Assertion: sodium nitrate's effect | /r/AtLocation | human epidemiological studies
Facets:
value: since
type: TEMPORAL
Source sentences:
text: The effects of exposure were first observed in animal studies, but have since been observed in human epidemiological studies (Dorsch 1984; Knox 1972; Super 1981).
text: The effects were first observed in animal studies, but have since been observed in human epidemiological studies (Table 8).