Carbon nanotubes caused DNA damage at low levels.

The new version says that "while pesticides have important uses, studies show that some pesticides cause health problems at certain levels of exposure."

High school as wonderful source of inspiration and cause for the birth of many professionals excelling on many fronts at national and international levels.

MgO causes problems at levels over 2.5%.

Sarin can cause runny noses at low levels and death at high levels.

It is possible to be hypersensitive to Vitamin D. There are some genetic conditions that could cause complications at much higher levels.

Biopollution may cause adverse effects at several levels of biological organization:

But now comes a provocative if inconclusive report that says aspartame may cause cancer, even at levels long considered safe.

A US study has concluded that tiny airborne particles from car exhausts may cause disease and death even at levels that meet air pollution standards.

In mammals it causes male sterility at high levels of exposure.