Health Facts

Health Facts

Highlights: Community Aircraft Noise: A Public Health Issue,  Karen Bowman, MN, RN, COHN-S, Karen Bowman & Associates, Inc.

Included below are sections and highlights from the article.  See the entire article with citations at: Highlights: Community Aircraft Noise: A Public Health Issue

On May 7, 2013 jet noise studies were conducted at (5) locations near the touch and go landing strip called “Outlying Field” (OLF) on Whidbey Island 3 miles southeast of Coupeville, WA. Positions 1-4 were outside locations; position 5’s noise measurements were inside a community member’s home. All the locations are in populated community locations where citizens may be exposed to military aircraft noise and without hearing conservation training nor the proper training and fitting of hearing protection, may sustain sensorineural noise induced hearing loss9 among a host of other diseases and conditions. The JGL noise studies determined that maximum sound levels were clearly above levels requiring hearing protection10 and they surpassed Washington State, the U.S. Environmental Protection Agency and the World Health Organization community noise protection guidelines.

Environmental and occupational noise exposures are major contributors to NIHL but it is not the only health effect that has been associated with loud noise. In fact loud noise has been shown to contribute to: cardiac problems including myocardial infarction, elevated triglycerides and cholesterol; immunotoxicity; cognitive impairment including slowed learning, performance and memory issues; psychosocial problems stemming from the lack of ability to communicate; sleep disturbances; exacerbation of depression and anxiety and overall general annoyance.17 18 Moreover, not only have such health effects been associated with noise exposure aircraft noise has been identified as a major offender.19 One study determined substantial disturbance is reached with flight noise of 55 dBA in the daytime and 45dBA at night outside.20 The pain and suffering associated around hearing loss is overwhelming.

Some studies around commercial airports identified higher psychiatric admissions, others identified higher prescription dispensation but these studies were not replicable. Another study cited a dose-response association with higher levels of military aircraft noise and depressiveness and nervousness.46

Noise, Stress Hormones and Health

Noise is a biological stressor. Excessive exposure to noise, as in aircraft or military aircraft noise, is a health risk and may be contribute to sleep disturbances, cardiovascular disease, hypertension47, myocardial infarction, gastrointestinal disease, migraine headaches and immunotoxicity.48

 When looking at the body holistically, it is easy to understand how environmental noise exposure disrupts the body’s homeostasis. Homeostasis defined is “a tendency of biological systems to maintain stability while continually adjusting to conditions that are optimal for survival.” 49One core component of non-auditory related health effects begins with stress. Hans Selye first coined the phrase “stress” and spent much of his career defining and researching the health effects associated with it. The stress reaction occurs when the body is exposed to physiological and/or psychological stimuli which Dr. Selye defined as “the general adaptation syndrome.” A simpler definition of stress from Dr. George Chrousos is “an animal’s state of threatened homeostasis.” 50 Much of the reviewed research shows that prolonged environmental noise, especially aircraft noise, causes enormous stress. A common question asked by researchers is there a particular personality type that complains of loud environmental noise and the answer is complicated? The answer is no. Individuals who have been identified as “noise sensitive” seem to not complain of health effects related to loud environmental noise any more than other individuals. However, some studies have indicated that if an individual has a perceived internal locus of control they tend to adapt better over time.51

Stress creates a cascade of releasing “fight or flight hormones” such as cortisol, adrenalin, epinephrine and norepinephrine which affect multiple systems in the body. When a person is exposed to loud noise a series of physiological responses occur; Adrenalin is released which increases the heart rate, blood pressure and breathing, blood is shunted to the vital organs like the brain and heart, reduced in less vital areas like the gastro-intestinal track, vasoconstriction occurs and muscles constrict, our mind becomes alert and focused. Continued releases of cortisol and other stress hormones leads to stress induced disease such as sleep disturbance, myocardial infarction, atherosclerosis and immunosuppression.52

