At the A1 level, '公害' (kōgai) is a very difficult word because it is abstract and formal. However, beginners can understand it by thinking of it as 'very bad dirtiness that makes people sick.' At this level, you mostly learn words like 'dirty' (汚い - kitanai) or 'water' (水 - mizu). You might see '公害' in a very simple picture book about the earth. Think of it as 'Public (公) Harm (害)'. If a factory makes the air black and people cough, that is '公害'. It is not a word you use to talk about your daily life, like 'I am eating' or 'I am going to school.' It is a word for the news. You should remember that '公' means everyone or the public, and '害' means something bad or harmful. So, '公害' is something bad for everyone. Even if you cannot use it in a sentence yet, if you see it, know it is about the environment and it is a negative thing. You might hear it when people talk about big cities having 'bad air.' In Japan, children learn this word early because it is part of their history, but for an English speaker starting Japanese, it is enough to know it means 'pollution.' Don't worry about the complex kanji yet, just focus on the sound 'kōgai' and the meaning of 'big environmental trouble.'
For A2 learners, '公害' (kōgai) starts to appear in basic readings about society or nature. You might learn it alongside words like 'factory' (工場 - kōjō), 'environment' (環境 - kankyō), and 'problem' (問題 - mondai). A simple way to use it at this level is '公害は問題です' (Pollution is a problem) or '公害をなくしたいです' (I want to eliminate pollution). You should begin to distinguish it from '汚い' (kitanai). While 'kitanai' is an adjective you use for a dirty shirt, '公害' is a noun for a social issue. You will see it in simple news articles for students (like NHK News Web Easy). It is often linked to 'air' (大気 - taiki) and 'water' (水質 - suishitsu). If you are visiting Japan, you might see this word on signs near construction sites or industrial areas. It is a good word to know because it helps you understand that Japanese society takes environmental issues very seriously. Remember the structure: [Noun] + は + [Noun] + です. For example, '騒音は公害です' (Noise is pollution). At this stage, you don't need to know the history of the word, just that it is the formal noun for pollution caused by companies or cities. It is a key word for discussing 'Environmental Problems' (環境問題), which is a common topic in Japanese proficiency tests.
At the B1 level, you are expected to understand '公害' (kōgai) in its full social context. This is the level where you should know that '公害' is not just 'dirty air,' but a specific legal and social category in Japan. You should be able to discuss the 'Seven Major Pollutions' (七大公害) which include noise, vibration, and odors. At B1, you can use more complex verbs with the word. For example: '工場が公害を引き起こした' (The factory caused pollution) or '政府は公害対策を立てるべきだ' (The government should create pollution measures). You will encounter this word in intermediate textbooks and JLPT N3/N2 materials. It is important to understand the nuance: '公害' implies a victim and a perpetrator. There is a sense of social responsibility. If you are writing an essay about the environment, using '公害' instead of just '汚染' shows you understand the social dimension of the problem. You should also be aware of the historical context, specifically that Japan had many '公害' problems in the 1960s, which led to very strict laws today. This word is essential for reading newspaper editorials or watching documentaries. You should also start to recognize compound words like '公害病' (pollution-induced disease) and '公害防止' (pollution prevention). It is a formal word, so use it in discussions about policy, history, or serious social issues.
At the B2 level, you should be comfortable using '公害' (kōgai) in academic or professional discussions. You should understand the legal definitions provided by the 'Basic Environment Act' (環境基本法). At this level, you can distinguish between '公害' and '環境破壊' (environmental destruction) or '環境負荷' (environmental load). You should be able to explain the 'Big Four Pollution Diseases' (四大公害病) and their impact on Japanese law and corporate ethics. Your vocabulary should include terms like '公害規制' (pollution regulations), '公害訴訟' (pollution lawsuits), and '公害認定' (official recognition of pollution victims). You might use the word in a sentence like: '高度経済成長の裏側で、深刻な公害が多発した' (Behind the rapid economic growth, serious pollution occurred frequently). This level requires you to understand the nuance of 'public nuisance' in a legal sense—how something like light or vibration can be classified as '公害' because it interferes with the public's right to a healthy life. You should also be able to discuss 'global-scale environmental problems' (地球規模の環境問題) and explain why the term '公害' is traditionally reserved for local, human-centric damage. In professional settings, you might use '公害' when discussing risk management or compliance. It is a word that carries a lot of weight, and using it correctly demonstrates a deep understanding of Japanese social history and legal structures.
For C1 learners, '公害' (kōgai) is a word that you analyze through a sociological and historical lens. You should be able to discuss the evolution of the term from the 'Kōgai' of the 1960s to the 'New Kōgai' (新公害) of the modern era, such as 'low-frequency sound' or 'electromagnetic waves.' You should understand the discourse around 'Environmental Justice' and how '公害' has shaped the Japanese environmental movement. At this level, you can read and summarize legal documents, supreme court rulings on '公害' cases, and academic papers on environmental economics. You should be able to use the word in complex rhetorical structures: '公害問題の解決は、単なる技術的な課題ではなく、倫理的、政治的な決断を要する' (Solving pollution problems is not merely a technical challenge but requires ethical and political decisions). You should also be familiar with the internationalization of the word; 'Kōgai' is sometimes used in international environmental studies to refer specifically to the Japanese experience of industrial pollution. You should understand the nuances of '公害' in relation to 'CSR' (Corporate Social Responsibility) and how modern companies strive to avoid being labeled as '公害企業' (polluting companies). Your ability to use '公害' should extend to metaphorical or high-level social criticism, discussing how certain social phenomena can be seen as a 'spiritual public nuisance' (精神的公害).
At the C2 level, you have a native-like grasp of '公害' (kōgai) and can use it with precision in any context, from legal drafting to philosophical debate. You understand the deepest historical roots of the term, dating back to the Ashio Copper Mine incident in the late 19th century, which is considered Japan's first '公害.' You can discuss the interplay between '公害' law and international environmental treaties. You are capable of analyzing the linguistic shift from '公害' (human-centered harm) to '環境問題' (ecosystem-centered problems) in Japanese policy documents over the last 50 years. You can engage in debates about the 'export of pollution' (公害輸出), where Japanese companies moved dirty industries to developing nations in the 1970s and 80s. Your usage of the word is nuanced and context-aware, recognizing when the term is being used to evoke the trauma of the 1960s to gain political leverage. You can write comprehensive reports on environmental policy that use '公害' correctly in its technical, legal, and historical senses. You are also aware of the most modern applications of the term, such as 'visual pollution' (景観公害) or 'information pollution' (情報公害), and can discuss whether these should be legally classified under the traditional '公害' framework. At this level, '公害' is not just a vocabulary word; it is a conceptual tool for understanding the relationship between the Japanese state, industry, and the public.

