- Understanding aviation noise
- Health impacts of noise
Today, we consider noise annoyance as the most prominent and immediate impact reaction to aviation noise. In other words, aircraft noise is well known as an environmental stressor negatively affecting human health. It is essential to understand the underlying mechanisms in order to tackle and (re)act on the problem of harmful effects of environmental conditions such as noise exposure.
Model of the impact of environmental noise
The link between aircraft noise annoyance and health outcomes
While the WHO did not commission a review on the relationship between annoyance due to aircraft noise and other health outcomes, it highlighted annoyance as a potential mediator of other long-term health impacts (WHO, 2018).
The WHO states that noise annoyance leads to anger, disappointment, dissatisfaction, withdrawal, helplessness, depression, anxiety, distraction, agitation or exhaustion and sleep disturbance (WHO, 2018). Noise provokes – through an indirect pathway – disturbance, cognitive and emotional responses summarised in the annoyance reaction (Babisch, 2002). Annoyance-related underlying neuroendocrine and neural activations affecting the organism's metabolic state might contribute to prolonged stress reactions. The multi-dimensional annoyance structure might be related to, or even contribute to, various undesirable health outcomes or even to manifest disorders.
Furthermore, it is suggested that health outcomes are linked to noise annoyance or, rather, noise annoyance contributes to the development of health outcomes. However, the causal pathway is not determined.
After the WHO (2018) guidelines on environmental noise were published (based on work between 2000 and 2015), ANIMA reviewed articles beyond the WHO cut off date on this topic to collate findings on the potential relationship and further understand this issue. Studies included in the review investigated the relationship between noise annoyance caused by aircraft and cardiovascular diseases, sleep, quality of life, mental health-related measures and physical activity.
In the following, the number of studies identified in the ANIMA review in addition to the WHO report (2018) together with their key messages are reported.
Three studies found a positive association between noise annoyance and hypertension; one indicated that the relative risk of hypertension among subjects reporting annoyance was significantly higher than in those not reporting annoyance. The second study showed that only people with higher noise annoyance levels had a more substantial effect on hypertension risk and the third study found higher rates for the use of antihypertensive medication in highly annoyed people than in those not highly annoyed. A cross-sectional study observed no significant association between blood pressure levels and aircraft noise annoyance. Measures differed substantially and, as all of the studies are cross-sectional, the evidence is not sufficient to draw consistent general conclusions.
Annoyance and sleep quality
Two studies investigated the link between annoyance and sleep quality and sleep disturbance; results of both studies – although differing in measures – indicate a possible association between self-reported sleep measures and noise annoyance.
Two studies focused on mental health and wellbeing related measures. One longitudinal study observed the relationship between aircraft noise annoyance and mental health-related quality of life (QoL). One cross-sectional study examined the relationship between aircraft noise annoyance and psychological distress.
The former study found a negative association between mental health-related quality of life and annoyance. Analysing the causal pathway revealed annoyance to mediate noise levels on future mental health-related QoL. Also, a reciprocal association between annoyance and mental health-related QoL was observed. Additionally, mental health-related QoL seemed to influence future annoyance ratings negatively.
The latter study found no association between noise exposure and psychological distress. However, psychological distress was linked to aircraft noise annoyance, with a substantial increase in distress for people who were extremely annoyed.
One longitudinal study showed that transportation noise annoyance is negatively associated with physical activity; a decrease in moderate physical activity was seen to be a result of a long-time noise annoyance (ten-year follow-up).
Results indicate that, to a certain extent, individual appraisals of noise contribute more to health outcomes than noise levels themselves. Some studies point out that noise annoyance might serve as a mediator between noise exposure and health outcomes. Long-term studies are needed to further investigate the causal relationship between annoyance and health outcomes. More complex models on how health outcomes are affected by noise, noise annoyance and its underlying factors also need further study.