Sunday March 18, 2018

Mornings are worst air pollution times in Delhi and other major cities

A view of Delhi: Wikimedia Commons

If you think mornings are the best time for outdoor exercise, you’re wrong.

Mornings experience the worst air pollution in four Indian cities, according to an analysis of particulate matter (PM) 2.5 data from IndiaSpend’s #Breathe air-quality sensors in Bengaluru, Chennai, Delhi and Mumbai between March 15 to April 15 2016.

Delhi: Best air quality —4 pm

Mornings were the worst time, with PM 2.5 levels reaching as high as 108.16 µg/m3 at 7 am. Air quality gradually improved as the day wore on, registering the cleanest air at 4 pm. (22.84 µg/m3). Pollution levels then picked up through the night.

Delhi topped the list of the world’s most-polluted cities, according to the World Health Organisation (WHO).

Bengaluru: Best air quality–midnight

The worst air was at 7 am, as PM 2.5 concentrations peaked at 61.54 micrograms per cubic metre of air (µg/m3). The air quality improved as the day wore on, worsening by evening at about 5 pm, reaching a late-evening high at 7 pm (57.60 µg/m3). The best air quality was registered around midnight, when PM 2.5 levels fell as low to 40.12 µg/m3.

Chennai: Best air quality—3 pm

The worst air was at 7 am, with PM 2.5 levels (61.54 µg/m3) reached their peak. Levels began to peak over the night and slide during the day, after 7 am. The best air quality was recorded in the afternoon, at 3 pm, with PM 2.5 levels reaching as low as 20.76 µg/m3.


Mumbai: Best air quality—5 pm

The worst hour for a Mumbaikar is 8 am, with PM 2.5 levels reaching 48.61 µg/m3; the air started to worsen after 5 am. The best air quality was registered at 5 pm, when PM 2.5 levels were 22.38 µg/m3.

Outdoor air pollution causes 670,000 deaths annually in India, according to a 2014 research paper from the Indian Institute of Management-Ahmedabad.

Air pollution has become a global concern with rising air pollution levels, as outdoor air pollution in cities and rural areas across the world estimated to cause 3.7 million premature deaths in 2012, according to the WHO.

Particulate matter is the term for particles found in the air, including dust, dirt, soot, smoke, and liquid droplets. These are classified according to their diameter. Particles less than 2.5 µm (micrometres) are called PM 2.5. They are approximately 1/30th the average width of a human hair. Particles between 2.5 to 10 µm in diameter are called PM 10.

PM 10 and PM 2.5 include inhalable particles that are small enough to penetrate the thoracic region of the respiratory system. The health effects of inhalable PM are well documented, caused by exposure over both the short-term (hours, days) and long-term (months, years). They include: Respiratory and cardiovascular morbidity such as aggravation of asthma, respiratory symptoms, and an increase in hospital admissions; and mortality from cardiovascular and respiratory diseases and from lung cancer.

There is good evidence of the effects of short-term exposure to PM 10 on respiratory health, but for mortality, and especially as a consequence of long-term exposure, PM 2.5 is a stronger risk factor than the coarse part of PM 10.

There is a close relationship between exposure to high concentrations of small particulates (PM 10 and PM 2.5) and increased mortality and morbidity from cardiovascular/respiratory diseases and cancer, both daily and over time, according to the WHO.

(In arrangement with, a data-driven, non-profit, public interest journalism platform. The views expressed are those of India Spend. Feebback at


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Pentavalent vaccine: Doctors raise red flag

In spite of the data presented in this paper from a large cohort, the authors point out that the evidence is merely circumstantial and not conclusive

the new Hepatitis B vaccine for adults is called Heplisav-B.
India's PV to be reexamined because of its harmful effects. .
  • Pentavalent vaccine was introduced in India six years ago
  • It is since then have been a cause of many deaths
  • Doctors want it to be reexamined before continuing its use

Pentavalent vaccine (PV), that was introduced by India a little over six years ago, doubled the deaths of children soon after vaccination compared to the DPT (Diphtheria-Pertussis-Tetanus) vaccine, according to a new study that calls for a “rigorous review of the deaths following vaccination with PV”.

Health officials have launched a campaign targeting nearly 24 million people with a one-fifth dose of the vaccine. Wikimedia Commons
PV has been cause of many deaths in past years. Wikimedia Commons

Government records show that there were 10,612 deaths following vaccination (both PV and DPT) in the last 10 years. There was a huge increase in these numbers in 2017, which the Health Ministry has promised to study. “The present analysis could be a starting point in the quest to reduce the numbers of such deaths,” authors of the new study say.

The study by Dr Jacob Puliyel, Head of Pediatrics at St Stephens Hospital, and Dr V. Sreenivas, Professor of Biostatistics at the All-India Institute of Medical Sciences (AIIMS), both in New Delhi, is published in the peer-reviewed Medical Journal of Dr D.Y. Patil University.

PV is a combination of the DPT vaccine and two more vaccines against Haemophilus influenza type B (Hib) and hepatitis B. Starting December 2011, PV was introduced into India’s immunisation programme to replace DPT vaccine in a staged manner with a view to adding protection against Hib and Hepatitis B without increasing the number of injections given to infants.

Doctors have raised concerns over these vaccines. Wikimedia Commons
Doctors have raised concerns over these vaccines. Wikimedia Commons

But sporadic reports of unexplained deaths following immunisation with PV had been a matter of concern. Puliyel, Sreenivas and their colleagues undertook the study to find out if these deaths were merely coincidental or vaccine-induced.

The authors obtained data of all deaths reported from April 2012 to May 2016 under the Right to Information Act. Data on deaths within 72 hours of administering DPT and PV from different states were used.

For their study, the authors assumed that all deaths within 72 hours of receiving DPT are natural deaths. Using this figure as the baseline, they presumed that any increase in the number of deaths above this baseline among children receiving PV must be caused by this vaccine.

Also Read: With Medicine Running Out, Venezuelans With Transplant Live in Fear

According to their analysis of the data provided by the government, there were 237 deaths within 72 hours of administering the Pentavalent vaccine — twice the death rate among infants who received DPT vaccine.

Extrapolating the data, the authors have estimated that vaccination of 26 million children each year in India would result in 122 additional deaths within 72 hours, due to the switch from DPT to PV.

“There is likely to be 7,020 to 8,190 deaths from PV each year if data from states with the better reporting, namely Manipur and Chandigarh, are projected nationwide,” their report says.

It is important to make sure that these vaccines are reexamined peroperly. VOA

The authors note that while the study looks at the short-term increase in deaths (within three days of vaccination) it does not calculate the potential benefits of PV on infant mortality, for example by protection against lethal diseases like Haemophilus influenza.

In spite of the data presented in this paper from a large cohort, the authors point out that the evidence is merely circumstantial and not conclusive. “These findings of differential death rates between DPT and PV do call for further rigorous prospective population-based investigations,” the study concludes. IANS