There are around 350,000 synthetic chemicals in use today and only a small fraction have been robustly tested for their long-term effects on our health. Many of these are used in manufacturing plastics and microplastics – the production of which has doubled since 2008 and is projected to triple by 2060.

Unknowns remain, but research is suggesting pervasive exposures to these manufactured substances is shaping human health. In particular, links are being identified with a range of non-communicable diseases, including some cancer types, metabolic disorders, neurological conditions and reproductive and developmental issues.

So, what do we know about how the chemical environment is influencing our health? Could AI and other emerging technologies shed new light on the effects of synthetic substances? And what does it all mean for regulation and wider policy protecting public health?

To discuss, our Chief Executive Jennifer Dixon is joined by:

Tracey Woodruff, Professor at University of California, San Francisco, and Director of the Program on Reproductive Health and the Environment (PRHE).
Thomas Hartung, Professor at Johns Hopkins University, and Director of the Centre for Alternatives to Animal Testing (CAAT).

Show notes

Woodruff et al (2025). Manufactured chemicals and children’s health – the need for new law.

Kleinstreuer & Hartung (2024). AI – it’s the end of tox as we know it (and I feel fine).

Nihart et al (2025). Bioaccumulation of microplastics in decedent human brains.

Financial Times (2023). ‘Global sperm counts are falling. This scientist believes she knows why.’

Programme on Reproductive Health and the Environment (PRHE). Scientific principles to protect public health.

Programme on Reproductive Health and the Environment (PRHE). Toxic matters.

52: ‘Chemical soup’: the everyday exposures affecting our health – with Tracey Woodruff and Thomas Hartung