Effect of Air Pollution on the Cognitive Function of Adolescents (ATENC!Ó)

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.

Study Overview

• Status: Completed
• Conditions: Risk Behavior; Attention Impaired; Risk-Taking; Social Preferences; Decision Making; Attention
• Intervention / Treatment: Other: Purifying the air with a Pure Airbox device (Zonair 3D); Other: Using a sham air purifier (same device without filters)

• Study Type: Interventional
• Enrollment (Actual): 2123
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Spain
  • Barcelona, Spain, 08003
    • ISGlobal

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 13 years to 16 years (Child)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

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

Exclusion Criteria:

• None

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Purified air; 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); Purifying the air of the classroom where the experiment is conducted using a Pure Airbox device (Zonair 3D); Other Names: Air filtering; Air cleaning
Sham Comparator: Normal air; 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); Use the air purifier (Pure Airbox, Zonair 3D) without filters in the classroom where the experiment is conducted; Other Names: Sham air cleaner

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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 Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	Obtained from a test administered approximately 90 minutes after entering the classroom
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	Obtained from a test administered approximately 90 minutes after entering the classroom
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	Obtained from a test administered approximately 90 minutes after entering the classroom
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	Obtained from a test administered approximately 90 minutes after entering the classroom
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	Obtained from a test administered approximately 90 minutes after entering the classroom
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.	Obtained from a test administered approximately 100 minutes after entering the classroom

Collaborators and Investigators

• Sponsor: Barcelona Institute for Global Health
• Collaborators: Recercaixa; Centre de Recerca per a l'Educació Científica i Matemàtica (CRECIM); Institute of Environmental Assessment and Water Research (IDAEA-CSIC); Economics and Bussiness Department, Universtitat Pompeu Fabra
• Investigators: Principal Investigator: Xavier Basagaña, PhD, Barcelona Institute for Global Health

Study record dates

Study Major Dates

• Study Start (Actual): November 23, 2018
• Primary Completion (Actual): June 11, 2019
• Study Completion (Actual): June 11, 2019

Study Registration Dates

• First Submitted: November 23, 2018
• First Submitted That Met QC Criteria: November 30, 2018
• First Posted (Actual): December 3, 2018

Study Record Updates

• Last Update Posted (Actual): June 12, 2025
• Last Update Submitted That Met QC Criteria: June 11, 2025
• Last Verified: June 1, 2025

More Information

Terms related to this study

• Keywords: Attention; Decision making; Air pollution; Particulate matter; Black carbon; Risk behavior; Social preferences; Air purifier; Air cleaner
• Other Study ID Numbers: PI2030

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: All collected IPD except identifying information for participants or high schools will be shared
• IPD Sharing Time Frame: Data will become available when publishing the results in a scientific journal, with no time restrictions
• IPD Sharing Access Criteria: Access to anyone via a public repository
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ANALYTIC_CODE

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No