 |
| Air pollution |
Outdoor air
pollution has been identified as a possible risk factor for preterm births
across the globe according to a study published in Journal of Environment International online February 10, 2017.[1]
The 2010 study estimated that 2.7–3.4 million preterm births may be prevented
if PM2.5 exposure is brought down.
It is estimated that 14·9 million babies were
born preterm worldwide in 2010.
There exists
a wide disparity between Preterm Births(PTBs) rates across the globe, European
countries have the lowest rate at 4-5% vs. countries in Africa and South Asia
with rates as high as 15–18%.
In South
Asia, about 1 million PM2.5 associated
PTBs happened in India, followed by China which contributed another 500,000.
A pregnant
woman in India or China will likely be exposed to 10 times more pollution as
compared to a woman in Canada or UK.
It is
estimated that in 2010, out of 135 million livebirths globally 14.9 million
babies (11.1%) were preterm, including both spontaneous and iatrogenic births. [2]
Exposure of
mother to fine particulate matter(PM) has been identified as one of the many risk
factors for PTBs as well low birth weight babies. The fine PM finds its way
into blood stream through lungs and causes pulmonary and placental
inflammation, coagulopathies, endothelial dysfunction and hematological
responses.
Fine
particles are produced from all types of combustion, including motor vehicles,
power plants, solid cooking fuels, residential wood burning, forest fires,
agricultural burning, and some industrial processes.
Desert dust
also contributes to Particulate Matter ( PM) and in Sub Saharan Africa, Middle East and
North Africa it is the major exposure.
"Air
pollution may not just harm people who are breathing the air directly - it may
also seriously affect a baby in its mother's womb," said Chris Malley,
lead author of the study which is based on data for 2010.
The study
further demonstrated that majority of the PM2.5 associated preterm
birth could be prevented by implementing strict emission control strategies in
these regions except in in Sub Saharan Africa, Middle East and North Africa
where nothing much can be done to change the geography of the area.
Johan
Kuylenstierna, co-author of the study, and SEI's policy director said "In
a city, maybe only half the pollution comes from sources within the city itself
- the rest will be transported there by the wind from other regions or even
other countries."
Nevertheless,
the study demonstrated that reduction of maternal PM2.5 exposure
through emission reduction strategies could bring down the global preterm rate,
limit in utero exposure to PM2.5 bringing down postnatal and
long term neonatal morbidity.
Exposure to PM2.5 is
also responsible for 9–14% of total preterm births globally out of the total
risk percentage. It should also be targeted along with other risk factors to
reduce the incidence of preterm birth.
No comments:
Post a Comment