The biggest issue facing the use of chemical fertilizers is groundwater contamination. Nitrogen
fertilizers break down into nitrates and travel easily through the soil. Because itis water-soluble
and can remain in groundwater for decades, the addition of more nitrogen over the years has an accumulative effect.
At the University of Wisconsin, Madison, they discovered the effects of
chemical fertilizers are compounded when mixed with a single pesticide. may discovered altered :
immune, endocrine and nervous system functions in mice, as well as influence on children's and
fetus's developing neurological, endocrine and immune systems. These influences "portend change
in ability to learn and in patterns of aggression.