Air pollution linked with blood pressure in London teens
Associations between pollutant levels and blood pressure were stronger for girls than boys in study
Peer-Reviewed PublicationIMAGE: THE RESEARCH SUGGESTS THAT IN ADOLESCENTS LIVING IN LONDON, UK, EXPOSURE TO HIGHER LEVELS OF THE POLLUTANT NITROGEN DIOXIDE WAS ASSOCIATED WITH LOWER SYSTOLIC BLOOD PRESSURE, WHILE EXPOSURE TO HIGHER LEVELS OF PARTICULATE MATTER 2.5 (PM2.5) WAS ASSOCIATED WITH HIGHER SYSTOLIC BLOOD PRESSURE. view more
CREDIT: MARIO LA PERGOLA, UNSPLASH, CC0 (HTTPS://CREATIVECOMMONS.ORG/PUBLICDOMAIN/ZERO/1.0/)
In a new analysis involving adolescents living in London, exposure to higher levels of the pollutant nitrogen dioxide was associated with lower systolic blood pressure, while exposure to higher levels of particulate matter 2.5 (PM2.5) was associated with higher systolic blood pressure. Alexis Karamanos of King’s College London and colleagues present these findings in the open-access journal PLOS ONE on February 8, finding that these associations are stronger for girls than for boys.
Exposure to air pollutants is linked to greater risk of cardio-respiratory disease, hospital visits, and death. Adolescents’ rapidly growing bodies may be particularly susceptible to long-lasting effects of exposure to air pollutants, including effects on blood pressure. However, most prior studies on air pollution and blood pressure have focused on adults.
To better understand these associations in adolescents, Karamanos and colleagues analyzed data collected as part of the Determinants of Adolescent Social Well-Being and Health (DASH) study, which tracks the well-being of thousands of ethnically diverse London schoolchildren over time. For this analysis, they used data on 3,284 adolescents in DASH to examine associations between blood pressure and exposure to pollution in the form of nitrogen dioxide and PM2.5; exposures were estimated based on annual mean levels of pollutants where each participant lived.
The researchers found that greater estimated exposure to nitrogen dioxide was associated with lower systolic blood pressure, and greater estimated exposure to PM2.5 was associated with higher systolic blood pressure. These associations were stronger in girls than in boys. No evidence of a relationship between nitrogen dioxide/PM2.5 and diastolic blood pressure was observed.
For example, a 1μg/m 3 increase in nitrogen dioxide was associated with a 0.30 mmHg (95% CI 0.18 to 0.40) decrease in systolic blood pressure for girls and 0.19 mmHg (95% CI 0.07 to 0.31) decrease in systolic blood pressure for boys. Meanwhile, a 1μg/m 3 increase in PM2.5 was associated with a 1.34 mmHg (95% CI 0.85 to 1.82) increase in systolic blood pressure for girls and 0.57 mmHg (95% CI 0.04 to 1.03) increase in systolic blood pressure for boys. The associations between pollutants and blood pressure were consistent regardless of ethnicity, body size, or socioeconomic status.
Eighty percent of the adolescents studied were from ethnic minority groups, and the residential estimates suggest that these adolescents were exposed to higher levels of the pollutants than their white peers.
The researchers call for further studies to help confirm and clarify these findings, particularly among young people from different socioeconomic backgrounds. They also note that levels of nitrogen dioxide and PM2.5 in London remain well above World Health Organization Guidelines, suggesting opportunities to reduce pollution and improve lifelong health for adolescents in the city.
Seeromanie Harding, from King’s College, London, adds: “This longitudinal study provides a unique opportunity to track exposures of adolescents living in deprived neighborhoods. Given that more than 1 million under 18s live in neighborhoods where air pollution is higher than the recommended health standards, there is an urgent need for more of these studies to gain an in-depth understanding of the threats and opportunities to young people’s development.”
#####
In your coverage please use this URL to provide access to the freely available article in PLOS ONE: https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0279719
Citation: Karamanos A, Lu Y, Mudway IS, Ayis S, Kelly FJ, Beevers SD, et al. (2023) Associations between air pollutants and blood pressure in an ethnically diverse cohort of adolescents in London, England. PLoS ONE 18(2): e0279719. https://doi.org/10.1371/journal.pone.0279719
Author Countries: UK, China, Brazil
Funding: The study was funded by the MRC (10.13039/N4 501100000265, MC_U130015185/MC_UU_12017/1/ MC_UU_12017/13) North Central London Consortium and the Primary Care Research Network. This work was also supported by the MRC Centre for Environment and Health, which is currently funded by the Medical Research Council (MR/S019669/1, 2019-2024). Infrastructure support for the Department of Epidemiology and Biostatistics was provided by the NIHR Imperial Biomedical Research Centre. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
JOURNAL
PLoS ONE
METHOD OF RESEARCH
Observational study
SUBJECT OF RESEARCH
People
ARTICLE TITLE
Associations between air pollutants and blood pressure in an ethnically diverse cohort of adolescents in London, England
ARTICLE PUBLICATION DATE
8-Feb-2023
COI STATEMENT
The authors have declared that no competing interests exist.
