Okay, I need to create a professional Wikipedia-style document about mercury (수은) under the categories of Environment → Pollution Substances → Heavy Metals. Let me start by understanding the requirements.

First, the structure: H1 for the title, an overview section, several sections with H2 and H3 headings, and maybe references or related documents. The content needs to be accurate, objective, detailed enough, easy to read, and use technical terms with explanations. Also, markdown formatting with proper hierarchy, lists, tables, code blocks if needed, and at least 800 characters.

Starting with the title: "수은" as H1. Then an overview section introducing mercury, its properties, sources, environmental impact, etc. Next sections could be about chemical properties, sources of pollution, environmental effects, health impacts, regulations, and mitigation strategies. Maybe include a table comparing different heavy metals or a list of common mercury compounds.

I should check the key points: mercury is a heavy metal, liquid at room temperature, toxic, used in various industries but harmful. Sources like industrial emissions, coal burning, artisanal gold mining. Environmental effects on water, soil, bioaccumulation in food chains. Health issues like neurological damage. Regulations like Minamata Convention.

Need to make sure each section has H2 and H3 headings. For example, under "환경 영향", maybe H3 for aquatic ecosystems, terrestrial environments, etc. Also include a references section with sources like WHO, EPA, or scientific studies.

Avoid markdown in the thinking process but ensure the final answer uses it. Check for technical terms: explain what heavy metals are if necessary. Use bullet points for lists, tables for comparisons. Make sure the language is clear and concise, avoiding jargon where possible but explaining it when used.

Let me outline the sections:

1. 제목: 수은 (H1)
2. 개요/소개
3. 화학적 성질 및 특성 (H2)
4. 물리적 성질 (H3)
5. 화학적 성질 (H3)
6. 오염원과 배출 경로 (H2)
7. 산업 배출 (H3)
8. 자연적 원인 (H3)
9. 환경 영향 (H2)
10. 수생 생태계 (H3)
11. 토양 및 대기 (H3)
12. 건강 영향 (H2)
13. 인간 건강 (H3)
14. 동물 및 생태계 (H3)
15. 규제와 관리 (H2)
16. 국제 협약 (H3)
17. 국내 정책 (H3)
18. 완화 전략 (H2)
19. 기술적 접근 (H3)
20. 정책적 조치 (H3)
21. 참고 자료 및 관련 문서

Now, fill each section with accurate info. For example, in chemical properties, mention its atomic number, symbol, melting point, etc. In sources, include coal-fired power plants, artisanal gold mining. Environmental impact: bioaccumulation in fish leading to mercury poisoning. Health effects: neurological damage, especially in fetuses. Regulations like the Minamata Convention.

Check for 800 characters. Each section should be detailed enough. Use tables if possible, maybe a table comparing mercury with other heavy metals. Ensure technical terms are explained, like "bioaccumulation" or "mercury poisoning."

Avoid any markdown in the thinking process but structure the final answer properly. Make sure to use H1, H2, H3 correctly, and include lists, tables where appropriate. Also, check for clarity and flow.