Articles
ENVIRONMENTAL POLLUTION-EFFECTS ON GROWTH AND DEVELOPMENT OF PLANTS
In areas of dense population and industrial centers such as Southern California’s Los Angeles Valley, the East Coast USA from Boston to Norfolk, Tokyo, Japan and Mexico City, Mexico, the photochemical oxidants of each center has spread and mingled with that of its neighbors to cover entire areas with eye-smarting, crop damaging, plant tissue killing substances causing serious economic overtones.
"Smog", a term applied to the photochemical oxidants arising from man’s excessive use of fossil fuels for every conceivable form of energy and power, results from the hydrocarbon wastes of combustion entering the earth’s atmosphere.
Through photochemical action in the presence of sunlight, hydrocarbons and nitrous oxides are converted to a series of so called photochemical oxidants.
Among these O3 Ozone, in superfluous amounts does serious damage to thousands of susceptible plants all over the world today.
This, of course, is only one of a substantial number of serious air pollutants, including sulfur dioxide, which results from the exhausts of an inexhaustible number of automobiles, countless stacks from industrial communities of our nations and the thousands of power plants which now dot most of the world.
By 1962 the characteristic brownish-gray smog had been occasionally observed by our commercial airline pilots extending in a continuous, visible pall from New York City to Dakar, West Africa at elevations above 20 000 feet.
These occurrences were noticed especially during the transition period between summer to autumn.
Within the past 30 years scientists have discovered various complicated ingredients to make up air pollution and many of the injurious effects they have on plant tissue, individually and in synergistic combination with others.
Index plants have been observed in which characteristic symptomology can be identified for specific pollutants.
We also have confirmed that within plants, Darwin’s law of survival of the fittest, through the process of natural selection, is taking place on an active scale in direct relationship to the presence of these airbourne pollutants occurring in amounts above 12 PPHM for 2 or more hours.
Readings far exceeding these are frequently recorded near metropolitan areas, and along heavily traveled highways.