Recently conducted research, published in the journal Epidemiology, studied 5,531 adults
from 28 peri-urban villages near Hyderabad city to find that women who are
exposed to high pollution levels in India are at significantly higher risk of
suffering from hypertension.
“Women spend most of their time near their
households in this study area – 83 per cent of their daily time as compared to
57 per cent for men – which could explain why we observe a stronger association
in women than in men”, said study author Ariadna Curto from Barcelona Institute
for Global Health (ISGlobal), Spain.
For the study, the research team measured
systolic and diastolic blood pressure of participants and estimated their
annual residential exposure to fine particulate matter (PM2.5) and black
carbon.
The participants also answered a survey to
determine socio-economic status, lifestyle and household characteristics,
including the type of cooking fuel which they generally used (biomass or
clean). Notably, all participants were exposed to fine particulate matter
levels above the 10 μg/m³ limit recommended by the World Health Organization
(WHO). Average exposure to PM2.5 in this study was 33 μg/m3.
Based on the blood pressure measurements, almost half of
participants (46 per cent) were identified as hypertensive, with high proportions
of participants with undiagnosed and untreated hypertension.
The results show that an increase of 1μg/m3 in PM2.5 exposure
was associated with a 4 per cent increase in hypertension prevalence in women
as well as a higher systolic and diastolic blood pressure – an increase of 1.4
mmHg and 0.87 mmHg respectively. In men, the association observed was weaker.
The research indicates that long-term exposure to particulate
matter is associated with a higher prevalence of hypertension, regardless of
the type of fuel used for cooking.
“In the light of our lack of association with black carbon, it
is important to keep in mind that this is a peri-urban area, where the sources
and chemical makeup of air pollution differ to urban areas mostly dominated by
traffic sources,” Curto said.
The
mechanisms by which air pollution could contribute to high blood pressure
“include inflammation and oxidative stress, which may lead to changes in
arterial function,” said study coordinator Cathryn Tonne. – Agencies
