A seaside cure may actually harm your health nowadays. A new research published in "Nature Geoscience" shows that we are in fact exposed to ozone smog on the coastal areas.

The team led by James Roberts, from the National Oceanic and Atmospheric Administration's Earth System Research Laboratory in Boulder, Colorado, has employed a newly developed technique called mass spectrometer that can assess the levels of nitryl chloride (ClNO2) (which boosts the ozone formation) in the air. This is the first method that can measure nitryl chloride amounts in the air.

The chemical appears when nitrogen oxides from ship fumes and city smoke reacts with chloride rich aerosols, like sea salt spray. Surprisingly high levels of nitryl chloride were detected by the research team in the southeastern US coast, near the cities of Houston and Miami.

"We saw nitryl chloride levels over one part per billion on several occasions, more than 20 times greater than previous estimates from numerical models," said Roberts.

The highest amounts of nitryl chloride were detected at night, as during the day the sunlight breaks down the nitryl chloride into chlorine and nitrogen dioxide. The extremely reactive chlorine atoms are crucial in boosting the ozone formation. In the upper atmosphere, ozone protects life on Earth by reflecting the harmful UV light, but in the lower atmosphere this gas provokes respiratory issues and boosts mortality rates in humans.

"Such chemistry could occur in any urban coastal regions, potentially leading to a globally significant effect," said Lucy Carpenter, an atmospheric chemist at the University of York, UK.

"Areas at risk are likely to include southern California and the eastern seaboard of the US, much of the Mediterranean region and large parts of southern Asia," said Roberts.

Others believe the issue is restricted to industrial areas.
"It is possible, if not likely, that the overall importance of nitryl chloride is limited to heavily polluted conditions relatively close to major nitrogen oxide sources, such as those investigated in this study," said Bill Keene, an atmospheric scientist at the University of Virginia.