Severe smog and ground-level ozone problems exist in many major cities around the world, from Mexico City to Beijing, and recently as we all know, in Delhi.
Smog is a visible form of air pollution that often appears as a thick haze. Smog is made up of a combination of air pollutants that can compromise human health, harm the environment, and even cause damage to property.
Smog can cause or aggravate health problems such as asthma, emphysema, chronic bronchitis and other respiratory problems as well as eye irritation and reduce immunity to colds and lung infections.
Children, senior citizens, and people with heart and lung conditions are especially vulnerable, but smog can impact even those of us in good health. Symptoms during high air pollution days range from eye and nose irritation, to amplification of allergy and respiratory infection, to increased cardiac and respiratory deaths.
Smog is a mixture of emissions under specific climate conditions. These emissions include:
industrial pollutants, car and other vehicle pollutants, open burning of waste and crop residues and incinerators.
Weather and place affect the severity of smog. Because temperature regulates the length of time it takes for smog to form, smog can occur more quickly and be more severe on a hot, sunny day. Summer smog is created when sunlight mixes with hydrocarbons and nitrogen oxides, creating ozone.
Ozone, a colorless, odorless gas, can be good when in the upper atmosphere as it acts as a barrier against harmful ultraviolet radiation but harmful when found near ground level. Ozone is what causes the burning eyes and respiratory distress associated with smog.
Ground-level ozone gas and the tiniest air pollution particles called PM2.5 play leading roles in air pollution. While the PM2.5 particles come directly from car exhaust fumes, factories and distant coal-fired electric plants, the ozone gas builds up in the afternoon when sunlight chemically reacts with air pollution on hot days. Heat waves can dramatically increase the levels of ozone, which can cause sunburn-like effects on our delicate lungs.
The small PM2.5 particles can enter our bloodstream directly through the alveoli of our lungs. Once in the blood stream, these particles act like cigarette smoke, triggering inflammation that makes cholesterol more sticky, leading to blockages and heart attacks years later. People living in the most polluted cities are likely to have up to a 10 percent higher chance of having a heart attack compared to those living in less polluted cities.
Exposure to smog can also lead to several different types of short-term health problems. These include:
Coughing and throat or chest irritation which generally lasts for a few hours after exposure to smog. However, ozone can continue to harm the lungs even after symptoms disappear.
There can be a worsening of asthma symptoms in patients of asthma. There can be difficulty in breathing and lung damage. Smog can make it feel difficult to breathe deeply, especially during exercise.
It’s important to note that smog affects everyone differently, and some people are more susceptible to its negative effects. Children, seniors, and people with asthma need to be especially careful on smoggy days.
Don’t take chances with smog on days when air quality is poor. The best approach is to spend less time outdoors and replace vigorous activities, like running or biking, with gentler options, such as walking.
You can also schedule your outside activities for the early morning or evening, when ozone levels are low. These simple steps can help protect you and your family on smoggy days, whether you live in a major city or you’re just passing through.