Children more vulnerable to air pollution effects

Air pollution is the new tobacco and the simple act of breathing kills 7 million people a year and harms billions more, said Dr Tedros Adhanom Ghebreyesus, the director general of the World Health Organisation (WHO) in an interview with The Guardian on Saturday.

An estimated 91% of the world’s population is exposed to air pollution, which is the world’s biggest environmental health risk, causing 4.2 million deaths from poor outdoor air and 3.8 million deaths from household exposure to dirty cookstoves each year.

In India, pollution kills 1.1 million people, according to the State of Global Air 2018 report, which links air pollutants to 10.6% of all deaths in the country.

Apart from asthma and other respiratory diseases, pollution causes deaths from stroke, chronic obstructive pulmonary disease, heart disease, lung infections and trachea, bronchus and lung cancers.

For children, the risk begins in the womb and continues through the newborn and early childhood periods, which has prompted the WHO to put the spotlight on air pollution and children’s health in a report that will be released on Monday, two days before the world’s first Global Conference on Pol- lution and Health on Oct 30.

The air quality in northern India deteriorates rapidly leading up to Diwali.

The level of PM2.5 (a fine dust particle that causes and exacerbates respiratory and lung diseases) in Delhi last year was 16 times more than the national standard and 40 times higher than the international safe limit of 20 microgram per cubic metre.

Delhi has 38 real-time and 10 manual pollution monitoring stations, compared to a handful in other major metros where data is inadequate.

An expecting mother’s exposure to polluted air has been linked to adverse pregnancy outcomes, including premature birth, low birth weight, abnormal birth length and head circumference, and small size for gestational age.

Children’s developing lungs are the most susceptible to injury because they breathe in faster, are more active, spend more time outdoors, and have immune systems that are still developing.

Children exposed to pollution have lower maximal lung functional capacity and are more susceptible to infections and the toxic effects of air pollutants as adults, leading to more exacerbations of chronic lung diseases, such as asthma and cystic fibrosis, and increased hospitalisations.

Smog — the toxic mist produced when airborne dust, carbon particles, noxious gases and ozone react chemically in the presence of sunlight — prevents ultraviolet B range reaching the earth’s surface, leading to vitamin D-deficiency weakening bones in children. The human skin needs coverts 7-dehydrocholesterol to cholecalciferol (vitamin D3) on exposure to ultraviolet B from the sun needed to build strong bones and prevent bone-loss (osteoporosis) in later life.

Pollution leads to lower memory and IQ, with infants being the most vulnerable to toxic chemicals in the first 1,000 days after birth, when most of the brain’s development happens. It also causes psychological and behavioural problems, development delays by age three and a fourpoint drop in IQ by age five, said a Unicef report released in 2017.

Even exposure to traffic noise is linked to behavioural problems. Sleeping in rooms exposed to sound of night-time traffic makes children hyperactive, sleepless and raises their blood pressure.

Regulations that lower pollution and reduce exposure to air toxins can counter some ill effects. Lowered sulphur dioxide in former East Germany following the reunification of Germany in 1990 led to improved lung function and fall in respiratory illnesses — such as bronchitis, sinusitis and frequent colds — in children.

Studies from the US have also shown that children who moved to states with better air have increased lung function and lower hospital admissions with respiratory complaints, like asthma, pneumonia, bronchitis and respiratory infections.