Semantron 21 Summer 2021

The environmental effects of lockdown

Cameron Brown

1.1 Why Bournemouth? Bournemouth is a popular coastal resort town on the south west coast of England. It has a population of 183,491 residents and a population density of 4,000 residents/km 2 . 1 The coronavirus lockdown imposed by the UK government in late March of 2020, 2 restricts many forms of transport and movement, with driving only being allowed for essential journeys. Therefore, air pollution in Bournemouthmight be able to show a significant reduction during the months of lockdown as it would otherwise have regular tourists throughout the year. Furthermore, due to recent high temperatures across the UK large amounts of people have gathered on the UK coastline, particularly in Bournemouth, and I wanted to investigate whether this could be seen in the data. 3 1.2 An Introduction to Ozone Ozone, O ₃ , is an allotrope of oxygen found as a gas both in the Earth ’ s troposphere (from the earth’s surface to roughly 12 kmaltitude) and the stratosphere (from12 km to 50-55 km), where the photolysis of ozone absorbs high frequency ultraviolet radiation, deadly to life on the surface, emitted by the sun. 4 However, tropospheric ozone is a pollutant; in general, elevated ground level ozone concentrations ( ≥ 120µg/m³) lasting for at least 6.6 hours have been associated with increased short-termmortality due to respiratory conditions in many epidemiological studies. 5 It also constitutes a significant proportion of photochemical smog. Ozone pollution can also reduce crop yields in many regions 6 and, as a greenhouse gas, contributes to global warming. 1.3 Ozone Precursors Ozone is a secondary pollutant; there are not any activities that emit significant amounts of ozone gas. Instead net ozone formation in the troposphere is caused by photochemical reactions of ozone in the presence of NO X (both NO and NO 2 ) and VOCs (volatile organic compounds) – these are called ozone precursors. NO x gases are mainly emitted from combustion occurring in air. Therefore, burning fossil 1 Office for National Statistics. ‘ 2011 Census aggregate data’ . (2016). UK data service (Edition: June 2016). http://infuse.ukdataservice.ac.uk/ . 2 Diver, T. ‘Boris Johnson announces UK lockdown: watch his speech in full’. (2020, March 23). The Telegraph. https://www.telegraph.co.uk/news/2020/03/23/boris-johnson-announces-uk-lockdownspeech-full/. 3 BBC South. ‘ Bournemouth beach: ‘Major incident’ as thousands flock to coast’ . (2020, June 25). BBC News. https://www.bbc.co.uk/news/uk-england-dorset-53176717. 4 Gleason, K.L. ‘ Sc ience: Ozone Basics’ . (2008, March 20). National Oceanic and Atmospheric Administration.https://web.archive.org/web/20171121051325/http://www.ozonelayer.noaa.gov/sc ience/basics.htm. 5 World Health Organization. ‘ Health Aspects of Air Pollution with Particulate matter, Ozone and Nitrogen Dioxide’ . (2003, January 15). https://web.archive.org/web/20050909162152/http://www.who.dk/document/e79097.pdf 6 Tai, P.K.A., Martin, M.V., Heald, C.L. ‘ Threat to global food security form climate change and ozone air pollution’ . (2014, July). Nature. https://dspace.mit.edu/bitstream/handle/1721.1/111641/Tai_2014_v1.6_manuscript.pdf?sequence =1&isAllowed=y.

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