Table 1.
Detailed information of each sub-ME.
| Sub-MEs | Classification | HVAC | Traffic | Comments |
|---|---|---|---|---|
| road 1 | Open source | None | Heavy | In suburb; extends along a viaduct, morning |
| road 2 | Open source | None | Light | Near park, not far from busy traffic, afternoon |
| road 3 | Open source | None | Heavy | Between high buildings, afternoon |
| road 4 | Open source | None | Light | Inside a hotel yard in downtown, night |
| bus 1 | Closed source | On | Change | Traffic light to heavy; window closed, door open intermittently, morning |
| bus 2 | Closed source | On | Heavy | Window closed, door open intermittently, afternoon |
| bus 3 | Closed source | On | Light | Window closed, door open intermittently, night |
| bus station 1 | Open source | None | Light | Very little traffic, morning |
| bus station 2 | Open source | None | Heavy | Near a viaduct, morning |
| bus station 3 | Open source | None | Heavy | Near crossroad, afternoon |
| bus station 4 | Open source | None | Light | Near hotel, night |
| taxi 1 | Closed source | On | Heavy | Downtown, noon |
| taxi 2 | Closed source | On | Light | Downtown, afternoon |
| subway car 1 | Closed receptor | On | Light | Downtown, morning, run on underground tunnel |
| subway car 2 | Closed receptor | On | Heavy | Downtown, noon, run on underground tunnel |
| subway car 3 | Closed receptor | On | Light | Downtown, night, run on underground tunnel |
| subway car UP 1 | Closed receptor | On | Heavy | Downtown, noon, run on above ground bridge |
| subway car UP 2 | Closed receptor | On | Light | Surburb, night, run on above ground bridge |
| subway station 1 | Closed source | None | Light | Morning, underground station |
| subway station 2 | Closed source | None | Heavy | Noon, underground station |
| subway station 3 | Closed source | None | Light | Night, underground station |
| subway station UP | Open source | None | Heavy | Between surburb & downtown, noon, ground level |
| Street food vendor | Open source | None | With open cooking and small restaurants, noon | |
| construction | Open source | None | Trucks fueling diesel; not far from heavy traffic, afternoon | |
| park | Open receptor | None | Big lake and trees; few people; near busy roads, morning | |
| underground mall | Closed receptor | None | Connects mall and subway station; dense population, small restaurants & clothes stores, noon | |
| schoolyard 1 | Open receptor | None | Near construction site and busy road; few people; trees, afternoon | |
| schoolyard 2 | Open receptor | None | Near busy-traffic road; dense population; trees, afternoon | |
| restaurant | Closed source | None | Small restaurants near school, full of students | |
| office 1/4 | Closed receptor | On | Window closed and door open sometimes. Office 1 is early in morning with few people; while office 4 is at night with denser population | |
| office (2&3 same) | Closed receptor | On | Big office with few people, window closed and door open, afternoon | |
| lab | Closed receptor | On | Small well-sealed lab, with generally nobody inside, afternoon | |
| mall | Closed receptor | On | Air conditioner only on during hazy day sampling; few people, afternoon | |
| hospital | Closed receptor | On | Dense population, doors were always opened | |
| supermarket | Closed receptor | None | Few people, not well isolated with outside |