公害 in 30 Seconds

  • 公害 (Kōgai) means 'pollution' or 'public nuisance' caused by human activity.
  • It is a formal, serious word often used in legal, social, and historical contexts.
  • It covers air, water, soil, noise, vibration, odors, and ground subsidence.
  • The word carries a strong nuance of social responsibility and harm to victims.

The Japanese word 公害 (こうがい - kōgai) is a profound term that translates most directly to 'pollution' or 'public nuisance.' However, its weight in the Japanese language is significantly heavier than the English word 'pollution' might suggest. It is composed of two kanji: 公 (kō), meaning 'public' or 'official,' and 害 (gai), meaning 'harm,' 'damage,' or 'mischief.' Together, they describe harm inflicted upon the public or the environment as a result of human activity, particularly industrial or urban development. In a sociological and legal context, 公害 refers to the degradation of the living environment and the resulting health damage to the residents in a specific area. This isn't just about a bit of litter on the street; it refers to systemic, often corporate-driven environmental destruction that affects the collective well-being.

Historical Weight
In post-war Japan, during the period of rapid economic growth (the 1950s to 1970s), the term became synonymous with the 'Big Four Pollution Diseases' (Minamata disease, Niigata Minamata disease, Itai-itai disease, and Yokkaichi Asthma). These tragedies cemented 公害 as a word associated with corporate negligence and the fight for environmental justice.

When using this word today, Japanese speakers distinguish between general 'contamination' (汚染 - osen) and 'public nuisance/pollution' (公害). While osen refers to the physical state of being dirty (like water or soil), kōgai focuses on the social and legal responsibility of the damage. If a factory dumps chemicals into a river, the river is osen (contaminated), but the resulting health issues for the townspeople are kōgai.

この地域はかつてひどい公害に悩まされていた。(This region used to suffer from terrible industrial pollution.)

Scope of the Term
Modern usage has expanded to include seven major types of pollution defined by Japanese law: air pollution, water pollution, soil contamination, noise, vibration, ground subsidence, and offensive odors. More recently, terms like 'light pollution' (光害 - hikari-gai) have also emerged under this umbrella.

People use 公害 when discussing environmental policy, history, law, and social activism. It is a formal word, often found in newspapers, textbooks, and news broadcasts. It carries a nuance of 'harm caused by a third party (usually a company or public entity) that impacts the health or living environment of many people.' Therefore, you wouldn't use it for a single person making a mess in their own yard; it requires a broader social impact.

政府は新しい公害防止策を打ち出した。(The government launched new pollution prevention measures.)

Modern Context
Today, the term is frequently used in discussions about sustainable development and ESG (Environmental, Social, and Governance) criteria. It serves as a reminder of Japan's past mistakes and its commitment to preventing such tragedies from recurring as it balances industrial output with environmental protection.

騒音も立派な公害の一つだ。(Noise is also a significant type of public nuisance.)

Using 公害 (kōgai) correctly requires understanding its role as a noun and its typical collocations. Since it refers to a broad phenomenon, it often acts as the subject of a sentence or the object of verbs related to prevention, causation, or suffering. To say 'pollution occurs,' you would use the verb hassei suru (発生する). To say 'to cause pollution,' you use hikiokosu (引き起こす). To say 'to suffer from pollution,' you use nayamu (悩む) or kurushimu (苦しむ).

Subject Marker (が/は)
When 公害 is the main topic, use は or が. Example: '公害は深刻な問題です' (Pollution is a serious problem). Here, the focus is on the state of the problem itself.

Because 公害 is a social issue, it is frequently paired with words like taisaku (対策 - measures), boushi (防止 - prevention), and saiban (裁判 - lawsuit). For instance, '公害対策' (pollution measures) is a very common compound noun used in government and corporate reports.

工場が公害を引き起こし、住民が訴えを起こした。(The factory caused pollution, and the residents filed a lawsuit.)

Specific Types
To be specific, you can prefix the type of pollution: 大気公害 (taiki kōgai - atmospheric pollution), 水質公害 (suishitsu kōgai - water quality pollution), or 騒音公害 (sōon kōgai - noise pollution). These are highly technical and formal.

