Air pollution: Want your kid to grow up healthy? Get out of Delhi

It’s scary, but it has to be told. If you want your kid to grow up into a normal, healthy person Delhi is not the place where he/she should be. Around 22 lakh school children in the national capital are growing up with irreversible lung damage.  The doctors’ prescription: Leave Delhi, right now, if you want to save your children from fatal lungs disorders, severe respiratory problems, nausea, palpitation, loss of vision, blood pressure and fatigue.

Representational Image. Reuters.

Delhi’s air is just too polluted.

A study conducted by scientists from Kolkata-based Chittaranjan National Cancer Institute (CNCI) has found that the number of killer respirable suspended particulate matter (RSPM) is increasing in the city’s air with alarming rate. The RSPM or PM10 levels spiked to 316 µg/m3 (microgram per cubic metre) in 2014, which are double that of Beijing from 161 µg/m3 in 2007.

Produced by vehicles and during combustion in industries, RSPMs are small and toxic particles that cause major respiratory ailments.

A total of 11,628 school-going children (7757 boys and 3871 girls) from 36 schools in different parts of Delhi were included in the study meant for assessments of their respiratory health status and degree of lung function impairment among them. The capital’s children were compared with 4,536 children (boys 2950 and girls 1586) from 15 schools of rural West Bengal and 2 schools from Khirsu and Kotdwar in Uttaranchal. The age of the children studied was between 4 to 17 years.

The study of respiratory health of the children was done on the basis of questionnaire survey and clinical examination, pulmonary function test (PFT) by spirometry, assessment of childhood obesity, examination of cellular lung reaction to inhaled pollutants by sputum cytology and cytochemistry, assessment of haematological and vascular changes associated with air pollution exposure following standard haematological procedure and assessment of behavioural characteristics.

The findings are as follows:

Prevalence of respiratory and associated symptoms

Compared to children elsewhere, Delhi’s children had 1.8 times more ‘upper respiratory symptoms’ such as sinusitis, running or stuffy nose, sneezing, sore throat and common cold with fever and two times more ‘lower respiratory symptoms’ like frequent dry cough, sputum-producing cough, wheezing breath, breathlessness on exertion, chest pain or tightness and disturbed sleep due to breathing problems). It suggests higher prevalence of underlying respiratory diseases.

It means, 23.1% of Delhi’s children who were studied had upper respiratory symptoms as against 14.6% children from elsewhere. Similarly, 17% children from the city had lower respiratory symptoms against 8% of the kids from elsewhere.

Notably, respiratory and associated symptoms were most prevalent in children from low socio-economic status, and least in children from families with higher socio-economic background.

Prevalence of current asthma was present in 4.6% children of Delhi against 2.5% of controls. Similarly, the instance of physician-diagnosed asthma was two-times in Delhi (1.7 vs. 0.9%).

About 15% of Delhi’s children had frequent eye irritation compared with only 4% in controls. Similarly, they had significantly higher prevalence of frequent headache (27.4 vs. 11.8%), nausea (11.2 vs. 5.6%), and palpitation (7.2 vs. 3.3%) and fatigue (12.9 v. 6.7%).

Effect of Delhi’s air pollution on children’s lung function

The results showed reduction of lung function in 43.5% schoolchildren of Delhi compared with 25.7% in control group. Delhi’s children had increased prevalence of restrictive (20.3% vs 14.3% in control), obstructive (13.6% vs. 8% in control) as well as combined (both restrictive and obstructive) type of lung functions deficits (9.6% vs. 3.5% in control).

In short, 7.3% schoolchildren of Delhi had severe lung function deficits compared with 2.2% children in the control group. Lung function reduction was more prevalent in girls than the boys both in rural and urban settings. An inverse relationship exists between socio-economic status (SES) and the prevalence of lung function deficits: lower the SES, greater the percentage of children with reduced lung function.

Cellular lung reaction to air pollution

Alveolar macrophage (AM), lungs cells that clean off microorganisms and dust particles, was two-three times higher in Delhi’s children than the subjects from less-polluted towns.

