The relationship between air pollution from heavy traffic and allergic sensitization, bronchial hyperresponsiveness, and respiratory symptoms in Dutch schoolchildren - Children's Health

Environmental Health Perspectives, Sept, 2003 by Nicole A.H. Janssen, Bert Brunekreef, Patricia van Vliet, Francee Aarts, Kees Meliefste, Hendrik Harssema, Paul Fischer

Table 1. Distribution of traffic characteristics and annual average
outdoor concentrations [micro]g/[m.sup.3]) at the schools.

Characteristics                         No.       Mean [  or -] SD

Traffic characteristics
  Truck traffic density (vehicles/
    weekday)                              24    13,146 [  or -] 4,880
  Car traffic density (vehicles/
    weekday)                              24    89,544 [  or -] 35,843
  Distance school--motorway (m)           24       220 [  or -] 111
  Distance homes--motorway (m)         2,083       407 [  or -] 230
Outdoor air pollution
  P[M.sub.2.5] ([micro]g/[m.sup.3])       24      20.5 [  or -] 2.2
  Soot ([micro]g/[m.sup.3])               24      10.3 [  or -] 2.1
  N[O.sub.2] ([micro]g/[m.sup.3])         24      34.8 [  or -] 5.2

                                                   25th
Characteristics                       Minimum   percentile   Median

Traffic characteristics
  Truck traffic density (vehicles/
    weekday)                           5,190      9,571       11,814
  Car traffic density (vehicles/
    weekday)                          30,399     61,013       87,843
  Distance school--motorway (m)           57        118          210
  Distance homes--motorway (m)             1        228          365
Outdoor air pollution
  P[M.sub.2.5] ([micro]g/[m.sup.3])       17.3       18.6         20.4
  Soot ([micro]g/[m.sup.3])                6.2        9.0         10.5
  N[O.sub.2] ([micro]g/[m.sup.3])         26.8       31.1         34.0

Characteristics                        75th percentile    Maximum

Traffic characteristics
  Truck traffic density (vehicles/
    weekday)                            16,817             22,326
  Car traffic density (vehicles/
    weekday)                           114,780            155,656
  Distance school--motorway (m)            330                389
  Distance homes--motorway (m)             556                999
Outdoor air pollution
  P[M.sub.2.5] ([micro]g/[m.sup.3])         22.1                2.44
  Soot ([micro]g/[m.sup.3])                 11.2               15.5
  N[O.sub.2] ([micro]g/[m.sup.3])           39.1               44.4

Table 2. Prevalence of respiratory or allergic symptoms
and results of the SPT and BHR test.

Symptoms (total n)                          No. (%)

Current (a) wheeze (2,071)                 194 (9.4)
Asthma ever (2,053)                        165 (8.0)
Current conjunctivitis (2,053)             150 (7.3)
Hay fever ever (2,040)                     146 (7.2)
Current itchy rash (2,060)                 305 (14.8)
Eczema ever (2,040)                        611 (30.0)
Current phlegm, no cold (2,045)            198 (9.7)
Current bronchitis (2,037)                 156 (7.7)
Elevated total IgE (881)                   351 (39.8)
Positive SPT, any allergen (1,141)         318 (27.9)
Positive SPT, indoor allergens (1,141)     250 (21.9)
Positive SPT, outdoor allergens (1,141)    170 (14.9)
FVC < 85% of predicted (1,726)             237 (13.7)
FE[V.sub.1] < 85% of predicted (1,724)     136 (7.9)
BHR (949)                                  192 (20.2)
Negative SPT and negative BHR (765)        481 (62.9)

(a) Current = in the past 12 months.

Table 3. Adjusted ORs (a) and 95% confidence limits (95% CI) of the
association between respiratory and allergic symptoms, traffic
characteristics, and annual average air pollution concentrations.

