根据目前的理论，污染地区不形成纳米尺寸的颗粒。观测表明，在上海、南京和北京等比较受污染的城市形成了新的颗粒。

“在实践中，它需要硫酸和二甲胺。这些大气中的集聚物通过一个分子一个分子生长，并在污染的空气中形成新的颗粒。”Markku Kulmala说。

New particles are formed also in the polluted air of major cities

https://www.sciencedaily.com/releases/2018/07/180719142148.htm

1. M. Kulmala, V.-M. Kerminen, T. Petäjä, A. J. Ding, L. Wang. Atmospheric gas-to-particle conversion: why NPF events are observed in megacities? Faraday Discussions, 2017; 200: 271 DOI: 10.1039/c6fd00257a

2. Lei Yao, Olga Garmash, Federico Bianchi, Jun Zheng, Chao Yan, Jenni Kontkanen, Heikki Junninen, Stephany Buenrostro Mazon, Mikael Ehn, Pauli Paasonen, Mikko Sipilä, Mingyi Wang, Xinke Wang, Shan Xiao, Hangfei Chen, Yiqun Lu, Bowen Zhang, Dongfang Wang, Qingyan Fu, Fuhai Geng, Li Li, Hongli Wang, Liping Qiao, Xin Yang, Jianmin Chen, Veli-Matti Kerminen, Tuukka Petäjä, Douglas R. Worsnop, Markku Kulmala, Lin Wang. Atmospheric new particle formation from sulfuric acid and amines in a Chinese megacity. Science, 2018; 361 (6399): 278 DOI: 10.1126/science.aao4839