What this is
A script, a set of animated sketches with narration, the evidence behind them, and a plan for testing fridge water ourselves with agar plates. The story is about how an everyday appliance could hide in plain sight, and about the human cost when a cause goes unseen.
It is not a campaign against filter makers or the people who service them. Chlorination is one of public health's great successes. The question is narrower: what happens in the last metre of pipe, after the filter has taken the chlorine out?
Where the evidence stands
Established
- Bacteria colonise carbon filters and plumbing.
- A 2024 study of in-fridge dispensers found Mycobacterium and Pseudomonas far more abundant after the water passed through.
- Opportunistic microbes matter most for people with weak immunity.
Plausible
- Taste may change slowly over months.
- Home filter units at high bacterial counts went with more gut illness in a 1991 trial.
- In one person, one tap-water bacterium persisted in the gut for weeks (2022).
Unmeasured
- Years of drinking from an ageing dispenser: any effect on a healthy gut, inflammation or ageing?
- No direct study that we could find.
- Whether low-dose microbes could even be protective is an open question we are researching too.
Every citation is checked against its record, and the notes say how far each has been read. Some AI research reports we received had invented or mislabelled references. Those are marked do not cite in the files.
Explore
The video
- AnimationTwenty-five early-Mac-style scenes with narration and sound.
- ScriptThe working script, with items still to verify flagged.
- Narration textThe voice-over, scene by scene.
The evidence
- Verified evidenceWhat each study says, read at the abstract or full-text level.
- Has anyone measured it?Water microbes, gut microbiome, inflammation and ageing, with audits of the full-text reads.
- Research agendaFifteen studies that would settle the open questions, in stages.
- Research promptsThe deep-research prompts, including one on whether low-dose microbes could be protective.
Test it yourself
Try it at home
- Read the agar plate protocol first. The plates stay sealed and are never opened, and anyone with a weak immune system should not handle them.
- Sample water from the dispenser, the kitchen tap and a sealed bottle for comparison.
- Photograph the plates in the same light every day or two, then count them in the plate counter.
- Share the numbers. Results, including empty plates, are the point.