Although tests were carried out on limited samples, the mean number of AM per high power field (hpf) in Delhi’s children was 5.2 in contrast to 1.7 AM per hpf in control. Hence, school children of the city had 3.1 times more AM in their sputum.

Marked increase in AM number signifies greater exposure to particulate pollution as AM represents the first line of cellular defence against inhaled pollutants.

Sputum analysis

Sputum of Delhi’s children contained four times more iron-laden macrophages (siderophages) than controls indicating covert pulmonary hemorrhage. Changes in the sputum cytology among the school children of Delhi positively correlated with ambient RSPM level.

Prevalence of hypertension or blood pressure

Arterial blood pressure was measured in 1,082 school children of Delhi (604 boys and 478 girls) and 726 of rural control (422 boys and 304 girls). The prevalence of hypertension in children was 6.2% (67/1082) in Delhi compared with 2.1% (15/726) in control. Thus, Delhi’s school children have 3-times more incidence of high blood pressure.

The difference in the proportion of hypertensive children in rural and urban areas was highly significant. Hypertension was more prevalent among girls than the boys both in Delhi and in control group. For instance, 7.9% of Delhi’s girls (38/478) had hypertension compared with 4.8% (29/604) of the boys. Similarly, 2.3% of control girls (7/304) had hypertension compared with 1.9% (8/422) of the boys. The difference in hypertension prevalence between girls and boys was statistically significant in Delhi, but not in control group.

Quite contrary to hypertension, pre-hypertension was found to be more in boys than in girls of Delhi (31.8% vs. 26.4%).

Behaviour and activities of children

Out of 2,630 children enrolled in Delhi for this study, 176 children (6.7%) had attention deficit hyperactivity disorder (ADHD). In contrast, 44 of 1645 control children (2.7%) examined during this period had ADHD. Thus, Delhi’s children had 2.5-times more ADHD prevalence than the controls.

Kids with ADHD act without thinking, are hyperactive, and have trouble focusing. They may understand what’s expected of them but have trouble following through because they cannot sit still, pay attention or focus on details.

Why are children so vulnerable to air pollution?

“Children generally spend more time and are also more active outdoors than the adults. They are active outdoors during midday when air pollution levels tend to be higher. They have significantly higher oxygen demands so their respiration rates are higher and they inhale more air per unit of body weight than adults. Because of their smaller stature, their breathing zone is lower. Therefore, they inhale air loaded with more particles. The diameters of their airways are smaller and therefore, they are more likely to be affected by inflammation produced by air pollution. Their lungs are still developing and hence are more vulnerable to airborne insults. Their immune defense is immature and hence less active against inhaled pathogens,” Dr Manas Ranjan Ray, co-investigator of the study and former head of the Department of Haematology, CNCI, told Firstpost.

What is the solution?

Scientists recommended the Central Pollution Control Board (CPCB) a list of short and long term solutions to the problem after evaluating their findings but unfortunately, the recommendations were never taken seriously by the authorities concerned, said Dr Ray.

According to the report, which came in the public domain after two years after its submission to the CPCB, the proposals to improve the situation are as follows:

