5.7.99 The health impacts of environmental noise are widely acknowledged. A number of reviews of noise-induced health effects have been published (for example, WHO 2011279), which highlight potential impacts on cardio-vascular disease, cognitive impairment, sleep disturbance and annoyance.
5.7.100 WHO consider the health burden of environmental noise in terms of Disability-Adjusted Life Years (DALYs). One DALY can be thought of as one lost year of "healthy" life. The sum of these DALYs across the population, or the burden of disease, can be thought of as a measurement of the gap between current health status and an ideal health situation where the entire population lives to an advanced age, free of disease and disability.
279 WHO, 2011. Burden of disease from environmental noise: Quantification of healthy life years lost in Europe. [online]
5.7.101 Therefore any noise impacts resulting in one DALY lost can be thought of as one lost year of
‘healthy life’. DALYs considers life expectancy and the incidence of disease, weighted by the severity of the disease (from 0 to 1, where 0 is full health and 1 is equivalent to death).Years Lost due to Disability (YLD) are calculated by multiplying the incident cases by duration and disability weight for the condition.
5.7.102 WHO estimate that, in EU Member States and other western European countries, DALYs lost are 61,000 years for ischaemic heart disease, 45,000 years for cognitive impairment of children, 903,000 years for sleep disturbance and 654,000 years for annoyance. Swift 280 provided a review of impacts in the vicinity of airports, focussing on sleep disturbance and stress as pathways leading to eventual cardiovascular outcomes and the potential mis-attribution of certain conditions, e.g. obesity and diabetes, as confounding factors whereas these conditions themselves may have resulted from sleep disturbance.
5.7.103 The noise assessment follows the methodology outlined in the DfT’s WebTAG framework for valuing the effects of environmental noise on health and amenity281. The effects considered include annoyance and sleep disturbance (amenity effects), and acute myocardial infarction (AMI, ie heart attack), hypertension-related stroke and hypertension-related dementia (health effects).
The impacts referred to under ‘amenity effects’ are considered in the health impact analysis as i) these effects are considered by Defra as pathways to other physiological adverse health
outcomes282; ii) the WHO constitution defines ‘health’ broadly in terms of “a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity” – this includes the disruption of healthy wellbeing in terms of both annoyance and sleep disturbance.
5.7.104 An N70 contour has been used to define the loss of tranquillity (where N70 is the number of noise events above 70 dB(A) per day) has, where possible, been applied as an indication of audible disturbance and loss of tranquillity. The 70 dB(A) level was chosen as an external single noise event will be attenuated by a minimum of 10 dB(A) by the fabric of a house with open windows.
The resulting internal noise level of 60 dB(A) is the noise level which is likely to interfere with conversation or with listening to the radio or the television.
5.7.105 The range of potential impacts is described in more detail below and with reference to specific studies.
SLEEP DISTURBANCE
5.7.106 Environmental noise can be a significant cause of sleep disturbance. Poor sleep causes endocrine and metabolic measurable perturbations and is associated with a number of
cardiovascular, psychiatric and social negative outcomes both in adults and children. Nocturnal environmental noise also provokes measurable biological changes in the form of a stress response, and clearly affects sleep architecture, as well as subjective sleep quality.
5.7.107 Noise-induced sleep perturbations are similar in their nature to those observed from other sleep disorders associated with ill health. Apart from these measurable effects and the subjective feeling of disturbed sleep, people who struggle with nocturnal environmental noise often also suffer the next day from daytime sleepiness and tiredness, annoyance, mood changes as well as decreased wellbeing and cognitive performance.
280 A Review of the Literature Related to Potential Health Effects of Aircraft Noise, Hales Swift, Purdue University, 2010.
281 Department for Transport, 2015. TAG Unit A3: Environmental Impact Appraisal. [online] Accessed 03/05/2016.
282Department for Environment, Food and Rural Affairs, 2014. Environmental noise: valuing impacts on sleep disturbance, annoyance, hypertension, productivity and quiet. [online] Accessed 03/05/2016.
5.7.108 There is emerging evidence that these short-term effects of environmental noise, particularly when the exposure is nocturnal, may be followed by long-term poor cardiometabolic outcomes.
