Does residential mobility during pregnancy induce exposure misclassification for air pollution?

Table 1 Descriptive statistics of the study population

Characteristics (N = 486)	N	%
Hospital/clinic
Tenon	115	23.7
Lariboisière	105	21.6
Port-Royal	173	35.6
Sainte-Félicité	80	16.5
La Muette	13	2.7
Education
Low (<Baccalaureat)	132	27.2
Middle (= Baccalaureat level)	159	32.7
High (> Baccalaureat)	195	40.1
Census block socioeconomic deprivation class
(most privileged) 1	96	19.7
2	96	19.7
3	92	18.9
4	111	22.8
(most deprived) 5	75	15.4
Missing value ^a	16	3.3
Occupational activity
1st trimester (T1)	398	81.9
2^de trimester (T2)	300	61.7
3rd trimester (T3)	112	23.0
Commuting modes
By foot	49	10.1
Bicycles / motorcycles	9	1.9
Car	10	2.1
Metro	320	65.9
Bus	51	10.5
Tramways	2	0.4
Missing value^b	45	9.3
IRIS of residence (N = 992 IRIS)	345^c	34.8^c
IRIS of occupation (N = 992 IRIS)^d
1st trimester (T1)	283	28.5
2^de trimester (T2)	229	23.1
3rd trimester (T3)	91	9.2

^aIt was not possible to geocode sixteen women due to incomplete postal address
^bMissing/no information regarding commuting mode
^cThe 486 women were distributed across 345 census blocks, representing 34.8% of the total number of census blocks in Paris (345/992)
^dNine women had the same residential and occupational census blocks (IRIS)

ISSN: 1476-069X