What does microcurie mean?
A microcurie is a very small unit of radioactivity, equal to one millionth of a curie and 37,000 becquerels. The curie is an older unit that remains common in medicine, environmental monitoring, and some industrial applications, although the becquerel is the standard SI unit for radioactive activity. A microcurie is therefore used when the quantity being measured is much smaller than a curie but still significant enough to report. For example, a medical test or environmental sample may contain a fraction of a microcurie, or several microcuries may be measured in contaminated water. The word is typically formal and scientific rather than everyday vocabulary, and it is often written with the symbol μCi. Its value lies in expressing trace radioactive activity precisely while retaining compatibility with the long-established curie scale.
nounA unit of radioactivity equal to one millionth of a curie, or 37,000 becquerels. It is used especially in medicine and environmental science to describe very small quantities of radioactive activity.
- A unit of radioactivity equal to one millionth of a curie, or 37,000 becquerels.
"The instrument detected a level of 0.2 microcuries in the sample."
"The scan showed only a negligible amount of radioactive material, below 0.1 microcurie."
"Researchers measured 3.5 microcuries in the water sample."
The plural is microcuries; quantities are typically written with a number and the unit abbreviation μCi.
"The samples contained less than one microcurie of radioactivity."
A microcurie packs a millionth of a curie into a unit small enough to describe trace radioactivity in medicine, industry, and environmental testing.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does microcurie come from?
The word combines the combining form micro-, meaning one millionth or very small, with curie, the unit named after French scientists Pierre and Marie Curie. The curie was adopted as a unit of radioactivity, and microcurie follows the standard metric pattern of forming a smaller unit with a numerical prefix. The prefix micro- comes from Greek mikros, meaning small, while curie is a proper name associated with the Curie family.
Related word forms
How microcurie is actually used
This is technical terminology used in scientific, medical, industrial, and regulatory contexts. It is normally used with a numerical value and may be abbreviated as μCi.
Easily confused with microcurie
A millicurie is one thousandth of a curie, whereas a microcurie is one millionth of a curie.
A curie is a much larger unit of radioactivity; a microcurie is one millionth of a curie.