new delhi mathura road lodhi road iitdelhi dhirpur in northwest delhi and gurgaon are among the ozone hotspots in april so far according to an analysis conducted by the system of air quality and weather forecasting and research safar the forecasting body under the union ministry of earth sciencesthe five locations exceeded the eighthour standard of 50 parts per billion ppb on most days in april of these gurugram reported the highest level of ozone as exceeded 100 ppb on most daysozone is a harmful gas that is found in two regions of the atmosphere up in the stratosphere it protects the earth from suns harmful rays in the troposphere which is the layer of atmosphere that humans live in the presence of more than permissible level of ozone can harm health and plants it can inflame a persons airways cause chest pain and wheezing in healthy humans for people with asthma or lung diseases the effect can be much worsethe analysis by safar found that delhi university pusa and t3 at igi airport were the stations that recorded low ozone concentrationsafars analysis said that april 810 saw the highest average ozone that crossed 60 ppb some stations saw high levels of ozone mainly due to an increase in volatile organic compounds voc the sources of voc are natural sources and vehicle exhaust high temperature also plays an important role said gufran beig the founder project director of safarif the temperature rises to 40 degrees celsius or above the production rate of ozone will increase and hence in the coming days we may see further rise in ozone beig saidhe added that ozone toxicity is higher than particulate matter and the health impact is immediate those with respiratory conditions asthma chronic obstructive pulmonary disease and particularly children with premature lungs and older adults are at risk when the ozone level increases more than the permissible limit of 50 ppb he saidground level ambient ozone is produced from the complex interaction between nitrogen oxides and vocs that are emitted by vehicles power plants factories and other combustion sources the compounds undergo cyclic reactions in the presence of sunlight to generate groundlevel ozone according to a study done by the centre for science and environment last year anumita roychowdhury the executive director for research and advocacy at cse said increase in the number of days exceeding ozone standard is a predictable trend in summer in delhi it has not drawn adequate regulatory attention stringent measures are needed ozone is not directly emitted by any source but gases from different sources react under the influence of sunlight to form ozone even short duration exposure can worsen symptoms in people suffering from asthma and respiratory conditions