In passive constructions, you might say '公害による被害' (damage caused by pollution). This is a standard way to link the cause to the effect. In many cases, 公害 is treated as a collective noun representing the entire complex of environmental issues facing a community.

高度経済成長期には、日本中で公害が社会問題となった。(During the period of high economic growth, pollution became a social issue throughout Japan.)

Negative Connotation
The word always carries a negative connotation. You will never hear it used in a positive or neutral light. It implies a violation of the right to a healthy life. Therefore, when you use it, you are inherently criticizing the source of the problem.

私たちは公害のない街を目指している。(We are aiming for a city free of pollution.)

Lastly, in very informal or metaphorical speech, some might use it to describe a person who is a 'public nuisance' (e.g., someone talking too loudly on a train), but this is rare and usually 'meiwaku' (迷惑) is preferred. Stick to environmental and social contexts for 公害 to be safe and accurate.

その工場は公害規制を守っていなかった。(That factory was not following pollution regulations.)

If you live in Japan or consume Japanese media, you will encounter 公害 (kōgai) in several specific environments. Most notably, it is a staple of the evening news (ニュース). Whenever there is a chemical spill, a debate over a new highway's noise levels, or an anniversary of a historic environmental disaster, the word kōgai will be featured prominently. It is the 'serious' word for environmental damage.

In the News
News anchors use it when reporting on 'Environmental Pollution' (環境公害). You might hear: '新しい公害対策法が施行されました' (A new pollution prevention law has come into effect). It sounds authoritative and grave.

Education is another primary place for this word. Every Japanese student learns about the history of Japan's economic miracle and the 'shadow' that accompanied it: the kōgai issues of the 1960s. In social studies (社会科 - shakaika) textbooks, chapters are dedicated to '公害の歴史' (The history of pollution). Because of this, even young people are very familiar with the term, though they may associate it more with history than their daily life.

学校で日本の公害の歴史について学んだ。(I learned about the history of Japanese pollution at school.)

In Legal and Activist Circles
If you go to a town hall meeting or follow environmental activists (環境活動家), you'll hear kōgai used to demand accountability. Phrases like '公害を許さない' (We will not tolerate pollution) or '公害裁判' (Pollution lawsuits) are common in these circles. It is a word of resistance.

You will also see it on signage. In industrial areas, you might see signs that say '公害防止の徹底' (Thoroughness in pollution prevention). These are reminders to workers and companies to follow environmental standards. Similarly, near airports or train tracks, you might see signs discussing '騒音公害' (noise pollution) and the measures being taken to mitigate it.

この看板には「公害防止」と書いてある。(This sign says 'Pollution Prevention'.)

In popular media, particularly documentaries or socially conscious anime/films, kōgai is a recurring theme. For example, Studio Ghibli films often touch on environmental destruction, and while they might use more poetic language, the underlying theme is the battle against kōgai. In Godzilla movies, the monster itself was originally a metaphor for the 'public harms' of nuclear testing and industrial waste.

ドキュメンタリー番組で公害患者の現状を知った。(I learned about the current situation of pollution victims through a documentary program.)

The most common mistake learners make is using 公害 (kōgai) as a synonym for 'dirty' or 'messy' in a personal context. It is important to remember that kōgai is a social and environmental term. You cannot say your room is kōgai just because you haven't cleaned it in a week. For that, you would use kitanai (汚い) or chirakatte iru (散らかっている).

Mistaking 公害 for 汚染 (Osen)
While they are related, they are not interchangeable. 汚染 (Osen) is the 'contamination' (the physical state). 公害 (Kōgai) is the 'public harm' (the social problem). You can have 'radioactive contamination' (放射能汚染), but the resulting health crisis is the 'public harm' (公害). Using kōgai when you just mean a dirty river can sound overly dramatic or clinical depending on the context.

Another mistake is forgetting that kōgai includes things that aren't 'pollution' in the traditional sense, like noise (sōon) or vibration (shindō). If you only use kōgai to mean 'chemical pollution,' you are missing half of its meaning in Japan. If a construction site is too loud, that is legally and socially a form of kōgai.

× 私の部屋は公害です。(My room is pollution.)
私の部屋は汚いです。(My room is dirty.)

Grammatical Misuse
Learners often try to use it as a verb (e.g., 公害する). This is incorrect. 公害 is a noun. You must use it with a verb like hikiokosu (cause) or umareru (arise). If you want to say 'to pollute,' the verb yogosu (汚す) or osen suru (汚染する) is much more natural.

A subtle mistake is using kōgai for global issues like 'climate change.' While climate change is a result of pollution, the term kōgai in Japan is historically and legally tied to local damage caused by specific industries. For global environmental issues, the term 環境問題 (kankyō mondai - environmental problems) is the standard choice.

× 地球温暖化は最大の公害だ。(Global warming is the biggest 'kōgai'.)
地球温暖化は深刻な環境問題だ。(Global warming is a serious environmental problem.)

Finally, watch out for the homophone kōgai (郊外), which means 'suburbs.' In spoken Japanese, the context usually makes it clear, but in writing, confusing the kanji for 'pollution' (公害) and 'suburbs' (郊外) would be a major error. Imagine telling someone you live in the 'pollution' instead of the 'suburbs'!

× 私は東京の公害に住んでいます。(I live in Tokyo's pollution.)
私は東京の郊外に住んでいます。(I live in the suburbs of Tokyo.)

To truly master 公害 (kōgai), you need to know the words that surround it and how they differ. Japanese has a rich vocabulary for environmental and social issues, and choosing the right word shows a high level of proficiency.

