✓ Practiceby Lab 10 Get started ›
Crossfire

Is there a level of these chemicals low enough to be safe?

What the experts say

Bruce LanphearMD, MPH · environmental epidemiologist, Simon Fraser University

For several of them, no. The dose-response curve has no threshold, and the harm per unit of exposure is steepest at the very bottom of the range.

What it rests onMeasured dose-response across four chemical and outcome pairs, anchored in his own pooled analysis of seven child cohorts, where the IQ decrement per unit of blood lead was significantly greater below 7.5 micrograms per decilitre than above it.

Source: erictopol.substack.com ↗
Joe SchwarczPhD · chemist, director of the McGill Office for Science and Society

Yes. Exposure is judged against a reference dose, and everyday exposure usually turns out to be a fraction of it.

What it rests onParacelsus's principle that only the dose makes the poison, applied through conventional reference-dose risk assessment, plus the observation that handling the item transferred nothing detectable and only immersion in oil at 160 degrees did.

Source: mcgill.ca ↗

Overview

Lanphear's strongest evidence is prenatal and early-childhood IQ, plus cardiovascular mortality across an entire adult population, and his unit is attributable deaths. Schwarcz is answering an individual adult deciding whether to throw away one kitchen utensil.

They are also not always discussing the same chemical: Lanphear's four examples are lead, asbestos, benzene and airborne particles, all of which have decades of human outcome data, while the reference-dose argument is being applied to a flame retardant with far less. A general adult user with no children is outside the population Lanphear's strongest evidence covers.

Where they agree

More than the framing suggests. Both accept these chemicals are toxic at some level and that the argument is about the shape of the curve at the bottom, not about whether the substances are hazardous.

Schwarcz states in the same article that flame retardants should not be in kitchen items at all, which is a precautionary position about production even while he declines to act on it as a consumer. Neither recommends discarding functioning household objects.

What would settle it

For Lanphear: a demonstrated threshold in a well-measured cohort, or evidence that the supralinear shape at low exposures is an artefact of confounding, measurement error or reverse causation. For Schwarcz: human outcome data at reference-dose-fraction exposures, or a reference dose revised downward on new evidence. Both would move on better measurement below current detection limits, which is where the disagreement actually lives.

Practice does not pick a winner here

You do, and your call is dated, kept, and yours to change. Follow the people you already trust and what they publish turns into a short daily practice.

Get started

Free to sign up and use. We do not ask for a card.