Road transport is 11% of PM2.5 primary emissions and also 11% of PM10 primary emissions.

Domestic combustion (i.e., wood (primarily) and coal fires in domestic settings) is the top category of PM10 (44% of total) and second highest for PM2.5 (27%), after "industrial processes and use of solvents" (32%).

Notably, the resurgence of wood-burning fires in domestic settings has substantially increased emissions from that category over the past two decades (more than doubling it at a time when most other sources have been decreasing), and worse that's disproportionately in urban areas.