公害 (Kōgai) vs. 汚染 (Osen)
公害 focuses on the social impact and harm to humans. 汚染 focuses on the physical contamination of a substance. Use 公害 for lawsuits and social issues; use 汚染 for scientific descriptions of water or air quality.

Another important word is 環境破壊 (kankyō hakai), which means 'environmental destruction.' While 公害 implies harm to humans, kankyō hakai is broader and can refer to the destruction of forests, coral reefs, or animal habitats where humans might not be directly affected in the short term.

公害 (Kōgai) vs. 迷惑 (Meiwaku)
迷惑 means 'nuisance' or 'trouble' in a general, often personal sense. If your neighbor's dog barks, it's meiwaku. If a factory's constant noise causes a whole neighborhood to lose sleep and suffer health issues, it's kōgai. 公害 is the 'official/legal' version of a nuisance.

For specific types of pollution, you might use スモッグ (smog) or 排気ガス (haiki gasu - exhaust gas). These are the *causes* of air pollution. While 公害 is the general category, these words describe the specific pollutants involved.

排気ガスによる大気汚染は、都市部の深刻な公害だ。(Air pollution caused by exhaust gas is a serious 'kōgai' in urban areas.)

Modern Alternatives
In modern business contexts, you might hear 環境負荷 (kankyō fuka), which means 'environmental load/burden.' This is a more neutral, technical term used in sustainability reports to describe the impact a company has on the environment, without the heavy historical baggage of the word kōgai.

Finally, there is 害毒 (gaidoku), which literally means 'poisonous harm.' This is a much stronger, more emotional word than 公害 and is usually used metaphorically to describe something that 'poisons' society, like 'harmful books' (有害図書) or 'harmful thoughts.' It is rarely used for actual physical pollution.

川の汚染を放置すれば、取り返しのつかない公害に発展する。(If river contamination is ignored, it will develop into an irreversible 'kōgai'.)

How Formal Is It?

Fun Fact

The term became globally famous in the 1960s. At that time, Japan was often called the 'Pollution Archipelago' (公害列島) because of its rapid and dirty industrialization.

Pronunciation Guide

UK koʊɡaɪ
US koʊɡaɪ
Flat (Heiban) pitch accent. The pitch stays relatively level throughout the word.
Rhymes With
妨害 (bōgai - interference) 災害 (saigai - disaster) 正解 (seikai - correct answer) 爽快 (sōkai - refreshing) 後悔 (kōkai - regret) 公開 (kōkai - public opening) 郊外 (kōgai - suburbs) 航海 (kōkai - voyage)
Common Errors
  • Pronouncing 'gai' as 'gay'. It should always be 'guy'.
  • Shortening the 'kō' sound. It is a long 'o' (double mora).
  • Confusing the pitch with 'kōgai' (suburbs), though they are often both heiban.
  • Adding a 'u' sound in the middle like 'ko-u-ga-i' with distinct breaks.
  • Mispronouncing 'kō' as 'koo' (like moon).

Difficulty Rating

Reading 4/5

The kanji are common but the context is often formal and complex.

Writing 4/5

Requires remembering the 'gai' in 'higai' or 'saigai'.

Speaking 3/5

The word itself is easy to pronounce, but usage requires specific collocations.

Listening 3/5

Clear pronunciation, but can be confused with 'suburbs' (kōgai).

What to Learn Next

Prerequisites

環境 (Environment) 問題 (Problem) 悪い (Bad) 工場 (Factory) 病気 (Illness)

Learn Next

汚染 (Contamination) 対策 (Measures) 防止 (Prevention) 訴訟 (Lawsuit) 規制 (Regulation)

Advanced

環境基本法 (Basic Environment Act) 外部不経済 (External diseconomy) 持続可能性 (Sustainability) 無過失責任 (Strict liability) 環境影響評価 (Environmental Impact Assessment)

Grammar to Know

Noun + による (Due to)

公害による健康被害 (Health damage due to pollution).

Noun + を引き起こす (To cause)

工場が公害を引き起こした (The factory caused pollution).

Noun + 対策 (Measures for...)

公害対策を立てる (To create measures for pollution).

Noun + として (As...)

公害として認定される (To be recognized as pollution).

Noun + のない (Without...)

公害のない街 (A town without pollution).

Examples by Level

1

公害は悪いです。

Pollution is bad.

A is B (Noun は Noun です).

2

水が公害で汚いです。

The water is dirty because of pollution.

で (de) marks the cause/reason.

3

公害を知っていますか?

Do you know about pollution?

を (o) marks the object of knowledge.

4

空気が公害で悪いです。

The air is bad due to pollution.

で (de) used as a reason.

5

公害はこわいです。

Pollution is scary.

こわい is an i-adjective.

6

これは公害の本です。

This is a book about pollution.

の (no) indicates the topic/category.

7

公害を止めましょう。

Let's stop pollution.

~ましょう (mashou) means 'let's'.

8

公害はどこにありますか?

Where is the pollution?

Asking for location.

1

この町は公害がありません。

This town has no pollution.

~がありません means 'there is no...'.

2

公害は体にとても悪いです。

Pollution is very bad for the body.

~に悪い means 'bad for...'.

3

工場が公害を作っています。

Factories are creating pollution.

~ています indicates an ongoing action.

4

公害を減らすことが大切です。

It is important to reduce pollution.

~ことが大切です means '...is important'.

5

昔、日本には公害がたくさんありました。

Long ago, there was a lot of pollution in Japan.

