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The UK’s air quality and emissions: are we making any inroads?

It’s clear that the present threat of climate change cannot
be ignored anymore. To do so would be inherently damaging — not only to the
individual, but to society, to mankind, and to the entirety of life on Earth.

As dramatic as it sounds, the stark fact is that it is extremely worrying. The impact of
climate change upon the planet will be nothing short of colossal-scale dramatics,
for every living creature here. Even Bill Nye, who holds a place in the hearts
of Americans akin to how British people embrace Sir David Attenborough, isn’t
sugar coating it.

“By the end of this century, if emissions keep rising, the
average temperature of the Earth could go up another four to eight degrees,”
Bill Nye said on Last Week Tonight.

Meanwhile, Sir David Attenborough’s appearance on Climate Change — The Facts allowed him
to deliver the difficult truth in a raw and uncompromisingly
clear message: that global warming is the greatest threat the planet has
witnessed in thousands of years.

It’s terrifying, but for the moment, it isn’t irreversible.
The world’s governments have, by and large, agreed to cleaning up their
emissions and waste in recent years. We’re recycling more and looking at
renewable sources of energy. We’re removing single-use plastics from our supply
chain and swapping our energy-inefficient appliances for more eco-friendly
options, such
as a gas combi boiler and energy-saving bulbs.

The question is whether or not we’re seeing an improvement
at all from our current efforts. One way to gauge improvements is via the air
quality statistics report released by the Department of Environment, Food, and
Rural affairs (DEFRA).

What effects the UK’s air quality?

Before we look at the specific elements that are monitored
for air quality purposes, it is important to understand what has an effect on
the UK’s air quality. We all know pollutants from vehicles and fossil fuels are
a prime contributor to dangerous emissions and poor air quality, but other
factors can also affect our air quality, such as:

  • Emissions from Europe and the wider world
  • Weather conditions, such as heat in the summer,
    can cause changes in air quality

A breakdown of what’s in the air


What is PM10?

PM stands for particulate matter. These particles could be
solid or liquid, come from natural or human sources, and can be a variety of sizes.
Particulate matter concentration in the air is measured in micrograms per cubic
metre (µg m–3). Particulate matter itself is measured in diameter from as small
as a nanometre (nm), such as viruses, to micrometres (µm), such as human hair
(100 µm).

PM10 covers particulate matter in the air that is
less than or equal to 10 µm in diameter. Some examples of particulate matter of
this size range include:

  • Dust (<10 µm)
  • Pollen (<10 µm)
  • Red blood cells (7-8 µm approx.)

Particulate matter in the air is grouped in two ways:
primary components, which are released into the air from a source directly
(such as pollen from a plant), and secondary components, which are created by
chemical reactions in the atmosphere, (such as sulphate, which forms when
sulphur dioxide oxidises in the air to create sulphuric acid, which then reacts
to ammonia to create ammonium sulphate in the air).

Why is PM10 bad?

Generally speaking, small particulates in the air are
considered to be harmful to human health. There is evidence to suggest
particulate matter with a diameter of 2.5 µm or less is particularly harmful;
carbon and trace metals in the air, for example. These particulates have been linked
to respiratory and cardiovascular illnesses.

Is it decreasing in the UK?

According to DEFRA, the levels of urban background PM10
pollution has reduced considerably between 1992 and 2018. The most
dramatic fall was between 1992 and 2000, with an average yearly reduction of
around 1.6 ?g/m3. However, the increase in PM10 between 2017 and
2018 has been noted as “statistically insignificant” by the report.


What is PM2.5?

Like PM10, PM2.5 refers to particular
matter polluting the air around us. It is measured the same way and covers
particulates with a diameter of 2.5 µm or less. Basically, these are some of
the smallest particulates in the air that the country monitors. Like PM10,
PM2.5 can come from manmade or natural sources and can be primary
components released directly from the source to the air, or secondary
components formed from a chemical reaction within the air.

