On World Environment Day, no one is safe from deadly ozone pollution
New Delhi, June 5: There is bad news as far as deadly ozone pollution is concerned on the World Environment Day celebrated across the globe on Monday.
According to the Centre for Science and Environment, a public interest research and advocacy organisation that promotes environmentally sound and equitable development strategies, ozone pollution is hitting a peak every summer in Delhi and the National Capital Region.
The CSE warned that no one is safe from the deadly ozone pollution, especially those suffering from asthma and respiratory problems. Moreover, increased heat wave and rising summer temperatures, inevitable with climate change, is worsening this trend.
It is dangerous if ozone increases even for a short duration, stated a press release issued by the Delhi-based organisation on Sunday, a day ahead of the World Environment Day.
The national capital has witnessed a significant ozone build-up this summer, adding to the public health risk -- shows the latest analysis done by the CSE. The organisation has analysed the real-time air quality data available from the key monitoring locations of Delhi Pollution Control Committee for the summer months of 2016 and 2017.
"Ground-level ozone is not directly emitted by any source. This is formed when oxides of nitrogen and a range of volatile gases, primarily from vehicles and other sources, are exposed to each other in sunlight.
Warm and stagnant air increase the formation of ozone. Ozone is extremely hazardous for human health. All neighbourhoods in Delhi - rich and poor - are at risk," stated the CSE.
According to Anumita Roychowdhury, executive director, research and advocacy and head of CSE's air pollution programme, "Delhi and the NCR are in the grip of multi-pollutant crisis. Even before the health risk from particulate matter could be addressed, deadly ozone has raised its ugly head in Delhi and the NCR. Without a time-bound implementation strategy and preventive action, this can deepen into serious public health crisis. This will spare neither the rich nor the poor."
Here we bring you the study of the CSE in a nutshell:
Why should we worry about ozone?
Early deaths due to ozone pollution are the highest in India. The new burden of disease study from the Health Effect Institute has shown that early deaths due to ozone have jumped by 148 per cent in India.
Ozone aggravates respiratory problems, especially chronic obstructive pulmonary disease. The HEI scientists used the chemical transport model for estimating the ozone, but the evidence of increasing ozone levels in India, especially in north India, is seen from the available measurements.
According to scientists, formation of ozone is expected to be higher in countries in tropics and sub-tropics and near the equator. To some extent, rising temperature is also aggravating this trend.
India will be well-advised to take early and stringent steps to control ozone precursors which are very difficult to control. This means stringent control of gaseous emissions from combustion sources including vehicles.
Ozone precursors like nitrogen oxides, carbon monoxides and volatile organic compounds also have serious local public health impacts.
Ozone is an extremely harmful gas, just a few hours of exposure to it can trigger serious health problems. It is particularly harmful for outdoor activities. It can have immediate health impact especially among those who are already suffering from respiratory and asthmatic problems even for short duration exposure.
Ozone worsens symptoms of asthma, leads to lung function impairment and damages lung tissues. Chest pain, coughing, nausea, headaches and chest congestion are common symptoms.
It can even worsen heart disease, bronchitis and emphysema. It increases emergency hospital visits and admissions related to respiratory diseases.
A study by the University of Southern California and reported in Lancet, has found that in high-ozone areas the relative risk of developing asthma in children playing three or more sports was more compared to children playing no sports.
Outdoor heavy exercise is not recommended -- with every breath, athletes particularly take in 10 to 20 times more air, and thus pollutants, as sedentary people.
Scientists inform that ozone is a powerful oxidiser, which means it can damage cells in a process akin to rusting. Children and the elderly are at special risk. There is a strong association between ozone and daily premature death counts.
Those with pre-existing diseases and lung diseases are at serious risk. Growing concentrations of nitrogen oxide and volatile organic compounds from combustion sources, especially from the explosive increase in diesel vehicles is adding to the deadly recipe of ozone in hot and extreme climate.
Also, ozone that gets created in the polluted environs of the city can also drift depending on the wind direction towards cleaner environs in rural periphery and begins to accumulate as it has less chances of reacting with other pollutants in cleaner environment. Hence it builds up fast at the outskirts. It is known to damage crops.
What do other governments do?
Ozone is included in the daily smog and health alert programmes in countries such as Mexico, the US and China, among others. In Mexico City, the elderly, children and those suffering from respiratory and cardiac problems are advised to stay indoors when levels of ozone go up.
The US-based National Research Council, part of the National Academies of Science, has recommended that local health authorities should keep the harmful effects of ozone in mind when advising people on polluted days. The US has therefore tightened the ozone standards.
Need urgent action
Delhi and the NCR needs much high degree of health protection for all and especially the high risk groups including the elderly, children, outdoor workers and people with asthma and lung disease.
Cost of inaction can be very high. Governments must have its implementation strategy for priority measures in place before the next winter:
Finalise and implement pollution source-wise comprehensive action plan directed by the Supreme Court in Delhi and the NCR. This should include targeted reduction of gaseous emissions from vehicles, industry and power plants.
Need stringent measures to reduce nitrogen oxide and a range of volatile hydrocarbons. Ensure timey implementation of BS VI emissions standards and control dieselization of vehicles segment to control NOx emissions.
Need time bound implementation to scale up public transport, walking and cycling to reduce vehicles usage and numbers.
Issue health alert on bad ozone days and link to graded response action plan.