Ian Shaw

As a professor at the University of Canterbury, Ian researches our future ability to procreate and prosper from the angle of endocrine disrupting chemicals in food. He says, “I am particularly interested in how these chemicals, which mimic hormones, affect human growth and development. Specifically, how bisphenol-A (used in plastics manufacture) may affect babies.”

You may not yet be outraged at chemical-related occurrences such as the shrinking size of alligator penises (due to plastic factory contaminants in lake habitats) and the reduction of human sperm counts (linked to food and beverage packaging), but we’re betting you will be by the time Professor Ian Shaw is done speaking. It turns out our reproductive end may come in the form of plastic water bottles or tin cans, a far cry from a smoke- and fire-filled apocalypse!

So. Alligator penises are getting smaller, girls are reaching puberty earlier and human sperm count is decreasing. What the hell is going on? In an answer hormones. Estrogen, the “female” hormone is mimicked by a number of chemicals used industrially. When pre-pubescent girls and men ingest these chemicals, the female aspects of their cells can be turned on – causing unnatural changes.

Bipshenol-A has this effect and is (worryingly) used to line the inside of tin cans. Similarly Genistein, ingested from soybeans, can have this affect on cells. 4-Nonylphenol is used in many industrial chemicals and is also estrogenic. So why does the estrogen receptor display such promiscuity? Biology always has a purpose. It may be because of natural triggers in the environment – a plant produces an estrogenic compound the year before it has a heavy seeding year. Potentially an animal ingests the compound and the estrogenic molecule triggers ovulation – poetry in motion.