Mary M. Haines

Aircraft and road traffic noise and children's cognition and health: a cross-national study

BACKGROUNDnExposure to environmental stressors can impair childrens health and their cognitive development. The effects of air pollution, lead, and chemicals have been studied, but there has been less emphasis on the effects of noise. Our aim, therefore, was to assess the effect of exposure to aircraft and road traffic noise on cognitive performance and health in children.nnnMETHODSnWe did a cross-national, cross-sectional study in which we assessed 2844 of 3207 children aged 9-10 years who were attending 89 schools of 77 approached in the Netherlands, 27 in Spain, and 30 in the UK located in local authority areas around three major airports. We selected children by extent of exposure to external aircraft and road traffic noise at school as predicted from noise contour maps, modelling, and on-site measurements, and matched schools within countries for socioeconomic status. We measured cognitive and health outcomes with standardised tests and questionnaires administered in the classroom. We also used a questionnaire to obtain information from parents about socioeconomic status, their education, and ethnic origin.nnnFINDINGSnWe identified linear exposure-effect associations between exposure to chronic aircraft noise and impairment of reading comprehension (p=0.0097) and recognition memory (p=0.0141), and a non-linear association with annoyance (p<0.0001) maintained after adjustment for mothers education, socioeconomic status, longstanding illness, and extent of classroom insulation against noise. Exposure to road traffic noise was linearly associated with increases in episodic memory (conceptual recall: p=0.0066; information recall: p=0.0489), but also with annoyance (p=0.0047). Neither aircraft noise nor traffic noise affected sustained attention, self-reported health, or overall mental health.nnnINTERPRETATIONnOur findings indicate that a chronic environmental stressor-aircraft noise-could impair cognitive development in children, specifically reading comprehension. Schools exposed to high levels of aircraft noise are not healthy educational environments.

Chronic aircraft noise exposure, stress responses, mental health and cognitive performance in school children

BACKGROUNDnPrevious research suggests that children are a high risk group vulnerable to the effects of chronic noise exposure. However, questions remain about the nature of the noise effects and the underlying causal mechanisms. This study addresses the effects of aircraft noise exposure on children around London Heathrow airport, in terms of stress responses, mental health and cognitive performance. The research also focuses on the underlying causal mechanisms contributing to the cognitive effects and potential confounding factors.nnnMETHODSnThe cognitive performance and health of 340 children aged 8-11 years attending four schools in high aircraft noise areas (16 h outdoor Leq > 66 dBA) was compared with children attending four matched control schools exposed to lower levels of aircraft noise (16 h outdoor Leq < 57 dBA). Mental health and cognitive tests were group administered to the children in the schools. Salivary cortisol was measured in a subsample of children.nnnRESULTSnChronic aircraft noise exposure was associated with higher levels of noise annoyance and poorer reading comprehension measured by standardized scales with adjustments for age, deprivation and main language spoken. Chronic aircraft noise was not associated with mental health problems and raised cortisol secretion. The association between aircraft noise exposure and reading comprehension could not be accounted for by the mediating role of annoyance, confounding by social class, deprivation, main language or acute noise exposure.nnnCONCLUSIONSnThese results suggest that chronic aircraft noise exposure is associated with impaired reading comprehension and high levels of noise annoyance but not mental health problems in children.

Noise and health in the urban environment.

Noise, including noise from transport, industry, and neighbors, is a prominent feature of the urban environment. This paper reviews the effects of environmental noise on the non-auditory aspects of health in urban settings. Exposure to transport noise disturbs sleep in the laboratory, but generally not in field studies, where adaptation occurs. Noise interferes with complex task performance, modifies social behavior, and causes annoyance. Studies of occupational noise exposure suggest an association with hypertension, whereas community studies show only weak relations between noise and cardiovascular disease. Aircraft and road-traffic noise exposure are associated with psychological symptoms and with the use of psychotropic medication, but not with the onset of clinically defined psychiatric disorders. In carefully controlled studies, noise exposure does not seem to be related to low birth weight or to congenital birth defects. In both industrial studies and community studies, noise exposure is related to increased catecholamine secretion. In children, chronic aircraft noise exposure impairs reading comprehension and long-term memory and may be associated with increased blood pressure. Noise from neighbors causes annoyance and sleep and activity interference health effects have been little studied. Further research is needed for examining coping strategies and the possible health consequences of adaptation to noise.