Past tense of 'there is'.

6

騒音も一つの公害です。

Noise is also a type of pollution.

も (mo) means 'also'.

7

公害について勉強しました。

I studied about pollution.

~について means 'about'.

8

公害のない世界を作りたいです。

I want to create a world without pollution.

~たいです indicates desire.

1

公害対策のために、新しい法律ができました。

A new law was created for pollution measures.

~のために means 'for the purpose of'.

2

この川は公害で魚が住めなくなりました。

Fish can no longer live in this river due to pollution.

Potential negative + なる (become unable to).

3

公害問題は、個人の努力だけでは解決できません。

The pollution problem cannot be solved by individual effort alone.

~だけでは~ない (not just with...).

4

住民たちは公害を止めるように訴えました。

The residents appealed to stop the pollution.

~ように訴える (appeal so that...).

5

大気汚染は、都市部で深刻な公害となっています。

Air pollution has become a serious public nuisance in urban areas.

~となっている indicates a current state.

6

公害病に苦しむ人々を助けなければなりません。

We must help people suffering from pollution-induced diseases.

~なければなりません means 'must'.

7

光害は、星が見えなくなる公害の一種です。

Light pollution is a type of pollution where stars become invisible.

Noun + の一種 (a type of...).

8

公害防止のために、工場にフィルターを設置した。

In order to prevent pollution, filters were installed in the factory.

Standard past tense causative context.

1

高度経済成長期、日本は深刻な公害問題に直面した。

During the period of high economic growth, Japan faced serious pollution problems.

~に直面する means 'to face/confront'.

2

企業は公害を発生させない社会的責任がある。

Companies have a social responsibility not to generate pollution.

Causative negative form (発生させない).

3

公害訴訟によって、被害者の権利が守られた。

The rights of the victims were protected through pollution lawsuits.

~によって indicates the means or agent.

4

土壌汚染が公害として認定されるまでには時間がかかった。

It took time until soil contamination was recognized as a public nuisance.

~として認定される (recognized as...).

5

騒音公害を減らすため、高速道路に防音壁を設置した。

In order to reduce noise pollution, soundproof walls were installed on the highway.

Compound noun '騒音公害'.

6

公害規制の強化により、川の水質が改善された。

River water quality improved due to the strengthening of pollution regulations.

~により (due to/by means of).

7

環境省は、新たな公害防止計画を策定している。

The Ministry of the Environment is formulating a new pollution prevention plan.

策定 (formulation) is a formal verb.

8

公害の歴史を繰り返してはならない。

We must not repeat the history of pollution.

~てはならない means 'must not'.

1

公害問題の原点は、企業の利益追求と住民の健康の対立にある。

The root of the pollution problem lies in the conflict between corporate profit-seeking and residents' health.

~にある (resides in/lies in).

2

水俣病は、典型的な産業公害の悲劇として世界的に知られている。

Minamata disease is known worldwide as a tragic example of industrial pollution.

典型的な (typical/classic).

3

現代の公害は、目に見えない化学物質によるものが増えている。

Modern pollution increasingly involves invisible chemical substances.

~によるもの (things caused by...).

4

公害輸出という言葉は、先進国が途上国に汚染産業を移転させることを指す。

The term 'pollution export' refers to developed countries moving polluting industries to developing countries.

~を指す (refers to...).

5

行政の不作為が、公害被害を拡大させた一因であると批判された。

Administrative inaction was criticized as one of the factors that expanded pollution damage.

不作為 (inaction) is a legal term.

6

公害反対運動は、日本の市民社会の形成に大きな影響を与えた。

The anti-pollution movement had a major impact on the formation of Japanese civil society.

~に影響を与える (to influence).

7

環境基本法は、公害の定義を明確にし、その防止を義務付けている。

The Basic Environment Act clarifies the definition of pollution and mandates its prevention.

義務付ける (to mandate/make compulsory).

8

振動公害は、周辺住民の精神的・肉体的な苦痛を引き起こす。

Vibration pollution causes mental and physical distress for nearby residents.

精神的・肉体的 (mental and physical).

1

公害という概念は、高度産業社会における負の遺産そのものである。

The concept of 'kōgai' is the very embodiment of the negative legacy of high industrial society.

~そのものである (is the very...).

2

法学的な観点から言えば、公害は人格権の侵害として捉えることができる。

From a legal perspective, pollution can be understood as an infringement of personal rights.

~として捉える (to perceive/treat as).

3

地球規模の環境変容と局所的な公害をどう統合的に扱うかが問われている。

The question is how to integrally handle global environmental changes and local pollution.

~が問われている (is being questioned/called into account).

4

公害認定患者への補償問題は、今なお未解決の側面を多く含んでいる。

The issue of compensation for officially recognized pollution victims still contains many unresolved aspects.

今なお (even now/still).

5

「公害」という言葉が内包する歴史的・感情的な重みは、他言語への翻訳を困難にする。

The historical and emotional weight contained in the word 'kōgai' makes its translation into other languages difficult.

内包する (to connote/contain within).

6

都市化に伴う新たな公害、例えば電磁波公害などに対する科学的検証が急務である。

Scientific verification of new types of pollution accompanying urbanization, such as electromagnetic pollution, is an urgent matter.

~に伴う (accompanying/along with).

7

公害の発生源を特定し、その社会的費用を内部化することが、現代の環境政策の根幹である。

Identifying the sources of pollution and internalizing their social costs is the core of modern environmental policy.

内部化 (internalization) is an economics term.