The immune system is a complex mechanism that keeps our body in homeostasis. Studies have shown that certain T cells (white blood cells that protect the body from disease organisms and other foreign bodies known as antigens) become suppressed with psychological stressors thereby reducing immunity. Chronic stress also affects the inflammatory response which raises the risk of viral infection. Stress has also been shown to exacerbate other diseases as well such as asthma and diabetes, and it increases the risk of certain gut conditions that affect the production of gastric acid thereby increasing the risks of ulcerative colitis, stress and peptic ulcers.53 One study found that environmental noise impaired the immune system of workers which potentially put them at a higher risk of experiencing negative health effects from toxic chemical exposures, though further research is needed in this area.54

Aircraft Noise and Health

An exhaustive literature search found few articles related to military aircraft flight noise. None were noted earlier than 1990. H. Ising and E. Rebentisch et al (1990) conducted noise studies in the Federal Republic of Germany; Munsterland and Franken. The document determined that the physical characteristics of military low-altitude flight noise are different in terms of other aircraft flight noise; the extremely high maximal sound level and the very rapid increase in sound during direct over-flights. This combination increases community annoyance and health symptoms. Low altitude over-flight noise has been associated with cardiovascular problems and sleep disturbances even during the “quiet” nights that follow over-flights.55

Research conducted by W. C. Meecham and W. Shaw shows a link with jet noise and mortality rates.56 One study conducted by Meister and Donatelle (2000), using four neighborhoods exposed to commercial aircraft airports and two control group communities (no aircraft noise), found noise annoyance very stressful for the exposed neighborhoods. All health measures were significantly worse in the exposed communities than the control communities. This study confirmed the strong link between aircraft noise, stress load and decreased health consequences. It also confirms aircraft noise seriously affects a person’s sense of well being as measured by a “sense of vitality.” Below, the Generalized Etiology Framework (Meister & Donatelle 2000) adeptly uncovers the etiology of commercial aircraft noise on human health.

Chronic Commercial Aircraft Noise Exposure → Increased Stress Load → Chronic Psycho-physiological Stress Activation → Adverse Health Effects + Reduced Quality of Life57

Stress hormones are also sensitive to light and dark and awake-sleeping patterns consequently affecting our sleep. According to Prasher (2009) sleeping individuals cannot determine what the noise is so noise is therefore interpreted as “danger.” The conclusion derived is that the level of noise is not necessarily the predictor of the stress reaction but the rather the meaning of the noise for that individual. Aircraft noise is interpreted as danger thereby effecting cortisol levels. Aircraft noise has been associated with sleep disturbances and increased night time cortisol levels.58 A study included in Deepak Prasher’s (2009) research found that even loud noise exposure during the day reduced effective sleep patterns down to 80%, and the rapid eye movement (REM) phase of sleep associated with dreaming was critically affected.59Sleep is the time the body repairs and without it the body cannot survive.

Perhaps one of the most studied health effects of environmental and aircraft noise is cardiovascular disease. As mentioned prior, environmental and aircraft noise creates stress and chronic stress, which in turn increases the heart rate, pulse and blood pressure while creating vasoconstriction. It also clogs the arteries with plaque causing atherosclerosis which often causes angina or myocardial infarction.60 The Los Angeles Airport Study determined that chronic exposure to aircraft noise raised systolic and diastolic blood pressure. These results were significant even though the blood pressure numbers remained within normal limits. Another study in Munich linked chronic noise exposure to both baseline systolic blood pressure and lower reactivity of the systolic blood pressure when doing a cognitive task under acute noise. After the new airport opened a significant increase in the systolic blood press was noted proving that there was a causal link between the airport noise and a rise in blood pressure.61

The HYENA study (2008) is the first study that assessed the relationships between the risk of hypertension (high blood pressure) and exposure to aircraft noise and traffic noise around the airport using 4,861 people between the ages of 45-70 who had lived for at least 5 years around six major European airports. When adjusted for demographic and other confounders, nighttime aircraft noise of 10 dB(A) (L night) was associated with hypertension. The study’s principle investigators used the WHO LAEQ-T indicator of exposure which is the A-weighted equivalent continuous noise level over a specific time period. Specific times both for night and day were assigned. The document also cited previous research that found aircraft noise as a hazard risk for high blood pressure which is a major risk factor for cardiovascular disease including stroke.62

