Translation guide
The English word 'emission' covers several distinct concepts in Japanese. The most common meaning is the release of gases, light, or particles, for which 排出 (はいしゅつ) and 放出 (ほうしゅつ) are standard. For car exhaust, 排気 (はいき) is used. In finance, 'issuance' of stocks or bonds is 発行 (はっこう). For radio waves or signals, 発信 (はっしん) or 放射 (ほうしゃ) apply. Note that direct translation is often unnatural; Japanese prefers specific verbs like 出す (だす) or 排出する (はいしゅつする) depending on context.
To express the act of discharging something into the environment, such as exhaust, smoke, or radiation.
General term for emission or discharge, especially of gases, liquids, or waste. Often used in environmental contexts.
工場は有害なガスを排出している。
The factory is emitting harmful gases.
二酸化炭素の排出を減らす必要がある。
We need to reduce carbon dioxide emissions.
Emission or release, often implying a sudden or large-scale discharge. Used for radiation, heat, or substances.
原子炉から放射線が放出された。
Radiation was emitted from the nuclear reactor.
Specifically refers to exhaust emissions from vehicles or engines.
この車は排気ガスが少ない。
This car has low emissions.
A casual, everyday way to say 'emit' or 'give off'. Use with specific nouns like 煙 (けむり, smoke) or 光 (ひかり, light).
その機械は変な音と煙を出している。
That machine is emitting a strange noise and smoke.
To refer to the act of officially issuing financial instruments.
Standard term for issuance of securities, currency, or official documents.
政府は新しい国債を発行した。
The government issued new government bonds.
その会社は新株を発行する予定だ。
The company plans to issue new shares.
To describe sending out electromagnetic signals or broadcasts.
Transmission or sending of signals, messages, or data. Common in telecommunications.
衛星が信号を発信している。
The satellite is emitting signals.
Emission of electromagnetic waves or radiation, often in physics contexts.
To express giving off energy in the form of light, heat, or sound.
Used for radiation of light, heat, or other energy forms. Often in scientific contexts.
太陽は熱と光を放射している。
The sun emits heat and light.
A formal verb meaning 'to emit' or 'to give off', used with nouns like 光 (ひかり, light), 音 (おと, sound), or 匂い (におい, smell).
その花は強い香りを発する。
The flower emits a strong fragrance.
English 'emission' is often used as a noun, but Japanese prefers verb phrases like 排出する or 出す. Using エミッション (emission in katakana) is rare and limited to technical contexts like 'emission control' (エミッションコントロール).
排出 (はいしゅつ) is for regular discharge, often with a sense of waste or byproduct. 放出 (ほうしゅつ) implies a release, sometimes sudden or large-scale, and can be used for stored energy or substances.
工場の排出物が川を汚染した。
The factory's emissions polluted the river.
排出物 (はいしゅつぶつ) means 'emissions' or 'discharge' as a tangible substance.
新しい法律は車の排気ガスを削減することを目指している。
The new law aims to cut vehicle emissions.
排気ガス (はいきガス) specifically means 'exhaust gas'.
The antenna emits radio waves.