While ozone is essential to protecting life on Earth, it’s beginning to become a threat to public health as the climate is warming.
9–18 miles high in the stratosphere, the ozone layer protects the Earth from ultraviolet radiation, but near the ground, ozone is a poisonous waste product, harmful to living organisms.
Once entering the human lungs, ozone reacts with proteins and fats, causing an inflammatory process. It could lead to intensification of asthma, and cause chronic bronchitis, hyperapnea, and cardiovascular diseases.
Ozone is mostly a summer problem, because of increased temperature and sunlight. It poses a greater threat to suburban environments. Photo: Toomas Tuul.
Warmer Climate: More Ozone
As the climate gets warmer, the level of ozone close to the ground is increasing at the fastest pace in Central and Southern Europe. The number of human deaths it causes is rising quickest in Belgium, France, Spain and Portugal. By the middle of this century, 10–14 per cent more people than now will die because of ozone, as concluded by a group of scientists, amongst them Hans Orru, an expert on air pollution at the Universities of Tartu and Umeå.
In the study, scientists assessed ozone content using two different models of the global climate (ECHAM4 and HadCM3), looking at an initial period (1961–1990), the present (1990–2009), the future (2021-2050), and the even more distant future (2041-2060), and its influence on the European climate. Because the genesis of ozone is directly linked to sunlight and temperature, it follows that as the climate gets warmer, the amounts of ozone increase. More ozone means greater harm to health.
The increase of ozone close to the ground induced by climate change has had the greatest effect in Belgium, Ireland, the Netherlands and Great Britain already since the 1960s. As Orru puts it, the population density of these countries, as well as the abundance of cars, leads to high ozone levels. Exhaust from cars produces a great part of the substances that lead to genesis of ozone.
While the ozone level is rising in Southern European countries, it is decreasing in Estonia and Nordic countries, meaning a smaller number of deaths. Although this is mostly related to a reduction in transaction of the antecedents of ozone, clouds probably have something to do with it as well. So, according to both climate models, climate warming means more cloudy days for us.
Considering the present amounts of the substances that are needed for ozone to form, the gas will cause nearly 30,000 cases of premature death by the middle of the century – almost 2,000 more cases than today.
Interestingly, it appears that ozone isn’t primarily a menace limited to big cities like ultrafine pollution particles are, because parts of ozone quite quickly react with other pollution in the cities and break down into less harmful compounds. Therefore, ozone poses a greater threat to suburban environments.
In Estonia, ozone contributes to about fifty premature deaths each year – about one death per week. The group of scientists led by Orru plans further research to study how ozone affects Estonians’ health.
Ozone is mostly a summer problem, because of increased temperature and sunlight.
