References:
“Acid Rain” (National Geographic) General article on how acid rain affects more than just forests and architecture http://environment.nationalgeographic.com/environment/global-warming/acid-rain-overview/
“The Killer Fog that Blanketed London” by Christopher Kline (History) Historical article about the Great Long Smog of 1952 http://www.history.com/news/the-killer-fog-that-blanketed-london-60-years-ago
“UK air pollution: How bad is it?” (BBC) Article detailing the current state of the United Kingdom’s air quality http://www.bbc.com/news/uk-26851399
https://www.youtube.com/watch?v=om-DG-yNYO8
https://www.youtube.com/watch?v=hdXtZFoYA_4
https://www.youtube.com/watch?v=Ms4v0Ekvyuw
https://www.nrc.gov/reading-rm/doc-collections/fact-sheets/chernobyl-bg.html
https://www.britannica.com/event/Chernobyl-disaster