                          Current wheeze          Asthma ever
                           OR (95% CI)            0R (95% CI)

Traffic characteristics (b)
  Truck traffic        1.96 (#) (0.88-4.38)     1.02 (0.43-2.44)
  Car traffic          0.56 (0.27-1.15)        10.92 (0.43-1.95)
  Distance
    school--highway    1.19 (0.71-1.97)        10.93 (0.54-1.61)
  Distance
    home--highway      1.20 (0.89-1.62)         1.04 (0.74-1.45)
Outdoor air pollution (c)
  P[M.sub.25]          1.51 (0.90-2.53)         1.03 (0.59-1.82)
  Soot                 1.43 (0.65-3.07)         1.36 (0.62-2.98)
  N[O.sub.2]           1.74 (#) (0.95-3.05)     1.39 (0.75-2.56)

                             Current
                         conjunctivitis          Hay fever ever
                           OR (95% CI)            OR (95% CI)

Traffic characteristics (b)
  Truck traffic        2.57 * (1.00-6.58)     2.40 (0.77-7.49)
  Car traffic          0.80 (0.35-1.83)       0.70 (0.26-1.89)
  Distance
    school--highway    1.55 (0.87-2.74)       1.04 (0.51-2.14)
  Distance
    home--highway      0.61 * (0.41-0.91)     0.92 (0.62-1.36)
Outdoor air pollution (c)
  P[M.sub.25]          2.08 * (1.17-3.71)     2.28 * (1.13-4.57)
  Soot                 2.54 * (1.15-5.60)     1.29 (0.40-4.14)
  N[O.sub.2]           2.60 ** (1.38-4.90)    1.98 (#) (0.95-4.33)

                             Current
                           itchy rash           Eczema ever
                           OR (95% CI)          OR (95% CI)

Traffic characteristics (b)
  Truck traffic        2.65 * (1.20-5.85)     1.27 (0.73-2.19)
  Car traffic          0.58 (.28-1.17)        0.69 (0.43-1.11)
  Distance
    school--highway    1.17 (0.71-1.92)       0.95 (0.67-1.34)
  Distance
    home--highway      0.90 (0.68-1.20)       1.00 (0.81-1.22)
Outdoor air pollution (c)
  P[M.sub.25]          1.63 (#) (0.91-2.89)   1.31 (0.94-1.83)
  Soot                 1.54 (0.68-3.49)       1.17 (0.71-1.92)
  N[O.sub.2]           1.25 (0.66-2.39)       1.27 (0.88-1.84)

                             Current               Current
                              phlegm              bronchitis
                           OR (95% CI)           OR (95% CI)

Traffic characteristics (b)
  Truck traffic        2.14 (0.73-6.30)        2.41 (0.82-7.13)
  Car traffic          0.48 (0.19-1.22)        0.84 (0.33-2.14)
  Distance
    school--highway    1.52 (0.80-2.91)        1.18 (0.60-2.31)
  Distance
    home--highway      0.88 (0.62-1.23)        1.21 (0.87-1.68)
Outdoor air pollution (c)
  P[M.sub.25]          1.53 (0.74-3.19)        1.71 (0.84-3.50)
  Soot                 2.41 (#) (0.96-6.04)    1.32 (0.44-3.94)
  N[O.sub.2]           1.72 (0.82-3.62)        1.37 (0.60-3.12)

(a) Adjusted for sex, age, current parental smoking, current pet
possession, parental education level, non-Dutch nationality, cooking
on gas, number of persons in the household, presence of an unvented
water heater in the kitchen, questionnaire not filled out by the
mother, and presence of mold stains in the kitchen, living room, or
bedroom. ORs for traffic densities and air pollution are expressed for
the difference between the maximum and the minimum of the exposure
variable; ORs for distance to the highway are expressed for the
difference between 100 and 400 m. (b) All four traffic characteristics
together in the same model. (c) All three air pollution components
separately in three different models; also adjusted for distance of
the home to the motorway. (#) p < 0.10; * p < 0.05; ** p < 0.01.

Table 4. Adjusted ORs (a) for elevated total IgE, SPT reactivity, lung
function, and BHR in relation to traffic-related characteristics and
annual average outdoor air pollution concentrations.

