Editing 1981 (section)

===Date unknown===
* January to March – Heavy snow [[:ja:五六豪雪|causes several houses and buildings to collapse]] in northwestern Japan; 152 are killed.
* [[Cuba]] suffers a major outbreak of [[dengue fever]], with 344,203 cases.<ref>{{cite web|url=http://w3.whosea.org/en/Section10/Section332/Section521_2454.htm|title=Dengue Bulletin 23 - DHF Epidemics in Cuba, 1981 & 1997: Some Interesting Observations|access-date=2005-05-26|url-status=dead|archive-url=https://web.archive.org/web/20050104014119/http://w3.whosea.org/EN/Section10/Section332/Section521_2454.htm|archive-date=January 4, 2005}}</ref>
* Use of [[crack cocaine]], a smokeable form of the drug, first reported in the United States and Caribbean.<ref>"[[Drug Enforcement Administration|DEA]] History Book, 1876–1990" (drug usage & enforcement), [[US Department of Justice]], 1991, USDoJ.gov webpage: [https://web.archive.org/web/20060823024931/http://www.usdoj.gov/dea/pubs/history/1985-1990.html DoJ-DEA-History-1985-1990].</ref>
* [[Luxor AB]] presents the [[ABC 800]] computer.
* ''[[Polybius (urban legend)|Polybius]]'', an urban legend game, is said to have been released in [[Portland, Oregon]]; there is no evidence for its existence.
* The [[State Council of the People's Republic of China]] lists the cities of Beijing, [[Hangzhou]], [[Suzhou, Jiangsu|Suzhou]] and [[Guilin]] as those where the protection of historical and cultural heritage, as well as natural scenery, should be treated as a priority project.
* [[Pepsi]] enters China.<ref>{{cite web|url=http://www.pepsico.com/Download/GCR_Sustainability_Report_EN_Final.pdf|title=Archived copy|access-date=2013-07-12|url-status=dead|archive-url=https://web.archive.org/web/20130611174211/https://www.pepsico.com/Download/GCR_Sustainability_Report_EN_Final.pdf|archive-date=June 11, 2013}}</ref>
* Around the end of 1981, China becomes the first country ever to reach a population of 1&nbsp;billion.<ref>{{Cite web |title=Chinese Population Hits 1 Billion |url=https://www.historychannel.com.au/this-day-in-history/chinese-population-hits-1-billion/ |archive-url=https://web.archive.org/web/20190422120137/https://www.historychannel.com.au/this-day-in-history/chinese-population-hits-1-billion/ |archive-date=22 April 2019 |website=History Channel Australia}}</ref>