As the Delhi government gets ready to implement a series of measures to tackle air pollution, the All India Institute of Medical Sciences (AIIMS) is set to lead the first large-scale study in nearly 18 years on links between respiratory and cardiovascular conditions, and air quality in the capital.
Following up on a landmark study conducted by its former medicine department chief Dr J N Pandey from 1997-98, AIIMS will be part of a three-centre initiative funded by the Indian Council of Medical Research (ICMR) to find how changes in the Air Quality Index (AQI) impacts admission of patients with respiratory and cardiovascular complaints.
“This study will cover adult and paediatric population and look at admissions in respiratory and cardiovascular diseases, which are increasingly being associated with air pollution. We have early ethical clearances for the study, and will try to start from January to capture the seasonal variation in pollutants,” said Dr Randeep Guleria, head of respiratory medicine, AIIMS.
Lady Hardinge Medical College’s paediatrics department and Vallabhbhai Patel Chest Institute (VPCI) will be the other two centres participating in the ICMR study.
Dr Pandey’s study, on outdoor air pollution and emergency room visits in Delhi hospitals, had showed that admissions increased on poor air quality days. This study was referred to by the Supreme Court in its historic judgment directing public transport in Delhi to be converted to CNG.
“We want to compare the new findings with the pre-CNG era findings to see the trajectory of hospital admissions and air pollution. There are new trends, too. For instance, we find that viral chest infections like H1N1 have been increasing in the three months after Diwali, when air quality dips,” said Dr Guleria.
According to doctors, the study will focus on the shift from upper to more serious lower respiratory tract infections; a “sudden spike” in heart attacks; atherosclerosis, or thickening of heart muscles; and increased recovery time needed by patients with long-term diseases like bronchial asthma.
“We will return to the homes of patients and monitor the air quality in their neighbourhood during the time of admission with the help of AQI data, studying different pollutants,” said Dr Guleria.
Apart from this, AIIMS is also looking at initiating a pollution study focussing on lung function tests and is ready to publish another study that links eye infections to bad air quality.
The institute has submitted a proposal to the UK’s Medical Royal Colleges Association for funding the study to monitor personal exposure in people using portable machines and conduct lung function tests in the long run.
“This study will also include pregnant women. This is a long-term study where we want to first study maternal and foetal health through pregnancy, and then follow-up on children born to mothers exposed to high air pollution,” said Dr Guleria.
Dr Neerja Bhatla, professor of gynaecology, AIIMS, said this study could throw light on the high number of premature delivery cases in the institute.
“Prematurity is growing and we are very interested to see its causes. In global cities where air quality is poor and in animal studies, particulates have been shown to cross the placenta and even get deposited in the foetus,” said Dr Bhatla said.
The institute’s ophthalmology department, meanwhile, has completed a year-long study on 5,000 patients as part of a follow-up on a 2002-03 exercise that showed how tear-film formation in the eye has moved from alkaline to acidic for people living near polluted areas.
The study, which is awaiting publication, has found that conditions associated with particulate matter spiked from 15-27 per cent in OPDs when air quality dipped.
“Conditions like redness in the eye, irritation and tear dysfunction increased by seven per cent in the winter months. We also found that these conditions are more in young males below the age of 40 who go out, and are exposed to poor air,” said Dr J S Titiyal, professor of opthalmology at AIIMS.
“We also found that eye allergies like conjunctivitis, which were earlier restricted to the spring season, are now surfacing in winters when pollutants are high, especially in young children,” said Dr Titiyal.
The department is also awaiting final clearances for a joint study to compare eye diseases related to pollution in Delhi and Florida, which “is known for its excellent air quality”, he said.