Urban noise and blood pressure of the population: A systematic review of studies in Belgrade

The Belgrade team for biological effects of noise, comprising experts in the fields of hygiene and cardiology, has carried out population studies in Belgrade on the sample of 2503 adults, 328 preschool children and 1113 schoolchildren to investigate the effects of urban noise on blood pressure. In the first phase of investigation acoustic measurements were performed on 115 streets of the central municipality "Stari grad" as a typical urban environment. Blood pressure measurements were performed using mercury sphygmomanometer in those subjects who did not have a diagnosed hypertension and were not under antihypertensive therapy. Among adults living in the streets with equivalent noise level (Leq) exceeding 45 dB (A) there was a significantly higher number of people with hypertension compared to areas with Leq ≤ 45 dB (A) (23.6% vs.17.5%). After statistical adjustments according to family history of hypertension, age, body mass index (BMI), smoking habits, physical activity and alcohol consumption among males, we found 58% increased odds for obtaining hypertension if they lived in noisy environments for more than 10 years (OR = 1.58; 95 CI = 1.03-2.42; p = 0.038). In females noise exposure and hypertension were not significantly related. In preschool children aged 3-7 and living in areas with night Leq > 45 dB (A) and attending kindergartens in the streets with daytime Leq > 60 dB (A) the prevalence of hypertensive values of blood pressure was higher compared to children from quiet streets (5,7 % vs. 1,5 %; p = 0,054). Systolic blood pressure was significantly higher (5 mmHg on average) in children from noisy streets and kindergartens compared to children from quiet environments (p < 0,01). Multiple regression after adjustments according to age, sex, BMI percentile-forage , family history of hypertension, and socioeconomic status revealed a significant positive correlation between the exposure to urban noise and systolic blood pressure (p = 0,009). In schoolchildren aged 7-11 and attending schools in streets with public transport we found a higher systolic blood pressure (1.3 mmHg on average) compared to children from schools without public transport, after adjustments according to age, sex, BMI, family history of hypertension, living conditions and health related behavioral habits (p < 0.05).