CME INDIA Presentation by Dr. Ashish K. Saxena, Consultant Diabetes and Clinical Cardiology, Ludhiyana.
Based on presentation at ACP -India chapter conference, Vizag; 18th – 20th November 2022.
Noise pollution is a major environmental problem. It is a top environmental risk to health across all age and social groups. Prolonged exposure to high levels of noise impairs human health and well-being.
Permissible noise level in India
- The CPCB has laid down the permissible noise levels in India for different areas. Noise pollution rules have defined the acceptable level of noise in different zones for both daytime and night time.
|In industrial areas, the permissible limit is 75 dB for daytime and 70 dB at night.|
|In commercial areas, it is 65 dB for daytime and 55 dB at night.|
|In residential areas, it is 55 dB for daytime and 45 dB at night.|
Noise pollution in India
- The city of Moradabad in Uttar Pradesh is the second-most noise polluted city globally, according to a recent report by the United Nations Environment Programme (UNEP).
- The report identifies 13 noise polluted cities in south Asia. Five of these, including Moradabad, are in India, which have recorded alarming levels of noise pollution:
- Moradabad (114 db)
- Kolkata (89 db)
- Asansol (89 db)
- Jaipur (84 db)
- Delhi (83 db)
Impact of Long-term exposure to environmental noise
- Long-term exposure to environmental noise is estimated to cause:
- 12,000 premature deaths.
- Contribute to 48,000 new cases of ischaemic heart disease per year in the european territory.
- It is estimated that 22 million people suffer chronic high annoyance.
- 6.5 million people suffer chronic high sleep disturbance.
The noise effect model
- Persistent and acute exposure to noise leads to increased development of cardiovascular risk factors (raised blood pressure, increases in blood lipids and blood sugar, greater cardiac output, increased blood viscosity, and activation of blood coagulation), mediated by mental and physiological stress reactions.
- In the long term, this leads in turn to the clinical manifestation of cardiovascular diseases such as hypertension, coronary heart disease, heart failure, arrhythmia, and stroke.
Credit: Dtsch Arztebl Int 2019; 116: 245–50
Dose–response relationships for noise and cardiovascular disease
- Dose–response relationships for noise and cardiovascular disease.
- It is the weighted day–evening–night sound level, with an increment of 5 dB(A)for the evening and 10 dB(A)for the night. CVD, cardiovascular disease; Hyp, hypertension.
Credit: Dtsch Arztebl Int 2019; 116: 245–50
Transportation Noise: Increase Mace Risk
- Exposure to both air pollution and transportation noise increases risk for MACE compared to exposure to one or neither pollutant. These pollutants may thus synergistically increase CVD risk via a mechanism that involves increased arterial inflammation.
Credit: J Am Coll Cardiol. 2020 Mar, 75 (11_Supplement_1) 1646
Road traffic noise, blood pressure, and hypertension
- A meta-analysis of 24 cross-sectional studies on the relationship between road traffic noise and the prevalence of hypertension reported a Significant( P < 0.05) higher prevalence, per 10 dB increase of the 16-h day-time average road traffic noise level (LAeq16h) in the range of <50 to >75 dB.
- Similarly, a significant higher systolic blood pressure per 10 dB increase of the road traffic noise level was found in middle-aged subjects participating in a large Danish cohort study, with Stronger and significant associations in men and older subjects.
Noise and coronary heart disease
- No direct evidence linking noise and coronary heart disease but many studies linked with noise and CHD risk factors like hypertension suggest indirect relationship between noise and coronary heart disease
- A meta-analysis including four cohort and one case–control study on the relationship between road traffic noise and the incidence of hypertension reported an
- OR of 1.17 (17%) (CI = 0.87–1.57, P = n.s.) per 10 dB increase of the 16-h average road traffic noise level (LAeq16h) in the range of <60 to >75 dB.
Noise and stroke
- Exposure to residential road traffic noise was associated with a higher risk for stroke among people older than 64.5 years of age, showing a risk increase per 10 dB increase of the noise level (LDEN) (incidence rate ratio = 1.27, CI = 1.13–1.43, P < 0.0001).
- Several studies within the last 10 years demonstrate a higher prevalence of annoyance, cardiovascular disease, or medication intake in persons exposed to aircraft noise.
Risk evaluation process
- The process of risk assessment (risk evaluation) comprises hazard identification (“Which health outcome is relevant?”).
