Your kitchen is probably your dirtiest air source
Frying a steak can briefly push fine-particle levels past a busy roadside. The fix is mostly about extraction.
Cooking - especially frying, searing, and anything that browns or smokes - is one of the largest sources of fine particulates (PM2.5) in most homes and many commercial kitchens. During cooking, indoor levels can briefly exceed what you’d breathe standing beside heavy traffic.
Why fine particles matter
PM2.5 is small enough to travel deep into the lungs, and WHO sets its annual guideline at just 5 µg/m³ - a low bar that indoor cooking spikes can blow straight past for short stretches. [8] It’s the accumulated dose that counts, so a hob worked hard every day adds up.
What actually helps
Extraction first: a hood that vents outside (rather than just recirculating) and genuinely covers the hob does most of the work. Back it with ventilation, and use HEPA filtration to bring the particle count down between cooking sessions.
Worth measuring
Because the spikes are short and invisible, a measurement or a live monitor is the only honest way to know whether your extraction is keeping up.