Q: Some scientists are saying that very low doses of chemicals can have an even greater effect on our bodies and that the industry science that Dow practices isn’t picking that up. What do you say?

A: One of the basic tenets of toxicology is “the dose makes the poison.” That is, as a dose increases, the likelihood of a toxic response increases as well.

Recently, some scientists have challenged this well-established tenet with a new hypothesis, that low doses of chemicals — below those that have previously shown no hazardous effect — are actually causing previously unrecognized toxicity. They are arguing that there is a low-dose effect of chemical exposure.

However, their science has not held up to scrutiny. When the scientific methods followed by these scientists were subject to a repeated study, the results were unable to be replicated. Thus, the low-dose hypothesis remains just that — an hypothesis that should be subjected to the scrutiny of scientific peers.

An alternative hypothesis is that low doses of chemicals can actually have a beneficial effect. This hypothesis, called “hormesis,” suggests that a substance that is harmful at high exposure levels can be beneficial at low levels. Although there is some limited evidence to support the hypothesis of hormesis, this concept remains as controversial as the low-dose theories of toxicity.

Dow believes that the weight of evidence supports the idea that low exposures to chemical substances present in the environment do not pose a significant risk of adverse effect. We remain open to scientific advances that will help better inform the regulatory process so that human populations can be adequately protected, while taking advantage of the benefits that modern chemistry can provide.