Fine particles in the air associated with higher blood pressure in London teens
A study of adolescents aged 11-16 in London has found long-term exposure to PM2.5 is associated with higher blood pressure, with stronger associations seen in girls.
Findings also show that exposure to high levels of nitrogen dioxide is associated with lower blood pressure in this group.
The paper, published today in PLOS One by researchers from King’s College London, examines the possible effects of long-term exposure to air pollution in children attending 51 schools across the capital.
Senior author Professor Seeromanie Harding, from King’s College London, said: “This longitudinal study provides a unique opportunity to track exposures of adolescents living in deprived neighbourhoods. Given that more than 1 million under 18s live in neighbourhoods where air pollution is higher than the recommended health standards, there is an urgent need for more of these studies to gain an in-depth understanding of the threats and opportunities to young people’s development.”
Air pollution particles are inhaled into the body and can get into the bloodstream, causing damage to blood vessels and airways. While the effect of air pollution on adult blood pressure is well known, few longitudinal studies have examined adolescents.
The period between 11-16 years of age is particularly important as adolescents continue to grow and develop. Negative effects on their organs at this stage could lead to life-long complications.
Researchers analysed data of 3284 adolescents and followed up from ages 11-13 and 14-16 years old. They measured systolic and diastolic blood pressure at participants schools.
The results show Particulate Matter (PM2.5), tiny pollutants in the air that come from car exhaust fumes, building and industry materials, were associated with higher blood pressure across all ages, and were particularly felt among girls (a μg/m3 increase in PM2.5 was associated with 1.34 mmHg increase in systolic BP for girls and 0.57 mmHg increase in systolic BP for boys). Higher blood pressure can raise the risk of hypertension, heart attacks and strokes in adulthood.
Interestingly, nitrogen dioxide (NO2), a pollutant which in London is predominately due to diesel traffic, was associated with lower blood pressure. Systolic blood pressure decreased by ~5 mmHg for boys and ~8 mmHg for girls when NO2 almost doubled from a low to a high concentration .
Previous research has shown NO2 may have damaging effects on the respiratory system, but the impacts of the pollutant on the cardiovascular system is less clear. However, a recent study from this group found that sitting next to a lit gas cooker - which emits NO2 - acutely lowers blood pressure in healthy adult volunteers by ~5 mmHg. That effect was explained by a rapid increase in circulating nitrite (NO2-) concentration in the blood.
Co-author Dr Andrew Webb from King’s College London said: “The effect of NO2 on blood pressure is similar to what we and other researchers have observed previously after ingesting green leafy vegetables or beetroot juice. These are rich in dietary nitrate (NO3-) which increases circulating nitrite (NO2-) concentration in the blood and lowers blood pressure, an effect which may also be sustained over weeks or months with continued ingestion of nitrate-rich vegetables. As NO2 also increases circulating nitrite (NO2-) concentration, this provides a potential explanation as to why elevated NO2 appears to be associated with lower blood pressure in the adolescents over years.”
Researchers also found adolescents from ethnic minority groups were exposed to higher annual average concentrations of pollution at home than their White UK peers, but impact of pollutants on blood pressure did not vary according to ethnicity, BMI, or economic status.
A study in 2021 found that 3.1m children across England go to schools in areas exceeding WHO limits on PM2.5 and 98 per cent of schools in London are in areas exceeding World Health Organization pollution limits.
Corresponding author Dr Alexis Karamanos, from King’s College London, said: “The findings highlight the potential detrimental role of exposure to higher concentrations of particulate matter on adolescents' blood pressure levels.”
"Further studies following the same adolescents over time in different socio-economic contexts are needed to understand whether and how exposure to higher pollutant concentrations may affect differently the cardiovascular health of children and adolescents.”
Data was taken from the DASH study, a multi-ethnic longitudinal study which reflects the diversity of London. DASH seeks to understand what contributes to ethnic differences in physical and mental health over the life course and is one of few studies worldwide which includes BP measurement data in childhood and adolescence.
JOURNAL
PLoS ONE
METHOD OF RESEARCH
Observational study
ARTICLE PUBLICATION DATE
8-Feb-2023
No comments:
Post a Comment