Noise Pollution Leads to Cardiovascular Diseases

Noise means ‘unwanted sound’. It is perceived as an environmental nuisance and stressor. Exposure to consistent noise of 85–90 dBA, exclusively over a lifetime in industrial surroundings, can lead to a progressive loss of hearing, with an enhancement in the threshold of hearing ability and sensitivity. Hearing impairments due to noise are a direct consequence of the impacts of sound energy on the inner part of ear which affects brain.

Noise is the Reason of High Blood Pressure: 

The evidence for the impact of noise on the cardiovascular system is clear from blood pressure studies in occupational surroundings. Most of occupational studies suggest that persons chronically exposed to regular noise at higher levels of 85 dB have greater blood pressure than those not exposed to such levels of noise. Exposure of noise is an indicator of exposure to physical and psycho social, which are also linked with high blood pressure. Unless these other risk factors are controlled, spurious associations between noise and blood pressure may arise. The recent study on pioneering longitudinal industrial noise has proved that noise levels predicted raised systolic and diastolic pressure in those doing complex but not simple jobs, and predicts increased mortality risk.

Cardiovascular Effects:

Besides the effects on cognitive responses, it has been explored that chronic exposure to noise may give birth to physiological effects in terms of high blood pressure. A study in Los Angeles Airport, consistent exposure to noise of aircraft was observed to be associated with alarmingly raised systolic and diastolic blood pressure. These increments were within the average levels and were not led to hypertension. After one year, the observations were the same, making it clear that these effects were not habituated. The recent study in Munich, chronic noise exposure was observed to be associated with baseline systolic blood pressure and minimum re-activity of systolic blood pressure to a cognitive task provided under acute noise. After opening of new airport, a drastic increase in systolic blood pressure was observed showing evidence for a link between chronic noise exposure and raised blood pressure. There was no association seen between noise and diastolic blood pressure.

Other Health Risks: 

Exposure to a very high intensity industrial noise is associated to high levels of adrenaline and noradrenaline. Catecholamine secretion reduced when workers wore hearing protection against noise. Many researches have shown raised cortisol in exposure to higher noise level. Cortisol is released in response to stress and low blood-glucose concentration. Its function is to enhance blood sugar, to suppress the immune system, and to assist the metabolism of fat, protein, and carbohydrates. It also minimizes formation of bones.

The evidence for consequences of environmental noise pollution on health is strongest for sleep, annoyance and cognitive reactions in adults as well as children. Occupational noise exposure also shows some association with raised blood pressure. Dose–response associations are demonstrated for annoyance and less consistently for blood pressure. The ultimate consequences of noise are drastic for those outcomes that, like annoyance, are categorized under ‘quality of life’ rather than ailments.

REFERENCES:

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2. Smith AP, Broadbent DE. Non-auditory Effects of Noise at Work: A Review of the Literature. HSE Contract Research Report No 30, London: HMSO, 1992
3. Civil Aviation Authority. Aircraft Noise and Sleep Disturbance: Final Report. DORA Report 8008: London, 1980
4. Rosenlund M, Berglind N, Pershagen G, Jarup L, Bluhm G. Increased prevalence of hypertension in a population exposed to aircraft noise. Occup Environ Med 2001; 58:769–73
5. Cavatorta A, Falzoi M, Romanelli A et al. Adrenal response in the pathogenesis of arterial hypertension in workers exposed to high noise levels. J Hypertens 1987; 5:463–6  

By: Shoaib Aslam M.Sc. (Hons.) Soil Science