The Global Threat Of Acidic Rain In Wheeling
In 1979, Wheeling, West Virginia recorded the most acidic rainfall in America's history measuring a mere 1.5 on the pH scale (Singh & Agrawal, 2007).
Rainwater usually is slightly acidic when compared to pure water which has a pH value of 7. Therefore, rainwater records a pH value of about 5.6 under normal circumstances. The difference in pH is attributed to the fact that rain interacts with different oxidants in the atmosphere which they react with, lowering their pH. According to a report published by the National Atmospheric Deposition Program, the lowest average pH level of rain recorded in the country is 4.3 (Wondyfraw, 2014).
For this reason, the levels recorded at Wheeling, West Virginia shocked the meteorological world. The amount of acidity in the rain was such high that its corrosiveness was comparable to that of a car battery (Boyle, 1984). The decreasing pH level of rainfall in the area was attributed to an increase in anthropogenic emissions.
Sulphur and Nitrogen are responsible for the formation of acidic rain or anthropogenic rainfall. The Sulphur present in the atmosphere is either a result of natural processes or human activity. The main natural sources of Sulphur dioxide include volcanic eruptions, decomposing vegetation and forest fires, planktons and sea spray, according to (Sivaramanan, 2015). However, these contribute to a small portion of the sulphuric dioxide present in the atmosphere. A majority of the sulphuric dioxide in the earth's atmosphere is produced by human activity. Specifically, human activity is responsible for almost 70% (69.4%) of the gas in the air (Sivaramanan, 2015). In particular, actions such as the industrial combustion of coal, burning of coal and wood within the household, and pollution caused by automobiles used in transportation are among the main producers of sulphur dioxide.
Description
Rain is normally slightly acidic, having a pH of 5.6. (Pure water, in contrast, has a pH of 7.0. The lower the number, the more acidic the liquid. For example, most fruit juices and soft drinks have a pH in the range of 2 – 3. A pH lower than 1 is not only unpleasant to the taste but is actually dangerous because it burns the skin).
The natural acidity in rain is due to dissolved carbon dioxide from the atmosphere. But the rain that is now failing in many parts of the industrialized world, even in regions remote from industry, is often much more acidic. The average pH of rain in the north-eastern United States has decreased over the past years and is now 4.3. Rain with a pH as low as 1.5 has been recorded at Wheeling, West Virginia. The Los Angeles basin routinely has fogs made up of suspended water droplets with a pH of 2.2 – 4.0./
Thirty years ago, the annual average pH of rain in the 'North–eastern United States had dropped from pH 5.6 down to pH 4.5-5.0. Now the average pH of rain in the region is between 4.0 and 4.3. Moreover, the acidity is spreading. By 1976, the average annual pH of rain as far south as the Carolinas and as far west as Mississippi had fallen to 4.5, and a single storm may yield rain far more acidic than the yearly average. Pawlick notes, 'One storm in Wheeling, West Virginia, produced rain at an incredible pH 1.5-the equivalent in corrosive strength to the acid in an automobile battery.'
