Low concentration chemicals spur toxicological debate

Deciding what risks particular chemicals pose and at what concentrations is the job of toxicologists and government regulators. As analytical chemistry has improved over the last decade or two, miniscule amounts of potentially hazardous chemicals have been detected in the environment and in people. This capability influences public thinking around chemical exposure: People worry when media reports surface around a new chemical detected in, for example, their drinking water. Yet is extremely expensive to get rid of every contaminant from water and of questionable value. 

The counterargument is that the tradition of looking at parts per million is outdated and more dilute concentrations matter in biology. Per- and polyfluroalkyl substances (PFAS) can be detected in almost everyone’s blood and levels in the environment have reportedly been underestimated. This matters because these ‘forever chemicals’ have been linked to greater risk of kidney cancer, decreased infant growth and a suppressed antibody response in adults and children