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| English: Southern end of the High Street, Keynsham, on a busy Saturday. (Photo credit: Wikipedia) |
Today we review research into the links between short term exposure to particulate matter of various sizes and impacts on blood pressure of school-age children who are particularly vulnerable because their higher breathing rate, as well as their generally greater activity than older people. Results indicate a clear association with Ultra Fine Particulates (diameter 20-30 nm) and higher blood pressure. In addition, repeated exposure to particulates may result in long-term chronically elevated pressures, as well as a chronic increase in arterial stiffness in children due to traffic-related air pollution.
Key Quotes:
“Short-term elevation in particulate air pollution has been associated with an increased risk for acute myocardial infarction and stroke”
“this is the first study of differences in children’s blood pressure in association with different size fractions of PM on the same day.. "
“In this study, children’s systolic blood pressure was positively associated with ambient UFP[ultra-fine particulates] measured in their school’s playground on the same morning”
“children might be more sensitive to air pollution because of their relatively higher ventilation rate and metabolic turnover, as well as the fact that some of the organ systems including the immune system are still in development… greater physical activity, spending more time outdoors, and their closer proximity to traffic exhaust emission sources compared with adults, might add to their vulnerability towards hypertensive effects of airborne particles”
“particle size is a determining factor in the effectiveness of particulate pollutants to cause rapid changes in the blood pressure of 6- to 12-year-old children”
“repeated particle-induced elevations in blood pressure also lead to repeated increases in arterial wall stress and may result in long-term chronically elevated pressures. Epidemiological evidence exists for a chronic increase in arterial stiffness in children due to traffic-related air pollution”
“Due to specific characteristics (high surface area, particle number, metal and organic carbon content) of UFP[ultra-fine particulates], they may be transferred directly into the circulation and cause systemic inflammation and peripheral vascular oxidative stress resulting in reductions of nitric oxide, enhancing vasoconstriction and as such change blood pressure.”
"Children attending school on days with higher ultrafine particulate concentrations (diameter < 100 nm) had higher systolic blood pressure. This association was largely dependent on particle size and was not confounded by the PM2.5 mass concentration.”
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