Tuesday, October 3, 2023

Why your child might be doing badly in exams

Children who faced air pollution while in womb, infancy, school or during exam times, ended up with lesser marks in competitive tests, worse college options, and lesser incomes later on in life.

As per the World Health Organisation (W.H.O.), air pollution kills 7 million people a year. That means, one person out of every 1,000 people living on our planet dies every year due to air-pollution-related problems. This is a staggeringly high number.

However, recent research has started to show that air pollution also affects social, economic, and educational outcomes. For example, it is found that children do worse in examinations on more polluted days. If such an exam is critical to the future career of the child, it ends up with the child earning a lower income ten years later.

These are under-the-radar problems that don’t get noticed easily because there is years of lag time between the cause and the effect. However, parents and policy-makers need to consider these in their planning.

Children and air pollution

There are many papers that highlight the ill effects of air pollution exposure on children.

Early-life exposure and health

An article on this website talks about air pollutants found in the placenta of pregnant women. From the placenta, such particles can enter the bloodstream of the foetus causing birth defects and other abnormalities.

A paper in the journal American Economic Association showed that reduction in traffic-related pollution led to improved health outcomes for infants. When the mothers lived within 2–10 km of a toll plaza, there was a 10.8% and 11.8% reduction in prematurity and low birth weight, respectively, after electronic toll collection was introduced at the plaza.

An article on this website gives research data on how air pollution causes thyroid problems in newborn babies.

Early-life exposure and education

A study published in the Journal of Human Resources studied parental exposure to suspended particulate matter in Texas, U.S.A. in the year of pregnancy and its effect on high school examination results of the child born. It found a statistically significant relationship between the two.

In Santiago, Chile, exposure to carbon monoxide pollution during pregnancy led to poor mathematical and language skills in the children born in their 4th standard (grade).

Scientists at Uppsala University, Sweden found a reduction in lead exposure through air pollution in early life reduced children’s educational performance, cognitive ability, and later on, incomes. This effect was noticed as the country switched from leaded to unleaded petrol (gasoline).

Short-term exposure and education

A study performed in Israel showed that taking a standardised exam on a polluted day reduced a child’s exam marks by 3.2%. As a result of this poor performance, for every 10 units of PM2.5 Air Quality Index rise on the days of examination, there was a 2.1% reduction in monthly earnings in adulthood. Sadly, this effect was noticed even when the pollution was below the levels considered safe by various government agencies.

Read on this website about various acronyms, numbers, and units concerning air pollution.

Long-term exposure and education

Air pollution may cause respiratory problems in children, such as asthma, cough, cold, and wheezing. This might lead to missing school days.

A study in Utah, U.S.A. estimated that for every 100 µg/m3 rise in PM10 particles, school absenteeism in children increased by 40%.

Indoor air pollution and education

It is important to distinguish between indoor air pollution and outdoor air pollution, which was used in the studies mentioned above. Indoor air pollution includes particles from outdoor or ambient air pollution. However, it also includes other sources of emissions, such as furniture, paints, chalk dust, and various cleaning products.

A study of elementary school children in Texas, U.S.A. found that when the classrooms were renovated, examination marks improved.

Another study conducted in England found that increased indoor air pollution, especially of PM10 particles, reduced test results in a statistically significant manner. This was especially noticeable among male, high-ability, and science, technology, engineering, and mathematics (STEM) students.


While all the studies above show a correlation between air pollution and educational outcomes, some are not able to show causality. That is, all of them show that the higher the air pollution, the more is the reduction in exam marks. But, they are not able to show that air pollution causes this reduction in marks.

To conclusively prove the causality, studies need to be of a different type. For example, a study that exposes some students to air pollution and others to unpolluted air can give more understanding of such a relation. However, ethically, such a study cannot knowingly expose children to the harm of air pollution.

Taking student test marks from polluted areas and comparing them with those from unpolluted areas is a good way of establishing this relationship.

Actionable tips

  1. Ensure that a pregnant woman faces as less air pollution as possible.
    Use air purifiers at home, and if possible, at workplace where the lady works.
  2. Keep infants in pollution-free parts of house.
    Use air purifier in the room infants sleep.
  3. Children’s study-room and bedroom should be pollution-free.
    While children cannot be stopped from going to schools and playing outdoors, let them be in cleaner air while indoors.

First published on: 16th January 2020

Image by Janko Ferlic from Pexels


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