Effect of Air Pollution on the Cognitive Function of Adolescents

NCT03762239 | Completed Results

• 1 other identifier: PI2030
• Study Type: interventional
• Target: 2,123
• Locations: 1 country
• Sites: 1

Brief 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. 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.

Conditions

Attention Impaired; Risk-Taking; Risk Behavior; Social Preferences; Decision Making; Attention

Keywords

Attention; Air pollution; Black carbon; Particulate matter; Risk behavior; Social preferences; Decision making; Air purifier; Air cleaner

Outcome Measures

Primary Outcomes (6)

• 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.

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

• 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.

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

• 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.

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

• 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.

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

• 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.

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

• 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.

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

Secondary Outcomes (6)

• Impulsivity (From ANT)

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

• Selective Attention (From ANT)

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

• Alerting Score (From ANT)

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

• Orienting Score (From ANT)

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

• Conflict Score (Executive Attention) (From ANT)

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

Study Arms (2)

Purified air

ACTIVE COMPARATOR

Purifying 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.

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

Normal air

SHAM COMPARATOR

Using 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.

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

Interventions

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

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

Also known as: Air filtering, Air cleaning

Purified air

Using a sham air purifier (same device without filters) OTHER

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

Also known as: Sham air cleaner

Normal air

Eligibility Criteria

• Age: 13 Years - 16 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Child (0-17)

You may qualify if:

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

You may not qualify if:

• None

Sponsors & Collaborators

• Barcelona Institute for Global Health: lead
• Recercaixa: collaborator
• Centre de Recerca per a l'Educació Científica i Matemàtica (CRECIM): collaborator
• Institute of Environmental Assessment and Water Research (IDAEA-CSIC): collaborator
• Economics and Bussiness Department, Universtitat Pompeu Fabra: collaborator

Study Sites (1)

ISGlobal

Barcelona, 08003, Spain

Location

MeSH Terms

Conditions

Risk-Taking

Interventions

Air Filters

Condition Hierarchy (Ancestors)

Behavior

Intervention Hierarchy (Ancestors)

Filtration; Chemistry Techniques, Analytical; Investigative Techniques; Equipment and Supplies

Results Point of Contact

• Title: Dr. Xavier Basagaña
• Organization: Barcelona Institute for Global Health (ISGlobal)

xavier.basagana@isglobal.org

(+34) 93 214 7306

Study Officials

• Xavier Basagaña, PhD

  Barcelona Institute for Global Health

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: Yes

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: November 23, 2018
• First Posted: December 3, 2018
• Study Start: November 23, 2018
• Primary Completion: June 11, 2019
• Study Completion: June 11, 2019
• Last Updated: June 12, 2025
• Results First Posted: June 12, 2025

Record last verified: 2025-06

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ANALYTIC CODE
• Time Frame: Data will become available when publishing the results in a scientific journal, with no time restrictions
• Access Criteria: Access to anyone via a public repository

Locations

ES (1)