8

景観公害の議論は、美意識という主観的な要素を法的にどう扱うかという難題を突きつけている。

The debate on visual pollution presents the difficult problem of how to legally handle the subjective element of aesthetic sense.

~を突きつけている (presenting/thrusting forward).

Common Collocations

公害を引き起こす
公害に悩む
公害対策を立てる
公害防止
公害訴訟
公害規制
公害病
公害問題
公害認定
公害の被害者

Common Phrases

四大公害病

— The 'Big Four Pollution Diseases' of Japan. These are the historical cases that defined the term.

四大公害病について歴史の授業で習った。

公害反対運動

— Anti-pollution movements. Grassroots activism against industrial damage.

公害反対運動が全国に広がった。

公害等調整委員会

— Environmental Dispute Coordination Commission. A government body in Japan.

公害等調整委員会に調停を申し立てる。

典型七公害

— The seven typical types of pollution defined by Japanese law.

典型七公害には、騒音や悪臭も含まれる。

新公害

— New types of pollution, such as high-tech waste or subtle environmental stressors.

新公害への対応が求められている。

精神的公害

— Spiritual or mental pollution. Metaphorical use for harmful social trends.

過剰な広告は精神的公害だという意見もある。

公害健康被害補償法

— The Act on Compensation, etc. for Pollution-related Health Damage.

公害健康被害補償法に基づき、補償金が支払われる。

公害輸出

— Pollution export. Moving dirty industries to other countries.

公害輸出は国際的な批判を浴びた。

公害防止管理者

— Pollution Control Manager. A professional certification in Japan.

彼は公害防止管理者の資格を持っている。

公害ゼロ

— Zero pollution. An ideal goal for cities and industries.

公害ゼロの社会を目指す。

Often Confused With

公害 vs 郊外 (Kōgai)

Means 'suburbs'. It has the same pronunciation but different kanji and a completely different meaning.

公害 vs 汚染 (Osen)

Means 'contamination'. It refers to the physical state, whereas 公害 refers to the social/legal harm.

公害 vs 災害 (Saigai)

Means 'disaster' (like earthquakes). 公害 is man-made, whereas 災害 is usually natural.

Idioms & Expressions

"公害の種"

— The source or 'seed' of pollution. Something that will eventually cause public harm.

その古い設備は公害の種になりかねない。

General
"公害の影"

— The 'shadow' of pollution. The dark side of industrial progress.

経済発展の裏には常に公害の影があった。

Literary
"公害を撒き散らす"

— To scatter or spread pollution everywhere. Used for irresponsible actors.

あの工場は公害を撒き散らしている。

Critical
"公害に蓋をする"

— To 'put a lid' on pollution. To cover up or ignore environmental problems.

公害に蓋をしても解決にはならない。

Critical
"公害の洗礼を受ける"

— To receive the 'baptism' of pollution. To be the first to suffer from a new environmental issue.

この町は工業化により公害の洗礼を受けた。

Literary
"公害と背中合わせ"

— To be 'back-to-back' with pollution. To live in a situation where pollution is a constant threat.

私たちの生活は公害と背中合わせだ。

General
"公害の犠牲になる"

— To become a victim of pollution.

多くの罪のない人々が公害の犠牲になった。

Formal
"公害の根を絶つ"

— To cut the 'roots' of pollution. To eliminate the cause completely.

公害の根を絶つための抜本的な改革が必要だ。

Formal
"公害の火種"

— The 'spark' of pollution. A small issue that could ignite a major pollution crisis.

小さな油漏れが公害の火種となった。

General
"公害を食い止める"

— To hold back or stop pollution from spreading.

水際で公害を食い止める。

General

Easily Confused

公害 vs 汚染

Both relate to things being dirty.

Osen is the technical/physical state of contamination. Kōgai is the social harm caused by that contamination to people.

放射能汚染 (radioactive contamination) vs. 公害病 (pollution disease).

公害 vs 環境破壊

Both involve the environment.

Kankyō hakai is broader and includes nature destruction (like cutting trees). Kōgai specifically implies harm to human health or living environment.

森林破壊 (forest destruction) vs. 水質公害 (water pollution).

公害 vs 迷惑

Both mean 'nuisance'.

Meiwaku is for personal, small-scale annoyances. Kōgai is for large-scale, often industrial or systemic harm to the public.

近所の騒音 (neighbor's noise) vs. 飛行機の騒音公害 (airplane noise pollution).

公害 vs 害毒

Both mean 'harm'.

Gaidoku is more metaphorical and refers to something that 'poisons' the mind or society. Kōgai is physical/environmental.

社会の害毒 (poisons of society) vs. 大気公害 (air pollution).

公害 vs 弊害

Both mean 'harmful effect'.

Heigai is used for systems or habits (like the bad effects of smoking or a school system). Kōgai is for environmental pollution.

制度の弊害 (evils of the system) vs. 公害対策 (pollution measures).

Sentence Patterns

A1

Noun は Noun です。

公害は悪いです。

A2

Noun が あります/ありません。

この町は公害がありません。

B1

Noun による Noun

公害による被害が広がっている。

B1

Noun を 防止するために ~

公害を防止するために木を植える。

B2

Noun が 社会問題となる

深刻な公害が社会問題となった。

B2

Noun に 直面する

日本はかつて公害問題に直面した。

C1

Noun の 原点は ~ にある

公害問題の原点は企業の姿勢にある。

C2

Noun という 概念は ~

公害という概念は時代とともに変化してきた。

Word Family

Nouns

公害 (Pollution)
加害者 (Perpetrator/Polluter)
被害者 (Victim)
公害病 (Pollution disease)

Verbs

害する (To harm/damage)
汚染する (To contaminate)
防止する (To prevent)

Adjectives

有害な (Harmful)
無害な (Harmless)
深刻な (Serious/Severe)

Related

環境 (Environment)
産業 (Industry)
訴訟 (Lawsuit)
健康 (Health)
対策 (Measures)

How to Use It

frequency

Common in news, education, and formal discussions; rare in casual daily conversation unless discussing a specific local problem.

