San Simón Coatepec

2.5.1 Ethical approval and procedural techniques

Ethical approval was granted by the following three ethics committees to conduct the study.

1) The Joint University College London and University College London Hospital Committees on the Ethics of Human Research: Committee Alpha.

2) The Hillingdon Health Agency Ethics Committee

3) The Ealing, Hammersmith and Hounslow Health Authority Hounslow Research Ethics Committee.

Ethical measures that were used in the study were: child and parent written consent for participation, child and parent information sheets, child information days one week before the testing sessions so that they are informed about the research and have time to consider whether to take part. One child from a low noise school refused to take part in the study. Children were free to withdraw from the study at any point and did not have to answer any question they do not want to. There was a debriefing of the children after the testing sessions.

2.5.2 Testing at the schools

For an summary outline of the classroom testing at baseline see Table 5, and for follow- up see Table 6.

Baseline Testing

The headteachers were asked for permission to conduct the research in their schools. The headteachers then approached the school governors and staff to ask for permission. Parents in the selected year 4 and 5 classes were sent letters explaining the research, an information sheet and a consent form to be signed. The study was introduced as a Health and Environment study in parents and children to the teachers, parents and children. This introduction did not focus on noise to avoid response bias, a technique successfully used in previous studies (Job et. al, 1991b). Cognitive performance tests,

motivation tasks and the questionnaire were group administered to the children in the morning in the classroom. Although the tasks were administered in the classroom, the tasks were carried out individually under exam conditions. Group administration was used since a questionnaire completed in a group situation is known to be conducive to co-operation in answering sensitive questions (Job & Bullen, 1987). The testing was conducted on 3 days each a week apart, controlling for questionnaire order and time o f day across noise exposure. Children who were identified as having a severe learning problem were assisted by the researchers. These children were already excluded on ‘a priori’ grounds (see exclusions section). This small sub-group were assisted so that they were not upset by failure and so they felt they could take part in the project.

The psychological scales were administered before the motivation task so that any feelings of failure induced by the first insoluble puzzle would not interfere with the responding. The motivation task was given as the last task of testing so that any transient m ood effects possibly induced from completing the psychological scales would be diminished. During piloting any change in mood induced by the

psychological scales had passed by the time of the motivation task. Activities that were read aloud to the children or were administer using an audio-tape were repeated if class­ room noise or aircraft noise detracted from audibility.

Testing was conducted in the classrooms in order produce a more realistic setting. Children’s performance may be a more accurate assessment o f their everyday

functioning than laboratory testing as the testing was conducted in the same situation that all other school performance is measured. The teachers were given the teacher questionnaire in the same month as the testing sessions.

Table 5.

An outline o f the protocol o f the classroom testing at baseline. (Chapter 2 Methods)

Testing Day W eek 1 T esting Day 1 W eek 2 Testing D ay 2 W eek 3 Testing D ay 3 Explanation of the Child and parental Psychological R esearch study to the children written consent Scales. Activities

Information sheets

obtained depression

anxiety handed out the

children

Long term memory and reading

comprehension

attributional style

Health and Socio-demographic cognitive performance Environment data collected from

the children

tests

Acute noise

Questionnaire

Short-term The reading task was

given. measurements Throughout memory Motivation behavioural performance task Acute noise measurements throughout Tim e T ak en

30 minutes 75 minutes 75 minutes

Follow-up testing

Testing at the schools was conducted in exactly the same way as in 1996 as far as possible, with the same research team. The head teachers were approached and asked for permission to conduct the follow-up research in their schools. Parents of the 1996 sample were sent letters explaining the research, an information sheet and a consent form to be signed. The study was introduced as a continuation of the 1996 study which was a health and environment study in parents and children.

In March 1997 testing was conducted in two schools exposed to high levels of aircraft noise (Bedfont Junior and Chatsworth Junior) and two schools exposed to low levels o f aircraft noise (Feltham Hill Junior and Hermitage Junior). In April 1997 testing was conducted in two schools exposed to high levels of aircraft noise (Springwell Junior and W ellington Primary) and two schools exposed to low levels o f aircraft noise (Wood End Park Junior and Strand on the Green Junior). The time delay between baseline and follow-up was not exactly 12 months for all schools; it was 11 months later for 3

schools, 12 months later for 3 schools, 10 months later for 1 school, 9 months later for 1 school. Due to pragmatic constraints (e.g. school timetable) is was impossible to have a uniform time delay across all the schools.

The testing was conducted on 3 days each a week apart, controlling for questionnaire order and time o f day across noise exposure (see Table 6, below). The question order remained the same as in 1996, except the sustained attention task replaced the

motivation task at the end of the third day of testing. The sustained attention task was given as the last task of testing of that any transient mood effects possibly induced from completing the psychological scales would be diminished.

The classrooms in which the testing was conducted differed from 1996, so it is possible that noise exposure at the classroom level may have changed between 1996 and 1997. This possibility will be considered when interpreting the results. Noise measurements were taken at the individual schools during testing will help quantify this difference.

Table 6.

An outline o f the protocol o f the classroom testing at follow-up. {Chapter 2 Methods)

Testing

Week 1

Week 2

Week 3

Day

Testing Day 1

Testing Day 2

Testing Day 3

Explanation of the Child and parental Psychological

Research