Body mass, weight control behaviours, weight perception and emotional well being in a multiethnic sample of early adolescents

Objective:To investigate weight perception, dieting and emotional well being across the range of body mass index (BMI) in a population-based multiethnic sample of early adolescents.Design:Cross-sectional population-based survey.Subjects:In total, 2789 adolescents 11–14 years of age from three highly deprived regional authorities in East London, in 2001.Measurements:Data were collected by student-completed questionnaire on weight perception, dieting history, mental and physical health, health behaviours, social capital and sociodemographic factors. Height and weight were measured by trained researchers. Overweight was defined as BMI ⩾85th centile and obesity as BMI ⩾98th centile. Underweight was defined as BMI⩽15th centile.Results:In all, 73% were from ethnic groups other than white British. Valid BMI were available for 2522 subjects (90.4%) of whom 14% were obese. Only 20% of overweight boys and 51% of overweight girls assessed their weight accurately. Accuracy of weight perception did not vary between ethnic groups. In all, 42% of girls and 26% of boys reported current dieting to lose weight. Compared with white British teenagers, a history of dieting was more common among Bangladeshi, Indian and mixed ethnicity boys and less likely among Pakistani girls. Self-esteem was not associated with BMI in girls but was significantly lower in obese boys than those of normal weight (P=0.02). Within ethnic subgroups, self-esteem was significantly lower in overweight white British boys (P=0.03) and obese Bangladeshi boys (P=0.01) and Bangladeshi girls (P=0.04), but significantly higher in obese black African girls (P=0.01) than those of normal weight. Obese young people had a higher prevalence of psychological distress (P=0.04), except among Bangladeshi teenagers, where overweight and obese young people had less psychological distress than those of normal weight (P=0.02). Birth outside the UK was associated with reduced risk of obesity in girls (P=0.02) but not with history of dieting, weight perception or psychological factors in either gender.Conclusion:High levels of current dieting for weight control and inaccurate perception of body mass are common across all ethnic groups. However, dieting history and the associations of obesity with self-esteem and psychological distress vary between ethnic groups. Interventions to prevent or treat obesity in black or minority ethnicity groups must consider cultural differences in the relationship between body mass, self-esteem and psychological distress.

The role of noise sensitivity in the noise-response relation: a comparison of three international airport studies.

In order to examine the role of noise sensitivity in response to environmental noise, this paper presents detailed comparisons of socio-acoustic studies conducted around international airports in Amsterdam, Sydney, and London. Earlier findings that noise sensitivity moderates the effect of noise on annoyance were examined to see if they could be replicated in each of the datasets, independent of the technique of measuring noise sensitivity. The relation between exposure to aircraft noise and noise annoyance was studied separately for groups of individuals with low, medium, and high noise sensitivity, with statistical adjustment for relevant confounders. Results support the previous findings that noise sensitivity is an independent predictor of annoyance and adds to the prediction of noise annoyance afforded by noise exposure level by up to 26% of explained variance. There is no evidence of a moderating effect, whereby the covariation between noise exposure level and annoyance is weak for people who score at the extreme high or low end of the sensitivity scale, and strong for people who score in the middle of the sensitivity scale. Generally, noise sensitivity appears to increase annoyance independently of the level of noise exposure after adjustment for relevant confounders. These findings were consistent across the three datasets.

The West London Schools Study: the effects of chronic aircraft noise exposure on child health

BACKGROUNDnPrevious field studies have indicated that childrens cognitive performance is impaired by chronic aircraft noise exposure. However, these studies have not been of sufficient size to account adequately for the role of confounding factors. The objective of this study was to test whether cognitive impairments and stress responses (catecholamines, cortisol and perceived stress) are attributable to aircraft noise exposure after adjustment for school and individual level confounding factors and to examine whether children exposed to high levels of social disadvantage are at greater risk of noise effects.nnnMETHODSnThe cognitive performance and health of 451 children aged 8-11 years, attending 10 schools in high aircraft noise areas (16 h outdoor Leq > 63 dBA) was compared with children attending 10 matched control schools exposed to lower levels of aircraft noise (16 h outdoor Leq < 57 dBA).nnnRESULTSnNoise exposure was associated with impaired reading on difficult items and raised annoyance, after adjustment for age, main language spoken and household deprivation. There was no variation in the size of the noise effects in vulnerable subgroups of children. High levels of noise exposure were not associated with impairments in mean reading score, memory and attention or stress responses. Aircraft noise was weakly associated with hyperactivity and psychological morbidity.nnnCONCLUSIONSnChronic noise exposure is associated with raised noise annoyance in children. The cognitive results indicate that chronic aircraft noise exposure does not always lead to generalized cognitive effects but, rather, more selective cognitive impairments on difficult cognitive tests in children.

Ethnicity, socio-economic status, overweight and underweight in East London adolescents.

