Written by Tatjana Djakovic, Staff Writer. Children in a highly polluted area had 2.56 times greater risk of above normal blood pressure.
Air pollution is a major concern in the United States and all over the world. It accounts for approximately 800,000 deaths annually 1. Even though pollution is mainly a problem in the developing countries, it is still a major concern in U.S. cities, especially in the presence of stagnating weather and high levels of traffic. High pollution results in an increased rate of hospitalizations due to respiratory illness, cardiovascular disease and mortality 2. Air pollution consists of gases and particulate matter, which are very small solid or liquid particles, emitted into the air 3.
This study examines the effects of air pollution on blood pressure in children, because blood pressure is an important factor in cardiovascular disease. The study included 166 children aged between 8 and 12 years living in Lahore, Pakistan. The children were separated into two groups which included those living in a highly polluted area and a low polluted area. The high pollution area was located next to a highway and the low pollution school was located next to a park. The measurements were taken outdoors as well as indoors, and humidity was also taken into consideration as it can alter the pollution levels. The blood pressure was measured by making five consecutive readings 4.
The mean concentration of daily particle size of 2.5 μM was 28.5 μg/m3 and 183 μg/m3 in the low and high pollution area, respectively. The results indicated that systolic blood pressure and diastolic blood pressure were significantly higher in children living in the highly polluted area than in those from the less polluted area which was independent of age, gender, height, weight, socioeconomic status, passive smoking and the urinary concentrations of sodium, potassium and creatinine. These changes in blood pressure are indicative of long term risk of cardiovascular disease. The researchers concluded that the odds of having a blood pressure above “normal” blood pressure (systolic <120 mmHg and diastolic <80 mmHg) was 2.56 times higher than in those living in the lower polluted area 4.
| Blood Pressure | Low Pollution School | High Pollution School | Percentage Difference | P-Value |
|---|---|---|---|---|
| Systolic blood pressure-mmHg | 108.3 | 115.9 | 0.071 | P<0.0001 |
| Diastolic blood pressure-mmHg | 66.4 | 70.9 | 0.067 | P=.002 |
The danger of the smaller, fine particles is due to their ability to reach more deeply into the lungs, although the mechanism of how the particles increase blood pressure is not completely clear.
In addition, particles that have been enriched in organic components activate the immune system that initiates inflammation and can increase damage to the cardiovascular system 5.
Recently, researchers have found that exposure to pollution causes changes in our DNA, which is associated with increased blood pressure 5.
It is advisable to live in non-urban areas which contain less pollution. Researchers also suggest taking antioxidants or anti-inflammatory supplements which might alleviate damages that are caused by pollution. In a study of 29 healthy middle-aged participants, it was shown that intake of 3g of fish oil per day for 4 weeks offered significant protection against cardiac and lipid affects when participants were exposed to high levels of pollution 6.
Source: Sughis, Muhammad, et al. “Blood pressure and particulate air pollution in schoolchildren of Lahore, Pakistan.” BMC Public Health 12.1 (2012): 378.
© 2012 Sughis et al.; licensee BioMed Central Ltd. the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0
Click here to read the full text study.
Posted September 13, 2013.
References:
- Organization WH. Air Quality and Health. 2009, 2009.
- O’Toole TE, Conklin DJ, Bhatnagar A. Environmental risk factors for heart disease. Rev Environ Health. 2008;23(3):167-202.
- Brook RD, Rajagopalan S, Pope CA, 3rd, et al. Particulate matter air pollution and cardiovascular disease: An update to the scientific statement from the American Heart Association. Circulation. 2010;121(21):2331-2378.
- Sughis M, Nawrot TS, Ihsan-ul-Haque S, Amjad A, Nemery B. Blood pressure and particulate air pollution in schoolchildren of Lahore, Pakistan. BMC Public Health. 2012;12(1):378.
- Bellavia A, Urch B, Speck M, et al. DNA hypomethylation, ambient particulate matter, and increased blood pressure: findings from controlled human exposure experiments. J Am Heart Assoc. 2013;2(3):e000212.
- Tong H, Rappold AG, Diaz-Sanchez D, et al. Omega-3 fatty acid supplementation appears to attenuate particulate air pollution-induced cardiac effects and lipid changes in healthy middle-aged adults. Environ Health Perspect. 2012;120(7):952-957.
