Figures (6)  Tables (4)

    • Figure 1. 

      Temperature in cafeterias A and B for five sampling points across four cycles.

    • Figure 2. 

      Relative humidity in cafeterias A and B at five sampling points across four cycles.

    • Figure 3. 

      Carbon dioxide in cafeterias A and B at five sampling points across four cycles.

    • Figure 4. 

      PM10 in cafeterias A and B at five sampling points across four cycles.

    • Figure 5. 

      Environmental conditions in cafeterias A and B that often affect the occupants.

    • Figure 6. 

      Present symptoms of occupants in cafeterias A and B that often affect the occupants.

    • Likelihood Level Criteria to consider
      Almost certain 5 8–10 parameters exceeding the acceptable limit
      Likely 4 5–7 parameters exceeding the acceptable limit
      Possible 3 3–4 parameters exceeding the acceptable limit
      Unlikely 2 1–2 parameters exceeding the acceptable limit
      Rare 1 No parameters exceeding the acceptable limit

      Table 1. 

      Likelihood for calculation of risk assessment

    • Severity Level Criteria to consider
      Catastrophic 5 90%–100% of the occupants based on three main symptoms
      Fatal 4 61%–90% of the occupants based on three main symptoms
      Serious 3 31%–60% of the occupants based on three main symptoms
      Minor 2 1%–30% of the occupants based on three main symptoms
      Negligible 1 No symptoms appeared

      Table 2. 

      Severity for calculation of risk assessment

    • No. Sample
      name      		 Total bacteria counts (cfu/m3) Total fungi counts (cfu/m3)
      Cafeteria A Cafeteria B Cafeteria A Cafeteria B
      1 Blank 1 - incubator 0 0 0 0
      2 Blank 2 - icebox 0 0 0 0
      3 Blank 3 - biostage 0 0 0 0
      4 1 71 336 643 18
      5 2 18 371 509 194
      6 3 161 459 446 230
      7 4 72 300 554 0
      8 5 107 1,466 821 177
      The acceptable limit for total bacteria counts based on ICOP 2010, Malaysia = 500 cfu/m3. The acceptable limit for total fungi counts based on ICOP 2010, Malaysia = 1000 cfu/m3.

      Table 3. 

      Total fungi counts and total bacteria counts in cafeterias A and B

    • Factor Cafeteria A Cafeteria B
      Body weight (BW) 62 kg 62 kg
      Inhalation rate (InhR) 20 m3/d 20 m3/d
      Exposure frequency (EF) 260 d/year 260 d/year
      Exposure duration (ED) 50 years 50 years
      Averaging time (ATnoncare)a 18,250 d
      (ED × 365 d)      		 18,250 d
      (ED × 365 d)
      Reference concentration (RfC)b 150 µg/m3 150 µg/m3
      Reference concentration (RfC)c 45 µg/m3 45 µg/m3
      Average concentration of PM10 in indoor air (c) 203 µg/m3 220 µg/m3
      a Average years of exposure. b Value taken from ICOP IAQ 2010. c Value taken from WHO 2021.

      Table 4. 

      Exposure factors for calculating the exposure dose in health risk assessment