Environment, Industrial revolution
Concern about the effect of human activity on the environment is a relatively new phenomenon, which can be directly linked to the the by-products of the Industrial Revolution. Whilst historians quibble over exactly when the Revolution began, they all agree that the period between 1760 and 1870* was a major turning point in human history and is as important to civilization as domesticating animals and plants. The development of efficient steam power led to the invention of machine tools, improved iron making and textiles.
*The earliest whispers of the industrialization tsunami were heard in rural Britain with James Hargreave’s invention in 1764 of the spinning jenny, which produced a lightly twisted yarn, upon which further more effective machines were devised. The so-called Second Industrial Revolution began around the 1830s and 1840s with the development of steamships and locomotives which allowed products created by the First Revolution to reach markets hundreds to thousands of miles from their point of manufacture.
The Revolution’s improved manufacturing efficiency came at a high cost to the environment in the form of air pollution due to coal consumption and toxic chemicals produced by the LeBlanc process* and water pollution due to the untreated human waste produced by the crowded busy bees who kept the industrial machines humming. In 1839, lawsuits against soda works using the process began, with plaintiffs complaining of an ecodisaster of biblical magnitude, over a century before the word ecodisaster was coined. In 1863, British Parliament passed the Alkali Acts, the first modern air pollution legislation which limited the amount of off-gassed HCl to 5% (still a massive amount by today’s standards). It was a pyrrhic victory: the manufacturers then dumped the aqueous-HCl solution into nearby bodies of water, killing fish and other aquatic life.
*An early industrial process for producing soda ash (sodium carbonate), one of the chemicals (the other being potash, known to us as potassium carbonate) critical in the glass, textile, soap and paper industries. A major byproduct of the LeBlanc process was hydrochloric acid (HCl) that was off-gassed into the environment. Post-script, industry moved to the less polluting and less wasteful Solvay process and thereafter to even more environmentally-friendly electrolytic processes.
Megacity air Pollution
During the century that followed, from 1850 to 1950, environmentalists focused on mitigating air pollution. The urgency of addressing air pollution stomped centre-stage with the Great Smog of London in December 1952, which is now believed to have killed 12,000 and hospitalised 150,000, and led to the Clean Air Act of 1956, restricting the burning of coal in urban Britain. Unfortunately, such legislation can only go so far; air pollution still exists in the world’s megacities (see image) and is intimately linked to the automobile industry. Data from Jinan, a city in eastern China, not surprisingly links increased emergency room admissions on days marked by greater pollution with PM2.5, SO2 and NO2. An epidemiologic study, also from China, collected data from 28 of that country’s largest hospitals and found that nearly 5% of ER visits were due to particulate matter, including that with an aerodynamic diameter of < 1µm.
Obviously, environmental quality is not limited to the air, but must take into account wherever humans have left their footprints. Examples include marine–e.g., Exxon Valdez, freshwater–Love Canal, and groundwater–e.g., Times Beach, Missouri, contamination from toxic chemicals. Less commonly, but with a far greater potential impact on public health, are criticality events from aging nuclear power plants–e.g., Chernobyl and Fukushima. As physicians, we cannot ignore the impact of environmental degradation on health.