Why 2% Is the Most Dangerous Number No One Is Talking About

The sheer quantity of chemicals being dumped into the environment is quickly growing—and we may only be seeing the beginning of the harm they are doing to us.

We’ve had a summer from hell, with July 2023 temporarily claiming the title of hottest month on record. But while the klaxons of Earth’s climate system have riveted nearly everyone’s attention, something else is silently happening to us and other species that could turn out to be just as big a disaster.

Nature is increasingly stewing in air- and water-borne toxins originating in industrial processes. Tens of thousands of chemicals, only a tiny proportion of which have been tested for safety, are making their way into the environment—from pharmaceuticals that have passed through human bodies, to plastics, pesticides, solvents, fire-retardants, and chemicals used in making cookware coatings.

Recent research shows that whole classes of these chemicals are affecting sexuality and disrupting reproduction—not just in humans, but in a host of other animal species as well. But the whole subject is controversial and is getting far too little attention, partly because reproduction and sexuality are culturally sensitive topics, and partly because the chemicals industry wields considerable political power. In this article, we’ll explore both the science and the controversy, and see why 2 percent is such a scary number in this context.