Those raindrops that keep falling on our heads may be acid rain. So says Dr. George W. Crawford, SMU professor of physics and president of the Texas Environmental Coalition, who has been following the trends of pollutants being added to the air in the Metro-plex for the last 10 years.
“After analyzing 19 rain samples taken from September through October 1984 and the 1983 data from the Texas Air Control Board, I’m convinced that acid rain is falling in the Metroplex,” Crawford says.
Acid rain is caused by air pollution from electric utilities, industrial facilities and motor vehicles. Sulfur dioxide and nitrogen oxides in the atmosphere mix with moisture and other pollutants, and from this chemical soup comes nitric and sulfuric acids. This acid material can stay in the atmosphere, riding the winds for days and often traveling hundreds of miles before returning to earth in the form of acid rain.
Normal rain has a pH value of 5.7. By comparison, the pH of vinegar is 3.1, and the pH of lemon juice is 2.3. According to Crawford’s measurements, the rain that fell in Dallas on the weekend of November 17 had a pH of 3.7-100 times more acidic than normal rain.
“Dry precipitation-acidic particles that are continually falling and building up-mixes with the rain. Therefore, the acidity of the liquid seeping down to feed growing plants and reacting with the paint on your car is much higher than that which is measured as the official acidity of the rain,” Crawford says.
As it moves through the earth, the acid leaches out heavy metals and carries them into our water supply.
But who’ll stop the rain?
Crawford says that nothing is being done locally. But Gary Rogan of the Environmental Health Laboratories of Dallas and Tom Porter of the Texas Air Control Board’s research division say that the acid rain problem in the Metroplex, if any, is minimal.
The Texas Air Control Board (TACB) has provided Crawford with the necessary equipment to make SMU an official acid rain measuring station. As the result of a November meeting, the TACB, the Environmental Health Laboratories and Crawford will work together to accurately measure acid rain. “There needs to be a tremendous reduction in the amount of pollution coming from Tarrant, Dallas and Denton counties,” says Crawford. “Meanwhile, every human being is paying a health price.”