No choice lah. Just have to protect yourself with HEPA air purifiers.
This kind of "slight" levels, can't really use mask and only increases discomfort in someway.
Only way to reduce exposure is to use HEPA filtration at home. You spend a lot of hours at home vs external.
Of coz, if outside is 150-200 ug/m3 (AQI 200 to 250), then yeah it's good to wear a FFP1 or N95. Coz then the benefits of using one is much more, at least for a large portion of the whole population.
Very short term 15 mins transient exposure can also trigger symtoms for the really sensitive, and in the case of severe asthma then you better hope your Ventolin neb can solve the issue or a trip to the 24-hr clinic on a PH or Sunday/A&E is not going to be cheap.
Shopping centres are ok. (worst case is cut down to 50% o external concentration) Comfort taxis are ok. (only about 20% of ext concentration)
MRT cabin in tunnels are somewhat ok (only about 60% of ext concentration)
etc
Remember, the "slight" haziness started 1st of July. It could very well only end in the latter part of Nov. (last year stopped ard 9th Nov). Longer term annual PM2.5 exposure is greatly affected by this.