Milestones in order. This is history, not a weekly activity grid.
- Snow and the pump
- Chlorination in US
- Allergy rise noted
- Strachan BMJ paper
- ALEX and farms
- Old Friends essay
- Biodiversity add-on
- Nuanced textbooks
Darker cells mean a higher score for this topic on that metric.
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Quick answers
Where should I start with Hygiene and balance?
Read Identity → How they live → Body & health, then use compare rails.
Is this page advice for Hygiene and balance?
Public-health education — not a care plan, prescription, or outbreak briefing.
What does the local lens add?
It names everyday desks for Change & defence before English norms look universal.
Are the scores a ranking of Hygiene and balance?
No — editorial 0–100 browsing aids inside this atlas only.
How do I compare Hygiene and balance to neighbours?
Use related cards and best-of / quiz rails after the first three chapters.
Which chapter is densest?
How they live and Body & health carry mechanisms; skim Identity first.
Hay fever was rare in early clinic notes and common in late-20th-century cities. That contrast invited theories.
Sanitation's century also emptied wards of cholera. Any honest history holds both graphs.
Timeline
John Snow maps cholera to a Soho pump — clean water as data, not fashion.
Jersey City's early municipal chlorination becomes a model for urban water.
Asthma and hay fever climb in many affluent countries as infections fall.
The hygiene hypothesis is named from family-size patterns in hay fever.
Alpine farm-child studies add livestock and stables to the exposure list.
Rook argues for co-evolved organisms rather than dirt as such.
Finnish and other work links surrounding biodiversity to atopic risk talk.
Texts warn against anti-hygiene readings while keeping the immune-training question open.
The timeline is intellectual history, not a lifestyle brand.
Keep exploring
More in Change & defence
Mutation and variants
Populations of genomes, not cartoon villains — RNA viruses copy sloppily, and public-health names track clusters that spread.
Familiarity 92Antibiotic resistance
A shared drug budget under selection in hospitals, farms and wastewater — stewardship, not a lab manual.
Familiarity 85Vaccines and immunity
Antibodies, memory cells and community arithmetic — conceptual, not a prescription and not an anti-vaccine tract.
Familiarity 94Biofilms
Surface cities of microbes — plaque and catheters explain persistence, without a grow-your-own kit.
Familiarity 38Horizontal gene transfer
Sideways DNA traffic — conjugation, transduction, transformation as names and history, not protocols.
Familiarity 45