Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
| Radiation effect | Gestation (weeks) | Threshold dose (mGy) |
|---|---|---|
| Embryonic death | 3–4 | 100–200 |
| Major malformations | 4–8 | 250–500 |
| Growth retardation | 4–8 | 200–500 |
| Irreversible whole body growth retardation | 8–15 | 250–500 |
| Severe mental disability | 8–15 > 16 |
60–500 > 1,500 |
| Microcephaly | 8–15 | > 20,000 |
| Decrease in intelligence quotient | > 16 | > 100 |
