Individually, we know that manychemicals are dangerous. Very little research is done on combinations of chemicals. An article appearing in the May 10, 2006 issue of Scientific American does look into the dangers some of these chemicals have in combination. Scientists at the University of California, Berkeley, have tested four herbicides, two fungicides and three insecticides commonly used in American cornfields. Low concentrations (0.1 ppb) of the chemicals did not have much effect on developing tadpoles. When the tadpoles were exposed to all nine chemicals they developed endemic infection. The survivors ended up smaller than their counterparts raised in clean waterâ€“despite taking longer to mature into adults. So individually, the chemicals did no harm, but in combination they were deadly. When you consider that there are about 100,000 different chemicals that we are exposed to, it may make you wonder what the long-term health effects are.