Figure 1
Location of Seremban District, Negeri Sembilan. (Adapted from Shamsuddin and Yaakup [14]).
Table 1
Sociodemographic Characteristics of Respondents and Wheezing Symptoms (n = 90).
| Variables | f (%) or mean (SD) | Wheezing Symptom | X2/t | P | |
|---|---|---|---|---|---|
| Yes (n = 17) f (%) or Mean (SD) | No (n = 73) f (%) or Mean (SD) | ||||
| Age* | 1.54 (0.51) | 1.35 (0.50) | 1.59 (0.49) | 1.772 | 0.080 |
| Sex | |||||
| Male | 50 (55.6) | 12 (24.0) | 38 (76.0) | 1.918 | 0.166 |
| Female | 40 (44.4) | 5 (12.5) | 35 (87.5) | ||
| Birth weight (kg)† | 3.05 (0.39) | 3.04 (0.39) | 3.05 (0.40) | 0.146 | 0.884 |
| Breastfeeding | |||||
| Yes | 86 (45.6) | 16 (18.6) | 70 (81.4) | 0.102 | 0.749 |
| No | 4 (4.4) | 1 (25.0) | 3 (75.0) | ||
| Duration of breastfeeding | |||||
| Less than 6 mo. | 33 (36.7) | 4 (12.1) | 29 (87.9) | 1.558 | 0.212 |
| 6 mo. and above | 57 (63.3) | 13 (22.8) | 44 (77.2) | ||
| Food allergy | |||||
| Yes | 10 (11.1) | 4 (40.0) | 6 (60.0) | 3.273 | 0.070 |
| No | 80 (88.9) | 13 (16.3) | 67 (83.8) | ||
| ETS exposure at home | |||||
| Yes | 50 (55.6) | 9 (18.0) | 41 (82.0) | 0.058 | 0.810 |
| No | 40 (44.4) | 8 (20.0) | 32 (80.0) | ||
| Age entering DCC | |||||
| Less than 1 y | 34 (37.8) | 10 (29.4) | 24 (70.6) | 6.852 | 0.037† |
| 1–2 y | 29 (32.2) | 6 (20.7) | 23 (79.3) | ||
| More than 2 y | 27 (30.0) | 1 (3.7) | 26 (96.3) | ||
| Duration of stay in DCC | |||||
| More than 3 y | 8 (8.9) | 1 (12.5) | 7 (87.5) | 4.565 | 0.012† |
| 1–3 y | 48 (53.3) | 13 (27.1) | 35 (72.9) | ||
| Less than 1 y | 34 (37.8) | 3 (8.8) | 31 (91.2) | ||
| Household income | |||||
| Low income | 18 (20.0) | 2 (11.1) | 16 (88.9) | 21.194 | <0.001† |
| Middle income | 67 (74.4) | 14 (20.9) | 53 (70.1) | ||
| High income | 5 (5.6) | 1 (20.0) | 4 (80.0) | ||
| Parent’s level of education | |||||
| High education | 64 (71.1) | 0 (0) | 26 (100.0) | 8.515 | 0.004† |
| Low education | 26 (28.9) | 17 (26.6) | 47 (73.4) | ||
| Family history of asthma | |||||
| Yes | 19 (21.1) | 4 (21.1) | 15 (78.9) | 0.074 | 0.786 |
| No | 71 (78.9) | 13 (18.3) | 58 (81.7) | ||
| Type of housing | |||||
| Detached house | 9 (10.0) | 0 (0) | 9 (100.0) | 2.373 | 0.305 |
| Terraced | 77 (85.6) | 16 (20.8) | 61 (79.2) | ||
| Apartments/condominium/flats | 4 (4.4) | 1 (25.0) | 3 (75.0) | ||
| Residence near major roadway | |||||
| Yes | 40 (44.4) | 5 (12.5) | 35 (87.5) | 1.918 | 0.166 |
| No | 50 (55.6) | 12 (24.0) | 38 (76.0) | ||
| Pets at home | |||||
| Yes | 19 (21.1) | 3 (15.8) | 16 (84.2) | 0.151 | 0.698 |
| No | 71 (78.9) | 14 (19.7) | 57 (80.3) | ||
| Carpets at home | |||||
| Yes | 44 (48.9) | 10 (22.7) | 34 (77.3) | 0.828 | 0.363 |
| No | 46 (51.1) | 7 (15.2) | 39 (84.8) | ||
[i] DCC = day care center; ETS = environmental tobacco smoke; SD = standard deviation.
