WWF's Your Plastic Diet priced plastic pollution at a credit card a week

By 2019 microplastics were already known to be everywhere — in oceans, animals, food — yet the public mostly acted at the margins of reusable straws and shopping bags. WWF's real objective was global: it wanted government-level change on plastic production, which required an issue people could personally feel. Rather than waiting for someone else's science, WWF commissioned the University of Newcastle in Australia to synthesise existing research on how much plastic humans actually ingest.

The study combined data from more than 50 studies and concluded that people ingest on average about 2,000 microplastic particles a week — roughly five grams, the equivalent of one credit card. The largest source was water, both bottled and tap; shellfish came second, contributing up to 0.5 grams a week because they are eaten whole, digestive system included. The researchers themselves noted the work 'builds on a limited set of evidence' and lacks data on particle weight and size distribution.

The campaign turned that number into the message. Films and print showed people unknowingly eating credit-card-sized portions of their meals; the yourplasticdiet.org site let people estimate their own intake and sign a pledge. WWF produced a kit of campaign materials that offices around the world adopted, and the petition it fed became one of the fastest and largest in the organisation's history.

Grey Worldwide Malaysia, which made the regional film, took a Bronze in Kancil for Good: Film & Branded Content at the 2019 Kancil Awards — the local stamp on a campaign that had become WWF's global voice on ingestion.

Quantify the invisible: one credit card a week

WWF commissioned the meta-study, so it owned the headline number instead of borrowing credibility from someone else's research.

Five grams means nothing to anyone; a credit card is an object every audience handles weekly, so the dose became unimaginable on contact.

The science was a synthesis of existing papers, not new lab work — speed and cost stayed low while the claim stayed citable.

The site calculator gave outrage somewhere to go: a signed petition WWF could carry to the United Nations.

A single grotesque image system (food you didn't order) translated across offices and languages without re-explaining the science.

Abstract environmental data moves nobody; a physical comparison does. Compress research into one object your audience already holds, then attach a one-click action.

WWF formally presented the petition at the UN General Assembly in October 2019 as part of its push for a global plastics treaty, and the credit-card image became the standard shorthand for human plastic ingestion, repeated by Reuters, CNN and the World Economic Forum. The campaign's dependence on one extrapolated number was a known trade: the Newcastle team itself flagged the thin evidence base, and the 2,000-particles figure is an average built from wide assumptions — but as a communications device, the conversion of invisible risk into a handled object did exactly what the brief demanded.