Nocturnal environmental noise may be the most worrying form of noise pollution in terms of its health consequences because of its synergistic direct and indirect (through sleep disturbances acting as a mediator) influence on biological systems.
5.7.109 Duration and quality of sleep needs to be regarded as risk factors or markers significantly
influenced by the environment and possibly amenable to modification through both education and counselling as well as through measures of public health. One of the means that should be proposed is avoidance at all costs of sleep disruptions caused by environmental noise.
CARDIOVASCULAR HEALTH
5.7.110 Aircraft noise exposure has been linked to increased risk of poor cardiovascular health.
Occurrences of hypertension (high blood pressure), heart attack, and stroke, increase by 7 to 17%283 with every 10dB increase in either aircraft or road traffic noise exposure. A study of exposure to aircraft noise around Heathrow found that people exposed to high levels of aircraft noise had a 24% higher chance of stroke, 21% higher chance of heart disease, and 14% higher chance of cardiovascular diseases compared to those exposed to low levels of aircraft noise.
PSYCHOLOGICAL HEALTH
5.7.111 Long term noise exposure is believed to have an influence on psychological health, although, with the exception of annoyance, there is not as strong a link as for other health outcomes.
5.7.112 Annoyance284, rather than aircraft noise levels, has been reported as being more closely associated with lower quality of life in some studies of residents’ responses to aircraft noise.285 5.7.113 Within studies of the effect of aircraft noise on children around London Heathrow, there was no
detected effect of aircraft noise on children’s psychological health or cortisol levels (which can be raised in children with depression).286,287
5.7.114 From the few studies on the effects of aircraft noise on adult psychological health, one found that there was a 28% increase in anxiety medication use corresponding with a 10dB increase in day-time noise (measured as LAeq 16 hour) and a 27% increase with 10dB increase in night-time aircraft noise.288
5.7.115 There was no association between sleep medication or anti-depressant medication use and day or night-time exposure to aircraft noise.289
NOISE IMPACTS ON EDUCATIONAL ATTAINMENT
5.7.116 Several studies have demonstrated that aircraft noise exposure, at school290, has detrimental
283 Basner, M., Babisch, W., Davis, A., Brink, M., Clark, C., Janssen, S., et al.,2014. Auditory and non-auditory effects of noise on health. Lancet, 383, 1325-1332.
284 http://publicapps.caa.co.uk/docs/33/ERCD1006.pdf
285 Schreckenberg, D., Meis, M., Kahl, C., Peschel, C., & Eikmann, T. 2010. Aircraft noise and quality of life around Frankfurt Airport. International journal of environmental research and public health, 7, 3382-3405.
286 Haines, M.M., Stansfeld, S.A., Brentnall, S., Head, J., Berry, B., Jiggins, M., et al. 2001a. The West London Schools Study: the effects of chronic aircraft noise exposure on child health. Psychological Medicine, 31, 1385-1396.
287 Haines, M.M., Stansfeld, S.A., Job, R.F., Berglund, B., & Head, J. (2001b). Chronic aircraft noise exposure, stress responses, mental health and cognitive performance in school children Psychological Medicine, 31, 265-277.
288 Babisch, W., Houthuijs, D., Pershagen, G., Cadum, E., Katsouyanni, K., Velonakis, M., et al. (2009). Annoyance due to aircraft noise has increased over the years--results of the HYENA study. Environment International, 35, 1169-1176
289 Jarup, L., Babisch, W., Houthuijs, D., Pershagen, G., Katsouyanni, K., Cadum, E., et al. (2008). Hypertension and exposure to noise near airports: the HYENA study. Environmental Health Perspectives, 116, 329-333.
impacts on children’s reading comprehension or memory skills,291 and is associated with impaired reading comprehension292. Though one study suggested that the main focus of effects of aircraft noise upon children should be at school rather than at home.293
5.7.117 A recent review of the health effects of noise exposure in children, suggested generic school noise exposure can have a detrimental effect on children’s cognitive skills such as reading and memory, and other studies have suggested exposure of children to noise is associated with increased hyperactivity symptoms.294
5.7.118 The exposure-response relationship between aircraft noise at school and reading comprehension has indicated that, as aircraft noise exposure increases, performance on reading tests
decreases295. In the UK study, reading age was delayed by up to 2 months for a 5dB increase in aircraft noise exposure.