2644 - CSUN ScholarWorks - California State University, Northridge

2731
Journal of Student Research Abstracts · 43
THE EFFECTS OF ENVIRONMENTAL POLLUTANTS ON PLANTS.
Erica Lorraine Hooper and Steve DeGusta (teacher). John F. Kennedy High School, 6715 Gloria Drive,
Sacramento, CA, 95831.
This experiment was conducted to show the effects of environmental pollutants on plants and to answer the
question, "Does chlorine, an environmental pollutant, disrupt the growth of plants?" Chlorine was used as the
pollutant and onion bulbs were used as a sample of plants.
Twenty small, white onion bulbs were placed on twenty test tubes. Ten tubes were filled with tap water, the
control group, and ten tubes were filled with chlorinated water at three PPM. Each root of each bulb was measured
and recorded daily for four days.
I had assumed that the chlorine would have a negative effect on the plants because of it's effect on humans.
Chlorine irritates human's sinuses and skin on contact. Chlorine tends to have a lower pH making it more
acidic which dries out the skin and sinus cavities. I thought the plants would have a similar reaction. This led
me to the hypothetical conclusion that if chlorine is harmful to the onion plants then the treated bulbs will have
shorter roots and less roots than those grown in tap water.
My hypothesis was not correct. According to my data the onion group grown in chlorinated water grew better
than the control grown in tap water. Each day the roots of the experimental group grew longer and faster
than the control group. Probability is less than 0.005. There were no other physical differences between the
two groups. Neither group changed color or shape.
The only explanation I have for this outcome is that the chlorine killed all of the bacteria making it easier
for the plants to grow but the concentration was not strong enough to do any harm to the plant itself.
2732
EFFECTS OF SALT WATER ON THE GERMINATION AND INCIPIENT
GROWTH OF MUSTARD SEEDS AND BLACK BEANS
E. Kim. Teacher: W.P. Van Duzee. Saugus High School, 21900 Centurion Way, Saugus, CA 91350.
The purpose of this experiment was to examine the effects of table salt, sodium chloride, on the germination
and development of mustard seeds, B. Juncea, and black beans, genus Glycine. Two containers each holding
soil and 100 mustard seeds were set in the same room in order to provide a constant temperature. Another
set of two containers each holding soil and 100 black beans were set in the same room as the mustard seeds.
Two containers containing the control plants-one container with mustard seeds and the other with black
beans-were watered without table salt once a day for 10 days. The remaining two containers containing the
experimental plants-one container with mustard seeds the other with black beans-were watered with a 10%
solution of salt once a day for 10 days. On the lOth day, the control group containing mustard seeds and black
beans were measured to have an average height of 1.09 inch and 1.38 inches, respectively. The experimental
group containing mustard seeds and black beans both showed no signs of growth. These results show that the
use of 10% salt water on mustard seeds and black beans prevents germination and growth.