*Mean (SD).
† Significant level at P value < 0.05.
Table 2
Sampling Sites and Environmental Conditions of 10 Air-Conditioned DCCs in Seremban District, Negeri Sembilan.
| DCC | Building Age (y) | Number of Occupants (2014/2015) | Type of Building | Location | Site | Temp (°C) Mean (SD) | R.H. (%) Mean (SD) | |
|---|---|---|---|---|---|---|---|---|
| A | 25+ | 16 | Private residential | Urban | Playroom | 28.40 (0.1) | 71.12 (0.4) | |
| B | 15+ | 20 | Private residential | Urban | *Near roadway | Playroom | 28.58 (0.2) | 65.63 (0.8) |
| C | 10+ | 14 | Private residential | Urban | *Near industrial area (<1 km) | Playroom | 31.18 (0.1) | 59.60 (0.5) |
| D | 25+ | 32 | Public residential | Urban | Playroom | 28.81 (0.3) | 67.00 (0.3) | |
| E | 25+ | 28 | Public residential | Urban | Playroom | 28.58 (0.2) | 72.78 (0.7) | |
| F | 5+ | 25 | Private residential | Urban | Playroom | 30.67 (0.1) | 74.30 (0.4) | |
| G | 10+ | 10 | Private residential | Urban | Playroom | 28.10 (0.2) | 69.8 (0.5) | |
| H | 10+ | 30 | Private residential | Urban | *Near construction site | Playroom | 27.30 (0.4) | 67.10 (0.4) |
| I | 5+ | 19 | Commercial building | Urban | *Near roadway | Playroom | 27.17 (0.2) | 79.00 (0.7) |
| J | 10+ | 17 | Private residential | Urban | *Near roadway | Playroom | 27.54 (0.1) | 78.00 (0.6) |
[i] DCC = day care center; R.H. = relative humidity; SD = standard deviation; Temp = temperature.
*Indicates that center near to pollution source.
Table 3
Prevalence of Health Symptoms and Severity of Symptoms Among Respondents in 10 DCCs (n = 90).
| DCC, N = 90 | Wheezing Only, n (%) | Night Cough Only, n (%) | Both Symptoms (Wheezing and Night Cough), n (%) | Wake up from Sleep, n (%) | Nebulizer Treatment, n (%) | Admit to Ward, n (%) | Doctor Diagnosed Risk of Asthma, n (%) |
|---|---|---|---|---|---|---|---|
| A n = 6 | 3 (50.0) | 5 (83.3) | 2 (33.3) | 3 (50.0) | 2 (33.3) | 0 (0) | 1 (16.7) |
| B n = 14 | 12 (78.6) | 5 (35.7) | 5 (35.7) | 9 (64.3) | 5 (35.7) | 1 (7.1) | 3 (21.4) |
| C n = 7 | 4 (57.1) | 7 (100.0) | 4 (57.1) | 6 (85.7) | 3 (42.9) | 2 (28.6) | 2 (28.6) |
| D n = 6 | 1 (16.7) | 4 (66.7) | 1 (16.7) | 0 (0) | 1 (16.7) | 1 (16.7) | 1 (16.7) |
| E n = 7 | 7 (100.0) | 4 (57.1) | 0 (0) | 2 (28.6) | 0 (0) | 0 (0) | 1 (14.3) |
| F n = 11 | 11 (100.0) | 7 (63.6) | 0 (0) | 1 (9.1) | 0 (0) | 0 (0) | 1 (9.1) |
| G n = 4 | 4 (100.0) | 2 (50.0) | 0 (0) | 2 (50.0) | 1 (25.0) | 1 (25.0) | 1 (25.0) |
| H n = 15 | 1 (6.7) | 10 (66.7) | 1 (6.7) | 4 (26.7) | 0 (0) | 0 (0) | 1 (6.7) |
| I n = 10 | 1 (10.0) | 2 (20.0) | 1 (10.0) | 1 (10.0) | 1 (10.0) | 1 (10.0) | 1 (10.0) |
| J n = 10 | 2 (20.0) | 6 (60.0) | 1 (10.0) | 3 (30.0) | 2 (20.0) | 1 (10.0) | 3 (30.0) |
[i] DCC = day care center.
