Air pollution impacts every stage of human life, report finds

Air pollution impacts every stage of human life from foetal development and the cognitive abilities of teenagers to adult mental health, according to a report that synthesises the findings of more than 35,000 studies from around the world.

The Environmental Research Group at Imperial College London published the review on Monday of a decade of scientific studies into air pollution.The London university team looked at findings from the World Health Organization (WHO), the UK Committee on the Medical Effects of Air Pollution, the Royal College of Physicians, the Health Effects Institute and the International Agency for Research on Cancer.

“The most important new finding is evidence related to both the impact of air pollution on brain health, including mental health and dementia, and early life impacts that could lead to future health burdens within the population,” the report said.

“Both represent significant, but currently unquantified costs to society and the economy,” it added.

The review found links between air pollution and the health of newborns in the first weeks of life, birth weight, miscarriages and stillbirths.

The fetus could be vulnerable because a mother might inhale air pollution particles, leading to adverse effects on development, the report read.

Chemicals associated with pollution can enter a pregnant woman’s blood, altering its flow, which could potentially slow or delay foetal growth.

More than 20 million babies with low birth weights are born every year and more than 15 million are born prematurely, according to the WHO.

But the impact of air pollution on reproductive health is not restricted to the mother. Lower volumes of sperm are also seen in men exposed to air pollution.Recent studies also showed that air pollution could hamper lung growth in children, affect their blood pressure and impact their cognitive and mental health.

The experts at Imperial said research on 2,000 children aged eight and nine found “on average, a child had lost around 5 percent of their expected lung volume because of the air pollution that they breathed.”

“This effect was most clearly linked with exposure to NO2 [nitrogen oxide], which is often used as a tracer for the diesel exhaust emissions,” their report said.

The report also found that air pollution causes asthma.

From 2017 to 2019, a study by Imperial College London estimated that London’s poor air quality led to more than 1,700 hospital admissions for asthma and serious lung conditions.

“This was 7 percent of all asthma admissions in children in the capital,” the report said.

The review also showed that exposure to air pollution can increase cardiac death, stroke risk and the development of cardiovascular disease later in life.

A European study considered stroke in nearly 100,000 people over a 10-year period and found some evidence of an association between long-term exposure to PM2.5 – which are very small air pollution particles that can pass beyond the nose and throat and enter the respiratory system – and stroke, especially among people over 60.