Empower citizens, tackle pollution
Do short-term emergency action and daily health alerts lower air pollution and cut health risks? This curiosity is strong today, especially after Delhi and the National Capital region implemented the first-ever Graded Response Action Plan (GRAP) to respond to daily air pollution levels. Several Indian cities want to implement GRAP. As short-term emergency action is different from the continuous action for longer-term air quality gains, cities want to know how short-term action can help. Can health alerts trigger public scares? The good news is that global evidence proves that short-term measures, while ramping up long-term reforms, actually helps.
Reducing smog peaks
There is a reason for this conversation today. The new analysis of the Environment Pollution (Prevention and Control) Authority (EPCA) and Centre for Science and Environment (CSE) shows first signs of improvement in winter air quality in Delhi-NCR after GRAP implementation. Smog peaks are lower this winter though the overall air quality is not even close to being declared clean yet. With this action and evidence, Delhi-NCR joins the global league of governments who issue daily health alerts and take emergency action for public health protection.
It is difficult for many to fathom how short-term daily action provides air quality and health benefits. Smog episodes occur when the weather is adverse, with calm or no wind, cold temperature, and a lower mixing height of air which traps the air and pollution very close to the ground-level. This increases exposure hugely. While nothing can be done to control the weather or to remove trapped emissions already emitted, short-term policy action can control further loading of emissions and prevent higher smog peaks and exposure. Of course, in the longer term, emissions must be permanently reduced so that peak episodes are not repeated.
Cities worldwide have shown improvement in air quality due to short-term emergency action during smog episodes. For instance, Santiago in Chile has found that daily alert action that includes a restriction on driving, shutting major factories and prohibition of biomass combustion among others, has led to an immediate decline in air pollution on alert days—by as much as 20 per cent compared with similar days without alerts. Similar action is being undertaken by Mexico City, Paris, and Beijing among others to tame the smog peak.
Growing emphasis on health alerts
Increasingly, governments are placing immense emphasis on daily health alerts and health bulletins to make the majority of city dwellers aware of the severity of daily air pollution and health risks to take precautions. Delhi-NCR's GRAP also includes a health advisory that says that those suffering from heart diseases, asthma, and other respiratory diseases may consider avoiding undue and prolonged exposure; minimising unnecessary travel, availing public transport and avoiding the use of private vehicles among others. But Delhi-NCR will have to roll out an effective daily health communication system.
Similar advisories in other countries are more elaborate and are widely disseminated. They advise children to discontinue vigorous outdoor activities regardless of duration. Outdoor physical education classes, sports practices, and athletic competitions are re-scheduled or cancelled. Those with heart or lung disease need to avoid outdoor activities. Advisories encourage the public to reduce unnecessary driving and promote carpools. They encourage employers to limit the amount of time their employees work outdoors.
Role of aggressive health alerts
New studies have found evidence of health benefits from the short-term daily action and health alerts for people. The Lancet review in January 2018 has shared evidence from Canada, which shows that air pollution alerts remain fundamental to public health protection, leading to the reduction in emergency room visits for asthma and chronic obstructive pulmonary disease.
It is often not clear to many if people take note of the daily health bulletin at all to take precautions. Even though several governments are communicating air quality risks on a daily basis, in reality, the penetration of this information remains limited and the response is lukewarm. This reduces the scope of impact. A US study in Portland and Houston in 2003-2005 found that one-third of the participants studied were aware of air quality alerts and 10-15 per cent of individuals reported changing behaviour in response to smog alerts. Thus, the extent of the benefit will depend on more aggressive and quality communication and outreach to make the public aware.
There is evidence of behavioural changes. The US-cross-sectional study in six US states in 2005 on the behavioural risk factor surveillance system, found that about a third of adults with asthma and 16 per cent without asthma reported a change in outdoor activity due to media alerts. The individual perception of poor air quality and health professional advice greatly increased the reported behaviour change. Health alerts also impact the attendance at outdoor events during a smog episode. The evidence in the Lancet Review of January 2018 has shown that air quality alerts in southern California reduced attendance at outdoor venues by about 2-3 per cent when people understood the perils of stepping outdoors. Smog alerts also increase the demand for health services during smog episodes. In the UK, text messaging about air quality has increased the use of health services among a group judged at risk for adverse effects of air pollution exposure.
Hong Kong has even gone to the extent of making its daily air quality index and alerts more health-based. It has replaced the Air Pollution Index system (similar to India's that classifies days based on the severity of air pollution), with an Air Quality Health Index (AQHI) system in 2013. Their AQHI is based on the cumulative health risk attributable to three-hour moving average concentrations of Ozone, NO2, SO2 and PM 2.5 or PM10. This is based on the relationship between local air pollution and hospital admissions and provides a locally relevant index with health reference. The health advice is given according to the degree of susceptibilities like existing heart or respiratory illnesses, children and the elderly, outdoor workers, and the general public.
Effectively communicating health advisory
This trend will be enhanced with more governments issuing pollution and health alerts and citizens becoming more aware and responsive. The public response will become sharper with growing citizen science and with more people receiving access to low-cost air quality monitors to track air quality. There is already a big shift towards personalised systems with small low-cost sensors and crowdsourcing of air quality data and mobile technologies used for warnings and guidance and to lodge complaints against polluters. People will respond more effectively.
There is an opportunity for improving the dissemination of health alerts in Delhi-NCR and other cities where real-time air quality monitoring is improving. At the national level, the Union Ministry of Environment, Forests and Climate Change is further refining the health advisory. To maximise health benefits from GRAP, emergency action will have to be supported by strong and effective public communication on health consequences.
Let us not shy away from a wider and more effective dissemination of health consequences for the fear of public scares. It is the state's obligation to let people know the risks arising from toxic air. With more matured awareness, people can take precautions to reduce the risks while supporting and pushing for hard action.
(The views expressed are strictly personal.)
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