A recent study suggested that outdoor air pollution is estimated to
contribute to more than two and a half million deaths each year. Specifically,
it calculated that each year, 470,000 people died as a result of ozone
depletion, and 2.1 million deaths were linked to fine particulate matter. Air
pollution increases respiratory and heart disease risks, with the young,
elderly, and infirm most vulnerable.
Epidemiological studies have shown that ozone and PM2.5 (particulates with
a diameter of less than 2.5 microns – about 30 times thinner than the width of
a human hair) have significant influences on human health, including premature
mortality. However, there are studies that they are suggesting that we may
overestimate PM2.5 mortality in regions with very high concentrations.
The WHO (World Health Organization) says it is difficult to identify the
world’s most polluted areas because many cities with high levels of air
pollution do not have monitoring systems in place. Further, the WHO adds
although most air pollution hot spots are located in developing nations, it
says that developed countries are also at risk and the issue is a major
environmental risk globally. As air quality is largely beyond the control of an
individual, the WHO says action needs to be taken by national and international
bodies. In 2005, WHO published its Air Quality Guidelines that recommended
limits for air pollutants, including PM2.5 and ozone. According to the WHO,
continued exposure to particles contributes to the risk of developing
cardiovascular and respiratory diseases, as well as lung cancer. As a matter of
fact. The WHO adds that the mortality in cities with high levels of pollution
exceeds that observed in relatively cleaner cities by 15%-20%. Even in the EU,
life expectancy is 8.6 months lower (as a result of) exposure to PM2.5 produced
by human activities. Ozone pollution is linked to breathing problems, such as
asthma, reduced lung function, and lung disease.
The research, conducted by an international team of scientists, also looked
at how changes to the planet’s climate system as a result of human activities
could have affected the impact of air pollution, such as changes in temperature
and humidity.
While being a contributing factor to climate change, previous studies had
considered how the emissions could create conditions that exacerbated poor air
quality, such as the way an increased concentration of chemicals interacted
with sunlight.
Another change is the way higher temperatures affect plants’ biochemical
characteristics. Trees use chemicals known as volatile organic compounds (VOCs)
to attract pollinators as well as deter damaging attacks from insects and
larger animals. However, higher temperatures can cause many tree species to
emit more VOCs into the atmosphere, which reacts with sunlight to form ozone or
more particulars.
Using a model of ozone and PM2.5 atmospheric concentrations from 1850 and
2000 the researchers concluded changes to the climate since pre-industrial
times accounted for only a small proportion of the current deaths related to
air pollution. Specifically, they calculated that about 3,700 deaths each year
could be attributed to the effects of past climate change on air quality.
Georgios Ardavanis – 02/12/2023