Table 1.
Proportion of children to have diagnosed autism or extreme levels on autistic trait measures within each group of increasing prenatal total mercury levels
| Prenatal blood mercury (μg/L)a | Diagnosed autism, % (n) | Autistic traits, % (n) | |||
|---|---|---|---|---|---|
| Poor social cognition | Poor sociability | Poor coherence | Repetitive behavior | ||
| ≤ 1.28 | 1.34 (11) | 12.7 (51) | 12.7 (68) | 12.4 (48) | 6.6 (30) |
| 1.29–1.68 | 0.51 (4) | 12.2 (53) | 12.6 (70) | 10.7 (45) | 6.9 (32) |
| 1.69–2.10 | 0.67 (5) | 11.8 (56) | 11.3 (66) | 7.8 (35) | 4.7 (24) |
| 2.11–2.74 | 1.81 (14) | 11.3 (58) | 11.1 (68) | 9.4 (46) | 5.9 (33) |
| 2.75–3.39 | 1.79 (7) | 9.6 (24) | 10.4 (32) | 12.3 (31) | 7.4 (20) |
| > 3.39 | 1.09 (4) | 13.0 (34) | 10.5 (32) | 8.4 (21) | 2.6 (7) |
| All affectedb | 1.16 (45) | 11.8 (276) | 11.6 (336) | 10.0 (226) | 5.8 (146) |
| Total N | 3885 | 2333 | 2902 | 2249 | 2529 |
| P (5df) | 0.112 | 0.840 | 0.827 | 0.181 | 0.102 |
df degrees of freedom
aFirst four quintiles and the last two deciles
bNote that overall the percentage of extreme autistic traits varies—it is as near to 10% as possible