Aangezien de luchtvervuiling door de verbranding van kolen, turf en hout in die tijd gigantisch hoog lag.
https://www.nber.org/system/files/working_papers/w21647/w21647.pdf&ved=2ahUKEwjQw5C7-MKUAxUdR_4FHSsgBm8QFnoECCgQAQ&usg=AOvVaw2wR7gbjif694TXRwnQLFvu
https://cepr.org/voxeu/columns/quantifying-impact-smoke-pollution-health-19th-century&ved=2ahUKEwjQw5C7-MKUAxUdR_4FHSsgBm8QFnoECEkQAQ&usg=AOvVaw0M2GD86bj7vALivkcXbYpA
https://www.scienceandindustrymuseum.org.uk/objects-and-stories/air-pollution