You can use an air purifier. The Hepa filters are effective in eliminating PM. Gases like NO2 and VOCs can be reduced with carbon filters. Make sure that your carbon filter is large and different get saturated too quickly.

Mask outdoors when its particularly bad, and use an air filter indoors.

IKEA has recently released a decent air filter for ~$40.

Good ones cost a bit more, but even the basic one removes plenty of small particles with an HEPA-like stage.

See the Dynomight air series, which starts with https://dynomight.net/air/

Don't go outside. Move only in cars. To be honest, going outside sucks in most cities.

In Paris a study showed +3 years of life expectancy for cyclists and +2 for public transport users, compared to car commuters. They correlated it with (not a surprise) the benefits of exercice. Sure the pollution effect is worse outside of your car but the gains of daily light exercise offsets the drawbacks of air pollution.

You can exercise in doors though

It’s not exercise, but NEAT (non-exercise activity thermogenesis).

The air in a car comes from the outside.

It passes through a filter.

Cars have basic filters, but it's not common for them to come with HEPA filters off the lot.