Background The developed world is experiencing an ‘epidemic’ of childhood obesity but little is known about the prevalence of obesity, or underweight, amongst adolescents from minority ethnic groups in the UK. An understanding of the prevalence of obesity and overweight in these populations is important since some ethnic groups may be particularly vulnerable to the adverse health effects associated with obesity. Study Objectives To examine levels of extreme obesity, obesity, overweight and underweight amongst a representative sample of adolescents from different ethnic groups in East London and to explore the association between socio-economic status and body mass index (BMI). Design A school-based survey of adolescents aged 11–14. Obesity and overweight were estimated using the 1990 UK growth reference (UK 90) and the International Obesity Task Force (IOTF) cut-off points. Extreme obesity was defined as a BMI more than three SD above the UK 90 mean. Underweight was examined by looking at those with a BMI below the 15th or the 5th UK 90 percentiles. Main Results A total of 2,482 adolescents were surveyed (response rate 84%), 73% from non-white ethnic groups. Although there were significant differences in BMI between ethnic groups, high levels of overweight were seen in all ethnic groups. More than one-third were overweight and one-fifth were obese using the UK 90; and over a quarter were overweight and almost one-tenth were obese using the IOTF cut-offs. Two per cent were extremely obese. Indian males were at higher risk of being overweight than white British males. The prevalence of obesity and overweight was similar in white British and Bangladeshi males. Overall the prevalence of underweight was slightly lower than that predicted by the UK 90, but South Asian ethnic groups, especially males, had a higher prevalence of underweight than other groups. No associations between BMI and measures of socio-economic status were found in this relatively deprived population. Conclusions The ‘epidemic’ of childhood obesity observed in the UK involves adolescents from all ethnic groups, although there are some differences between ethnic groups in the prevalence of overweight. Indian males appear to be at increased risk of being overweight. There is no evidence of a simultaneous increase in underweight amongst this population overall, but Bangladeshi, Indian and Pakistani boys appear to be at increased risk of being underweight.

Multilevel modelling of aircraft noise on performance tests in schools around Heathrow Airport London

Study objective: To examine the effects of chronic exposure to aircraft noise on childrens school performance taking into account social class and school characteristics. Design: This is a cross sectional study using the National Standardised Scores (SATs) in mathematics, science, and English (11 000 scores from children aged 11 years). The analyses used multilevel modelling to determine the effects of chronic aircraft noise exposure on childrens school performance adjusting for demographic, socioeconomic and school factors in 123 primary schools around Heathrow Airport. Schools were assigned aircraft noise exposure level from the 1994 Civil Aviation Authority aircraft noise contour maps. Setting: Primary schools. Participants: The sample were approximately 11 000 children in year 6 (approximately 11 years old) from 123 schools in the three boroughs surrounding Heathrow Airport. Main results: Chronic exposure to aircraft noise was significantly related to poorer reading and mathematics performance. After adjustment for the average socioeconomic status of the school intake (measured by percentage of pupils eligible for free school meals) these associations were no longer statistically significant. Conclusions: Chronic exposure to aircraft noise is associated with school performance in reading and mathematics in a dose-response function but this association is confounded by socioeconomic factors.

Children's cognition and aircraft noise exposure at home-the West London Schools Study

In this study, two investigations were carried out with adult Long-Evans rats exposed to increasing concentrations of styrene. In the first experiment, the hearing of rats, which were forced to walk in a special wheel during the exposure, was compared to that of rats which were sleepy in their cage. The active rats were exposed to styrene concentrations ranging from 300 to 600 ppm, whereas the sedentary rats were exposed from 500 to 1000 ppm for 4 weeks, 5 days per week, 6 hours per day. In the second experiment, designed to evaluate the hearing risks at threshold limit values, active rats were exposed either to a noise having a Leq8h of 85 dB (equivalent level of a continuous noise for a typical 8-h workday), or to 400-ppm styrene or to a simultaneous exposure to noise and styrene. In both experiments, auditory function was tested by auditory-evoked potentials from the inferior colliculus and completed by morphological analyses of the organ of Corti. The results of the first experiment showed that the same amount of styrene-induced hearing loss can be obtained by using concentrations approximately 200 ppm lower in active rats than in sedentary rats. The second investigation showed that, in spite of the low-intensity noise and the low-concentration of styrene, there is a clear risk of potentiation of styrene-induced hearing loss by noise. These findings and exposure conditions were discussed and extrapolated with regard to the risk assessment for human beings. The authors propose to decrease the French threshold limit value of styrene for ensuring a high level of protection for human hearing.

Cultural identity, acculturation, and mental health among adolescents in east London’s multiethnic community

Study objective: To investigate cultural identity as a risk factor for mental health problems among adolescents. Design: A cross sectional school based population survey. Mental health problems were measured using the strengths and difficulties questionnaire. Pupils were classified into one of four cultural identity types on the basis of friendship and clothing choices. Setting: East London. Participants: 2623 adolescents (aged 11–14) from a representative sample of 28 schools in east London. Results: In comparison with marginalised adolescents who chose friends from neither their own or other cultures, fewer mental health problems were found among adolescents making culturally integrated friendship choices (friends from own and other cultures: ORu200a=u200a0.6, 0.4 to 0.9), boys making integrated friendship choices (ORu200a=u200a0.45, 0.22 to 0.91), and specifically among Bangladeshi pupils with integrated friendship choices (ORu200a=u200a0.15, 0.04 to 0.55). Conclusion: As measures of cultural identity, integrated friendship choices overall, and specifically for boys and Bangladeshi pupils, are associated with lower levels of adolescent mental health problems.