Old attic insulation can hurt indoor air quality when it becomes wet, deteriorated, or contaminated

https://keegansixt891.evergrovio.com/posts/why-you-need-to-clean-your-crawl-space-right-now-2

Old attic insulation can hurt indoor air quality when it becomes wet, deteriorated, or contaminated, allowing biological pollutants and allergens to linger indoors.