Table 3.

Mean (± SD) of cognitive outcomes by characteristics of participants.

Characteristics	n (%)a	Working memory (WM) (2-back numbers, d´ × 100)		Superior WM (3-back numbers, d´ × 100)		Inattentiveness (HRT-SE, ms)
		Baseline	Change	Baseline	Change	Baseline	Change
All	2,618 (100)	224 ± 126	30 ± 156	118 ± 100	20 ± 130	272 ± 90	–38 ± 89
Sex
Male	1,316 (50.3)	229 ± 129	25 ± 155	123 ± 103	16 ± 129	261 ± 89*	–35 ± 89
Female	1,302 (49.7)	220 ± 122	35 ± 157	113 ± 96	23 ± 132	284 ± 89	–41 ± 88
Type of school
Public	860 (32.8)	215 ± 129*	36 ± 149	111 ± 102*	32 ± 126*	274 ± 91	–39 ± 89
Private	1,758 (67.2)	229 ± 124	27 ± 159	121 ± 99	14 ± 132	271 ± 89	–38 ± 89
Maternal education
Primary or less	337 (12.9)	188 ± 134*	25 ± 162	82 ± 91*	25 ± 130	308 ± 88*	–40 ± 92
Secondary	743 (28.4)	213 ± 124	32 ± 160	118 ± 102	14 ± 132	274 ± 90	–31 ± 93
University	1,538 (58.7)	237 ± 122	30 ± 153	126 ± 100	21 ± 130	264 ± 88	–41 ± 85
SES vulnerability at home
Less deprived	980 (37.4)	233 ± 124*	29 ± 151	127 ± 102*	18 ± 131	265 ± 89*	–38 ± 87
Middle deprived	807 (30.8)	227 ± 125	27 ± 159	116 ± 98	27 ± 131	274 ± 92	–37 ± 91
High deprived	831 (31.7)	212 ± 128	34 ± 159	110 ± 100	15 ± 130	281 ± 88	–39 ± 89
School Pair
Low polluted	1,328	226 ± 125	36 ± 154	120 ± 100	23 ± 131	272 ± 89	–42 ± 86
High polluted	1,290	222 ± 126	24 ± 158	116 ± 100	16 ± 130	273 ± 90	–34 ± 91
Residential PM2.5 from traffic
1st quartile	635	224 ± 128	32 ± 157	121 ± 101	17 ± 125	275 ± 94	–38 ± 83
2nd quartile	662	229 ± 124	22 ± 159	117 ± 103	21 ± 139	272 ± 90	–38 ± 86
3rd quartile	659	224 ± 126	37 ± 150	123 ± 98	15 ± 128	271 ± 89	–41 ± 93
4th quartile	662	220 ± 125	29 ± 157	111 ± 98	25 ± 129	271 ± 86	–37 ± 92
aNumber of participants with data at baseline. *p < 0.05 when testing equality between groups.