Some examples of these tiny particulates are:

  • Combustion particles (<2.5 µm)
  • Nanotube electrodes (1 µm)
  • Trace metals (<2.5 µm)

Why is PM2.5 bad?

Similarly, to PM10, PM2.5 is bad news
for respiration. These tiny particles can cause, as well as aggravate,
respiratory diseases, cause plaque deposits in the arteries, and even lead to
heart attacks or strokes. PM2.5 tend to stay in the air much longer
than PM10 due to being lighter, which means people have a greater
chance of inhaling them. Plus, as they are so small, the nose and lungs are not
always able to filter them before they reach our lungs. The elderly and
children are particularly vulnerable to this.

Is it decreasing in the UK?

PM2.5 has decreased for urban background
pollution compared to 2009, with the average yearly concentration of 9.5 ?g/m3
in 2017 the lowest in the recorded range. As with PM10, the increase
between 2017 and 2018 is seen as “statistically insignificant”.


What is N02?

NO2 is nitrogen dioxide, and it is measured in
the air in micrograms (µg). It is produced by burning fossil fuels, such as
coal, as a primary component released directly into the air. It can also be
produced as a secondary component when nitrogen oxide and ozone react in the
air, producing nitrogen dioxide and oxygen.

Why is NO2 bad?

DEFRA notes that NO2
can inflame the lungs, damage how our lungs work, and aggravate the
symptoms of asthma. NO2 also has an adverse effect on crops and

Is it decreasing in the UK?

NO2 levels have indeed reduced in the long term
(since 1990) as well as in recent years within the UK. In particular, there was
a rapid decrease in the amount of NO2 in the air between 1992 and
2002, with an average yearly reduction of around 2.7 ?g/m3.


What is O3?

O3 is ozone, and like NO2, it is
measured in ?g. No doubt we’ve all heard about the ozone — it protects the
Earth from ultraviolet rays from the sun, and it is being destroyed by manmade
emissions. Ozone is a good thing, we’re all told.

Well, yes and no. As AirNow explains, when it comes to
ozone, it is “good up
high, bad nearby”. Essentially, when ozone is high up in the planet’s
stratosphere, it’s good. It’s protecting us, and we’re also not breathing it in
at this level. But at ground level, (the troposphere), ozone is bad news for
people and plants alike.

Why is O3 bad?

O3 created at ground level is usually created by
chemical reactions between nitrogen and volatile organic compounds, which in
turn, come from industrial emissions, vehicles, and solvents. It is
particularly prominent in the summer months, as these chemical reactions occur
under the heat of the sun.

Breathing in high concentrations of O3 at ground
level can cause:

  • Throat irritation
  • Lung irritation and coughing
  • Chest pains
  • Reduced lung function
  • Inflammation of the lungs

It also damaged crops and makes plants more susceptible to
diseases and pests.

Is it decreasing in the UK?

No — the levels of urban background ozone pollution have
been increasing over the long-term, though DEFRA notes that the last decade has
been “stable”. Between 2017 and 2018, the concentration of O3
increased from 58.3 ?g/m3 to 62.8 ?g/m3. There are a few reasons why this
increase may have occurred:

  • Hot
    weather conditions create high ozone concentrations, and so, the heatwaves
    experienced in the UK in 2018, 2006, and 2003 – will have caused notable
    increases in O3.
  • The
    UK and Europe have reduced their nitrogen oxide emissions as a whole. Nitrogen
    oxide is known to reduce ozone formation. This is something of a double-edged
    sword: we have reduced nitrogen oxide emissions, which has in turn reduced
    nitrogen dioxide pollution in the air (which is formed from nitrogen oxide
    and ozone reacting in the air, producing nitrogen dioxide and oxygen). But in
    doing so, the ozone in the air has nothing to react to, meaning it stays!

When it comes to emissions and air quality, the UK is
certainly seeing improvements in most areas. We still have a lot of work to do,
particularly with our O3 levels. We also need to take drastic action
in other climate change-causing behaviours, such as waste and recycling.