistency Throughout the Attention Network Task-Flanker Task (Post ANT)

    This is a measure related to attentiveness that is calculated as hit reaction time standard error for correct responses (HRT-SE).

    A higher HRT-SE indicates highly variable reactions during the ANT test that is related to inattentiveness.

    A lower HRT-SE indicates indicates consistent reaction times and thus, a better attention performance.

    Measured: Obtained from a test administered approximately 90 minutes after entering the classroom

  2. Combined Risk Taking Score

    The "Combined risk taking score" measures how willing the person is to take risks and is calculated as 0.4729985 × "Risk preference score" + 0.5270015 × "Willingness to take risks", as defined in Falk et al (2018). The "Combined risk taking score" is a weighted average of two z-scores ("risk preference score" and "willingness to take risks" score), and therefore it can be interpreted as a z-score. The central value of "Combined risk taking score" is 0 and represents the population mean. The higher the values of the "Combined risk taking score", the more willing is the person to take risks. The "Risk preference score" is the final node in the risk tree (see the online appendix of Falk et al (2018)), which is a value between 1 and 32, ranked by the level of risk aversion, which was then transformed to a z-score. The "Willingness to take risks" refers to the answer to the question on one's willingness to take risks, with values from 0 to 10), which was then transformed to a z-score.

    Measured: Obtained from a test administered approximately 100 minutes after entering the classroom

  3. Combined Patience Score

    The "Combined patience score" measures the patience of the person and is calculated as 0.7115185 × "Time preference score" + 0.2884815 × "Self assessment of patience", as defined in Falk et al (2018). The "Combined patience score" is a weighted average of two z-scores ("time preference score" and "self assessment of patience" score), and therefore it can be interpreted as a z-score. The central value of "Combined patience score" is 0 and represents the population mean. The higher the values of the "Combined patience score" the more patience the person has. The "Time preference score" was obtained from the final node in the time tree (see the online appendix of Falk et al (2018)), which is a value between 1 and 32, ranked by the level of patience, which was then transformed to a z-score. The "Self assessment of patience" score refers to the answer to the question on the self-assessment of patience, with values from 0 to 10, which was then transformed to a z-score.

    Measured: Obtained from a test administered approximately 100 minutes after entering the classroom

  4. Positive Reciprocity Score

    The "Positive reciprocity score" measures positive reciprocity. A person with high reciprocity agrees with the statement "When someone does me a favor, I am willing to return it". The score is calculated as 0.4847038 × "Willingness to return favor" + 0.5152962 × "Size of gift", as defined in Falk et al (2018). The "Positive reciprocity score" is a weighted average of two z-scores ("willingness to return a favor" score and "size of gift" score), and therefore it can be interpreted as a z-score, with the central value of 0 representing the population mean. Higher values of the score imply more positive reciprocity. "Willingness to return favor" refers to the answer to the question on the willingness to return a favor, ranked from 0 to 10 and then transformed to a z-score. "Size of gift" refers to the answer to the question on the reported size of the gift that would return to a stranger, from a list of 7 possible values (from 0 to 30€, by 5€ steps), then transformed to a z-score.

    Measured: Obtained from a test administered approximately 100 minutes after entering the classroom

  5. Altruism Score

    The "Altruism score" measures the altruism of a person and is calculated as 0.6350048 × "Willingness to give to good causes" + 0.3649952 × "Hypothetical donation", as defined in Falk et al (2018). The "Altruism score" is a weighted average of two z-scores ("willingness to give to good causes" score and "hypothetical donation" score), and therefore it can be interpreted as a z-score, with the central value of 0 representing the population mean. Higher values of the score imply more altruism. "Willingness to give to good causes" refers to the answer to the question on the willingness to give to good causes, ranked from 0 to 10 and then transformed to a z-score. "Hypothetical donation" refers to the answer to the question on the size of the hypothetical donation one would be willing to make, transformed to a z-score.

    Measured: Obtained from a test administered approximately 100 minutes after entering the classroom

  6. Trust Score

    Answer to the question "I assume that people have only the best intentions", which is ranked from 0 to 10. Higher values imply more trust.

    Measured: Obtained from a test administered approximately 100 minutes after entering the classroom

Secondary outcomes (6)
  1. Impulsivity (From ANT)

    Number of incorrect responses (responses made in the opposite direction to the direction of the target arrow) Lower score indicates a better attention performance. Total range score: 0-38.

    Measured: Obtained from a test administered approximately 90 minutes after entering the classroom

  2. Selective Attention (From ANT)

    Number of omission errors (failure to respond) Lower score indicates a better attention performance Total range score: 0-21. Higher values represent a worse outcome

    Measured: Obtained from a test administered approximately 90 minutes after entering the classroom

  3. Alerting Score (From ANT)

    Alerting represents the ability to maintain a state of high vigilance to incoming stimuli It is calculated by subtracting the median reaction time for double cue from median reaction time for the no cue condition (calculations performed after removing the incongruent trials). A lower score indicates a better attention performance

    Measured: Obtained from a test administered approximately 90 minutes after entering the classroom

  4. Orienting Score (From ANT)

    Orienting is the ability to select information and it is calculated by subtracting the median reaction time for spatial cue from the reaction time for central cue (calculations performed after removing the incongruent trials).A lower score indicates a better attention performance

    Measured: Obtained from a test administered approximately 90 minutes after entering the classroom

  5. Conflict Score (Executive Attention) (From ANT)

    Conflict generally refers to the ability to monitor and resolve conflict among responses and in this study it is calculated as the median reaction time for each flanker condition (across cue conditions) and subtracting the congruent from the incongruent reaction times. A lower score indicates a better attention performance

    Measured: Obtained from a test administered approximately 90 minutes after entering the classroom

  6. Self Assessment of How Good They Are in Math

    Answer to the question on math skills, ranging from 0 to 10. The higher the score, the better the person feels s/he is doing in math.

    Measured: Obtained from a test administered approximately 100 minutes after entering the classroom

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted3 Dec 2018
  2. Study start23 Nov 2018
  3. Primary completion11 Jun 2019
  4. Study completion11 Jun 2019

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Prevention
Allocation
Randomised
Intervention model
Parallel groups
Masking
Single blind
Who is masked
Participant
Enrolment
2,123 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT03762239
Sponsor's protocol ID
PI2030
Acronym
ATENC!Ó
Status last verified
Jun 2025
First submitted
23 Nov 2018
Last updated
12 Jun 2025
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Yes: All collected IPD except identifying information for participants or high schools will be shared

Questions about this trial

What is this clinical trial studying?

A study testing Purifying the air with a Pure Airbox device (Zonair 3D) in people with Attention Impaired and Risk-Taking, run by Barcelona Institute for Global Health at 1 site in Spain.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 12 Jun 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Spain. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

Yes. Results are posted in the registry (first posted 12 Jun 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Response Speed Consistency Throughout the Attention Network Task-Flanker Task (Post ANT) (time frame: Obtained from a test administered approximately 90 minutes after entering the classroom). The study lists 6 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 12 Jun 2025.

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