Question

Discuss the air pollution disaster in Donora. What pollutants were involved? Where did they come from? How did they become concentrated?

Short answer

The pollutants involved were sulfur dioxide, carbon monoxide, and particulate matter, originating from industrial plants. They became concentrated due to a temperature inversion.

Step-by-step solution

Understanding the Context of Donora

The Donora air pollution disaster occurred in Donora, Pennsylvania, in October 1948. It is one of the earliest well-documented air pollution events, known for causing severe health issues over a few days due to stagnant weather conditions.

Identifying the Pollutants Involved

The primary pollutants involved in the Donora disaster were sulfur dioxide (SO2), carbon monoxide (CO), and particulate matter. These pollutants were especially problematic due to their high concentrations during the disaster.

Source of the Pollutants

These pollutants originated from the local industrial activities in Donora. The town housed several industries, including a zinc plant and steel mills, which emitted large quantities of these pollutants into the air as byproducts of their operations.

Mechanism of Concentration

The pollutants became concentrated due to a weather phenomenon known as a temperature inversion. This occurs when a layer of warm air traps cooler air at the surface, preventing the dispersion of pollutants and causing them to accumulate in the lower atmosphere.

Key concepts

Sulfur dioxide

Sulfur dioxide ( ext{SO}_2) plays a significant role in air pollution events due to its harmful properties. This colorless gas arises mainly from the burning of fossil fuels in power plants and industrial processes. In Donora, the main contributors were local industries such as the zinc plant and steel mills. These facilities burned coal, a fossil fuel rich in sulfur, releasing sulfur dioxide as a byproduct.

Exposure to high levels of ext{SO}_2 can lead to serious health problems like respiratory issues and aggravated asthma. In 1948, during the Donora disaster, sulfur dioxide concentrations soared beyond safe levels, primarily due to stagnant air conditions caused by a temperature inversion.

• Sources: Industries burning fossil fuels, specifically coal.
• Health Effects: Respiratory problems, aggravated asthma.
• Role in Donora: High concentrations exacerbated by industrial emissions and weather conditions.

Temperature inversion

The phenomenon of temperature inversion played a pivotal role in the events at Donora. Under normal conditions, air closer to the earth's surface is warmer and rises, allowing pollutants to disperse into the upper atmosphere. However, a temperature inversion flips this situation.

An inversion occurs when a layer of warm air overlays cooler air trapped below it. This barrier prevents air from rising, thus impeding the dispersion of pollutants. In Donora, this weather event lasted for several days, leading to a buildup of harmful pollutants like sulfur dioxide and particulate matter at ground level.

• Effect: Prevents normal pollutant dispersal, leading to increased pollution concentration at the surface.
• Occurrence: Can last several days under the right atmospheric conditions.
• Impact in Donora: Trapped industrial emissions, resulting in intense air pollution and health impacts.

Industrial pollution

Industrial pollution is a major source of environmental contamination, as evidenced by the events in Donora. Various industries emit pollutants such as sulfur dioxide, carbon monoxide, and particulate matter during their operations. In Donora, prominent contributors were the zinc plant and steel mills.

These industries emitted large volumes of pollutants as part of their production processes. The burning of coal and other fossil fuels was a common practice in these facilities, generating harmful substances which were released into the air.

• Main Pollutants: Sulfur dioxide, carbon monoxide, and particulate matter.
• Key Sources: Zinc plant, steel mills, and other industrial facilities.
• Impact: Contributed to health problems and environmental damage during the Donora air pollution disaster.