State of the Environment Bulgaria 2003
What are the impacts of noise?
The acoustic environment in the large cities of the country, the industrial zones and the recreational areas present serious problems. The continuous increase in motor vehicle traffic and mistakes in town have caused increased noise pressure on the environment. Development of communities near noisy highways and boulevards continues without giving sufficient thought to noise protection. Residential buildings are often erected very close to existing industrial facilities thus violating the defined hygienic protection zones.
Because of the potential impact of noise pollution on health, and its increase in the city environment, a national system for control was established in 1972 for limiting and decreasing of the city noise under the administrative management of the Ministry of Health and through the operation of the National Centre for Hygiene, Medical Ecology and Nutrition and HEI.
The annual control system ascertains exceedences of the admissible noise levels within the cities of the country, including clearly unfavourable acoustic environments in the central city parts, near the highways and the railways.
The unfavourable acoustic environment in the settlements, industrial centres and near the bigger road highways is caused by the increased traffic of motor vehicles, unsuccessful town planning decisions and construction, without incorporating noise protection for the population.
Measurement of the noise pollution in the large cities within the country finds regular exceedence of the admissible noise levels (from 55-60dB (A)) in the range of 64% - 86% in the monitored stations.
The health effect from the impact from the city noise is related to its stress, including potential damage to the organs and systems, and the unfavourable impact on the home and workplace.
The possible bodily reactions to acute noise pollution include:
Impact on the central nervous system – changes in the encephalogram, nervous overstrain, mental disturbances, mental disequilibria, memory disturbances and bile.
Impact on the vegetative nervous system – intensified excitation that could lead to a number of cardiac, circular and other trends.
Impact on the cardiovascular system – changes in the cardio rhythm (tachycardia), vasoconstriction and other changes that lead to increase of the arterial pressure.
Impact on the respiratory system – changes of the respiratory rhythm.
Impact on the digestive system – slowing of food’s passage in the ventricular-intestinal tract and injuries to the stomach and the intestines.
Impact on the endocrine system – changes in the level of blood sugar, increase of the main metabolism, detain of water in the organism etc..
Acting as a stress factor, noise pollution attacks almost all organs and systems of the human body. Among the unfavourable factors of the settlement environment it is known with its versatile impact. Due to its importance as a risk factor for human health, it is as potentially harmful as air, water or soil pollution.
After the collection and processing of relevant statistical data, the risk may be presented in quantitative terms. This can assist management decision making regarding optimisation of the acoustic environment.
Last update on March 2003