                                                SPT reactivity

                         Elevated total          Any allergen
                         IgE (n = 881)           (n = 1,141)
                          OR (95% CI)            OR (95% CI)

Traffic characteristics (c)
  Truck traffic        1.32 (0.51-3.39)      1.38 (0.67-2.85)
  Car traffic          1.39 (0.81-3.19)      1.09 (0.57-2.07)
  Distance
    school--highway    1.33 (0.73-2.41)      1.14 (0.72-1.82)
  Distance
    home--highway      0.99 (0.73-1.35)      1.00 (0.75-1.33)
Outdoor air pollution (d)
  P[M.sub.2.5]         1.45 (0.74-2.84)      1.33 (0.83-2.11)
  Soot                 2.67 * (1.16-6.12)    1.24 (0.64-2.41)
  N[O.sub.2]           3.12 ** (1.81-5.38)   1.70 * (1.03-2.81)

                                    SPT reactivity

                        Indoor allergens      Outdoor allergens
                          (n = 1,141)            (n = 1,141)
                          OR (95% CI)            OR (95% CI)

Traffic characteristics (c)
  Truck traffic        1.13 (0.51-2.51)      2.83 * (1.18-6.82)
  Car traffic          1.29 (0.64-2.59)      0.59 (0.26-1.30)
  Distance
    school--highway    1.09 (0.65-1.83)      1.39 (0.79-2.42)
  Distance
    home--highway      0.99 (0.73-1.35)      1.12 (0.80-1.59)
Outdoor air pollution (d)
  P[M.sub.2.5]         1.17 (0.70-1.94)      1.90 * (1.06-3.40)
  Soot                 1.39 (0.69-2.81)      1.41 (0.63-3.17)
  N[O.sub.2]           1.94 * (1.13-3.33)    1.69 (#) (0.91-3.14)

                           FVC < 85%         FE[V.sub.1] < 85%
                           predicted             predicted
                        (n = 1,726) (b)       (n = 1,724) (b)
                          OR (95% CI)           OR (95% CI)

Traffic characteristics (c)
  Truck traffic        0.96 (0.36-2.59)      1.19 (0.34-4.23)
  Car traffic          1.40 (0.61-3.22)      1.13 (0.40-3.16)
  Distance
    school--highway    1.13 (0.59-2.15)      0.85 (0.38-1.83)
  Distance
    home--highway      0.85 (0.61-1.18)      0.88 (0.58-1.33)
Outdoor air pollution (d)
  P[M.sub.2.5]         0.54 * (0.29-1.00)    0.88 (0.37-2.09)
  Soot                 1.12 (0.41-3.09)      1.45 (0.43-4.85)
  N[O.sub.2]           0.78 (0.38-1.61)      1.55 (0.69-3.49)

                        BHR (n = 949)
                         OR (95% CI)

Traffic characteristics (c)
  Truck traffic        0.90 (0.38-2.14)
  Car traffic          1.34 (0.63-2.87)
  Distance
    school--highway    1.09 (0.64-1.86)
  Distance
    home--highway      1.11 (0.79-1.57)
Outdoor air pollution (d)
  P[M.sub.2.5]         0.93 (0.51-1.68)
  Soot                 1.44 (0.66-3.14)
  N[O.sub.2]           1.22 (0.66-2.27)

(a) Adjusted for sex age, current parental smoking, current pet
possession, parental education level, non-Dutch nationality, cooking on
gas, number of persons in the household, presence of an unvented water
heater in the kitchen, questionnaire not filled out by the mother, and
presence of mold stains in the kitchen, living room, or bedroom. ORs
for traffic densities and air pollution are expressed for the
difference between the maximum and the minimum of the exposure
variable; ORs for distance to the highway are expressed for the
difference between 100 and 400 m. (b) Additional adjustment for cough
or cold at the time of the lung function measurement, and bronchitis,
severe cold or flu in the 3 weeks preceding the measurement and season.
All four traffic characteristics together in the same model. (d) All
three air pollution components separately in three different models;
also adjusted for distance of the home to the motorway. * p < 0.10;
(#) p < 0.05; ** p < 0.01.