- Exposure assessment (“How many are affected”).
- Dose-response assessment (“Threshold of effect”).
- This information is summarized in, what is called, “risk characterization” (“health hazard characterization”).
- It involves the interpretation of the available evidence from the available data and other scientific disciplines, and is subject to the discussion of uncertainties including chance, bias and validity of studies as well as transparency, replicability and comprehensiveness of reviews
- As a result of the risk evaluation process, a quantitative estimate about the likelihood that the hazard will affect exposed people will be derived. Usually attributable risk percentages will be calculated
- This will serve as key information for any kind of risk management including regulatory options
Noise exposure ready-reckoner (Daily exposure)
- For each task or period of noise exposure in the working day look up in the table on the left the exposure points corresponding to the sound pressure level and duration (e.g. exposure to 93 dB for 1 hour gives 80 exposure points);
- Add up the points for each task or period to give total exposure points for the day;
- Look up in the table on the right the total exposure points to find the corresponding daily noise exposure (e.g. a total exposure points for the day of 280 points gives a daily noise exposure of between 89 and 90 dB).
Solutions for Reducing Noise
Actions to reduce noise in the workplace
- Occupational safety and health professionals and employers can take the following actions to reduce noise in the workplace.
- Buy Quiet – select and purchase low-noise tools and machinery.
- Maintain tools and equipment routinely (such as lubricate gears).
- Reduce vibration where possible.
- Isolate the noise source in an insulated room or enclosure.
- Place a barrier between the noise source and the employee.
- Isolate the employee from the source in a room or booth (such as sound wall or windows).
WHO Guidelines for Noise
- The researchers did not attempt to account for demographic, socioeconomic or other health risk factors in their analysis, and they suggest further research could help tease apart the effect of noise pollution from these other factors.
As a next step, the team plans to examine the data in more detail for insights into which sources of transportation noise may have the greatest health impact.
- Reduce an individual’s exposure to transportation noise at home, even in urban areas.
- Examples include better enforcement of noise ordinances.
- Infrastructure to block road noise.
- Rules for air traffic.
- Low-noise tires for vehicles.
- Better noise insulation for buildings.
- Like most sources of pollution, noise is an issue that must be managed. Regulatory frameworks and legal requirements are in place in many countries including India.
CME INDIA Quick Take-Aways
|Many cities of India have recorded alarming levels of noise pollution.|
|Long-term exposure to environmental noise is estimated to cause 12,000 premature deaths and Contribute to 48, 000 new cases of ischemic heart disease per year.|
|Persistent and acute exposure to noise leads to increased development of cardiovascular risk factors mediated by mental and physiological stress reactions.|
|Further research needed to tease apart the effect of noise pollution from other routine factors.|
|Policy interventions could help to reduce Long-term exposure to environmental noise .|
CME INDIA Tail-Piece
What is decibels?
- Decibels (dB) are the units of measure for indicating the intensity or loudness of a sound that help predict thresholds when a noise starts to annoy people or when sleep disturbance emerges.
Does frequency matter?
- While the loudness of noise is important, the frequency, in terms of high or low pitch, and temporal patterns of sound also determine the physical and psychological effects it has on the listener.
Immediate hearing loss?
- Physically, proximity to very loud abrupt sounds, such as a gunshot over
140 dB, could rupture the ear’s tympanic membrane, causing immediate
Music and hearing loss
- Listening to music with earphones at the maximum volume – ranging between 90 and 100 dB at the eardrum – could start to cause hearing damage after only 15 minutes per day.
Permanent hearing loss
- Regular exposure to over 85 dB for an 8-hour day or longer can cause permanent hearing damage.
What is a soundscape?
- The International Organization for Standardization (ISO) defines a soundscape as “[the] acoustic environment as perceived or experienced and/or understood by a person or people, in context”.
- In other words, soundscape encompasses the way people perceive, experience and
respond to the full range of sounds in a place at a given time.
- As an emerging discipline, soundscape studies try to look at the issue of urban acoustic environments more holistically, taking a listener-centred perspective.
- Dtsch Arztebl Int 2019; 116: 245–50
- Eur Heart J. 2014 Apr;35(13):829-36.
- J Am Coll Cardiol. 2020 Mar, 75 (11_Supplement_1) 1646
- Eur Heart J. 2014 Apr;35(13):829-36.
- Noise Health. 2002;4(16):1-11.
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