Common Mistakes
  • Using 公害 for a dirty room. 私の部屋は汚い (My room is dirty).

    公害 is for public/social environmental harm, not personal messiness.

  • Using '公害する' as a verb. 公害を引き起こす (To cause pollution).

    公害 is a noun only and does not take 'suru'.

  • Confusing 公害 with 郊外 (suburbs). 東京の郊外に住んでいます (I live in the suburbs of Tokyo).

    These are homophones. Check the kanji and context carefully.

  • Using 公害 for all environmental issues like global warming. 地球温暖化は環境問題だ (Global warming is an environmental problem).

    公害 is traditionally for local, industrial harm to humans.

  • Using 汚染 when talking about legal responsibility. 公害訴訟 (Pollution lawsuit).

    汚染 is scientific; 公害 is social/legal. In court, it's always 公害.

Tips

Learn the pairs

Always learn 公害 with the verb 引き起こす (hikiokosu - to cause). It is the most natural way to use the word in a sentence.

Historical Weight

When you use the word 公害, remember it carries the weight of Japan's past environmental tragedies. It's a very serious word.

Noun usage

Remember that 公害 is a noun. You cannot say 'kōgai suru'. Use 'kōgai o hikiokosu' or 'osen suru' instead.

Watch for homophones

If you hear 'kōgai' in a travel context, it probably means 'suburbs' (郊外). If you hear it in a news context, it's 'pollution' (公害).

Use compound nouns

Compound nouns like 公害対策 (pollution measures) are very common in professional Japanese. Use them to sound more advanced.

Nuance

If you are complaining about a loud neighbor, use 'meiwaku' (nuisance). If you are complaining about a factory's noise, use 'kōgai'.

The Seven Types

In Japan, '公害' legally includes seven things: air, water, soil, noise, vibration, smell, and ground sinking. Knowing this helps in formal tests.

The 1970 Diet

Japan's 1970 parliament session is called the 'Pollution Diet' (公害国会). It's a great fact to know for advanced cultural understanding.

Vs. Global Warming

Remember that 公害 is usually for local issues. For global issues like the ozone layer, use 'kankyō mondai'.

Public Harm

Break it down: 公 (Public) + 害 (Harm). This literal translation will always lead you to the right meaning.

Memorize It

Mnemonic

Think of 'Kō' as 'Co-' (Company/Collective) and 'Gai' as 'Guy'. A bad 'Company Guy' causing 'Public Harm'.

Visual Association

Imagine a giant factory chimney (the 'Gai'/Harm) sticking out of a public park (the 'Kō'/Public).

Word Web

大気 (Air) 水質 (Water) 騒音 (Noise) 工場 (Factory) 住民 (Residents) 法律 (Law) 裁判 (Trial) 健康 (Health)

Challenge

Try to find one news article today (in Japanese or English about Japan) that mentions an environmental issue and see if '公害' would be the appropriate word to describe it.

Word Origin

The term '公害' (kōgai) first appeared in the late 19th century (Meiji era) to describe general public harm. It gained its specific environmental meaning during the industrialization of Japan.

Original meaning: Public (公) Harm (害). Originally used for anything that harmed the general public interest, not just pollution.

Sino-Japanese (Kango). Compound of two Chinese characters.

Cultural Context

Be respectful when discussing the 'Big Four' diseases. Many victims are still alive and the legal battles for compensation continue to this day.

In English, we often use 'pollution' for everything. In Japan, using '公害' specifically points to the social/human impact, whereas 'environmental issues' is broader.

The film 'Minamata' (2020) starring Johnny Depp about the Minamata disease. The manga/anime 'Nausicaä of the Valley of the Wind' which is a metaphor for pollution and nature. Godzilla (1954), which serves as a metaphor for the public harm of nuclear testing.

Practice in Real Life

Real-World Contexts

Environmental News

  • 深刻な公害
  • 公害の恐れがある
  • 公害防止策を導入する
  • 新たな公害問題

History Class

  • 公害の歴史
  • 四大公害病
  • 公害反対運動の激化
  • 高度経済成長と公害

Legal/Courtroom

  • 公害訴訟を提起する
  • 公害被害の認定
  • 賠償責任の追及
  • 公害調停

Corporate Social Responsibility

  • 公害ゼロを目指す
  • 公害防止管理者
  • 自主的な公害規制
  • 公害リスクの管理

Urban Living

  • 騒音公害
  • 振動公害
  • 光害の防止
  • 近隣公害

Conversation Starters

"日本の公害の歴史について何か知っていますか? (Do you know anything about the history of pollution in Japan?)"

"あなたの国では、どのような公害が問題になっていますか? (What kind of pollution is a problem in your country?)"

"騒音も公害の一種だと思いますか? (Do you think noise is also a type of pollution?)"

"公害をなくすために、私たちは何ができるでしょうか? (What can we do to eliminate pollution?)"

"最近の「光害」についてどう思いますか? (What do you think about the recent 'light pollution'?)"

