The brief articles in this section are designed to provide perspective on some of the important scientific concepts and phrases that are used in everyday discussions about environment, health and safety principles.
Today’s scientific equipment and techniques can detect even minute levels of many substances in the body through tools, such as biomonitoring. Visit the Biomonitoring Overview section to learn about how ACC, in conjunction with other organizations, supports research to develop scientific tools to interpret this information and what it may mean to public health.
As scientists measure and study very small amounts of particles, they may refer to “parts per” when talking about contents, or concentrations, of a chemical in air or water. Visit the Measuring Parts per Million section to better understand just how much—or how little—scientists are talking about when they measure down to parts per million, billion or trillion.