Table 4
Sampling Point and Number of Air Samples of the Investigated DCCs.
| Sampling Points | No. of Rooms | No. of Air Samples for PM2.5 and PM10 Level | No. of Air Samples for Microbial Count (TBC and TFC) |
|---|---|---|---|
| Playroom | 10 | 10 | 60 |
| Bedroom | 10 | 10 | 60 |
| Outdoor (outside the building) | – | 10 | 40 |
[i] DCC = day care center; No. = number; PM = particulate matter; TBC = total bacterial count; TFC = total fungus count.
Table 5
Mean and Standard Deviation of IAQ Parameters from the Investigated DCCs.
| Rooms/Area | PM2.5 Level (μg/m3) | PM10 Level (μg/m3) | TBC (CFU/m3) | TFC (CFU/m3) |
|---|---|---|---|---|
| Playroom | ||||
| Mean ± SD | 69.35 ± 47.61 | 81.11 ± 45.29 | 566.63 ± 359.03 | 643.25 ± 312.09 |
| Min–Max | 17–170 | 28–144 | 155–1310 | 268–1182 |
| Bedroom | ||||
| Mean ± SD | 113.21 ± 103.52 | 79.91 ± 46.42 | 754.80 ± 326.22 | 699.68 ± 385.61 |
| Min–Max | 30–430 | 30–170 | 229–1279 | 269–1489 |
| Outdoor | ||||
| Mean ± SD | 70.11 ± 49.23 | 79.61 ± 43.69 | 204.21 ± 123.11 | 568.42 ± 313.17 |
| Min–Max | 39–540 | 29–350 | 178–980 | 200–560 |
[i] DCC = day care center; IAQ = indoor air quality; ICOP = Indoor Air Quality Code of Practice; NAAQ = National Ambient Air Quality; PM = particulate matter; SD = standard deviation; TBC = total bacterial count; TFC = total fungus count.
Table 6
Mean Concentrations of Indoor Air Quality Parameters at 10 Air-Conditioned DCCs Investigated in the District of Seremban, Negeri Sembilan.
| DCC | Carbon Dioxide (ppm)* | PM2.5 (μg/m3)† | PM10 (μg/m3)* | Airborne Bacteria (CFU/m3)* | Airborne Fungi (CFU/m3)* |
|---|---|---|---|---|---|
| A | 578.38 | 170.00‡ | 133.00 | 1310‡ | 514 |
| B | 669.25 | 134.00‡ | 144.00 | 751‡ | 1182‡ |
| C | 527.50 | 17.00 | 29.00 | 579‡ | 268 |
| D | 474.00 | 25.00 | 28.60 | 401 | 1161‡ |
| E | 519.78 | 98.00‡ | 99.80 | 221 | 662 |
| F | 480.89 | 80.00‡ | 130.00 | 155 | 460 |
| G | 848.00 | 68.00‡ | 72.00 | 894‡ | 549 |
| H | 1322.00‡ | 47.00‡ | 67.00 | 401 | 634 |
| I | 427.38 | 21.40 | 34.00 | 231 | 534 |
| J | 621.86 | 32.00 | 35.00 | 1100‡ | 268 |
Figure 2
Comparison of PM2.5 and PM10 levels in each of the DCCs investigated. Abbreviations: CFU = colony-forming unit; DCC = day care center; PM = particulate matter.
Figure 3
Comparison of TBC levels in each of the DCCs investigated. Abbreviations: CFU = colony-forming unit; DCC = day care center; TBC = total bacterial count.
Figure 4
Comparison of TFC levels in each of the DCCs investigated. Abbreviations: CFU = colony-forming unit; DCC = day care center; TFC = total fungus count.