Journal Prompts

もし自分の住んでいる町で公害が発生したら、あなたはどうしますか? (What would you do if pollution occurred in your town?)

経済の発展と公害の防止、どちらがより重要だと思いますか? (Which do you think is more important: economic development or pollution prevention?)

あなたが知っている公害病について、その原因と影響を書いてください。 (Write about a pollution-induced disease you know, its cause, and its impact.)

未来の世界では公害はなくなっていると思いますか? (Do you think pollution will be gone in the future world?)

「公害」という言葉の重みについて、自分の考えを述べてください。 (State your thoughts on the weight of the word 'kōgai'.)

Frequently Asked Questions

10 questions

No. In Japan, it also includes noise, vibration, bad smells, and light pollution. Anything that harms the public's living environment due to human activity can be called 公害.

It is common in the news and schools, but you wouldn't use it to describe a small mess in your house. It's a 'serious' word for big problems.

汚染 (osen) is 'contamination' (the physical state). 公害 (kōgai) is 'public harm' (the social/legal issue). If a river is dirty, it's 汚染. If that dirtiness makes a whole town sick, it's 公害.

Usually, no. Global warming is called '環境問題' (kankyō mondai - environmental problem). 公害 is typically used for local, direct harm to a specific community.

You can say '騒音公害' (sōon kōgai). It's a very common term for noise that affects a neighborhood's quality of life.

Only metaphorically and very rarely. Calling someone a 'kōgai' is like calling them a 'toxic public nuisance.' It's very strong and usually 'meiwaku' is better.

Japan suffered from terrible industrial pollution in the 1950s and 60s (like Minamata disease). These events changed Japanese law and society, making '公害' a very heavy word.

They are Minamata disease, Niigata Minamata disease, Itai-itai disease, and Yokkaichi Asthma. They are the classic examples of 公害 in Japan.

No, it's only a noun. You use it with verbs like '引き起こす' (cause) or '防止する' (prevent).

Think of '公' as public (like in 公園 - park) and '害' as harm (like in 害虫 - harmful insect). Public Harm = Pollution.

Test Yourself 180 questions

writing

Write a sentence using '公害' and '深刻な' (serious).

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writing

Translate: 'Factories cause pollution.'

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writing

Write a short sentence about noise pollution.

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writing

Translate: 'We should prevent pollution.'

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writing

Write a sentence about the history of pollution in Japan.

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writing

Translate: 'Pollution is bad for health.'

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writing

Write a sentence using '公害対策'.

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writing

Translate: 'The river was polluted.'

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writing

Write a sentence about pollution lawsuits.

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writing

Translate: 'A world without pollution.'

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writing

Write a sentence using '公害病'.

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writing

Translate: 'Noise and vibration are pollution.'

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writing

Write a sentence about corporate responsibility regarding pollution.

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writing

Translate: 'Pollution became a social problem.'

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writing

Write a sentence using '大気公害'.

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writing

Translate: 'I learned about pollution at school.'

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writing

Write a sentence using '公害防止'.

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writing

Translate: 'Pollution is a legacy of the past.'

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writing

Write a sentence using '光害'.

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writing

Translate: 'New laws for pollution.'

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speaking

Pronounce: 公害 (こうがい)

Read this aloud:

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speaking

Say 'Pollution is a problem' in Japanese.

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speaking

Say 'Noise pollution' in Japanese.

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speaking

Say 'Stop the pollution' in Japanese.

Read this aloud:

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speaking

Explain what 'Kōgai' means in simple Japanese.

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speaking

Say 'I want to live in a city without pollution.'

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speaking

Say 'The factory caused pollution.'

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speaking

Say 'Pollution measures are important.'

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speaking

Say 'I studied the history of pollution.'

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speaking

Say 'Noise is a type of pollution.'

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speaking

Say 'Pollution victims need help.'

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speaking

Say 'Light pollution makes stars invisible.'

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speaking

Say 'We must repeat the history of pollution.' (Negative)

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speaking

Say 'Air pollution is serious.'

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speaking

Say 'Water quality is improving.'

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speaking

Say 'New laws were passed.'

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speaking

Say 'Companies have responsibility.'

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speaking

Say 'The trial is over.'

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speaking

Say 'I'm worried about pollution.'

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speaking

Say 'Let's protect the environment.'

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listening

Listen and identify: 'Kōgai wa shakai mondai desu.'

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listening

Listen and identify: 'Kōjō ga kōgai o hikiokoshita.'

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listening

Listen and identify: 'Sōon kōgai ni nayande iru.'

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listening

Listen and identify: 'Kōgai taisaku o tateru.'

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listening

Listen and identify: 'Kōgai-byō no kanja.'

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listening

Listen and identify: 'Hikari-gai de hoshi ga mienai.'

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listening

Listen and identify: 'Kōgai soshō ga hajimatta.'

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listening

Listen and identify: 'Kōgai-nashi no sekai.'

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listening

Listen and identify: 'Kōgai bōshi no tame ni.'

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listening

Listen and identify: 'Shinkoku na kōgai mondai.'

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listening

Listen and identify: 'Taiki kōgai o herasu.'

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listening

Listen and identify: 'Kōgai no rekishi o manabu.'

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listening

Listen and identify: 'Kōgai kisei o mamoru.'

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listening

Listen and identify: 'Akushū kōgai no kurujō.'

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listening

Listen and identify: 'Kōgai o yurusanai.'

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/ 180 correct

Perfect score!

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