Urban Tree Canopy and Asthma, Wheeze, Rhinitis, and Allergic Sensitization to Tree Pollen in a New York City Birth Cohort

http://dx.doi.org/10.1289/ehp.1205513



Table 1. Child, maternal, household, and neighborhood characteristics.
Characteristic Enrolled in prenatal sample (= 727) Visit completed at age 5 years (= 492) Visit completed at age 7 years (= 427) IgE antibodies assessed at age 7 years (= 288)
aPolycyclic aromatic hydrocarbon (PAH) exposure was dichotomized based on a median split (prenatal personal monitor value of 2.26 g/m3) among participants followed to age 5. ­bAssessment was based on the BRQ. cAssessment was based on the ISAAC Questionnaire. dIgE antibodies were dichotomized at 0.35 IU/mL to define allergic sensitization to each specific allergen.
Child [n (%)]        
Male 351 (48) 228 (46) 197 (46) 137 (48)
Dominican 473 (65) 301 (61) 254 (59) 161 (56)
Black 254 (35) 191 (39) 173 (41) 127 (44)
Mother and household [n (%)]        
Tobacco smoke in the home during pregnancy 246 (34) 155 (32) 149 (35) 113 (40)
Active maternal smoking during pregnancy 79 (11) 46 (9) 46 (11) 34 (12)
PAH exposurea 347 (51) 224 (48) 210 (51) 159 (57)
Medicaid 657 (91) 450 (92) 388 (91) 266 (92)
Maternal asthma 114 (22) 79 (21) 66 (23) 51 (27)
Mother reports previous live birth 399 (55) 264 (54) 231 (54) 157 (55)
Mother reports any other previous pregnancy (e.g., miscarriage, stillbirth) 149 (21) 108 (22) 94 (22) 69 (24)
Child health outcomes assessed during follow-up [n (%)]        
Asthma diagnosed by age 5b   137 (28)    
Wheeze at age 5c   126 (26)    
Rhinitis at age 5c   15 (3)    
Asthma diagnosed by age 7b     152 (36)  
Wheeze at age 7c     106 (25)  
Rhinitis at age 7c     20 (5)  
Any specific allergic sensitizationd       131 (45)
Allergic sensitization to tree pollend       54 (19)
0.25-km buffer prenatal neighborhood (mean ± SD)        
Population density (thousands/km2) 43 ± 14 42 ±14 43 ± 14 42 ± 14
Area poverty (percent of residents below federal poverty line) 37 ± 7 37 ± 7 37 ± 7 37 ± 7
Area racial composition (percent of residents reporting black race) 40 ± 27 42 ± 28 43 ± 28 45 ± 28
Traffic volume (estimated average daily traffic in thousands of vehicles) 11 ± 4 11 ± 4 11 ± 4 11 ± 4
Park coverage (percent of land area covered by park land) 8 ± 9 8 ± 9 8 ± 9 8 ± 9
Tree canopy coverage (percent of land area covered by tree canopy) 15 ± 8 16 ± 8 16 ± 8 16 ± 8