Table 7
Association Between IAQ Parameters and Wheezing Symptom Among Respondents in 10 DCCs Investigated.
| IAQ Parameters | Wheezing Symptom | t Statistic* | df | P value | 95%CI | ||
|---|---|---|---|---|---|---|---|
| Yes (n = 17) Mean (SD) | No (n = 73) Mean (SD) | Upper | Lower | ||||
| Carbon dioxide (ppm) | 626.97 (193.96) | 703.57 (320.17) | 0.945 | 88 | 0.347 | –84.52 | 237.71 |
| Particulate matter 2.5 (μgm3) | 82.67 (64.61) | 66.25 (42.68) | –1.285 | 88 | 0.020† | –41.71 | –0.39 |
| Particulate matter 10 (μgm3) | 84.38 (54.75) | 80.35 (43.21) | –0.329 | 88 | 0.743 | –28.40 | 20.32 |
| Total bacterial count (CFU/m3) | 778.65 (335.63) | 517.26 (348.17) | –2.806 | 88 | 0.006† | –446.51 | –76.25 |
| Total fungal count (CFU/m3) | 670.05 (404.31) | 637.01 (290.38) | –0.391 | 88 | 0.697 | –201.18 | 135.10 |
[i] CFU = colony-forming unit; CI = confidence interval; DCC = day care center; df = degrees of freedom; IAQ = indoor air quality; SD = standard deviation.
* Student’s t test.
† P < 0.05 is significant.
Table 8
Factors Associated with Wheezing Symptoms Among Toddlers in Day Care Centers in the District of Seremban.
| Variables | Simple Logistic Regression | Multiple Logistic Regression* | ||||
|---|---|---|---|---|---|---|
| Regression Coefficient (b) | Crude OR | P | Regression Coefficient (b) | Adjusted OR | P | |
| Age | –0.966 | 0.381 | 0.085 | |||
| Sex | ||||||
| Male | 0.793 | 2.211 | 0.173 | |||
| Female | 1.00 | |||||
| Birth weight (kg) | –0.103 | 0.902 | 0.883 | |||
| Breastfeeding | ||||||
| Yes | 1.00 | |||||
| No | 0.377 | 1.458 | 0.749 | |||
| Duration of breastfeeding | ||||||
| Less than 6 mo | –0.762 | 0.467 | 0.219 | |||
| 6 mo and greater | 1.00 | |||||
| Food allergy | ||||||
| Yes | –1.234 | 0.291 | 0.083 | |||
| No | 1.00 | |||||
| ETS exposure at home | ||||||
| Yes | 0.130 | 1.139 | 0.810 | |||
| No | 1.00 | |||||
| Age enter DCC | ||||||
| Less than 1 y | 1.914 | 6.783 | 0.087 | |||
| 1–2 y | 2.383 | 10.833 | 0.037† | |||
| More than 2 y | 1.00 | |||||
| Duration of stay in DCC | ||||||
| More than 3 y | –0.389 | 1.677 | 0.015† | |||
| 1–3 y | 0.956 | 2.600 | 0.392 | |||
| Less than 1 y | 1.00 | |||||
| Household income | ||||||
| Low income | –0.693 | 0.500 | 0.607 | |||
| Middle income | 0.055 | 1.057 | <0.001† | |||
| High income | 1.00 | |||||
| Parent’s level of education | ||||||
| High education | 1.00 | |||||
| Low education | –20.186 | 2.890 | 0.004† | –56.090 | 1.790 | 0.035† |
| Family history of asthma | ||||||
| Yes | –0.174 | 0.841 | 0.786 | –2.439 | 1.087 | 0.040† |
| No | 1.00 | |||||
| Type of housing | ||||||
| Detached house | –20.104 | 0.051 | 0.380 | |||
| Terraced | –0.240 | 0.787 | 0.840 | |||
| Apartment/condominium/flat | 1.00 | |||||
| Residence near major roadway | ||||||
| Yes | 0.793 | 2.211 | 0.173 | |||
| No | 1.00 | |||||
| Pets at home | ||||||
| Yes | 0.270 | 1.310 | 0.698 | |||
| No | 1.00 | |||||
| Carpets at home | ||||||
| Yes | 0.494 | 1.639 | 0.366 | |||
| No | 1.00 | |||||
| DCC Status | ||||||
| Acceptable | 1.00 | |||||
| Not acceptable | –1.153 | 2.316 | 0.040† | 2.004 | 7.417 | 0.032† |
[i] Multicollinearity and interaction term was checked and not found. Hosmer-Lemeshow test, (P = 0.300). Classification table (overly correctly classified percentage = (69.3%). Ngelkerke R2 = 0.28.
DCC = day care center; ETS = environmental tobacco smoke; LR = logistic regression; OR = odds ratio.
* Forward LR multiple logistic regression model was applied.
† Significant level at p < 0.05.