  1. Children’s health is most acutely affected by air pollution exposures. Therefore, potential adverse effects of air pollution   on fetus, infant and child should be the main consideration while setting up standard for an air pollutant as well as             during revision of existing standards, and there should be a sufficient margin of safety.
  2. Epidemiological studies have identified particulates, especially PM2.5, as the most harmful air pollutant in South Asia. It is recommended that regular monitoring of this pollutant may be carried out in the country because of its harmful effect on human health.
  3. Children generally spend two-third of their time indoor either at home or at school. Therefore, indoor air quality seems to have significant influence on children’s health.
  4. Ozone is one of the most harmful air pollutants. Children are particularly susceptible to adverse health effects of ozone. Considering its toxicity, regular monitoring of ozone in Delhi and elsewhere in the country is recommended.
  5. Ozone is a secondary pollutant. It is not directly emitted from the sources, but formed via complex chemical reactions between oxides of nitrogen, hydrocarbons and sunlight. As a result, ozone levels tend to be highest in the afternoon. Teachers and parents/guardians should be enlightened in the matter.
  6. Considering the high prevalence of lung function deficits among schoolchildren of the city, all children aged nine years and above in Delhi should undergo lung function test at least once in a year, and those having lung function deficits should be monitored at regular intervals. The medical facilities at the schools should include a separate unit for respiratory health, and every unit should be equipped with a spirometer and trained technicians. Where the schools’ own medical facilities are absent, the appropriate authority should make alternative arrangements.
  7. In view of the high percentages of children with hypertension in Delhi, blood pressure of the children should be checked regularly at the schools’ medical facilities or elsewhere at least once in a year. More frequent follow up should be undertaken for those children with hypertension and/or obesity. Since hypertension affects some organ functions, medical conditions such as enlarged heart and abnormalities in kidney and eye functions should also be checked.
  8. Since parental smoking has been found to be associated with respiratory problems in their children, the school authority should impress upon the parents/guardians to quit smoking for the sake of the child during parent-teacher meetings.
  9. Diesel exhausts contain fine and ultrafine particles that are very harmful particularly for the children. Therefore a child’s exposure to diesel fumes should be avoided as far as practicable. In view of this, school buses and other vehicles used for transportation of the school children everywhere in the country should be changed from diesel to cleaner fuel like CNG or LPG.
  10. The government should recognize childhood obesity as a significant problem in cities. It requires intervention by family-based and school-based multi component programs that include promotion of physical activity, parents’ awareness, behavioural counselling and nutrition education in the line of recommendations of different dietic associations.
  11. Fast food and aerated beverages add excess calorie to the body. Delhi already has a large number of overweight and obese children. Obesity is a risk factor for several diseases, including problems of the heart and lung.
  12. High intake of fresh fruit and vegetables has beneficial effect on overall health as well as functioning of the lungs.
  13. In general, city and land use pattern should encourage designing and redevelopment of communities to promote mass transit, carpooling, pedestrian walkways and bicycle use.
  14. While allotting sites for new schools and child care facilities, due considerations should be given on their distance from roads with heavy traffic and other sources of air pollution. In essence, they should be away from hot spots of localized pollution.
  15. Information about air pollution in the country- its potential sources, health consequences and possible ways of abatement should be disseminated among the children. They are quick learners and their youthful exuberance can be utilized for spreading the message of environmental safety among the masses to garner public support that holds the key to success for every pollution mitigation projects.

What does the government say?

“I have written wrote to (Union Environment Minister) Mr Prakash Javadekar on the issue of increase in levels of air pollution in the national capital and that checking it must be treated as a priority. An action plan to improve air quality in Delhi as recommended by a high power committee headed by the then Chief Secretary of Delhi was sent to the Union Ministry of Environment, Forests and Climate Change in February. As a follow-up of this action plan, the concerned departments, including DDA, MCD, NDMC, Delhi Police etc. have been requested to prepare time bound implementation plans. The concerned departments are working on the action points identified for them,” Delhi Environment Minister Asim Ahmed Khan told Firstpost.

Asked about Delhi receiving pollution non-maintenance of CNG buses, he said since the NCR (national capital region) is a contiguous area with high population density and multiple pollutant sources, it is difficult to pinpoint and isolate the source of pollution in Delhi alone.

“There are reports about scientific studies, which indicate Delhi is receiving pollution from neighbouring towns and industries present in NCR. Therefore, comprehensive, coordinated and integrated efforts are required to improve the air quality in Delhi while accounting the emissions from nearby states and from Delhi itself to understand a casual relationship between emissions and impact on air quality,” he said.

Khan requested the Union minister to convene a meeting of various stakeholders in the NCR region and ask them to set up joint check posts well within their territories to ensure that overloaded vehicles can be checked and turned back before they enter Delhi.


Published Date: Apr 04, 2015 12:12 pm | Updated Date: Apr 04, 2015 12:16 pm


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