One study (Huss, et al. 2010) used the Swiss National Cohort and the national census which included demographic data on where citizens lived as its cohort. The study included hospitalizations and ICD-9 codes in the identified areas. It also included 65 airports and airfields in Switzerland. Zurich, the largest airport had a dedicated noise exposure model, the other 64 used an exposure model from the Federal Office of Civil Aviation. The study was adjusted for confounders and it was determined that acute and chronic noise exposure in particular aircraft noise is associated with high blood pressure, heart attacks, increased cardiovascular medication and cardiovascular morbidity and mortality. The risk of death from heart attacks was higher in individuals exposed to aircraft noise of 60 dB(A) or more and when you combined aircraft noise when associated with particulate matter PM10 exposure and adjusted for socio-demographic and geographical variables. 63

Lastly, a multi-airport retrospective study of approximately 6 million older people residing near airports in the United States utilized 2218 zip codes surrounding 89 airports in the contiguous states was conducted in 2009. The researchers used ICD-9 codes from hospital admissions to determine if groups exposed to commercial aircraft around commercial airports were at higher risk for negative cardiac outcomes and despite limitations related to potential misclassification of exposure there was a statistical significance relating airplane noise and cardiovascular disease related hospitalizations among older people living around airports.64

Summary

This document articulates the serious health effects of environmental noise exposure in particular aircraft and military aircraft noise at the community level. Health effects range from sleep disturbance, depression, anxiety and cognitive impairment to atherosclerosis, cardiac disease, myocardial infarction and even death. Cardiovascular disease, including hypertension and myocardial infarction has the most statistically significant data and sadly it is the most serious of the negative health effects associated with aircraft noise. The continued over activation of stress hormones are not only key factors in cardiac disease but also in immune-toxicity causing a host of other conditions ranging from the increased probability of accidents to the development of other acute and chronic diseases.

 Aircraft noise, especially as a night time exposure, exacerbates the release of the hormones which dramatically throws the body out of homeostasis and health. Aircraft noise, in particular low-altitude over-flights, is a public health issue that must be addressed to reduce the negative health outcomes of community members for generations to come. Current mitigation strategies for low flying aircraft according to Hartmut Ising, et al (1990) should range from reducing over-flight noise levels to 115db(A), a maximum sound level increase speed of 60 dB(A) and a reduction of over-flights.65

The community of Coupeville has sustained noise levels above “community noise exposure levels” for State and National guidelines and law. The Washington State (Chapter 70.107 RCW NOISE CONTROL/WAC 173-60) state that the maximum noise in a residential setting should be no greater than 55dBA and between 10pm-7am the maximum noise should be reduced by 10dBA = 45dBA. The JGL Acoustics study confirmed Position (5), which was a private residence, had noise measurements of Lmax 81.1 dBA at 8:30pm; surpassing state guidelines.66 The EPA sets noise standards as 70 dBA 24 hour Leq. JGL Acoustics noise measurements for Coupeville were: Lmax levels ranged from 119.2-113.4dBA and predicted Laverage over 24 hours 64.1-75.0; again over guidelines established by Washington State and the EPA.67 The World Health Organization recommends no more than <30dBA inside the bedroom for good quality sleep and no higher than<40dBA outside the bedroom to prevent adverse health effects.68

The citizens of Coupeville Washington are chronically exposed to loud, low-flying military aircraft. Studies confirm a host of diseases and injuries are associated with this type of noise hazard such as but not limited to: stress, psychosocial trauma, increased potential for accidents, decreased memory and cognitive function and lastly cardiac disease ending in potential death by myocardial infarction. Recommendations include implementing industrial hygiene control measures starting with eliminating the hazard or closing the OLF. Further recommendations include conducting a well thought out Environmental Impact Statement in conjunction with a Health Impact Assessment. Both must have stakeholder involvement including Coupeville citizens to fully assess determinants of health and community impact. Doing so will promote health and homeostasis not only for individuals, but for the community as a whole. Further research is needed to address the health effects associated with military aircraft and military low-altitude flight noise especially using current military aircraft/jet technology to not only protect citizens but Navy personnel as well. Additionally, further research is needed to critically assess all human and environmental health impacts associated with this phenomenon and more importantly development of control measures to abate the effects of this chronic environmental noise exposure.

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